How much better is SH-AWD on the TLX compared to the systems in the current line up?
03-26-2014, 10:28 AM
#41
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P-AWS is not the equal of SH-AWD, you're absolutely right.
P-AWS, however, works to flatten the vehicle in a corner.
The bottom line is that a P-AWS car will get through a corner better than the same car without P-AWS, even if it will not get through the corner better than the same car with SH-AWD.
I get tired of posting that autocross video of Jeff Palmer using an RLX, but if you have time you might want to look at that and see how flat the big old RLX/Legend is taking those tight turns.
No, it's not SH-AWD.
But it's not like it totally sucks, either. :-)
P-AWS, however, works to flatten the vehicle in a corner.
The bottom line is that a P-AWS car will get through a corner better than the same car without P-AWS, even if it will not get through the corner better than the same car with SH-AWD.
I get tired of posting that autocross video of Jeff Palmer using an RLX, but if you have time you might want to look at that and see how flat the big old RLX/Legend is taking those tight turns.
No, it's not SH-AWD.
But it's not like it totally sucks, either. :-)
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internalaudit (03-26-2014)
03-26-2014, 10:45 AM
#42
I can't tell you how many times I have argued with Honda personnel that there is no such thing as engine "braking."
I understand what you quoted, and I understand your point.
It's a matter of perspective and detail.
The kind of drag that people are talking about, and the kind of VSA interference that people are talking about, is not what I am talking about.
I want the car to be smart enough to realize that you're not in trouble, and that you want to use an aggressive implementation of AHA with less mitigation of it by the VSA, when the car realizes that you're not "in trouble" as much as you do "mean business."
I'm sure I'm saying that badly, but if we talked it all through we'd be on the same side, I think, and we'd both want the car to be doing the same thing.
I understand what you quoted, and I understand your point.
It's a matter of perspective and detail.
The kind of drag that people are talking about, and the kind of VSA interference that people are talking about, is not what I am talking about.
I want the car to be smart enough to realize that you're not in trouble, and that you want to use an aggressive implementation of AHA with less mitigation of it by the VSA, when the car realizes that you're not "in trouble" as much as you do "mean business."
I'm sure I'm saying that badly, but if we talked it all through we'd be on the same side, I think, and we'd both want the car to be doing the same thing.
No arguing with that so I'm not sure what your point of saying there's no such thing as engine braking comes from.
http://en.wikipedia.org/wiki/Engine_braking
And if you don't want your car to interfere turn off the VSA. The car lets you do whatever you want then. I've gotten the SHAWD sideways without the VSA. Again I don't know what you mean by that.
If you're talking about varying levels of control this is still a 4 door sedan and not a "sports" version by any stretch of the imagination and will not have varying levels of control. Personally I feel like everyone would be better drivers if traction control systems were taken out of the mix and people were forced to learn how to drive properly. All the tech today makes idiot drivers faster and gives them a false sense of confidence.
The system still distributes torque under deceleration like the RLX using regenerative braking which is why the car stays balanced under braking. The only system that does not shut down under any circumstance unless the fuse is pulled is the ABS.
If you complained about the AMG system being intrusive I'd understand but this is far from intrusive. It gives you one option to shut it down and then does what it say's it does. I'm okay with that.
03-26-2014, 10:51 AM
#43
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Engine braking is exactly what slows you down when you close the throttle. The same thing that semi's use to slow their trucks down incase of a lack of pressure in their brake lines.
No arguing with that so I'm not sure what your point of saying there's no such thing as engine braking comes from.
No arguing with that so I'm not sure what your point of saying there's no such thing as engine braking comes from.
If you want to call that braking, that's fine, but we just need to be clear what's going on.
My problem with referring to engine braking [sic] all the time is that it gives newer drivers the wrong idea of what is going on with hell/toe or ball-n-ball shifting and rev matching.
You hell/toe only to rev match, not to brake the car.
You brake faster with the engine disconnected from the driveline. If you have not gone clutch in to disconnect the motor, then the rotating mass of the engine, which is considerable, is keeping you from getting to maximum threshold braking in the best time possible.
If you are trying to get full threshold braking with the motor engaged, then you are not doing what you think you are doing.
As long we we are on the same wave length with that, and with all due respect to all the evidence that you are going to find that refers to engine braking [sic], then I concede your point in the interests of conversational amity.
:-)
Last edited by George Knighton; 03-26-2014 at 10:54 AM.
03-26-2014, 10:53 AM
#44
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Did I make sense, or am I sounding like an idiot again?
03-26-2014, 10:55 AM
#45
03-26-2014, 11:08 AM
#46
If the engine is moving then it is not braking so much as it is not moving you ahead at the same rate.
If you want to call that braking, that's fine, but we just need to be clear what's going on.
My problem with referring to engine braking [sic] all the time is that it gives newer drivers the wrong idea of what is gong on with hell/toe or ball-n-ball shifting and rev matching.
You hell/toe only to rev match, not to brake the car.
You brake faster with the engine disconnected from the driveline. If you have not gone clutch in to disconnect the motor, then the rotating mass of the engine, which is considerable, is keeping you from getting to maximum threshold braking in the best time possible.
If you are trying to get full threshold braking with the motor engaged, then you are not doing what you think you are doing.
As long we we are on the same wave length with that, and with all due respect to all the evidence that you are going to find that refers to engine braking [sic], then I concede your point in the interests of conversational amity.
:-)
If you want to call that braking, that's fine, but we just need to be clear what's going on.
My problem with referring to engine braking [sic] all the time is that it gives newer drivers the wrong idea of what is gong on with hell/toe or ball-n-ball shifting and rev matching.
You hell/toe only to rev match, not to brake the car.
You brake faster with the engine disconnected from the driveline. If you have not gone clutch in to disconnect the motor, then the rotating mass of the engine, which is considerable, is keeping you from getting to maximum threshold braking in the best time possible.
If you are trying to get full threshold braking with the motor engaged, then you are not doing what you think you are doing.
As long we we are on the same wave length with that, and with all due respect to all the evidence that you are going to find that refers to engine braking [sic], then I concede your point in the interests of conversational amity.
:-)
For new drivers mis-construing a concept does not change the fact that this is exactly what engine braking is. This is exactly why trucks shift down before going down a hill and let the engine take the force of deceleration instead of using all the air pressure from their brakes to slow down. It allows for a consistent rate of deceleration. Should you be using it to brake alone. Nope. But there is a reason why trucks especially ones with decent control rely on the engine to slow it down.
This is also why you down shift before a turn, to be in the right gear to exit and also allow the brakes to work at maximum efficiency without locking the wheels up.
Rev-matching will smoothen out a downshift and engine braking is effective in keeping the stability of a car.
In a perfect world you may be able to achieve slightly faster braking without the engine but this is not a perfect world and there is NO way you can stop a car faster consistently without using the engine as well. Drive a manual transmission car without the ABS and see what happens when you clutch and brake.
The point of using the engine along with braking is to ensure you do not lock the wheels or actuate ABS. When ABS kicks on or when you lock your wheels you are effectively increasing your braking distance. In order to ensure threshold braking you use the engine in accordance with the brakes to bring a car to a halt.
Do a winter cross event and see what happens without using the engine and just braking. The car will not react as well. If the power is engaged you will be able to control the car better.
The rest of this is a repost to illustrate this point
Ok, so this is going to take a while cause there are a lot of factors to examine.
Most tests that people see of extreme braking situations involves a comparison to ABS and non ABS vehicles. During those tests the brakes are slammed and the car car then locks up its wheels and slides a good distance before coming to a halt. ABS on the other hand actuates the brakes intermittently to allow some slip and allow the wheels to turn and stop, turn and stop, turn and stop. That's how you come to a full stop.
Check this website out if you want more info on braking.
http://www.drivingfast.net/car-control/braking.htm
In the picture you see 4 different ways of making your vehicle come to a stop.
1. Threshold braking
2. ABS braking
3. Locked wheels
4. Cadence braking
Attachment 107230
Watch the video and see how ABS works. It intermittently causes the brakes to release.
If you want a bigger description of what each entails check out the URL but for the purposes of this discussion we're going to focus on the first 3.
Threshold braking is great in dry condition where you are at the limits of adhesion and have not locked the brakes. People that know how to drive their cars exceptionally well or motorcycle riders without ABS know how to do this. On a bike you can't afford to ever lock up your tires or your bike will step out of line.
ABS intermittently lets the tires roll and lock up then roll again. Your tires then have a chance to slow down but not come to a complete halt causing a lock up. The reason this is the quicker way to stop for most is because most people mash the brakes and this system kicks in to prevent any lock up.
Downshifting allows your tires to slow down and maintain threshold braking (meaning not lock up) without going beyond the limits of adhesion.
Locked wheels would be mashing the brakes to the point of the tires going beyond what grip it is capable of thus locking up the wheels.
Keep in mind if you drive an automatic or manual transmission car and you lock the brakes the engine will cut out unless you are in neutral. This is exactly why you down shift so the transmission reduces drive therefore slowing the wheels down and still keeping with the speed the vehicle is traveling at.
What you want to do as a good driver is let ABS do its job.
What you want to do as an experienced driver is prevent ABS from kicking in meaning you are within the limits of adhesion and by downshifting you prevent ABS from having to cut your brakes out intermittently.
In the best situation your ABS will work like it does in the picture. In icy situations your ABS will cut in consistently to prevent slippage meaning you have no brakes at all.
This is why it is better to keep your wheels turning at a consistently decreasing rate rather than ABS cutting in and preventing your brakes from doing its job. It happens more often than not an people blame it on speed which is a factor but losing control has nothing to do with speed. That has to do with abs letting your car go because of lack of traction.
ABS has saved a lot of lives which is why the system still exists.
If anyone here rides on track this will all make sense because the same physics applies to a car. This is exactly the reason why I get so annoyed when people say a bike can stop faster than a car. Theoretically it can but conditions change and most importantly rider's change. If a rider doesn't know what he can or cannot do no technology is going to save his ass.
Last edited by d1sturb3d119; 03-26-2014 at 11:11 AM.
03-26-2014, 12:05 PM
#47
6G TLX-S
RWD chassis is a vehicle platform specifically designed for RWD vehicles, such as the Infiniti-G, Lexux-GS, most BMW, most MB, Honda-S2000, Acura-NSX platforms; and those base cars are all RWD.
One can't build a FWD vehicle on a RWD chassis, and vice versa; because the structure integrity and handling dynamics will be all wrong.
So, if AWD is implemented on top of a RWD chassis, the resulting AWD vehicle will also exhibit RWD characteristics. For example, in case of the Infiniti AWD, the system is able to distribute 100% of engine power to the rear wheels, in effect transforming the AWD vehicle into a RWD one.
But, if AWD is implemented on top of a FWD chassis, the resulting AWD vehicle will still exhibit FWD characteristics, because even though the AWD system is able to distribute 100% power to the front wheels, there is absolutely no way that 100% power can be directed to the rear wheels like the AWD-on-RWD-chassis vehicle.
This is the difference between the AWD-on-FWD-chassis and the AWD-on-RWD-chassis. The two will never behave the same way due to the inherited FWD and RWD characteristics and/or limitations.
03-26-2014, 12:12 PM
#48
P-AWS is not the equal of SH-AWD, you're absolutely right.
P-AWS, however, works to flatten the vehicle in a corner.
The bottom line is that a P-AWS car will get through a corner better than the same car without P-AWS, even if it will not get through the corner better than the same car with SH-AWD.
I get tired of posting that autocross video of Jeff Palmer using an RLX, but if you have time you might want to look at that and see how flat the big old RLX/Legend is taking those tight turns.
No, it's not SH-AWD.
But it's not like it totally sucks, either. :-)
P-AWS, however, works to flatten the vehicle in a corner.
The bottom line is that a P-AWS car will get through a corner better than the same car without P-AWS, even if it will not get through the corner better than the same car with SH-AWD.
I get tired of posting that autocross video of Jeff Palmer using an RLX, but if you have time you might want to look at that and see how flat the big old RLX/Legend is taking those tight turns.
No, it's not SH-AWD.
But it's not like it totally sucks, either. :-)
03-26-2014, 12:27 PM
#49
The biggest disadvantage to SH-AWD has been that it only works throttle down.
So you could get through one or two corners in a carousel nicely, but might get into trouble in the third because you'd have to lift.
Once you'd done it a few times, you'd learn the fastest way...but you would always have this nagging feeling that it was not as quick as it could be because it only vectored throttle applied.
They have made a very big deal describing to us how the RLX SH-AWD is able to use the electric motor to apply negative drag on the inside wheel of a corner without using the AHA system.
So we know that with the RLX SH-AWD they're bragging that it works off throttle as well as throttle down.
My guess is that they've found some way to provide negative torque on the inside wheel of the TLX SH-AWD, or decided on a more aggressive application of the AHA system to do something equivalent; namely, an AHA system that works to do something on long U and carousel turns, not just the tighter autocross turns for which it works currently!
:-)
So you could get through one or two corners in a carousel nicely, but might get into trouble in the third because you'd have to lift.
Once you'd done it a few times, you'd learn the fastest way...but you would always have this nagging feeling that it was not as quick as it could be because it only vectored throttle applied.
They have made a very big deal describing to us how the RLX SH-AWD is able to use the electric motor to apply negative drag on the inside wheel of a corner without using the AHA system.
So we know that with the RLX SH-AWD they're bragging that it works off throttle as well as throttle down.
My guess is that they've found some way to provide negative torque on the inside wheel of the TLX SH-AWD, or decided on a more aggressive application of the AHA system to do something equivalent; namely, an AHA system that works to do something on long U and carousel turns, not just the tighter autocross turns for which it works currently!
:-)
Located on either side of the hypoid gear that drives the rear axle, two identical Direct Electromagnetic Clutch systems control the amount of drive torque that reaches each rear wheel, and provide limited-slip differential function. An electric coil controls the pressure applied to a clutch, which slows the sun gear in a planetary gear set to modulate the torque that is sent to the wheel. The amount of torque transmitted to each rear wheel can vary continuously, between zero and 100 percent, depending on the conditions.
When cornering under deceleration (with the throttle closed), torque being applied to the outside rear wheel is varied to change the impact on the vehicles momentum from an inward yaw moment to an outward yaw moment, helping vehicle stability
Audi's AWD system today is still less effective.
03-26-2014, 01:05 PM
#50
Grandpa
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No. I saw it and liked it, and did not have anything to add to it. We'd just be quibbling if I pretended that I did not like it.
Just don't be surprised if they've tried to find a way to get the inside rear wheel to act like the RLX SH-AWD by giving you "less than zero" to yaw the car even better.
:-)
Just don't be surprised if they've tried to find a way to get the inside rear wheel to act like the RLX SH-AWD by giving you "less than zero" to yaw the car even better.
:-)
03-26-2014, 01:26 PM
#51
Racer
Thread Starter
FWD chassis is a vehicle platform specifically designed for FWD vehicles, such as the A4/A6/Passat, RLX/TL/Accord, Maxima/Altima, ES/Camry platforms; and those base cars are all FWD.
RWD chassis is a vehicle platform specifically designed for RWD vehicles, such as the Infiniti-G, Lexux-GS, most BMW, most MB, Honda-S2000, Acura-NSX platforms; and those base cars are all RWD.
One can't build a FWD vehicle on a RWD chassis, and vice versa; because the structure integrity and handling dynamics will be all wrong.
So, if AWD is implemented on top of a RWD chassis, the resulting AWD vehicle will also exhibit RWD characteristics. For example, in case of the Infiniti AWD, the system is able to distribute 100% of engine power to the rear wheels, in effect transforming the AWD vehicle into a RWD one.
But, if AWD is implemented on top of a FWD chassis, the resulting AWD vehicle will still exhibit FWD characteristics, because even though the AWD system is able to distribute 100% power to the front wheels, there is absolutely no way that 100% power can be directed to the rear wheels like the AWD-on-RWD-chassis vehicle.
This is the difference between the AWD-on-FWD-chassis and the AWD-on-RWD-chassis. The two will never behave the same way due to the inherited FWD and RWD characteristics and/or limitations.
RWD chassis is a vehicle platform specifically designed for RWD vehicles, such as the Infiniti-G, Lexux-GS, most BMW, most MB, Honda-S2000, Acura-NSX platforms; and those base cars are all RWD.
One can't build a FWD vehicle on a RWD chassis, and vice versa; because the structure integrity and handling dynamics will be all wrong.
So, if AWD is implemented on top of a RWD chassis, the resulting AWD vehicle will also exhibit RWD characteristics. For example, in case of the Infiniti AWD, the system is able to distribute 100% of engine power to the rear wheels, in effect transforming the AWD vehicle into a RWD one.
But, if AWD is implemented on top of a FWD chassis, the resulting AWD vehicle will still exhibit FWD characteristics, because even though the AWD system is able to distribute 100% power to the front wheels, there is absolutely no way that 100% power can be directed to the rear wheels like the AWD-on-RWD-chassis vehicle.
This is the difference between the AWD-on-FWD-chassis and the AWD-on-RWD-chassis. The two will never behave the same way due to the inherited FWD and RWD characteristics and/or limitations.
I was thinking about going I4 but if the SH-AWD does give a lot of driving pleasure, I will go for the V6 AWD model then.
Was reading Consumer Reports at the library Saturday and Acura is highly regarded, after Lexus, in terms of reliability.
03-26-2014, 01:29 PM
#52
Three Wheelin'
Sure. What exactly about my post makes it appear to be a joke?
I wasn't claiming that P-AWS was BETTER than SH-AWD. All I said was that for me, at the end of the day it felt "similar" in helping control how the car handles turning.
My point in all of that was simply to say that P-AWS offers the ability to get better handling from the vehicle compared to having NOTHING or paying a premium for SH-AWD. It's a nice "middle-ground".
SH-AWD isn't required by every day drivers. P-AWS offers a nice alternative without the added cost.
I wasn't claiming that P-AWS was BETTER than SH-AWD. All I said was that for me, at the end of the day it felt "similar" in helping control how the car handles turning.
My point in all of that was simply to say that P-AWS offers the ability to get better handling from the vehicle compared to having NOTHING or paying a premium for SH-AWD. It's a nice "middle-ground".
SH-AWD isn't required by every day drivers. P-AWS offers a nice alternative without the added cost.
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03-26-2014, 01:36 PM
#53
Racer
Thread Starter
I wonder if the P-AWS will help in wintry road conditions since I live in Canada, the Great White North:
http://www.hondanews.com/channels/ac...-demonstration
http://www.hondanews.com/channels/ac...-demonstration
03-26-2014, 01:56 PM
#54
Three Wheelin'
^ I can't comment necessarily for snow, but I can tell you from first-hand experience with icey road conditions, it doesn't help at all. The car still behaves like a FWD with no P-AWS or other enhancements.
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internalaudit (03-26-2014)
03-26-2014, 03:45 PM
#55
Sure. What exactly about my post makes it appear to be a joke?
I wasn't claiming that P-AWS was BETTER than SH-AWD. All I said was that for me, at the end of the day it felt "similar" in helping control how the car handles turning.
My point in all of that was simply to say that P-AWS offers the ability to get better handling from the vehicle compared to having NOTHING or paying a premium for SH-AWD. It's a nice "middle-ground".
SH-AWD isn't required by every day drivers. P-AWS offers a nice alternative without the added cost.
I wasn't claiming that P-AWS was BETTER than SH-AWD. All I said was that for me, at the end of the day it felt "similar" in helping control how the car handles turning.
My point in all of that was simply to say that P-AWS offers the ability to get better handling from the vehicle compared to having NOTHING or paying a premium for SH-AWD. It's a nice "middle-ground".
SH-AWD isn't required by every day drivers. P-AWS offers a nice alternative without the added cost.
OP is saying that he lives in an area where adverse weather is an issue. My honest advise would be go with an SH-AWD in case an Acura TLX is on his list.
P-AWS - SH-AWD Two total different animals.
You are stating "P-AWS in my RLX feels very similar in handling and performance."
"I think you guys will be impressed with P-AWS. I've experienced SH-AWD once in a loaner TL while my old 3G TL was in service a couple years ago. And from what I remember, the P-AWS in my RLX feels very similar in handling and performance. I still get that same exhilaration when coming out of a tight corner and how well the car quickly corrects it's attitude."
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internalaudit (03-26-2014)
03-26-2014, 04:08 PM
#56
Three Wheelin'
Come on, it's incomparable; not only from a technical aspect but from a driving experience. If you would try to corner with P-AWS like you can with SH-AWD this would be dangerous. Besides the capability's in adverse weather with SH-AWD you are on a total different level.
OP is saying that he lives in an area where adverse weather is an issue. My honest advise would be go with an SH-AWD in case an Acura TLX is on his list.
You are stating "P-AWS in my RLX feels very similar in handling and performance."
OP is saying that he lives in an area where adverse weather is an issue. My honest advise would be go with an SH-AWD in case an Acura TLX is on his list.
You are stating "P-AWS in my RLX feels very similar in handling and performance."
I also wasn't replying to the OP. If you actually read my response you'd get the context in which I was replying which was to a different post (Weather).
Last edited by holografique; 03-26-2014 at 04:13 PM.
03-26-2014, 04:21 PM
#57
03-26-2014, 04:43 PM
#58
FWD chassis is a vehicle platform specifically designed for FWD vehicles, such as the A4/A6/Passat, RLX/TL/Accord, Maxima/Altima, ES/Camry platforms; and those base cars are all FWD.
RWD chassis is a vehicle platform specifically designed for RWD vehicles, such as the Infiniti-G, Lexux-GS, most BMW, most MB, Honda-S2000, Acura-NSX platforms; and those base cars are all RWD.
One can't build a FWD vehicle on a RWD chassis, and vice versa; because the structure integrity and handling dynamics will be all wrong.
So, if AWD is implemented on top of a RWD chassis, the resulting AWD vehicle will also exhibit RWD characteristics. For example, in case of the Infiniti AWD, the system is able to distribute 100% of engine power to the rear wheels, in effect transforming the AWD vehicle into a RWD one.
But, if AWD is implemented on top of a FWD chassis, the resulting AWD vehicle will still exhibit FWD characteristics, because even though the AWD system is able to distribute 100% power to the front wheels, there is absolutely no way that 100% power can be directed to the rear wheels like the AWD-on-RWD-chassis vehicle.
This is the difference between the AWD-on-FWD-chassis and the AWD-on-RWD-chassis. The two will never behave the same way due to the inherited FWD and RWD characteristics and/or limitations.
RWD chassis is a vehicle platform specifically designed for RWD vehicles, such as the Infiniti-G, Lexux-GS, most BMW, most MB, Honda-S2000, Acura-NSX platforms; and those base cars are all RWD.
One can't build a FWD vehicle on a RWD chassis, and vice versa; because the structure integrity and handling dynamics will be all wrong.
So, if AWD is implemented on top of a RWD chassis, the resulting AWD vehicle will also exhibit RWD characteristics. For example, in case of the Infiniti AWD, the system is able to distribute 100% of engine power to the rear wheels, in effect transforming the AWD vehicle into a RWD one.
But, if AWD is implemented on top of a FWD chassis, the resulting AWD vehicle will still exhibit FWD characteristics, because even though the AWD system is able to distribute 100% power to the front wheels, there is absolutely no way that 100% power can be directed to the rear wheels like the AWD-on-RWD-chassis vehicle.
This is the difference between the AWD-on-FWD-chassis and the AWD-on-RWD-chassis. The two will never behave the same way due to the inherited FWD and RWD characteristics and/or limitations.
That's what most people believe about chassis design. That is not true and that is not how the systems work.
Chassis design does change to a minor extent but with regard to suspension mounting points and technology employed. The body does have changes given the presence or lack of a tunnel for the drive shaft for the rear wheels.
You can build whatever you want if there is space and money involved. There are people out there that will adapt a frame to do whatever they want it to do like the RWD integra.
Read the Chassis Handbook By Bernd Heißing, Metin Ersoy and it will give you a better idea of how the designs are categorized.
http://books.google.com/books?id=NSl...hassis&f=false
You either have a transversely mounted drivetrain. Engine mounted sideways
Or a longitudinally mounted drivetrain. Engine and transmission in line
This is where the handling characteristics are affected.
A Transversely mounted drivetrain tends to have a higher center of gravity but is better with regard to space management.
A Longitudinally mounted drivetrain has a lower center of gravity and distributes the weight more efficiently but can take up more space with regard to the layout of the car.
That is what changes the handling not the chassis alone. You yourself mention that the Infinity sends 100% of the power to the back wheels and passively sends power to the front which is not great for an average driver. The chassis has nothing at all to do with how the computers are designed to distribute torque.
If the TL had its transfer case changed to send all the power to the back you would see nothing but oversteer. The fact is that Acura designed the car to be very well balanced and docile without the bite of an RWD car. There is no FWD chassis design affecting it. Yes the base model is FWD but that changes nothing handling wise when AWD is added to it. In fact the TL's AWD system is advanced enough to compete with the system employed in Audi's costing $70,000 dollars primarily because they use older outdated tech and people still buy without know how it works.
Simple mods can make your car oversteer like there's no tomorrow. Or a different transfer case with it set to sending all the power to the rear. A sway bar for instance will kick the tail end out and make the TL feel like a RWD car.
Don't confuse what the computer does to what the chassis is designed for. The drivetrain layout decides how a car will handle. There are RWD cars that understeer not because they have a transversely mounted drivetrain but because the front wheels are not setup correctly to do their job. That comes down to suspension tuning. Nothing else.
Here's an FWD car doing RWD stuff!
Last edited by d1sturb3d119; 03-26-2014 at 04:54 PM.
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03-26-2014, 05:44 PM
#59
holografique....Thanks for your post and I agree with your statement. I think your comment wasn't taken in the context and almost too literally. I agree that if one person is not requiring the capabilities of the AWD (not worried about snow, rain or ice) and all that one person wants is enhance steering, the P-AWS can actually be a great system to provide flat cornering. As you stated quite well, a person who doesn't want to invest the extra $$ in the SH-AWD, the P-AWS takes a regular FWD and brings it to a enhanced level and differentiates itself from what other FWD sedans offer.
I haven't driven the P-AWS but when I get a chance, I will and I feel that this may be the best option for me as I don't drive in the snow, rain or ice with my Acuras (If I decide to go for another Acura)....I am not a maniac behind the wheel so a V6 P-AWS tech with a bodykit may be what the doctor ordered....
I haven't driven the P-AWS but when I get a chance, I will and I feel that this may be the best option for me as I don't drive in the snow, rain or ice with my Acuras (If I decide to go for another Acura)....I am not a maniac behind the wheel so a V6 P-AWS tech with a bodykit may be what the doctor ordered....
The following 2 users liked this post by weather:
holografique (03-28-2014),
Rocket_man (03-26-2014)
03-26-2014, 06:27 PM
#60
I have read that not all Subaru AWD are the same so you'll have to figure out which ones are better. They throw the jargon of symmetric blah blah but I don't care about that. I just want to know which AWD is most pro-active and so far the SH-AWD has had good reviews.
Hopefully, the one in the TLX will be an improvement over the current one, that's already received decent reviews/praises from journalist especially on wintry road conditions.
Hopefully, the one in the TLX will be an improvement over the current one, that's already received decent reviews/praises from journalist especially on wintry road conditions.
The difference between the Subaru AWD systems is mainly between the automatic, CVT or manual transmission; how much power goes to the front tires or back tires. They are all symmetric AWD. All of the systems are proactive which is what the you originally asked.
03-26-2014, 06:46 PM
#61
03-26-2014, 06:54 PM
#62
^^^ *lol* I said "IF" I decide to go .... and I didn't say that it would be my next car. I could come back to Acura in 3 or 4 years 
I am not going to lie to you though, this winter has been really hard on my psychy and maybe I am a little too moodie and spiteful.
Don't tell my g/f....I have been blaming my moodiness on my bloaty'ness *lol*
I am not going to lie to you though, this winter has been really hard on my psychy and maybe I am a little too moodie and spiteful.Don't tell my g/f....I have been blaming my moodiness on my bloaty'ness *lol*
03-26-2014, 07:02 PM
#63
^^^ *lol* I said "IF" I decide to go .... and I didn't say that it would be my next car. I could come back to Acura in 3 or 4 years I am not going to lie to you though, this winter has been really hard on my psychy and maybe I am a little too moodie and spiteful.
Don't tell my g/f....I have been blaming my moodiness on my bloaty'ness *lol*
I am not going to lie to you though, this winter has been really hard on my psychy and maybe I am a little too moodie and spiteful.Don't tell my g/f....I have been blaming my moodiness on my bloaty'ness *lol*
03-26-2014, 07:12 PM
#64
*blushing* Yup.....
03-26-2014, 07:26 PM
#65
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Terragotti (03-27-2014)
03-26-2014, 07:49 PM
#66
Oh come on nothing. I'm entitled to state the way I felt in my personal experience driving the two regardless of the technical specifications. At the end of the day it's what the driver feels and experiences when driving the vehicles. Yes, under more specific or extreme conditions I'm sure the two perform very different from each other. But last I checked, most of the interstates around here in Atlanta didn't quality for track racing...
I also wasn't replying to the OP. If you actually read my response you'd get the context in which I was replying which was to a different post (Weather).
I also wasn't replying to the OP. If you actually read my response you'd get the context in which I was replying which was to a different post (Weather).
I'm not posting here for the sake of argument, only facts will tell the story and help forum members with their questions.
03-27-2014, 02:11 AM
#67
6G TLX-S
That's what most people believe about chassis design. That is not true and that is not how the systems work.
Chassis design does change to a minor extent but with regard to suspension mounting points and technology employed. The body does have changes given the presence or lack of a tunnel for the drive shaft for the rear wheels.
You can build whatever you want if there is space and money involved. There are people out there that will adapt a frame to do whatever they want it to do like the RWD integra.
Chassis design does change to a minor extent but with regard to suspension mounting points and technology employed. The body does have changes given the presence or lack of a tunnel for the drive shaft for the rear wheels.
You can build whatever you want if there is space and money involved. There are people out there that will adapt a frame to do whatever they want it to do like the RWD integra.
Sure with adequate chassis strengthening, time and money; one can do all type of crazy stuff, such as making a RWD car out of a FWD chassis, and even bolting a V8 motor in a FWD Honda Civic. But how about safety and long term reliability ?
Will a volume-selling production automobile company do it ? The answer is NO.
There is no volume-selling production automobile company on earth that has released RWD production vehicles based on a dedicated FWD chassis, other than some mickey-mouse tune shops that have put together some monsters which may not even be street legal.
In factory OEM form, a FWD chassis is optimized for FWD vehicles, and a RWD chassis is optimized for RWD vehicles.
You either have a transversely mounted drivetrain. Engine mounted sideways
Or a longitudinally mounted drivetrain. Engine and transmission in line
This is where the handling characteristics are affected.
A Transversely mounted drivetrain tends to have a higher center of gravity but is better with regard to space management.
A Longitudinally mounted drivetrain has a lower center of gravity and distributes the weight more efficiently but can take up more space with regard to the layout of the car.
That is what changes the handling not the chassis alone. You yourself mention that the Infinity sends 100% of the power to the back wheels and passively sends power to the front which is not great for an average driver. The chassis has nothing at all to do with how the computers are designed to distribute torque.
Or a longitudinally mounted drivetrain. Engine and transmission in line
This is where the handling characteristics are affected.
A Transversely mounted drivetrain tends to have a higher center of gravity but is better with regard to space management.
A Longitudinally mounted drivetrain has a lower center of gravity and distributes the weight more efficiently but can take up more space with regard to the layout of the car.
That is what changes the handling not the chassis alone. You yourself mention that the Infinity sends 100% of the power to the back wheels and passively sends power to the front which is not great for an average driver. The chassis has nothing at all to do with how the computers are designed to distribute torque.
I think you have confused between RWD and the potential to oversteer. Modern RWD vehicles don't necessariy always have the tendency to oversteer.
I too agree that oversteering is not for the faint of heart, and only understeering is a lot easier for the average drivers to recover from.
So this is exactly why nowdays, automakers tend to tune their RWD vehicles with a mild understeer characteristics, in order to make their RWD vehicles safer for the average drivers.
RWD BMW/MB/Lexus/Infiniti/etc. vehicles (with 100% power going to the rear wheels) ARE designed for the general public.
In fact, RWD vehicles are for everyone and always associated with performance automobiles, especially with luxury auto brands.
But the chassis has to be meticulously designed by computers to remain structural sound when given the bulk of the engine power applied to either the front end or the rear end of the chassis, depending on FWD or RWD applications.
If the TL had its transfer case changed to send all the power to the back you would see nothing but oversteer. The fact is that Acura designed the car to be very well balanced and docile without the bite of an RWD car. There is no FWD chassis design affecting it. Yes the base model is FWD but that changes nothing handling wise when AWD is added to it. In fact the TL's AWD system is advanced enough to compete with the system employed in Audi's costing $70,000 dollars primarily because they use older outdated tech and people still buy without know how it works.
Simple mods can make your car oversteer like there's no tomorrow. Or a different transfer case with it set to sending all the power to the rear. A sway bar for instance will kick the tail end out and make the TL feel like a RWD car.
Don't confuse what the computer does to what the chassis is designed for. The drivetrain layout decides how a car will handle. There are RWD cars that understeer not because they have a transversely mounted drivetrain but because the front wheels are not setup correctly to do their job. That comes down to suspension tuning. Nothing
else.
Here's an FWD car doing RWD stuff!
Simple mods can make your car oversteer like there's no tomorrow. Or a different transfer case with it set to sending all the power to the rear. A sway bar for instance will kick the tail end out and make the TL feel like a RWD car.
Don't confuse what the computer does to what the chassis is designed for. The drivetrain layout decides how a car will handle. There are RWD cars that understeer not because they have a transversely mounted drivetrain but because the front wheels are not setup correctly to do their job. That comes down to suspension tuning. Nothing
else.
Here's an FWD car doing RWD stuff!
You've missed my point.
My point is not about whether AWD-on-FWD-chassis performs better or worst than AWD-on-RWD-chassis, nor about whether FWD and RWD chassis will understeer or oversteer, nor about how advance or not it is the Acura SH-AWD when implemented on the Honda FWD chassis.
My point is that vehicles with AWD-on-RWD-chassis can mimic the drive and feel of RWD vehicles due to their abilities to direct 100% engine power going entirely to the rear wheels, with the front wheels solely doing steering control and the rear wheels solely putting power to the ground; and this is not vehicles with AWD-on-FWD-chassis is able to duplicate.
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BEAR-AvHistory (03-27-2014)
03-27-2014, 01:59 PM
#68
Structural integrity is a major consideration in designing a FWD or RWD chassis, because the front end or the rear end of the chassis has to withstand the bulk of the engine power (depending on FWD or RWD applications), while at the same time making the chassis as light in weight and as cheap in manufacturing cost as possible.
Sure with adequate chassis strengthening, time and money; one can do all type of crazy stuff, such as making a RWD car out of a FWD chassis, and even bolting a V8 motor in a FWD Honda Civic. But how about safety and long term reliability ?
Will a volume-selling production automobile company do it ? The answer is NO.
There is no volume-selling production automobile company on earth that has released RWD production vehicles based on a dedicated FWD chassis, other than some mickey-mouse tune shops that have put together some monsters which may not even be street legal.
In factory OEM form, a FWD chassis is optimized for FWD vehicles, and a RWD chassis is optimized for RWD vehicles.
But isn't this how all RWD vehicles work, with 100% engine power all going to the 2 rear wheels ? Does it mean that all RWD vehicles, such as BMW, MB, Lexus, Infiniti, etc., are not great for average drivers ?
I think you have confused between RWD and the potential to oversteer. Modern RWD vehicles don't necessariy always have the tendency to oversteer.
I too agree that oversteering is not for the faint of heart, and only understeering is a lot easier for the average drivers to recover from.
So this is exactly why nowdays, automakers tend to tune their RWD vehicles with a mild understeer characteristics, in order to make their RWD vehicles safer for the average drivers.
RWD BMW/MB/Lexus/Infiniti/etc. vehicles (with 100% power going to the rear wheels) ARE designed for the general public.
In fact, RWD vehicles are for everyone and always associated with performance automobiles, especially with luxury auto brands.
But the chassis has to be meticulously designed by computers to remain structural sound when given the bulk of the engine power applied to either the front end or the rear end of the chassis, depending on FWD or RWD applications.
Most RWD vehicles, except sport cars such as 911, will exhibit mild understeer, because their automakers deliberately tuned them this way.
You've missed my point.
My point is not about whether AWD-on-FWD-chassis performs better or worst than AWD-on-RWD-chassis, nor about whether FWD and RWD chassis will understeer or oversteer, nor about how advance or not it is the Acura SH-AWD when implemented on the Honda FWD chassis.
My point is that vehicles with AWD-on-RWD-chassis can mimic the drive and feel of RWD vehicles due to their abilities to direct 100% engine power going entirely to the rear wheels, with the front wheels solely doing steering control and the rear wheels solely putting power to the ground; and this is not vehicles with AWD-on-FWD-chassis is able to duplicate.
Sure with adequate chassis strengthening, time and money; one can do all type of crazy stuff, such as making a RWD car out of a FWD chassis, and even bolting a V8 motor in a FWD Honda Civic. But how about safety and long term reliability ?
Will a volume-selling production automobile company do it ? The answer is NO.
There is no volume-selling production automobile company on earth that has released RWD production vehicles based on a dedicated FWD chassis, other than some mickey-mouse tune shops that have put together some monsters which may not even be street legal.
In factory OEM form, a FWD chassis is optimized for FWD vehicles, and a RWD chassis is optimized for RWD vehicles.
But isn't this how all RWD vehicles work, with 100% engine power all going to the 2 rear wheels ? Does it mean that all RWD vehicles, such as BMW, MB, Lexus, Infiniti, etc., are not great for average drivers ?
I think you have confused between RWD and the potential to oversteer. Modern RWD vehicles don't necessariy always have the tendency to oversteer.
I too agree that oversteering is not for the faint of heart, and only understeering is a lot easier for the average drivers to recover from.
So this is exactly why nowdays, automakers tend to tune their RWD vehicles with a mild understeer characteristics, in order to make their RWD vehicles safer for the average drivers.
RWD BMW/MB/Lexus/Infiniti/etc. vehicles (with 100% power going to the rear wheels) ARE designed for the general public.
In fact, RWD vehicles are for everyone and always associated with performance automobiles, especially with luxury auto brands.
But the chassis has to be meticulously designed by computers to remain structural sound when given the bulk of the engine power applied to either the front end or the rear end of the chassis, depending on FWD or RWD applications.
Most RWD vehicles, except sport cars such as 911, will exhibit mild understeer, because their automakers deliberately tuned them this way.
You've missed my point.
My point is not about whether AWD-on-FWD-chassis performs better or worst than AWD-on-RWD-chassis, nor about whether FWD and RWD chassis will understeer or oversteer, nor about how advance or not it is the Acura SH-AWD when implemented on the Honda FWD chassis.
My point is that vehicles with AWD-on-RWD-chassis can mimic the drive and feel of RWD vehicles due to their abilities to direct 100% engine power going entirely to the rear wheels, with the front wheels solely doing steering control and the rear wheels solely putting power to the ground; and this is not vehicles with AWD-on-FWD-chassis is able to duplicate.
You're missing the whole point again. There is no such thing as an FWD or RWD chassis.
There are chassis types and they are engineered differently for different goals but there is nothing associated purely to FWD or RWD.
If you believe there is please send me a link to the information you used to support your belief.
These are the different chassis configurations that exist.
Ladder frame
Backbone tube
X-frame
Perimeter frame
Platform Frame
Superleggera
Unibody
Sub frame
All of which have absolutely nothing to do with FWD or RWD which is Drivetrain.
This is why Honda uses the Subframe design. Read the article at the end carefully to understand how this all works. Honda uses a mix of Sub-frame chassis design and a Uni body structure which they do not market as a unibody structure since the engine is not built into it. The use the subframe on the front to cradle the engine and a subframe on the rear to hold the suspension components.
The reason why this design changes nothing with regard to FWD and RWD is because the body of the car acts as the chassis as a whole.
This is the reason why Acura can make both the FWD and AWD TL's is the subframe design and its ability to be swapped out. The Unit body structure of the car has the infrastructure for an AWD platform to be incorporated mainly because of the tunnel for the driveshaft.
Honda is famous for their chassis design because the Unit body structure on all their cars across the board is so stiff and rigid making it a prime candidate for the crazy mods people do. This is the reason why people love putting honda's on the track. The engine's are great but the foundation for the suspension and overall handling characteristics of this package are unparalleled. Any Honda across the line is designed like this. Other car companies cannot say the same.
So your claim that the chassis on the Honda is FWD is a moot point because the chassis for the AWD TL's are swapped out for the AWD TL's engine and drivetrain and can be adapted for other purposes.
You claim that an RWD chassis will mimic RWD behavior on and AWD because of chassis desgin but again, that is impossible primarily because that concept doesn't exist but also because the chassis is not going to directly contribute to handling feel the way suspension will. Understeer and oversteer are a byproduct of drive distribution and suspension setup. Stability and rigidity are a a byproduct of chassis design.
All these factors are exacerbated on a motorcycle given the fact that chassis design plays a major role in stability and overall rigidity. It has nothing to do with understeer or oversteer again.
http://www.honda.com/newsandviews/ar...spx?id=5931-en
Video on chassis design in the Fit.
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internalaudit (03-27-2014)
03-27-2014, 03:32 PM
#69
Yes I was referring to your post in which you said you were confused. I am pleased with the SH-AWD drive but that was not the key of me buying that model, I bought this model simply for the feel of power over the base model more so than for the SH-AWD. I commented on earlier post in which I stated I had to drive more aggressively to get the benefit of SH-AWD, well atleast thats my perception.
What does my comment have anything to do with why you bought your TL? I am glad you like the power and I am happy for you.
Like I said... I am confused to why people would be disappointed in it when the purpose of torque vectoring IMO, IS to get out of that corner aggressively. If the car can go in a certain direction perfectly fine without torque vectoring.... why would you even want it to kick in at all? It's like people saying ABS is not working properly because the braking distance is longer. The whole point of ABS is not to make the car stop faster. The point of it is to give you the ability to control the direction of the car while braking. You get where I am coming from?
Unless, those expectations are for the SH-AWD to defy laws of physics... then I would have no idea how to respond to that.
Last edited by C8N; 03-27-2014 at 03:43 PM.
03-27-2014, 04:25 PM
#70
Suzuka Master
I do think that it is fair to say that a manufacturer has FWD or RWD chassis in a figurative way as that the manufacturer built the car first and foremost as a certain configuration. I also believe the the advantage of a RWD design is that it usually translates into the front wheels being able to be pushed further forward as opposed to FWD or a AWD design (A6) that is sued to accommodate a FWD configuration. That is the one thing I love about my M37S is how little front overhang there was and that helped the RWD dynamics IMO. My A6 has a far longer front overhang because the re is a model that comes in FWD only.
03-27-2014, 06:00 PM
#71
I agree, but there are FWD and RWD car designs and people equate that to the chassis. The A6 is a universal design where there are FWD and AWD options. Many RWD designs are adapted to support AWD, but in the the AWD is usually a reactive design where power is sent to the front wheels only under pre-determined slip criteria. Honda opted for FWD designs where the chassis and drive train are designed to support FWD with AWD occasionally sending power to the rear wheels, again under certain criteria. What I like about Acuras AWD in the new RDX is that under acceleration it sends some initial power to the rear wheels. Thisis helpful for my gf because her old RDX and even a FWD new RDX would spins its front wheel going up my driveway becasue the weight shift took traction off the front wheels enough for the wheel with power to slip. Her 14 AWD RDX because as it accelerates up keeps power going to the rear wheels as long as she accelerates at a decent pace up the driveway and never looses any front wheel traction. Sure I would prefer SH-AWD, but at least it is not lame sitting there all the time like most AWD systems on RWD biased cars.
I do think that it is fair to say that a manufacturer has FWD or RWD chassis in a figurative way as that the manufacturer built the car first and foremost as a certain configuration. I also believe the the advantage of a RWD design is that it usually translates into the front wheels being able to be pushed further forward as opposed to FWD or a AWD design (A6) that is sued to accommodate a FWD configuration. That is the one thing I love about my M37S is how little front overhang there was and that helped the RWD dynamics IMO. My A6 has a far longer front overhang because the re is a model that comes in FWD only.
I do think that it is fair to say that a manufacturer has FWD or RWD chassis in a figurative way as that the manufacturer built the car first and foremost as a certain configuration. I also believe the the advantage of a RWD design is that it usually translates into the front wheels being able to be pushed further forward as opposed to FWD or a AWD design (A6) that is sued to accommodate a FWD configuration. That is the one thing I love about my M37S is how little front overhang there was and that helped the RWD dynamics IMO. My A6 has a far longer front overhang because the re is a model that comes in FWD only.
People misconstruing these fundamental concepts talk about chassis design without knowing about how chassis design affects anything. Properly analyzing the behavior of the chassis or drivetrain or suspension comes from understanding the concept in its entirety.
You cannot claim that a manufacturer has a FWD or RWD chassis bias because they tune the car based on what it is supposed to achieve not based off what the base model is designed to do. Assuming that the FWD TL affects anything in the AWD TL is asinine and has nothing to do with each other because the chassis is different from each other!
The cradle they put the motor in, the subframe that is a mounting point for the rear end of the car and other associated components are all designed from scratch.
Overhang again has nothing to do with where the weight of the car is located. Popping the hood of the car is an easy test for that. If the motor is located behind the front wheels you will get crisp steering, motor ahead of the front wheels and you'll see understeer.
Also an I4 config is smaller than a V6 config. The reason why you feel the M37 is better is because of how the engine is mounted. Again very little to do with overhang. Overhang is a by product of how the engine is mounted in the engine bay. The infiniti feels more like a RWD because you're steering is more reactive primarily because of how the weight is distributed.
Audi V8 sits far in front of the front axles. Because they are trying to optimize cabin space in the car. Changes how everything else in the car is mounted.
The Infinity's motor sits partially between the front axle increasing your center of gravity and decreasing cabin space especially for the rear seats.
So the gist of all this is you're handling is a result of where the engine is mounted in the car. If its over the front axle you are left with less space and a higher center of gravity.
If its ahead of the front axle you're left with a ton of space a lack of crisp handling but a more utilitarian vehicle overall.
Again nothing to do with engine config more to do with what the end product is designed for.
Last edited by d1sturb3d119; 03-27-2014 at 06:02 PM.
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03-27-2014, 06:11 PM
#72
Suzuka Master
I again agree with you and think people use the wrong terminology. The Audi is likely more forward because it needs to support the Quattro AWD. I am not expert, far from it, but I think when you have a car that need to send more power to the front wheels it means more likely the engine will be further forward like Audi. With Infiniti the AWD is barely used and does not send much power forward so they can push the more back further. That changes the weight ratio front to back and further gives people the misconception that a given platform is FWD or RWD. What people should,say that would be more accurate would be a FWD or RWD platform rather that use the word chassis.
03-27-2014, 06:40 PM
#73
I again agree with you and think people use the wrong terminology. The Audi is likely more forward because it needs to support the Quattro AWD. I am not expert, far from it, but I think when you have a car that need to send more power to the front wheels it means more likely the engine will be further forward like Audi. With Infiniti the AWD is barely used and does not send much power forward so they can push the more back further. That changes the weight ratio front to back and further gives people the misconception that a given platform is FWD or RWD. What people should,say that would be more accurate would be a FWD or RWD platform rather that use the word chassis.
It's not that the Infiniti doesn't use the AWD but the fact that it is a passive system and only uses it if there's slip detected. Is that less safe, possibly in a really bad situation but if I wanted something that let's me have fun I'd buy the Infinity. If I wanted something that's aggressive but very safe in all conditions I'd buy the TL.
Either FWD or RWD platform or Drivetrain. Chassis design will change based on how the power needs to be delivered. So like you're saying there's never a case of an AWD car with an FWD platform because that's just not possible!
03-27-2014, 07:00 PM
#74
6G TLX-S
You're missing the whole point again. There is no such thing as an FWD or RWD chassis.
There are chassis types and they are engineered differently for different goals but there is nothing associated purely to FWD or RWD.
If you believe there is please send me a link to the information you used to support your belief.
These are the different chassis configurations that exist.
Ladder frame
Backbone tube
X-frame
Perimeter frame
Platform Frame
Superleggera
Unibody
Sub frame
All of which have absolutely nothing to do with FWD or RWD which is Drivetrain.
This is why Honda uses the Subframe design. Read the article at the end carefully to understand how this all works. Honda uses a mix of Sub-frame chassis design and a Uni body structure which they do not market as a unibody structure since the engine is not built into it. The use the subframe on the front to cradle the engine and a subframe on the rear to hold the suspension components.
The reason why this design changes nothing with regard to FWD and RWD is because the body of the car acts as the chassis as a whole.
This is the reason why Acura can make both the FWD and AWD TL's is the subframe design and its ability to be swapped out. The Unit body structure of the car has the infrastructure for an AWD platform to be incorporated mainly because of the tunnel for the driveshaft.
Honda is famous for their chassis design because the Unit body structure on all their cars across the board is so stiff and rigid making it a prime candidate for the crazy mods people do. This is the reason why people love putting honda's on the track. The engine's are great but the foundation for the suspension and overall handling characteristics of this package are unparalleled. Any Honda across the line is designed like this. Other car companies cannot say the same.
So your claim that the chassis on the Honda is FWD is a moot point because the chassis for the AWD TL's are swapped out for the AWD TL's engine and drivetrain and can be adapted for other purposes.
You claim that an RWD chassis will mimic RWD behavior on and AWD because of chassis desgin but again, that is impossible primarily because that concept doesn't exist but also because the chassis is not going to directly contribute to handling feel the way suspension will. Understeer and oversteer are a byproduct of drive distribution and suspension setup. Stability and rigidity are a a byproduct of chassis design.
All these factors are exacerbated on a motorcycle given the fact that chassis design plays a major role in stability and overall rigidity. It has nothing to do with understeer or oversteer again.
http://www.honda.com/newsandviews/ar...spx?id=5931-en
Video on chassis design in the Fit.
There are chassis types and they are engineered differently for different goals but there is nothing associated purely to FWD or RWD.
If you believe there is please send me a link to the information you used to support your belief.
These are the different chassis configurations that exist.
Ladder frame
Backbone tube
X-frame
Perimeter frame
Platform Frame
Superleggera
Unibody
Sub frame
All of which have absolutely nothing to do with FWD or RWD which is Drivetrain.
This is why Honda uses the Subframe design. Read the article at the end carefully to understand how this all works. Honda uses a mix of Sub-frame chassis design and a Uni body structure which they do not market as a unibody structure since the engine is not built into it. The use the subframe on the front to cradle the engine and a subframe on the rear to hold the suspension components.
The reason why this design changes nothing with regard to FWD and RWD is because the body of the car acts as the chassis as a whole.
This is the reason why Acura can make both the FWD and AWD TL's is the subframe design and its ability to be swapped out. The Unit body structure of the car has the infrastructure for an AWD platform to be incorporated mainly because of the tunnel for the driveshaft.
Honda is famous for their chassis design because the Unit body structure on all their cars across the board is so stiff and rigid making it a prime candidate for the crazy mods people do. This is the reason why people love putting honda's on the track. The engine's are great but the foundation for the suspension and overall handling characteristics of this package are unparalleled. Any Honda across the line is designed like this. Other car companies cannot say the same.
So your claim that the chassis on the Honda is FWD is a moot point because the chassis for the AWD TL's are swapped out for the AWD TL's engine and drivetrain and can be adapted for other purposes.
You claim that an RWD chassis will mimic RWD behavior on and AWD because of chassis desgin but again, that is impossible primarily because that concept doesn't exist but also because the chassis is not going to directly contribute to handling feel the way suspension will. Understeer and oversteer are a byproduct of drive distribution and suspension setup. Stability and rigidity are a a byproduct of chassis design.
All these factors are exacerbated on a motorcycle given the fact that chassis design plays a major role in stability and overall rigidity. It has nothing to do with understeer or oversteer again.
http://www.honda.com/newsandviews/ar...spx?id=5931-en
Video on chassis design in the Fit.
But stability and rigidity are NOT a byproduct of chassis (Platform?) design. Stability and rigidity are some of the primary factors in determining how the FWD or RWD platform is designed, because either the front end or the rear end of the platform has to be strategically strengthened or reinforced in order to withstand the bulk of the engine power.
A FWD platform will need to have much stronger front end, due to the front wheels doing the double duties of steering control and putting 100% engine power to the ground, while the rear wheels are basically free wheeling.
The resulting production (FWD or RWD) platform has to be cheap to manufacture and light in weight, meaning that strengthening and reinforcing are applied only to critical areas and only if absolutely necessary in order to meet the rigidity and structural integrity requirements.
If a FWD platform and a RWD platform are interchangeable, then Honda wouldn't need to spend $$$$$ to develop dedicated RWD platforms for the RWD NSX and the RWD S2000, since Honda can simply reuse any one of it's many existing FWD platforms.
Like I said before, my point is that vehicles with AWD-on-RWD-platform can mimic the drive and feel of RWD vehicles due to their abilities to direct 100% engine power going entirely to the rear wheels, with the front wheels solely doing steering control and the rear wheels solely putting power to the ground; and this is not vehicles with AWD-on-FWD-platform is able to duplicate.
03-27-2014, 08:11 PM
#75
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Reads like word game so some words from the dictionary
The frame, wheels, and machinery of a motor vehicle, on which the body is supported.
In the case of vehicles, the term rolling chassis means the frame plus the "running gear" like engine, transmission, driveshaft, differential, and suspension.
Since just about the only place you can get a body on frame construction is a truck or some SUV’s that whole discussion while interesting does not apply to the TL.
The structural elements of a vehicle classified as a unibody chassis includes everything but bolted-on body panels.
Point is the TL/TLX is built on the Accord platform as is the RLX. The Accord platform was engineered & optimized from the get go as a FWD unit. Only Audi has been able to get premium status with a FWD platform & the did it by adding AWD to the mix.
For low volume production Honda has neither the money X $100 million to develop a true RWD platform which is generally accepted as a right of passage into tier one so they added the AWD system from the truck, much smaller investment, to give the feel & selling points of a RWD.
Worked for Audi, but Audi has had a luxury cache going back into the 1920’s.
Interesting point. Was reading a Motor Trend & in the spy section they were discussing a new unreleased 3 box Nissan product. Speculation was it was a FWD due to the spacing of the front box.
Typical review:
With its flagship sedans, formerly the RL and now the RLX, Acura has struggled to maintain parity with the likes of rivals Lexus and Mercedes-Benz. That difficulty had to do with Acura's insistence on a front-wheel-drive platform fitted with a V-6 engine, pitted against rear-wheel-drive V-8 cars, and relative size. Acura's flagship sedans tended to compare with second-tier cars from the competition. Despite the large cabin and impressive Krell audio system, Acura stuck to its guns with the 2014 Acura RLX model .
The frame, wheels, and machinery of a motor vehicle, on which the body is supported.
In the case of vehicles, the term rolling chassis means the frame plus the "running gear" like engine, transmission, driveshaft, differential, and suspension.
Since just about the only place you can get a body on frame construction is a truck or some SUV’s that whole discussion while interesting does not apply to the TL.
The structural elements of a vehicle classified as a unibody chassis includes everything but bolted-on body panels.
Point is the TL/TLX is built on the Accord platform as is the RLX. The Accord platform was engineered & optimized from the get go as a FWD unit. Only Audi has been able to get premium status with a FWD platform & the did it by adding AWD to the mix.
For low volume production Honda has neither the money X $100 million to develop a true RWD platform which is generally accepted as a right of passage into tier one so they added the AWD system from the truck, much smaller investment, to give the feel & selling points of a RWD.
Worked for Audi, but Audi has had a luxury cache going back into the 1920’s.
Interesting point. Was reading a Motor Trend & in the spy section they were discussing a new unreleased 3 box Nissan product. Speculation was it was a FWD due to the spacing of the front box.
Typical review:
With its flagship sedans, formerly the RL and now the RLX, Acura has struggled to maintain parity with the likes of rivals Lexus and Mercedes-Benz. That difficulty had to do with Acura's insistence on a front-wheel-drive platform fitted with a V-6 engine, pitted against rear-wheel-drive V-8 cars, and relative size. Acura's flagship sedans tended to compare with second-tier cars from the competition. Despite the large cabin and impressive Krell audio system, Acura stuck to its guns with the 2014 Acura RLX model .
Last edited by BEAR-AvHistory; 03-27-2014 at 08:21 PM.
03-27-2014, 08:48 PM
#76
OK, rather than using the word "chassis", I now use the word "platform" instead, since most passenger cars nowadays are built on unibody structure.
But stability and rigidity are NOT a byproduct of chassis (Platform?) design. Stability and rigidity are some of the primary factors in determining how the FWD or RWD platform is designed, because either the front end or the rear end of the platform has to be strategically strengthened or reinforced in order to withstand the bulk of the engine power.
A FWD platform will need to have much stronger front end, due to the front wheels doing the double duties of steering control and putting 100% engine power to the ground, while the rear wheels are basically free wheeling.
The resulting production (FWD or RWD) platform has to be cheap to manufacture and light in weight, meaning that strengthening and reinforcing are applied only to critical areas and only if absolutely necessary in order to meet the rigidity and structural integrity requirements.
If a FWD platform and a RWD platform are interchangeable, then Honda wouldn't need to spend $$$$$ to develop dedicated RWD platforms for the RWD NSX and the RWD S2000, since Honda can simply reuse any one of it's many existing FWD platforms.
Like I said before, my point is that vehicles with AWD-on-RWD-platform can mimic the drive and feel of RWD vehicles due to their abilities to direct 100% engine power going entirely to the rear wheels, with the front wheels solely doing steering control and the rear wheels solely putting power to the ground; and this is not vehicles with AWD-on-FWD-platform is able to duplicate.
But stability and rigidity are NOT a byproduct of chassis (Platform?) design. Stability and rigidity are some of the primary factors in determining how the FWD or RWD platform is designed, because either the front end or the rear end of the platform has to be strategically strengthened or reinforced in order to withstand the bulk of the engine power.
A FWD platform will need to have much stronger front end, due to the front wheels doing the double duties of steering control and putting 100% engine power to the ground, while the rear wheels are basically free wheeling.
The resulting production (FWD or RWD) platform has to be cheap to manufacture and light in weight, meaning that strengthening and reinforcing are applied only to critical areas and only if absolutely necessary in order to meet the rigidity and structural integrity requirements.
If a FWD platform and a RWD platform are interchangeable, then Honda wouldn't need to spend $$$$$ to develop dedicated RWD platforms for the RWD NSX and the RWD S2000, since Honda can simply reuse any one of it's many existing FWD platforms.
Like I said before, my point is that vehicles with AWD-on-RWD-platform can mimic the drive and feel of RWD vehicles due to their abilities to direct 100% engine power going entirely to the rear wheels, with the front wheels solely doing steering control and the rear wheels solely putting power to the ground; and this is not vehicles with AWD-on-FWD-platform is able to duplicate.
The Uni body stucture of a car has to be rigid to begin with whether the rear is free wheeling or not. The car has to survive years and years of flexing to maintain its shape.
This is why I say nothing changes because the rear just has its sub frame updated to include the drivetrain that the car is using.
Honda spends money to develop new chassis in the case of the NSX and S2K because of how the engine's are mounted in accordance with the body shape. This is why these platforms are not shared with any cars across the range.
Notice where the S2K's engine sits. It is also longitudinally mounted. This isn't just a subframe change, its positioned for the best balance possible. Same with the NSX which has a transversely mounted engine.
Also take into consideration the unibody structure. Honda doesn't make any car's with the same dimensions. That's why they spend the money.
Note how the drive train sits in the car.
Look at how the engines sit on the chassis. This is why they re-engineer the chassis for these car's. They aren't really known for their legroom and comfort. They are designed to be sporty which is why the chassis design changes.
Again AWD on FWD platform as you mention doesn't make sense. Please just do the reading and understand that is not a concept that exists!
When there is drive going to the back wheels and the front wheels that doesn't change the fact that there needs to be good structural rigidity overall.
So the fact that the TL as a base car is FWD doesn't change anything. If they built the TL with an RWD platform in mind, you would have less space in the cabin, non existent trunk and would be completely wasteful given what Acura stand for.
Again the AWD system in the Infiniti is a passive system that sends power to the front only when slip is detected. The TL system is an active AWD system and is always distributing power which is what makes you feel like the car is not as lively to drive. The infiniti system acts like a RWD system and vectors torque using the brakes. Compared to the TL system that is stone age tech but, both have their benefits and both have their disadvantages. Again, the chassis has nothing to do with why the systems do what they do. It is computer controlled! If the TL sent all its power to the back you wouldn't be claiming that it feels like an FWD platform.
The feel you are talking about is computer controlled. Simple as that!
Last edited by d1sturb3d119; 03-27-2014 at 08:55 PM.
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internalaudit (03-28-2014)
03-27-2014, 10:49 PM
#77
I don't know what sparked this, however...
RWD generally means the engine is mounted closer to the center of the car. This biases the heavy mass of the powertrain to the middle of the car.
FWD generally means the engine is mounted north of the front axle, typically taking the transmission along with it. This pushes more weight forward.
Add AWD to either, and you'll come a bit closer to a common ground in chassis balance between the two.
Packaging is affected by the FWD/RWD choice, but in that case, just make the car smaller/larger to compensate... as the leaders in the luxury car field have done for many, many years.
RWD generally means the engine is mounted closer to the center of the car. This biases the heavy mass of the powertrain to the middle of the car.
FWD generally means the engine is mounted north of the front axle, typically taking the transmission along with it. This pushes more weight forward.
Add AWD to either, and you'll come a bit closer to a common ground in chassis balance between the two.
Packaging is affected by the FWD/RWD choice, but in that case, just make the car smaller/larger to compensate... as the leaders in the luxury car field have done for many, many years.
03-28-2014, 02:19 AM
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This is why I say nothing changes because the rear just has its sub frame updated to include the drivetrain that the car is using.
So the fact that the TL as a base car is FWD doesn't change anything. If they built the TL with an RWD platform in mind, you would have less space in the cabin, non existent trunk and would be completely wasteful given what Acura stand for.
So the fact that the TL as a base car is FWD doesn't change anything. If they built the TL with an RWD platform in mind, you would have less space in the cabin, non existent trunk and would be completely wasteful given what Acura stand for.
Looks like a lot of cut & paste in some of this stuff. The “superleggera” frame pictured above is actually a standard space frame. Superleggera is Italian for super light & was generally applied to alloy bodied cars back in the day.
There were a few very light tube frames made, mostly by Maserati, but were commonly called “Birdcage” & used in sports racers.
The frame pictured is not a super light duraluminium because the pictured mounting points for the suspension would require a steel frame not a light weight small tube alloy one.
My frame is not all that heavy, but its no way superlight.
Last edited by BEAR-AvHistory; 03-28-2014 at 02:32 AM.
03-28-2014, 07:49 AM
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If I'm correct in what I'm reading you've typed, you seem to be counting more systems than SH-AWD in your evaluation of the car's stability.
I'm not looking at AHA and VSA as if they're part of SH-AWD, although I fully agree and admit that the systems are integrated, and fully admit that you're correct about what you have said.
But...what SH-AWD's capabilities could be improved if we found a way to do with the conventional cars what we are doing with the RLX Hybrid SH-AWD, by using the gears and clutches themselves to provide some drag without applying the brakes.
03-28-2014, 07:53 AM
#80
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Ichishima has always cracked me up. But, be careful...there's a subtle change in his facial features that indicate more or less that he's pissed. And that's not really a man you want pissed.
:-)
Although I'm not at the top of this thread, I've enjoyed reading the posts from people who are obviously genuine enthusiasts, even if we're not in complete sync with everything.
:-)
Although I'm not at the top of this thread, I've enjoyed reading the posts from people who are obviously genuine enthusiasts, even if we're not in complete sync with everything.