Finally forged pistons, springs, retainers and race camshafts for our cars!!!
11-27-2009, 10:23 AM
#1
J36Twingt28r's,nextgt30r
Thread Starter
Finally forged pistons, springs, retainers and race camshafts for our cars!!!
SO I JUST CALLED KMS MOTORSPORTS AND THEY SAID THAT THE FORGED PISTONS, ETC FIT THE 03 AND ABOVE HONDA ACCORD V6!!
I KNOW IM GONNA BE PICKING UP A SET!! ANYONE HAVE EXPERIENCE WITH THIS COMPANY? THIS IS THE LINK. http://www.honda-performance.com/sea...?zoom_query=v6
11-27-2009, 06:32 PM
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actually the pistons are low compresion and they were out for a while and unless you have a turbo or a supercharger dont get em.... they r made for 42 psi which will slow ur car down a lot
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11-27-2009, 09:24 PM
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Rightbme and u had this convo before but the one he found are low compression turbo built pustones 42psi lol now what im really wondering about is will the cam fot the j35 types motor?
11-27-2009, 11:09 PM
#10
J36Twingt28r's,nextgt30r
Thread Starter
i mean u can see in my sig that i plan on stroking my engine to j36, and plan on bumping my compression up. so if i do that and install the low compression pistons i found will my compression ratio drop? i mean i know that high compression and boost don't really mix. BASICALLY, IM A NEWB AND WANNA KNOW WILL ANYTHING I BUY FROM KMS PISTONS, ETC DECREASE MY HORSEPOWER?? THANKS 
11-28-2009, 01:01 AM
#11
SO i do plan on going turbo next year however what does it mean when u say it will make my car much slower i mean u can see in my sig that i plan on stroking my engine to j36, and plan on bumping my compression up. so if i do that and install the low compression pistons i found will my compression ratio drop? i mean i know that high compression and boost don't really mix. BASICALLY, IM A NEWB AND WANNA KNOW WILL ANYTHING I BUY FROM KMS PISTONS, ETC DECREASE MY HORSEPOWER?? THANKS
i mean u can see in my sig that i plan on stroking my engine to j36, and plan on bumping my compression up. so if i do that and install the low compression pistons i found will my compression ratio drop? i mean i know that high compression and boost don't really mix. BASICALLY, IM A NEWB AND WANNA KNOW WILL ANYTHING I BUY FROM KMS PISTONS, ETC DECREASE MY HORSEPOWER?? THANKS If you put low compression pistons in the engine you will lose power, since less compression will mean less horsepower. Once you turbo the engine the low compression pistions will help you make more HP by allowing you to run more boost.
So if you are worried about running around with less power for awhile then wait on installing the pistons until you are ready for the turbo build.
11-28-2009, 01:52 AM
#12
Three Wheelin'
A piston being designed and tested to hold 42 psi of boost is irrelevant to its compression setup. They could be designed and tested to hold 42 psi in a 8:1 CR setup. The same type of material and forging is used for that particular piston if you get them in 12.0:1 CR application.
So being made for 42 psi doesnt in any way shape or form say that they're low CR, to the point which you make it sound, as if it will completely kill your motor.
My 9.5:1 CR pistons, running in NA form, had barely to almost non-existent difference. Something an average driver would've hardly noticed whether the motor was running 11.0:1 CR or 9.5:1 CR
Ring sealing and Piston:Cylinder wall clearance is also important. You could pretty much have a 10.0:1 CR motor make more power than a 11.0:1 CR motor, simply due to the first one having more cylinder pressure, which could be due to a better ring seal, smaller piston:cylinder wall clearance, less blow-by. And another factor is Ignition Timing. A more aggressive timing can be run in the 10.0:1 CR, which results in higher power output, and can be equal to the higher CR, where max timing would be lower then in 10.0:1 CR.
So, CR isn't always such a big enemy.
Our motor tends to run at its max timing, and adjusted accordingly based on knock. If max timing you could run let's say at 20 degrees BTDC on 11.0:1 CR. on 10.0:1 CR, max could be at 28 degrees BTDC. This is all also based on load. But let me not get all scientific about it.
These pistons are also for high reving, to compliment the valve train components they offer. There's no other reason to upgrade the valve train other than if you wanna rev higher (at least in our case, unless you're doing a P&P and bigger valves ), and reving higher aside from needing better valve springs and retainers and seals, pistons have to also be considered. You see, high performance pistons aren't always referred to as "boost pistons", High reving also needs its own treatment . And then a balanced crank comes after
Last edited by Opel; 11-28-2009 at 01:55 AM.
11-28-2009, 02:16 AM
#13
94 DC4 RS LSV/Turbo
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^ correct... you motor junkie...
cr is really subjective... some people live by the rule of thumb that if you want to make more power you want low cr and max boost... well lately the thinking has changed... you see guys running high cr.. and max boost... take for example an 8second b-series... figure it would have to be 13:1 cr and running 40psi and of course high octane fuel...
some people don't understand the balance
if you have 2 setups
A. 12.5:1 cr and 8psi boosted
B. 9:1 cr and 20psi boosted
A>B on the whp output
cr is really subjective... some people live by the rule of thumb that if you want to make more power you want low cr and max boost... well lately the thinking has changed... you see guys running high cr.. and max boost... take for example an 8second b-series... figure it would have to be 13:1 cr and running 40psi and of course high octane fuel...
some people don't understand the balance
if you have 2 setups
A. 12.5:1 cr and 8psi boosted
B. 9:1 cr and 20psi boosted
A>B on the whp output
11-28-2009, 11:13 AM
#15
^ correct... you motor junkie...
cr is really subjective... some people live by the rule of thumb that if you want to make more power you want low cr and max boost... well lately the thinking has changed... you see guys running high cr.. and max boost... take for example an 8second b-series... figure it would have to be 13:1 cr and running 40psi and of course high octane fuel...
some people don't understand the balance
if you have 2 setups
A. 12.5:1 cr and 8psi boosted
B. 9:1 cr and 20psi boosted
A>B on the whp output
cr is really subjective... some people live by the rule of thumb that if you want to make more power you want low cr and max boost... well lately the thinking has changed... you see guys running high cr.. and max boost... take for example an 8second b-series... figure it would have to be 13:1 cr and running 40psi and of course high octane fuel...
some people don't understand the balance
if you have 2 setups
A. 12.5:1 cr and 8psi boosted
B. 9:1 cr and 20psi boosted
A>B on the whp output
11-28-2009, 12:19 PM
#16
Three Wheelin'
Lets say, you have an 11.0:1 CR that makes 300 hp NA
Max boost on this on 93 octane gas before it detonates is 10 psi, and you're making 500 hp.
The same motor with 10.0:1 CR (being ignition timing isn't changed) would make somewhere around 280 hp (so look, only about 20 hp loss with a drop of 1 point in CR). But now here's the kicker, because of that 1 point drop in CR, you are now able to run 15 psi of boost. Thats 5 additional psi on top of 10 psi you were able to run with 11.0:1 CR. That 5 psi on a decent size turbo, could mean ~ 120 whp.
So with a drop of 1 point in CR comes a loss of about 20-30 hp (for arguments sake) but that also comes with a gain of being able to run much more boost, which makes up for the loss crated by lower CR, and surpasses it by FAR!
11.0:1 CR =300 hp + 10 PSI = 500 hp
10.0:1 CR =280 hp + 15 PSI = 600 hp
These numbers are not accurate. They're just used for the example, so you can understand the difference between the setups.
11-28-2009, 12:33 PM
#17
Under construction
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^^^^^^^ 
sorry i was just admiring the knowledge you guys have about engines.
shouldn't you guys be working at acura or something??? sounds like you guys know your stuff better then some of their techs lol
sorry i was just admiring the knowledge you guys have about engines.
shouldn't you guys be working at acura or something??? sounds like you guys know your stuff better then some of their techs lol
11-28-2009, 03:27 PM
#18
Team Owner
^ correct... you motor junkie...
cr is really subjective... some people live by the rule of thumb that if you want to make more power you want low cr and max boost... well lately the thinking has changed... you see guys running high cr.. and max boost... take for example an 8second b-series... figure it would have to be 13:1 cr and running 40psi and of course high octane fuel...
some people don't understand the balance
if you have 2 setups
A. 12.5:1 cr and 8psi boosted
B. 9:1 cr and 20psi boosted
A>B on the whp output
cr is really subjective... some people live by the rule of thumb that if you want to make more power you want low cr and max boost... well lately the thinking has changed... you see guys running high cr.. and max boost... take for example an 8second b-series... figure it would have to be 13:1 cr and running 40psi and of course high octane fuel...
some people don't understand the balance
if you have 2 setups
A. 12.5:1 cr and 8psi boosted
B. 9:1 cr and 20psi boosted
A>B on the whp output
If octane were unlimited, then high compression and high boost would rule. However, in real life, low compression and high boost will produce much, much more power.
11-28-2009, 03:30 PM
#19
Team Owner
Ok, look:
Lets say, you have an 11.0:1 CR that makes 300 hp NA
Max boost on this on 93 octane gas before it detonates is 10 psi, and you're making 500 hp.
The same motor with 10.0:1 CR (being ignition timing isn't changed) would make somewhere around 280 hp (so look, only about 20 hp loss with a drop of 1 point in CR). But now here's the kicker, because of that 1 point drop in CR, you are now able to run 15 psi of boost. Thats 5 additional psi on top of 10 psi you were able to run with 11.0:1 CR. That 5 psi on a decent size turbo, could mean ~ 120 whp.
So with a drop of 1 point in CR comes a loss of about 20-30 hp (for arguments sake) but that also comes with a gain of being able to run much more boost, which makes up for the loss crated by lower CR, and surpasses it by FAR!
11.0:1 CR =300 hp + 10 PSI = 500 hp
10.0:1 CR =280 hp + 15 PSI = 600 hp
These numbers are not accurate. They're just used for the example, so you can understand the difference between the setups.
Lets say, you have an 11.0:1 CR that makes 300 hp NA
Max boost on this on 93 octane gas before it detonates is 10 psi, and you're making 500 hp.
The same motor with 10.0:1 CR (being ignition timing isn't changed) would make somewhere around 280 hp (so look, only about 20 hp loss with a drop of 1 point in CR). But now here's the kicker, because of that 1 point drop in CR, you are now able to run 15 psi of boost. Thats 5 additional psi on top of 10 psi you were able to run with 11.0:1 CR. That 5 psi on a decent size turbo, could mean ~ 120 whp.
So with a drop of 1 point in CR comes a loss of about 20-30 hp (for arguments sake) but that also comes with a gain of being able to run much more boost, which makes up for the loss crated by lower CR, and surpasses it by FAR!
11.0:1 CR =300 hp + 10 PSI = 500 hp
10.0:1 CR =280 hp + 15 PSI = 600 hp
These numbers are not accurate. They're just used for the example, so you can understand the difference between the setups.
11-28-2009, 03:31 PM
#20
B will walk all over A any day of the week. You've waaay wrong on that one. For a given octane you can run a given ratio of boost and compression.
If octane were unlimited, then high compression and high boost would rule. However, in real life, low compression and high boost will produce much, much more power.
If octane were unlimited, then high compression and high boost would rule. However, in real life, low compression and high boost will produce much, much more power.
11-28-2009, 03:34 PM
#21
Team Owner
SO i do plan on going turbo next year however what does it mean when u say it will make my car much slower i mean u can see in my sig that i plan on stroking my engine to j36, and plan on bumping my compression up. so if i do that and install the low compression pistons i found will my compression ratio drop? i mean i know that high compression and boost don't really mix. BASICALLY, IM A NEWB AND WANNA KNOW WILL ANYTHING I BUY FROM KMS PISTONS, ETC DECREASE MY HORSEPOWER?? THANKS
i mean u can see in my sig that i plan on stroking my engine to j36, and plan on bumping my compression up. so if i do that and install the low compression pistons i found will my compression ratio drop? i mean i know that high compression and boost don't really mix. BASICALLY, IM A NEWB AND WANNA KNOW WILL ANYTHING I BUY FROM KMS PISTONS, ETC DECREASE MY HORSEPOWER?? THANKS If you go from 11:1 to say 9:1 you'll lose about 5-7% of your power and 10% fuel economy. 5% of 258 isn't that bad at all.
However, you will be able to run an extra 10+psi of boost and will likely make 25% more power than 11:1 once it's boosted on pump gas. Tuning will be easier and usually when something goes wrong, you have a better chance of the engine holding with the lower compression.
11-28-2009, 04:13 PM
#22
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Thats not quiet right.
A piston being designed and tested to hold 42 psi of boost is irrelevant to its compression setup. They could be designed and tested to hold 42 psi in a 8:1 CR setup. The same type of material and forging is used for that particular piston if you get them in 12.0:1 CR application.
So being made for 42 psi doesnt in any way shape or form say that they're low CR, to the point which you make it sound, as if it will completely kill your motor.
My 9.5:1 CR pistons, running in NA form, had barely to almost non-existent difference. Something an average driver would've hardly noticed whether the motor was running 11.0:1 CR or 9.5:1 CR
Ring sealing and Piston:Cylinder wall clearance is also important. You could pretty much have a 10.0:1 CR motor make more power than a 11.0:1 CR motor, simply due to the first one having more cylinder pressure, which could be due to a better ring seal, smaller piston:cylinder wall clearance, less blow-by. And another factor is Ignition Timing. A more aggressive timing can be run in the 10.0:1 CR, which results in higher power output, and can be equal to the higher CR, where max timing would be lower then in 10.0:1 CR.
So, CR isn't always such a big enemy.
Our motor tends to run at its max timing, and adjusted accordingly based on knock. If max timing you could run let's say at 20 degrees BTDC on 11.0:1 CR. on 10.0:1 CR, max could be at 28 degrees BTDC. This is all also based on load. But let me not get all scientific about it.
These pistons are also for high reving, to compliment the valve train components they offer. There's no other reason to upgrade the valve train other than if you wanna rev higher (at least in our case, unless you're doing a P&P and bigger valves ), and reving higher aside from needing better valve springs and retainers and seals, pistons have to also be considered. You see, high performance pistons aren't always referred to as "boost pistons", High reving also needs its own treatment . And then a balanced crank comes after
A piston being designed and tested to hold 42 psi of boost is irrelevant to its compression setup. They could be designed and tested to hold 42 psi in a 8:1 CR setup. The same type of material and forging is used for that particular piston if you get them in 12.0:1 CR application.
So being made for 42 psi doesnt in any way shape or form say that they're low CR, to the point which you make it sound, as if it will completely kill your motor.
My 9.5:1 CR pistons, running in NA form, had barely to almost non-existent difference. Something an average driver would've hardly noticed whether the motor was running 11.0:1 CR or 9.5:1 CR
Ring sealing and Piston:Cylinder wall clearance is also important. You could pretty much have a 10.0:1 CR motor make more power than a 11.0:1 CR motor, simply due to the first one having more cylinder pressure, which could be due to a better ring seal, smaller piston:cylinder wall clearance, less blow-by. And another factor is Ignition Timing. A more aggressive timing can be run in the 10.0:1 CR, which results in higher power output, and can be equal to the higher CR, where max timing would be lower then in 10.0:1 CR.
So, CR isn't always such a big enemy.
Our motor tends to run at its max timing, and adjusted accordingly based on knock. If max timing you could run let's say at 20 degrees BTDC on 11.0:1 CR. on 10.0:1 CR, max could be at 28 degrees BTDC. This is all also based on load. But let me not get all scientific about it.
These pistons are also for high reving, to compliment the valve train components they offer. There's no other reason to upgrade the valve train other than if you wanna rev higher (at least in our case, unless you're doing a P&P and bigger valves ), and reving higher aside from needing better valve springs and retainers and seals, pistons have to also be considered. You see, high performance pistons aren't always referred to as "boost pistons", High reving also needs its own treatment . And then a balanced crank comes after
okay so how come ur motor blew len? and lowering compression on no boost will lower hp which is what i was saying...
11-28-2009, 04:49 PM
#24
J36Twingt28r's,nextgt30r
Thread Starter
OPEL AND IHC
U GUYS SURELY ARE AMAZING!! So this is my game plan then next year j36 stroke, using j32a3 block, tl-s cams, pistons, etc bumping my CR to 11.0:1. i will be running approx, 300whp, 280lb tq. THEN IN THE FALL: i will be getting turbo running 8psi max, until i bump my CR down to 10.0:1, then run maybe 12-13psi!!! 450-500 hp DD her i come!! 
ANYONE KNOW FROM EXPERIENCE OR PURE KNOWLEGE IF THE KMS VALVETRAIN STUFF (SPRINGS, RETAINERS,EXCLUDING THE PISTONS) WILL BENEFIT ME IN ANY WAY? plus do you guys think the racing cams from KMS would be better than the TL-S cams?
U GUYS SURELY ARE AMAZING!! So this is my game plan then next year j36 stroke, using j32a3 block, tl-s cams, pistons, etc bumping my CR to 11.0:1. i will be running approx, 300whp, 280lb tq. THEN IN THE FALL: i will be getting turbo running 8psi max, until i bump my CR down to 10.0:1, then run maybe 12-13psi!!! 450-500 hp DD her i come!! ANYONE KNOW FROM EXPERIENCE OR PURE KNOWLEGE IF THE KMS VALVETRAIN STUFF (SPRINGS, RETAINERS,EXCLUDING THE PISTONS) WILL BENEFIT ME IN ANY WAY? plus do you guys think the racing cams from KMS would be better than the TL-S cams?
11-28-2009, 05:56 PM
#25
Team Owner
You don't rate pistons on how much boost they will handle. You rate them by how much hp and torque they will take. An engine that makes 500hp with 2psi will be harder on pistons than an engine that makes 450hp on 10psi.
This "made for 42psi" is nonsense.
11-28-2009, 05:59 PM
#26
2011 ZCP E92 M3!!
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im just like u...im just scolling trough looking if this thrend had some pics to make me understand what are they talking about...but none so far
11-28-2009, 06:00 PM
#27
Team Owner
OPEL AND IHC U GUYS SURELY ARE AMAZING!! So this is my game plan then next year j36 stroke, using j32a3 block, tl-s cams, pistons, etc bumping my CR to 11.0:1. i will be running approx, 300whp, 280lb tq. THEN IN THE FALL: i will be getting turbo running 8psi max, until i bump my CR down to 10.0:1, then run maybe 12-13psi!!! 450-500 hp DD her i come!!
ANYONE KNOW FROM EXPERIENCE OR PURE KNOWLEGE IF THE KMS VALVETRAIN STUFF (SPRINGS, RETAINERS,EXCLUDING THE PISTONS) WILL BENEFIT ME IN ANY WAY? plus do you guys think the racing cams from KMS would be better than the TL-S cams?
U GUYS SURELY ARE AMAZING!! So this is my game plan then next year j36 stroke, using j32a3 block, tl-s cams, pistons, etc bumping my CR to 11.0:1. i will be running approx, 300whp, 280lb tq. THEN IN THE FALL: i will be getting turbo running 8psi max, until i bump my CR down to 10.0:1, then run maybe 12-13psi!!! 450-500 hp DD her i come!! ANYONE KNOW FROM EXPERIENCE OR PURE KNOWLEGE IF THE KMS VALVETRAIN STUFF (SPRINGS, RETAINERS,EXCLUDING THE PISTONS) WILL BENEFIT ME IN ANY WAY? plus do you guys think the racing cams from KMS would be better than the TL-S cams?
I highly suggest you build it for boost the first time. Use the low compression pistons from the start. You're only losing a very small amount of hp in NA form and you won't have to pull the engine again to get it ready for boost.
For those of you worried about driving around with low compression, don't worry, many cars of the '70s and '80s came that way from the factory. My GN came with an 8:1 compression ratio and it was nice running 16-18psi on 91 octane, double what you can run in an 11:1 engine. Running 26psi on 100 unleaded was nice too. With methanol injection and 100 unleaded, 29psi was daily driver trim.
11-28-2009, 06:04 PM
#28
Team Owner
Lower compression will cause a slight loss without boost but you would be hard pressed to feel the difference.
The way I look at it is I would gladly give up 5% power to gain 25% when the boost hits.
11-28-2009, 06:55 PM
#29
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You're waaaaaaaaaay off. They will cause a slight power loss with no boost, nothing drastic.
You don't rate pistons on how much boost they will handle. You rate them by how much hp and torque they will take. An engine that makes 500hp with 2psi will be harder on pistons than an engine that makes 450hp on 10psi.
This "made for 42psi" is nonsense.
You don't rate pistons on how much boost they will handle. You rate them by how much hp and torque they will take. An engine that makes 500hp with 2psi will be harder on pistons than an engine that makes 450hp on 10psi.
This "made for 42psi" is nonsense.
11-28-2009, 06:57 PM
#30
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The supercharged engines were blowing due to a lack of tuning but Opel can elaborate on that.
Lower compression will cause a slight loss without boost but you would be hard pressed to feel the difference.
The way I look at it is I would gladly give up 5% power to gain 25% when the boost hits.
Lower compression will cause a slight loss without boost but you would be hard pressed to feel the difference.
The way I look at it is I would gladly give up 5% power to gain 25% when the boost hits.
okay thats what im saying so now where r u coming from you still loose power if ur not going boost lmaoo
11-28-2009, 07:00 PM
#31
Team Owner
first off no im not wayyy off second of the car will loose power with no boost. what i mean by saying that is if he does not go turbo or sc he will loose power... now before u go and ramble on and on find out and dont try to shout me out and say im way off and other bs. thank u
Your point is valid, lower compression will equal lower hp in NA form all else being equal.
The part you're way off is rating a piston by how much boost it will hold. You can't do this. Stock pistons would hold 42psi boost if the car only made 250hp at 42psi.
11-28-2009, 07:21 PM
#32
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You will lose power with all else being equal but as Opel mentioned, you may get a better ring seal with a high performance low compression piston.
Your point is valid, lower compression will equal lower hp in NA form all else being equal.
The part you're way off is rating a piston by how much boost it will hold. You can't do this. Stock pistons would hold 42psi boost if the car only made 250hp at 42psi.
Your point is valid, lower compression will equal lower hp in NA form all else being equal.
The part you're way off is rating a piston by how much boost it will hold. You can't do this. Stock pistons would hold 42psi boost if the car only made 250hp at 42psi.
thank you....
thats what i meant but i didnt explain my self enough my bad. better ring seal not always solve the problem... but lc does lol ....
11-28-2009, 08:12 PM
#33
All motor
I thought upping the CR and adding cams would really change the whole performance of the car. Someone over @V6 pee (can't put the 3 letters next to each other...odd) did the TL-s cams and bumped up to 11:1 CR on the J33 auto and gained 45 WHEEL hp. I figured with some rather aggressive cams that number should be over 50 easy. I assume the J33 5AT gains should be similar to the 3.0 6MT gains, which is why I'm hoping for almost 300whp with just bolt ons/cams/high CR.
Great find btw! I knew KMS was around but did not know they had stuff for us J serious'ers! I'd like to know the lift and duration of the cams though...to compare to the TL-s. I'm sure they are more aggressive, but by how much I don't know.
Great find btw! I knew KMS was around but did not know they had stuff for us J serious'ers! I'd like to know the lift and duration of the cams though...to compare to the TL-s. I'm sure they are more aggressive, but by how much I don't know.
11-29-2009, 12:44 AM
#35
Team Owner
Of course. High compression and boost will yield more power. But it's going to be octane limited. Octane is the reason lower compression and higher boost makes more power.
I read over the pistons in the first link....
13:1 compression along with boost in the mid/upper 30psi range is not abnormal on methanol. I'm not talking about meth injection, I'm talking an engine running on pure methanol.
The key here is they were using methanol. Part of the reason for the ultra high compression is to gain back part of the power that is lost when running on methanol. With it's 130 octane, slower burn rate, and the fact that it needs twice as much fuel to make the same power (read extra cooling), these huge numbers are possible.
Keep in mind that if it were possible to run 13:1 comp @ 35psi boost on gasoline, there would be much more power being made than on methanol. Unfortunately no race gasoline has enough octane to support those numbers without scattering the engine all over the road.
Another point, turbos don't spool well on pure methanol, another reason for the ultra high compression ratios. Higher compression will help spool a little.
In determining compression ratio, there are many things to be considered. Number one is if you want it to be pump gas friendly or if it's going to be a race gas only car. Octane for octane, lower compression and higher boost is going to make more power. If the goal is only 400hp and you can do it with stock compression and a little boost, keeping the stock 11:1 compression will give you a slight edge in spool, fuel economy, and power. However, if you want to make 600hp on 91 octane, 8.5:1 compression and 20psi boost is what you need.
Typically, a high compression low boost car is going to make more power off boost but won't have that surge that nails your head to the seat once spooled. A low compression high boost engine is going to be much more brutal. You floor it and it pushes you back just a little at first and then you feel the skin on your face being stretched back and the metal frame of your seat being pushed into your back through the padding. I personally like the being punched in the face feeling of high boost.
I read over the pistons in the first link....
13:1 compression along with boost in the mid/upper 30psi range is not abnormal on methanol. I'm not talking about meth injection, I'm talking an engine running on pure methanol.
The key here is they were using methanol. Part of the reason for the ultra high compression is to gain back part of the power that is lost when running on methanol. With it's 130 octane, slower burn rate, and the fact that it needs twice as much fuel to make the same power (read extra cooling), these huge numbers are possible.
Keep in mind that if it were possible to run 13:1 comp @ 35psi boost on gasoline, there would be much more power being made than on methanol. Unfortunately no race gasoline has enough octane to support those numbers without scattering the engine all over the road.
Another point, turbos don't spool well on pure methanol, another reason for the ultra high compression ratios. Higher compression will help spool a little.
In determining compression ratio, there are many things to be considered. Number one is if you want it to be pump gas friendly or if it's going to be a race gas only car. Octane for octane, lower compression and higher boost is going to make more power. If the goal is only 400hp and you can do it with stock compression and a little boost, keeping the stock 11:1 compression will give you a slight edge in spool, fuel economy, and power. However, if you want to make 600hp on 91 octane, 8.5:1 compression and 20psi boost is what you need.
Typically, a high compression low boost car is going to make more power off boost but won't have that surge that nails your head to the seat once spooled. A low compression high boost engine is going to be much more brutal. You floor it and it pushes you back just a little at first and then you feel the skin on your face being stretched back and the metal frame of your seat being pushed into your back through the padding. I personally like the being punched in the face feeling of high boost.
11-29-2009, 04:00 AM
#36
OPEL AND IHC U GUYS SURELY ARE AMAZING!! So this is my game plan then next year j36 stroke, using j32a3 block, tl-s cams, pistons, etc bumping my CR to 11.0:1. i will be running approx, 300whp, 280lb tq. THEN IN THE FALL: i will be getting turbo running 8psi max, until i bump my CR down to 10.0:1, then run maybe 12-13psi!!! 450-500 hp DD her i come!!
ANYONE KNOW FROM EXPERIENCE OR PURE KNOWLEGE IF THE KMS VALVETRAIN STUFF (SPRINGS, RETAINERS,EXCLUDING THE PISTONS) WILL BENEFIT ME IN ANY WAY? plus do you guys think the racing cams from KMS would be better than the TL-S cams?
U GUYS SURELY ARE AMAZING!! So this is my game plan then next year j36 stroke, using j32a3 block, tl-s cams, pistons, etc bumping my CR to 11.0:1. i will be running approx, 300whp, 280lb tq. THEN IN THE FALL: i will be getting turbo running 8psi max, until i bump my CR down to 10.0:1, then run maybe 12-13psi!!! 450-500 hp DD her i come!! ANYONE KNOW FROM EXPERIENCE OR PURE KNOWLEGE IF THE KMS VALVETRAIN STUFF (SPRINGS, RETAINERS,EXCLUDING THE PISTONS) WILL BENEFIT ME IN ANY WAY? plus do you guys think the racing cams from KMS would be better than the TL-S cams?
Last edited by ussi; 11-29-2009 at 04:03 AM.
11-29-2009, 04:11 AM
#37
Team Owner
The cams will fit into J35 heads. Alot of people, including myself have put type-s (j35) cams into the j32 heads, so the reverse would work as well.
Dude, do you want to do 2 motor builds in 1 year? I doubt it. Build it right the first time...if you want to go turbo, build your motor for that. If you plan to be revving your car high upgrade your valvetrain. It will also give you a margin of error. And before everyone gets carried away and excited about lowering their compression for boost keep in mind that there are 30 psi cars running at 8:1 or 9:1 compression, so keep in mind all the above examples are mostly theory since no one here is building a 42psi TL. If you're planning on running 15psi MAX no need to lower the compression much further than 10:1 or so. You're not even going to lose that much noticable power either (even with my supercharger off). Trust me, that's what I did
Dude, do you want to do 2 motor builds in 1 year? I doubt it. Build it right the first time...if you want to go turbo, build your motor for that. If you plan to be revving your car high upgrade your valvetrain. It will also give you a margin of error. And before everyone gets carried away and excited about lowering their compression for boost keep in mind that there are 30 psi cars running at 8:1 or 9:1 compression, so keep in mind all the above examples are mostly theory since no one here is building a 42psi TL. If you're planning on running 15psi MAX no need to lower the compression much further than 10:1 or so. You're not even going to lose that much noticable power either (even with my supercharger off). Trust me, that's what I did
What I was trying to say in a nutshell is lower the compression to fit the desired boost/hp/octane levels.
I like to go a little extra low with the compression because it gives a larger margin of safety with very little downside. Besides, if you change your mind later on and want to run more boost the engine is ready for it.
11-29-2009, 10:24 AM
#38
J36Twingt28r's,nextgt30r
Thread Starter
The cams will fit into J35 heads. Alot of people, including myself have put type-s (j35) cams into the j32 heads, so the reverse would work as well.
Dude, do you want to do 2 motor builds in 1 year? I doubt it. Build it right the first time...if you want to go turbo, build your motor for that. If you plan to be revving your car high upgrade your valvetrain. It will also give you a margin of error. And before everyone gets carried away and excited about lowering their compression for boost keep in mind that there are 30 psi cars running at 8:1 or 9:1 compression, so keep in mind all the above examples are mostly theory since no one here is building a 42psi TL. If you're planning on running 15psi MAX no need to lower the compression much further than 10:1 or so. You're not even going to lose that much noticable power either (even with my supercharger off). Trust me, that's what I did
Dude, do you want to do 2 motor builds in 1 year? I doubt it. Build it right the first time...if you want to go turbo, build your motor for that. If you plan to be revving your car high upgrade your valvetrain. It will also give you a margin of error. And before everyone gets carried away and excited about lowering their compression for boost keep in mind that there are 30 psi cars running at 8:1 or 9:1 compression, so keep in mind all the above examples are mostly theory since no one here is building a 42psi TL. If you're planning on running 15psi MAX no need to lower the compression much further than 10:1 or so. You're not even going to lose that much noticable power either (even with my supercharger off). Trust me, that's what I did
thanks ussi
yeah i guess i will build my car for boost then!!!. so i will upgrade my valvetrain, with the low compression pistons when i do my j36 stroke. and ussi ur right most likely after im done the j36 stroke and valvetrain i will have the turbo done at the latest jan 2011 , with 10.0:1 CR or lower @15psi. thanks for the information guys!! u guys really know ur stuff!! someday i will too
11-29-2009, 10:32 AM
#39
J36Twingt28r's,nextgt30r
Thread Starter
hey ihc,opel, and ussi. u guys think that changing my car from open to semi-closed deck will help make my car more daily driver friendly. or do u think running a CR of 9:1 or so with 18psi more driver friendly than CR of 10:1 with 12-15 max psi? and also thanks again for all the amazing information everyone has put into this tread!! special thanks to ussi, Ihc, opel, and others.
11-29-2009, 11:20 AM
#40
Safety Car
ALEX SU......if u got the hook up at honda to be an engineer....hook us up!!!... id be down to redesign and design some really nasty shit for them I really think their engineers are either too old to realize whats going on around them or simply dumb. they say they test their cars and all that crap it doesnt seem to me like they really do much to it to get this or any other honda really up to par with todays beatings that people give the cars they own.