09 RL SH-AWD Changes
02-11-2008, 03:06 PM
#1
Safety Car
Thread Starter
09 RL SH-AWD Changes
So what are the real changes? I have breezed through over 20 new pages of posting, and cannot really find anything concrete. Acuranews.com has vague references to SH-AWD has been made more responsive, but no details.
Did they change the bias on acceleration, cornering, etc. Is it still 80/20 FR to 20/80, have they changed the acceleration device to give more either an increased level or increased range of overdriving of the rear wheels, or is it still the variable 5%. Etc., etc, etc.
And regards suspension, does this mean A-Spec is gone, revised, or what?
Thanks!
Did they change the bias on acceleration, cornering, etc. Is it still 80/20 FR to 20/80, have they changed the acceleration device to give more either an increased level or increased range of overdriving of the rear wheels, or is it still the variable 5%. Etc., etc, etc.
And regards suspension, does this mean A-Spec is gone, revised, or what?
Thanks!
02-11-2008, 07:47 PM
#2
Senior Moderator
Straight from the source....
Cliff's notes:
-SH-AWD didn't activate until 2nd gear in the 2005-8 RL, now it activates in 1st gear
-outside rear wheel can now be overdriven by up to 5.7%, was 5% in 2005-8
-front-rear and side-side torque shifts occur faster
-other items unchanged
http://www.hondanews.com/categories/793/releases/4412
Super Handling All-Wheel Drive™ System
Super Handling All-Wheel Drive™ (SH-AWD™) is an innovative all-wheel drive system that continually distributes the optimum amount of torque not only between the front and rear wheels, but also between the left and right rear wheels. The result of the specific right/left wheel torque distribution (or torque vectoring) is more neutral, accurate steering when cornering under power that front-drive, rear-drive or conventional all-wheel-drive can't equal.
The previous RL's SH-AWD™ system didn't initiate rear side-to-side torque distribution until Second gear. However, on the 2009 RL new control parameters allow rearward torque delivery in First gear. Plus, front-to-rear and side-to-side power transfer happens much quicker with improved precision. The benefit of the revised SH-AWD™ system is improved accuracy, quicker response, and more power able to be applied to a specific rear wheel.
Torque splits are as follows:
--During straight-line cruising and moderate cornering below half throttle, up to 70-percent of engine torque is delivered to the front wheels. NB note--no change
--In full-throttle straight line acceleration, up to 40-percent of the power is sent to the rear axle. NB note--no change
--In hard cornering, up to 70-percent of available torque goes to the rear wheels for enhanced chassis balance. Up to 100-percent of this torque can be applied to the outside rear wheel that can also be overdriven up to 5.7-percent by a built-in acceleration device. NB note--only change is in overdrive rate--it was 5%, now 5.7%
SH-AWD™ incorporates a unique rear differential that continually varies the amount of torque delivered to the left and right rear wheels. SH-AWD™ generates a yaw moment during cornering by specifically routing torque from the engine. When cornering, a planetary gearset overdrives (or accelerates) the rear wheels while individual right and left clutch packs selectively direct torque to either or both rear wheel(s), driving them faster than the average of the front wheels to dramatically enhance the cornering, steering feel, overall handling and stability of the RL. The result is class leading cornering precision as well as enhanced traction in inclement weather.
Direct Yaw Control System Theory
SH-AWD™ counters understeer with a unique Direct Yaw Control system. Rotating an outside rear wheel faster than the average speed of the two front wheels allows the system to generate vehicle "yaw" while turning. By relieving the front tires of some of the work of turning the car, the system reduces understeer and the vehicle stays more balanced and controllable. In addition, with the cornering load more evenly distributed between the front and rear tires, the total cornering grip is increased. In conventional vehicles, cornering is created almost entirely by the steering angle of the front tires. With the RL, cornering is created by steering angle of front tires combined with the extra drive torque supplied by an outside rear tire.
Direct Yaw Control is a significant advance over conventional drive systems. To deal with high power output, front- or rear-drive systems generally use some type of limited-slip differential to maintain traction while under power. However, a linking effect of the inside and outside drive wheels in these systems resists turning. This linking effect is a factor that works against the front tires as they attempt to turn the vehicle. Conventional AWD systems have a similar linking effect between the inboard and outboard tires as well as between the front and rear axles, thus causing a similar resistance to turning. This is part of the reason why traditional AWD systems typically lack the more nimble feel of the best two-wheel drive systems. By using drive torque to help rotate the car, the RL is more responsive, neutral and predictable, while simultaneously offering all of the usual foul-weather benefits of all-wheel drive.
Electronic Controls and Parameters
The logic and control of SH-AWD™ is integrated with the RL engine's Electronic Control Unit (ECU) and Vehicle Stability Assist™ (VSA®) ECU. The Engine ECU provides engine rpm, throttle position, intake manifold pressure, and transmission gear ratio data. The VSA® ECU provides data on lateral g, yaw rate, wheel rotation speed and steering angle. The SH-AWD™ ECU monitors the status of the acceleration device and the distribution of right and left Direct Electromagnetic Clutch torque. Traction is calculated based on the information from the engine ECU. During a hard acceleration situation, lateral g and steering angle are used to calculate the torque split between the right and left rear wheels. At the same time, this data is used to control the total amount (ranging between 0.6- and 5.7-percent) of rear wheel acceleration.
SH-AWD™ System Layout
SH-AWD™ is a seamlessly operating, full-time all-wheel drive system that requires no driver interaction for operation. A torque transfer unit is bolted directly to the front-mounted transaxle. Attached to the front differential ring gear is a helical gear that provides input torque to the transfer unit. A short horizontal shaft and a hypoid gear set within the case turn the propeller shaft ninety degrees and move it to the vehicle center line. Lightweight carbon fiber dual driveshafts carry power to the rear differential unit.
Torque vectoring takes place in the rear differential which contains three planetary gear and clutch sets. Torque from the driveshaft passes through the differential's first clutch/planetary gearset, which as a unit is called the Acceleration Device.
Output torque from the Acceleration Device is channeled to a hypoid gear that turns the output 90-degrees to drive the rear axle shafts. A matched pair of Direct Electromagnetic Clutch systems (one on each side) send power to each rear wheel. These clutch systems can be controlled as a pair to alter the front/rear torque split, or depending on the situation, the rear wheels can receive between 30- to 70-percent of the engine's total output. The right and left Direct Electromagnetic Clutch systems can be controlled independently, to allow up to 100-percent of the total rear axle torque to go to only one rear wheel.
Acceleration Device
Positioned at the front of the RL rear drive unit, the Acceleration Device typically passes torque to the rear axle at very close to a one-to-one ratio. However, in cornering the Acceleration Device's output shaft spins faster than its input shaft.
The Acceleration Device uses a compact planetary gearset to achieve its speed increase. Hydraulic actuators operate clutch packs that control the planetary gearset. When the input shaft is locked with the planetary gear carrier, there is no ratio change (this is the traditional straight-line acceleration mode). During cornering, the carrier is coupled with the case, and the output shaft speed increases up to 5.7-percent. A speed sensor at the hypoid gear (located downstream of the Acceleration device) provides a constant feedback loop to the SH-AWD™ Electronic Control Unit to ensure that the system is working properly.
Direct Electromagnetic Clutch Systems
Located on either side of the hypoid gear that drives the rear axle are two identical Direct Electromagnetic Clutch systems that control the amount of drive torque that reaches each rear wheel. With the 2009 RL, the speed and accuracy of this electromagnetic clutch system is far more precise than previous versions thus providing an improved limited-slip differential function. In addition, the acceleration device incorporates a low- and high-range that delivers different levels of rear wheel overdrive depending on vehicle velocity and lateral acceleration. A computer-controlled electric coil controls the pressure applied to a clutch, which slows the sun gear within a planetary gearset to modulate the torque being sent to the rear wheel. The amount of torque transmitted to each rear wheel continually varies between zero and 100-percent, depending on driving conditions.
Under deceleration (throttle closed) while cornering, torque to the outside rear wheel is varied to change from an inward to an outward yaw moment, helping improve vehicle stability. A search coil sensor allows the ECU to estimate the clutch plate coefficient of friction (which changes with heat build-up) and then adjusts voltage sent to the electromagnetic coil that controls the clutch to compensate. To ensure that the amount of torque transmitted remains optimized as miles and wear accumulate, the coils provide a feedback loop that the ECU uses to adjust voltage to the electromagnetic clutches thus compensating for clutch wear.
-SH-AWD didn't activate until 2nd gear in the 2005-8 RL, now it activates in 1st gear
-outside rear wheel can now be overdriven by up to 5.7%, was 5% in 2005-8
-front-rear and side-side torque shifts occur faster
-other items unchanged
http://www.hondanews.com/categories/793/releases/4412
Super Handling All-Wheel Drive™ System
Super Handling All-Wheel Drive™ (SH-AWD™) is an innovative all-wheel drive system that continually distributes the optimum amount of torque not only between the front and rear wheels, but also between the left and right rear wheels. The result of the specific right/left wheel torque distribution (or torque vectoring) is more neutral, accurate steering when cornering under power that front-drive, rear-drive or conventional all-wheel-drive can't equal.
The previous RL's SH-AWD™ system didn't initiate rear side-to-side torque distribution until Second gear. However, on the 2009 RL new control parameters allow rearward torque delivery in First gear. Plus, front-to-rear and side-to-side power transfer happens much quicker with improved precision. The benefit of the revised SH-AWD™ system is improved accuracy, quicker response, and more power able to be applied to a specific rear wheel.
Torque splits are as follows:
--During straight-line cruising and moderate cornering below half throttle, up to 70-percent of engine torque is delivered to the front wheels. NB note--no change
--In full-throttle straight line acceleration, up to 40-percent of the power is sent to the rear axle. NB note--no change
--In hard cornering, up to 70-percent of available torque goes to the rear wheels for enhanced chassis balance. Up to 100-percent of this torque can be applied to the outside rear wheel that can also be overdriven up to 5.7-percent by a built-in acceleration device. NB note--only change is in overdrive rate--it was 5%, now 5.7%
SH-AWD™ incorporates a unique rear differential that continually varies the amount of torque delivered to the left and right rear wheels. SH-AWD™ generates a yaw moment during cornering by specifically routing torque from the engine. When cornering, a planetary gearset overdrives (or accelerates) the rear wheels while individual right and left clutch packs selectively direct torque to either or both rear wheel(s), driving them faster than the average of the front wheels to dramatically enhance the cornering, steering feel, overall handling and stability of the RL. The result is class leading cornering precision as well as enhanced traction in inclement weather.
Direct Yaw Control System Theory
SH-AWD™ counters understeer with a unique Direct Yaw Control system. Rotating an outside rear wheel faster than the average speed of the two front wheels allows the system to generate vehicle "yaw" while turning. By relieving the front tires of some of the work of turning the car, the system reduces understeer and the vehicle stays more balanced and controllable. In addition, with the cornering load more evenly distributed between the front and rear tires, the total cornering grip is increased. In conventional vehicles, cornering is created almost entirely by the steering angle of the front tires. With the RL, cornering is created by steering angle of front tires combined with the extra drive torque supplied by an outside rear tire.
Direct Yaw Control is a significant advance over conventional drive systems. To deal with high power output, front- or rear-drive systems generally use some type of limited-slip differential to maintain traction while under power. However, a linking effect of the inside and outside drive wheels in these systems resists turning. This linking effect is a factor that works against the front tires as they attempt to turn the vehicle. Conventional AWD systems have a similar linking effect between the inboard and outboard tires as well as between the front and rear axles, thus causing a similar resistance to turning. This is part of the reason why traditional AWD systems typically lack the more nimble feel of the best two-wheel drive systems. By using drive torque to help rotate the car, the RL is more responsive, neutral and predictable, while simultaneously offering all of the usual foul-weather benefits of all-wheel drive.
Electronic Controls and Parameters
The logic and control of SH-AWD™ is integrated with the RL engine's Electronic Control Unit (ECU) and Vehicle Stability Assist™ (VSA®) ECU. The Engine ECU provides engine rpm, throttle position, intake manifold pressure, and transmission gear ratio data. The VSA® ECU provides data on lateral g, yaw rate, wheel rotation speed and steering angle. The SH-AWD™ ECU monitors the status of the acceleration device and the distribution of right and left Direct Electromagnetic Clutch torque. Traction is calculated based on the information from the engine ECU. During a hard acceleration situation, lateral g and steering angle are used to calculate the torque split between the right and left rear wheels. At the same time, this data is used to control the total amount (ranging between 0.6- and 5.7-percent) of rear wheel acceleration.
SH-AWD™ System Layout
SH-AWD™ is a seamlessly operating, full-time all-wheel drive system that requires no driver interaction for operation. A torque transfer unit is bolted directly to the front-mounted transaxle. Attached to the front differential ring gear is a helical gear that provides input torque to the transfer unit. A short horizontal shaft and a hypoid gear set within the case turn the propeller shaft ninety degrees and move it to the vehicle center line. Lightweight carbon fiber dual driveshafts carry power to the rear differential unit.
Torque vectoring takes place in the rear differential which contains three planetary gear and clutch sets. Torque from the driveshaft passes through the differential's first clutch/planetary gearset, which as a unit is called the Acceleration Device.
Output torque from the Acceleration Device is channeled to a hypoid gear that turns the output 90-degrees to drive the rear axle shafts. A matched pair of Direct Electromagnetic Clutch systems (one on each side) send power to each rear wheel. These clutch systems can be controlled as a pair to alter the front/rear torque split, or depending on the situation, the rear wheels can receive between 30- to 70-percent of the engine's total output. The right and left Direct Electromagnetic Clutch systems can be controlled independently, to allow up to 100-percent of the total rear axle torque to go to only one rear wheel.
Acceleration Device
Positioned at the front of the RL rear drive unit, the Acceleration Device typically passes torque to the rear axle at very close to a one-to-one ratio. However, in cornering the Acceleration Device's output shaft spins faster than its input shaft.
The Acceleration Device uses a compact planetary gearset to achieve its speed increase. Hydraulic actuators operate clutch packs that control the planetary gearset. When the input shaft is locked with the planetary gear carrier, there is no ratio change (this is the traditional straight-line acceleration mode). During cornering, the carrier is coupled with the case, and the output shaft speed increases up to 5.7-percent. A speed sensor at the hypoid gear (located downstream of the Acceleration device) provides a constant feedback loop to the SH-AWD™ Electronic Control Unit to ensure that the system is working properly.
Direct Electromagnetic Clutch Systems
Located on either side of the hypoid gear that drives the rear axle are two identical Direct Electromagnetic Clutch systems that control the amount of drive torque that reaches each rear wheel. With the 2009 RL, the speed and accuracy of this electromagnetic clutch system is far more precise than previous versions thus providing an improved limited-slip differential function. In addition, the acceleration device incorporates a low- and high-range that delivers different levels of rear wheel overdrive depending on vehicle velocity and lateral acceleration. A computer-controlled electric coil controls the pressure applied to a clutch, which slows the sun gear within a planetary gearset to modulate the torque being sent to the rear wheel. The amount of torque transmitted to each rear wheel continually varies between zero and 100-percent, depending on driving conditions.
Under deceleration (throttle closed) while cornering, torque to the outside rear wheel is varied to change from an inward to an outward yaw moment, helping improve vehicle stability. A search coil sensor allows the ECU to estimate the clutch plate coefficient of friction (which changes with heat build-up) and then adjusts voltage sent to the electromagnetic coil that controls the clutch to compensate. To ensure that the amount of torque transmitted remains optimized as miles and wear accumulate, the coils provide a feedback loop that the ECU uses to adjust voltage to the electromagnetic clutches thus compensating for clutch wear.
The following users liked this post:
Sapoverde69 (04-25-2022)
02-11-2008, 09:35 PM
#4
Senior Moderator
Suspension
Again, straight from the source:
http://www.hondanews.com/categories/757/releases/4410
Cliff's notes:
Spring rate increased 6% front and 10.5% rear, and rear sway bar thickness increased by 11%. Should give a firmer ride.
No word about A-Spec yet, but from the description they incorporated the spring rates. Yessssss. All the same, a magnetic ride control like on the MDX would be welcome for those who want a limo ride.
FRONT DOUBLE-WISHBONE SUSPENSION
The front suspension is a double-wishbone design with a large subframe mount and a special compliance bushing. In addition, the coil spring rate has increased (by 6-percent front and 10.5-percent rear), the dampers have been recalibrated for improved performance, and the rear stabilizer bar increases in diameter by 11-percent. These upgrades combine to reduce chassis attitude changes to ensure a flat ride during acceleration, cornering, and hard braking.
Specific performance goals for the RL suspension included better response over rough roads, improved steering feel, optimized geometry, and overall component ruggedness. The steering knuckles, upper control arms, lower control arms and subframe assembly are all constructed of lightweight aluminum.
REAR MULTI-LINK SUSPENSION
The rear suspension is a multi-link design with a new enlarged subframe mount and a longer upper control arm. As a result, the vehicle roll center is optimized for better turning response, improved cornering stability and more control in extreme conditions.The optimized geometry results in more linear toe and camber changes during suspension travel. Improved roll stiffness also enhances the RL's cornering capabilities. The suspension design also has anti-lift characteristics to reduce the pitching motion of the body during hard braking.
As a result of the new compliance bushing and the specially designed suspension, harshness and road noise are significantly reduced while ride comfort is measurably improved.In an effort for weight savings, lightweight aluminum is used in the construction of the control arms and subframe. The components are also stiffer to withstand the higher side loads that improved SH-AWD, the larger 18-inch diameter tires and the stiff unit body design create.
http://www.hondanews.com/categories/757/releases/4410
Cliff's notes:
Spring rate increased 6% front and 10.5% rear, and rear sway bar thickness increased by 11%. Should give a firmer ride.
No word about A-Spec yet, but from the description they incorporated the spring rates. Yessssss. All the same, a magnetic ride control like on the MDX would be welcome for those who want a limo ride.
FRONT DOUBLE-WISHBONE SUSPENSION
The front suspension is a double-wishbone design with a large subframe mount and a special compliance bushing. In addition, the coil spring rate has increased (by 6-percent front and 10.5-percent rear), the dampers have been recalibrated for improved performance, and the rear stabilizer bar increases in diameter by 11-percent. These upgrades combine to reduce chassis attitude changes to ensure a flat ride during acceleration, cornering, and hard braking.
Specific performance goals for the RL suspension included better response over rough roads, improved steering feel, optimized geometry, and overall component ruggedness. The steering knuckles, upper control arms, lower control arms and subframe assembly are all constructed of lightweight aluminum.
REAR MULTI-LINK SUSPENSION
The rear suspension is a multi-link design with a new enlarged subframe mount and a longer upper control arm. As a result, the vehicle roll center is optimized for better turning response, improved cornering stability and more control in extreme conditions.The optimized geometry results in more linear toe and camber changes during suspension travel. Improved roll stiffness also enhances the RL's cornering capabilities. The suspension design also has anti-lift characteristics to reduce the pitching motion of the body during hard braking.
As a result of the new compliance bushing and the specially designed suspension, harshness and road noise are significantly reduced while ride comfort is measurably improved.In an effort for weight savings, lightweight aluminum is used in the construction of the control arms and subframe. The components are also stiffer to withstand the higher side loads that improved SH-AWD, the larger 18-inch diameter tires and the stiff unit body design create.
02-11-2008, 10:23 PM
#6
Safety Car
Thread Starter
Originally Posted by neuronbob
Cliff's notes:
-SH-AWD didn't activate until 2nd gear in the 2005-8 RL, now it activates in 1st gear
-outside rear wheel can now be overdriven by up to 5.7%, was 5% in 2005-8
-front-rear and side-side torque shifts occur faster
-other items unchanged
http://www.hondanews.com/categories/793/releases/4412
Super Handling All-Wheel Drive™ System
-SH-AWD didn't activate until 2nd gear in the 2005-8 RL, now it activates in 1st gear
-outside rear wheel can now be overdriven by up to 5.7%, was 5% in 2005-8
-front-rear and side-side torque shifts occur faster
-other items unchanged
http://www.hondanews.com/categories/793/releases/4412
Super Handling All-Wheel Drive™ System
This is a quote from the 2007 RDX, which quotes the 5.7%, presumably for at least the 2006 model, considering when the RDX was released. I had asked either here or TOV what the real story was a year or more ago, but no one really answered.
The implication from putting the two articles (RL and RDX) together is that the RL is constantly overdriven at 0.7% and the acceleration device can increase that speed by 5% for a total of 5.7%. But it was never clearly stated in any RL info that the total overdrive was 5.7%, until now, I guess.
http://www.hondanews.com/categories/764/releases/3560
The rear drive unit of the RL sedan has a clutch and planetary gear set, called the "acceleration device," that can increase the speed of the rear axle up to 5.7%. In contrast, the RDX's rear driveshaft is constantly overdriven by 1.7% - and the resulting overdrive effect is regulated by the left and right rear clutch packs. The difference in the chosen rear axle speed increase is due to the differing handling dynamics of the two vehicles.
02-12-2008, 01:49 PM
#7
Trolling Canuckistan
Originally Posted by Chas2
This is some of the same inconsistencies that Acura has put out in the past.
This is a quote from the 2007 RDX, which quotes the 5.7%, presumably for at least the 2006 model, considering when the RDX was released. I had asked either here or TOV what the real story was a year or more ago, but no one really answered.
This is a quote from the 2007 RDX, which quotes the 5.7%, presumably for at least the 2006 model, considering when the RDX was released. I had asked either here or TOV what the real story was a year or more ago, but no one really answered.
Trending Topics
02-12-2008, 01:55 PM
#8
Trolling Canuckistan
Originally Posted by neuronbob
No word about A-Spec yet, but from the description they incorporated the spring rates. Yessssss. All the same, a magnetic ride control like on the MDX would be welcome for those who want a limo ride.
This is one of the misconceptions of the sport MDX. Many people have been told that "comfort mode" give you the same ride as the base MDX where "sport mode" gives you a firmer ride. In reality, "comfort mode" is softer than a base MDX and "sport mode" is stiffer.
MRF suspension is an absolute must for the RL IMO, if not in this MMC (which I don't think is happening) we should have the option when it gets the FMC.
MRF>A-spec........ It's about a million times more sophisticated and can control nose dive and body roll in ways that a coil spring can't.
02-12-2008, 02:29 PM
#9
Safety Car
Thread Starter
Originally Posted by black label
This was probably a typo as the RDX (and MDX) accelerate the outside wheel 1.7% no more no less. It is a much less sophisticated SH-AWD than what the RL uses.
"The rear drive unit of the RL sedan has a clutch and planetary gear set, called the "acceleration device," that can increase the speed of the rear axle up to 5.7%.
In contrast, the RDX's rear driveshaft is constantly overdriven by 1.7% - and the resulting overdrive effect is regulated by the left and right rear clutch packs. The difference in the chosen rear axle speed increase is due to the differing handling dynamics of the two vehicles."
The RL write up says that the acceleration device can drive the rears up to 5% from some implied slightly overdriven floor (maybe 0.7%, maybe not). Here is a quote from the Acuranews.com archive on the 2005-07 RLs. It could be interpreted as 5% max overdrive or a range of 5% on top of the floor (i.e. some close to one-to-one ratio plus 5%)
I know it is cutting hairs, but this kind of stuff just shows sloppy configuration control between product press releases. Other examples are givng the correct metric sizing of the Odyssey PAX wheels, while calling the RL PAX wheels 18 x 8, or the 2007 and 2008 brochures showing a 80-20 to 20-80 Front Rear distribution range on SH-AWD RLs, while 2005-2006 show 70-30 to 30-70, which is what is in all the press releases regardless of year (i.e. 2005-2008) .
"Acceleration Device
Positioned at the front of the RL rear drive unit, the Acceleration device typically passes torque rearward to the rear axle at very close to a one-to-one ratio. In cornering, however, the Acceleration device's output shaft spins faster than its input shaft.
The Acceleration assembly uses a compact planetary gearset to achieve its speed increase. Hydraulic actuators operate clutch packs that control the planetary gearset. When the input shaft is locked with the planetary gear carrier, there is no ratio change (this is the straight-line mode). During cornering, the carrier is coupled with the case, and the output shaft speed increases up to five percent. "
The 2007 MDX SH-AWD write up with respect to the rear overdrive speed is simpler and more straight forward.
"The SH-AWD™ system in the 2007 MDX is mechanically closely related to the system in the 2007 RDX™. (The system in the RL sedan differs mechanically from the RDX and MDX systems, but is similar in principle.) A torque transfer unit is bolted directly to the front-mounted transaxle. Attached to the front differential's ring gear is a helical gear that provides input torque to the transfer unit. A short horizontal shaft and a hypoid gear set within the case send power to the propeller shaft, which in turn carries it to the rear drive unit. The MDX rear axle is geared to turn 1.7% faster than the front axle."
I guess this is like splitting hairs on a gnat's @ss...
02-12-2008, 02:31 PM
#10
Safety Car
Thread Starter
Originally Posted by black label
The MRF suspension can provide both a firmer ride (like an A spec) or a softer ride (like a limo).
This is one of the misconceptions of the sport MDX. Many people have been told that "comfort mode" give you the same ride as the base MDX where "sport mode" gives you a firmer ride. In reality, "comfort mode" is softer than a base MDX and "sport mode" is stiffer.
MRF suspension is an absolute must for the RL IMO, if not in this MMC (which I don't think is happening) we should have the option when it gets the FMC.
MRF>A-spec........ It's about a million times more sophisticated and can control nose dive and body roll in ways that a coil spring can't.
This is one of the misconceptions of the sport MDX. Many people have been told that "comfort mode" give you the same ride as the base MDX where "sport mode" gives you a firmer ride. In reality, "comfort mode" is softer than a base MDX and "sport mode" is stiffer.
MRF suspension is an absolute must for the RL IMO, if not in this MMC (which I don't think is happening) we should have the option when it gets the FMC.
MRF>A-spec........ It's about a million times more sophisticated and can control nose dive and body roll in ways that a coil spring can't.
02-12-2008, 02:40 PM
#11
Safety Car
Thread Starter
[QUOTE=neuronbob]Again, straight from the source:
http://www.hondanews.com/categories/757/releases/4410
Great info. Thanks!
I could have sworn that this was not up the day they released the RL MMC, but no matter, this is good stuff.
Did you notice what kind of engine is in the Specifications? Why couldn't we have that in the first place?
http://www.hondanews.com/categories/759/releases/4414
POWERTRAIN
Engine Type 3.5-liter, SOHC, 60-degree VTEC® V-6
Horsepower 300 hp@ 6,300 rpm
Torque 271 lb-ft @ 5,000 rpm
Just being a smart @$$
http://www.hondanews.com/categories/757/releases/4410
Great info. Thanks!
I could have sworn that this was not up the day they released the RL MMC, but no matter, this is good stuff.
Did you notice what kind of engine is in the Specifications? Why couldn't we have that in the first place?
http://www.hondanews.com/categories/759/releases/4414
POWERTRAIN
Engine Type 3.5-liter, SOHC, 60-degree VTEC® V-6
Horsepower 300 hp@ 6,300 rpm
Torque 271 lb-ft @ 5,000 rpm
Just being a smart @$$
02-12-2008, 03:02 PM
#12
Trolling Canuckistan
Originally Posted by Chas2
I do not think it was a typo. TheRDX press release is consistent with what you said, that the RDX is 1.7% over driven, while the RL can do much more. Bold is my emphasis.
"The rear drive unit of the RL sedan has a clutch and planetary gear set, called the "acceleration device," that can increase the speed of the rear axle up to 5.7%.
In contrast, the RDX's rear driveshaft is constantly overdriven by 1.7% - and the resulting overdrive effect is regulated by the left and right rear clutch packs. The difference in the chosen rear axle speed increase is due to the differing handling dynamics of the two vehicles."
"The rear drive unit of the RL sedan has a clutch and planetary gear set, called the "acceleration device," that can increase the speed of the rear axle up to 5.7%.
In contrast, the RDX's rear driveshaft is constantly overdriven by 1.7% - and the resulting overdrive effect is regulated by the left and right rear clutch packs. The difference in the chosen rear axle speed increase is due to the differing handling dynamics of the two vehicles."
The Sport MDX weighs a wopping 5 lbs more than a tech MDX. The differences between the 2 are wheel appearance (they are the same size with same tires), thicker stabilizer bars, perforated leather, auto leveling headlights, and the MRF suspension. The wheels on a sport look lighter, but that's only a guess, theoretically thicker stabilizer would weigh more. Auto leveling headlights would have to weigh more than ones that don't auto level right? Roll all that together in a very non scientific equation and my guess is that the MRF suspension can't add more than 5-10lbs. Having driven both a Sport and Tech MDX, it's well worth what ever weight it does add.
Thread
Thread Starter
Forum
Replies
Last Post
joflewbyu2
5G TLX (2015-2020)
105
08-18-2019 10:38 PM
