LS6 Cam Detuning
LS6 Cam Detuning Hi All,
I am building an E36 M3 for NASA ST3, which has a power to weight restriction of 10:1. I tried to do some googling, but have come up short with an answer for my question (probably people withholding information?). I am looking for insight on the ability, methods, results, etc of a cammed LS1/6 being detuned.
The cam I am looking at is the GM ASA cam along with CNC'd heads. This cam usually makes around 410whp and I would have to be detuned to ~320whp. Has anyone ran a combination of a throttle stop (how much), air restriction (what size) and timing detuning?
I'd like to be cammed as I have a theory that would maximize low end torque while staying within HP restrictions at the top end. I'd like to see if my theory is right or wrong. I'd also like to have to cam to run time attack uncorked.
Thank you,
Bart
I am building an E36 M3 for NASA ST3, which has a power to weight restriction of 10:1. I tried to do some googling, but have come up short with an answer for my question (probably people withholding information?). I am looking for insight on the ability, methods, results, etc of a cammed LS1/6 being detuned.
The cam I am looking at is the GM ASA cam along with CNC'd heads. This cam usually makes around 410whp and I would have to be detuned to ~320whp. Has anyone ran a combination of a throttle stop (how much), air restriction (what size) and timing detuning?
I'd like to be cammed as I have a theory that would maximize low end torque while staying within HP restrictions at the top end. I'd like to see if my theory is right or wrong. I'd also like to have to cam to run time attack uncorked.
Thank you,
Bart
TECH Senior Member
Joined: Jun 2016
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From: Central Cal.
Hi All,
I am building an E36 M3 for NASA ST3, which has a power to weight restriction of 10:1. I tried to do some googling, but have come up short with an answer for my question (probably people withholding information?). I am looking for insight on the ability, methods, results, etc of a cammed LS1/6 being detuned.
The cam I am looking at is the GM ASA cam along with CNC'd heads. This cam usually makes around 410whp and I would have to be detuned to ~320whp. Has anyone ran a combination of a throttle stop (how much), air restriction (what size) and timing detuning?
I'd like to be cammed as I have a theory that would maximize low end torque while staying within HP restrictions at the top end. I'd like to see if my theory is right or wrong. I'd also like to have to cam to run time attack uncorked.
Thank you,
Bart
I am building an E36 M3 for NASA ST3, which has a power to weight restriction of 10:1. I tried to do some googling, but have come up short with an answer for my question (probably people withholding information?). I am looking for insight on the ability, methods, results, etc of a cammed LS1/6 being detuned.
The cam I am looking at is the GM ASA cam along with CNC'd heads. This cam usually makes around 410whp and I would have to be detuned to ~320whp. Has anyone ran a combination of a throttle stop (how much), air restriction (what size) and timing detuning?
I'd like to be cammed as I have a theory that would maximize low end torque while staying within HP restrictions at the top end. I'd like to see if my theory is right or wrong. I'd also like to have to cam to run time attack uncorked.
Thank you,
Bart
Hi All,
I am building an E36 M3 for NASA ST3, which has a power to weight restriction of 10:1. I tried to do some googling, but have come up short with an answer for my question (probably people withholding information?). I am looking for insight on the ability, methods, results, etc of a cammed LS1/6 being detuned.
The cam I am looking at is the GM ASA cam along with CNC'd heads. This cam usually makes around 410whp and I would have to be detuned to ~320whp. Has anyone ran a combination of a throttle stop (how much), air restriction (what size) and timing detuning?
I'd like to be cammed as I have a theory that would maximize low end torque while staying within HP restrictions at the top end. I'd like to see if my theory is right or wrong. I'd also like to have to cam to run time attack uncorked.
Thank you,
Bart
I am building an E36 M3 for NASA ST3, which has a power to weight restriction of 10:1. I tried to do some googling, but have come up short with an answer for my question (probably people withholding information?). I am looking for insight on the ability, methods, results, etc of a cammed LS1/6 being detuned.
The cam I am looking at is the GM ASA cam along with CNC'd heads. This cam usually makes around 410whp and I would have to be detuned to ~320whp. Has anyone ran a combination of a throttle stop (how much), air restriction (what size) and timing detuning?
I'd like to be cammed as I have a theory that would maximize low end torque while staying within HP restrictions at the top end. I'd like to see if my theory is right or wrong. I'd also like to have to cam to run time attack uncorked.
Thank you,
Bart
You are able to do as you please with the motor but it cannot exceed 10:1 weight to hp. Limiting RPM would limit me to ~4500rpm. I am looking to see if people have ran a cam with a throttle body restriction and/or throttle stop to make use of all the RPM but not exceed their HP limitations.
You are able to do as you please with the motor but it cannot exceed 10:1 weight to hp. Limiting RPM would limit me to ~4500rpm. I am looking to see if people have ran a cam with a throttle body restriction and/or throttle stop to make use of all the RPM but not exceed their HP limitations.
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We have been building engines for restrictor racing for 20 years. That cam is all wrong for what you are trying to accomplish, as are the others. You are going to need something like a 210/220 on a 107-108. You'll need something around a 60mm restrictor if using a 78mm TB to hit your rwhp goal of 320.
You cant really have one cam to do both. The cam that shines under 6k rpm with a restrictor wont be ideal for un-corked time attack.
You cant really have one cam to do both. The cam that shines under 6k rpm with a restrictor wont be ideal for un-corked time attack.
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Verdad Gallardo We have been building engines for restrictor racing for 20 years. That cam is all wrong for what you are trying to accomplish, as are the others. You are going to need something like a 210/220 on a 107-108. You'll need something around a 60mm restrictor if using a 78mm TB to hit your rwhp goal of 320.
You cant really have one cam to do both. The cam that shines under 6k rpm with a restrictor wont be ideal for un-corked time attack.
You cant really have one cam to do both. The cam that shines under 6k rpm with a restrictor wont be ideal for un-corked time attack.
I am using a 5.7 because that is the motor I have been using, it is currently making 375whp and 360wtq on the stock ls6 setup.
We have done everything from 2.0L 4 cylinders to 5.0L V12 and everything in between. Gearing all depends on the track. There was a 6.0L V8 we used to do that made about 600ft/lb through two 28mm restrictors. And if memory serves me right, the old C5R 7.0L engine made about 600ft/lb through two 25mm restrictors.
I imagine its not legal to be done with just the tune unless there is a stipulation in the rules for a sealed pcm.
Which would be perfect because you could have that pcm to be tuned to 310rwhp with the rev limiter set to 5k (or somewhere lower most likely) and then for time attack stuff slap in another pcm that revs out and is tuned for the cam you want to use. Restrictor racing is all about torque since when the rules are applied properly everyone is just as fast top speed. Its all about reaching terminal velocity the fastest.
I imagine its not legal to be done with just the tune unless there is a stipulation in the rules for a sealed pcm.
Which would be perfect because you could have that pcm to be tuned to 310rwhp with the rev limiter set to 5k (or somewhere lower most likely) and then for time attack stuff slap in another pcm that revs out and is tuned for the cam you want to use. Restrictor racing is all about torque since when the rules are applied properly everyone is just as fast top speed. Its all about reaching terminal velocity the fastest.
We have done everything from 2.0L 4 cylinders to 5.0L V12 and everything in between. Gearing all depends on the track. There was a 6.0L V8 we used to do that made about 600ft/lb through two 28mm restrictors. And if memory serves me right, the old C5R 7.0L engine made about 600ft/lb through two 25mm restrictors.
I imagine its not legal to be done with just the tune unless there is a stipulation in the rules for a sealed pcm.
Which would be perfect because you could have that pcm to be tuned to 310rwhp with the rev limiter set to 5k (or somewhere lower most likely) and then for time attack stuff slap in another pcm that revs out and is tuned for the cam you want to use. Restrictor racing is all about torque since when the rules are applied properly everyone is just as fast top speed. Its all about reaching terminal velocity the fastest.
I imagine its not legal to be done with just the tune unless there is a stipulation in the rules for a sealed pcm.
Which would be perfect because you could have that pcm to be tuned to 310rwhp with the rev limiter set to 5k (or somewhere lower most likely) and then for time attack stuff slap in another pcm that revs out and is tuned for the cam you want to use. Restrictor racing is all about torque since when the rules are applied properly everyone is just as fast top speed. Its all about reaching terminal velocity the fastest.
So, from your experience, an LS6 with a cam/heads/intake can be detuned to ~320whp (and whatever TQ number) by a combination of throttle restriction, restrictor plates and timing detuning? I'd like to not reduce working RPM unless I then gear down my final drive to a 3.38 (from my 3.91).
Thank you Jensen!
Well that makes it easier. Just flash and go for each style of racing.
There are many ways to achieve what you want.
As spider has said you could do it with tune only. My only concern there (without limiting rpm) would be egt's as you would be pulling a lot of timing to lose 100ish horsepower. Why I suggested an RPM limit.
Throttle stop setup. Essentially the same thing as a restrictor.
An actual restrictor. Best place to put it is right behind the air filter and as far from the TB as possible. We have some right behind the TB too though, all depends on the space available
Fuel flow. Not what youre after but a great way to restrict power by sanctioning bodies
There are many ways to achieve what you want.
As spider has said you could do it with tune only. My only concern there (without limiting rpm) would be egt's as you would be pulling a lot of timing to lose 100ish horsepower. Why I suggested an RPM limit.
Throttle stop setup. Essentially the same thing as a restrictor.
An actual restrictor. Best place to put it is right behind the air filter and as far from the TB as possible. We have some right behind the TB too though, all depends on the space available
Fuel flow. Not what youre after but a great way to restrict power by sanctioning bodies
