Low-End Torque
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Low-End Torque I would like to discuss low-end torque for a bit. I was debating going FI for a while, and even own a supercharger kit (which I have all but concluded that it will be put back up for sale since it is not the route I ultimately want to go). I feel like my car is simply a dog off-idle until about 3k. I'm not looking for neck snapping power, far from it. I would just like to know what I can do to improve it.
My car is a 2002 Camaro with a 6 speed. It has 3:73 gears (which I have no interest in swapping back to 4:10s) and a cam somewhere in the vicinity of 234/238 and about 600 lift with supporting mods. Stock heads and ported LS6 intake and TB.
I'm quite certain I would like to do something. Even if it involves swapping out cams, although I don't want to lose the rev-happy nature of the car. Heads and intake are the obvious idea, but what will that do for sub-3k rpm power? Any thoughts? Thanks in advance
My car is a 2002 Camaro with a 6 speed. It has 3:73 gears (which I have no interest in swapping back to 4:10s) and a cam somewhere in the vicinity of 234/238 and about 600 lift with supporting mods. Stock heads and ported LS6 intake and TB.
I'm quite certain I would like to do something. Even if it involves swapping out cams, although I don't want to lose the rev-happy nature of the car. Heads and intake are the obvious idea, but what will that do for sub-3k rpm power? Any thoughts? Thanks in advance
What is the lobe separation of your cam? You could get an adjustable timing chain to advance it a couple degrees to bring the torque in earlier. Also What do you have as far as exhaust? Lengthening the collectors can have a big impact on low end torque with a true dual set up and chambered mufflers.
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What is the lobe separation of your cam? You could get an adjustable timing chain to advance it a couple degrees to bring the torque in earlier. Also What do you have as far as exhaust? Lengthening the collectors can have a big impact on low end torque with a true dual set up and chambered mufflers.
I never thought about advancing the timing on my cam. Thank you for that! Maybe that in conjunction with some heads and intake. I'll run it by my mechanic. Any other ideas?
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There are much more expert cam guys on here than me but from the research and reading I have done the duration of that cam is geared toward high RPM power. You want shorter duration, a tighter LSA and possibly mill the heads to compensate for the loss of dynamic compression from more overlap. The result will be a nice strong torque curve that starts at 2000, not 3500 where the larger cams start to come on.
Yes you will lose peak horsepower but for many, that is not really where they use the power so it becomes a matter of dyno numbers and bragging rights.
Yes you will lose peak horsepower but for many, that is not really where they use the power so it becomes a matter of dyno numbers and bragging rights.
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You are going to want to drop that IVC from where you are to ~38-42 degrees.
Depending on how much overlap you believe you can handle..you could probably drop down to a 110-112 LSA and work on various combinations around a 222-226 duration.
The physics are simple. It is all about cylinder pressure. Either through increased compression (heads) or a 'shorter' duration camshaft that closes that intake valve sooner.
Look for threads on 'Street-Sweeper' type cams, or some of the discussions about LSA's of 110 or lower. I agree with you ..changing gear ratio's while 'effective' in increasing acceleration, is not the same as having the instantaneous throttle response that comes from pure engine torque.
Just ask the guys with more cubic inches...same principle.
Hope that helps.
..WeathermanShawn..
Depending on how much overlap you believe you can handle..you could probably drop down to a 110-112 LSA and work on various combinations around a 222-226 duration.
The physics are simple. It is all about cylinder pressure. Either through increased compression (heads) or a 'shorter' duration camshaft that closes that intake valve sooner.
Look for threads on 'Street-Sweeper' type cams, or some of the discussions about LSA's of 110 or lower. I agree with you ..changing gear ratio's while 'effective' in increasing acceleration, is not the same as having the instantaneous throttle response that comes from pure engine torque.
Just ask the guys with more cubic inches...same principle.
Hope that helps.
..WeathermanShawn..
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Verdad Gallardo Also if your thinking about possibly changing the cam check out Patrick G's thread "Torque comming out of my ears" the dyno graph is on page 15 and shows it compaired to a much larger cam. That's an amazing grind that was used in a m6 car with about the same gearing as you.
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Couldn't a bump in compression (milling his stock ls6 heads) solve part or most of his problem concerning lack of lowend torque?
Out of curiosity do you have a graph and could you post it? How much tq do you have at 3000 rpms? If its less then 330 I see your complaint. My old h/c full bolt on 346 made 350 rwtq at 2800 rpms. For reference my 402 makes 420+ rwtq at 3000 rpms, talk about a world of difference.
Hopefully you can just bump compression by milling those heads and see better lowend tq.
I figured your 3.73's would have your setup feeling very quick ?!?!
Out of curiosity do you have a graph and could you post it? How much tq do you have at 3000 rpms? If its less then 330 I see your complaint. My old h/c full bolt on 346 made 350 rwtq at 2800 rpms. For reference my 402 makes 420+ rwtq at 3000 rpms, talk about a world of difference.
Hopefully you can just bump compression by milling those heads and see better lowend tq.
I figured your 3.73's would have your setup feeling very quick ?!?!
PatG made a thread about "torque out his ears," and his was a 224 LSK lobed cam, but he also had AFR heads. Anything more than .600 lift won't make too much difference on stock heads. But definately keep it under the 230 mark if you're wanting low end torque. Somewhre in the 222-228 range as was stated earlier.
to be honest, I have no idea. It was installed by TTP when they rebuilt my engine. It is their Equalizer v3 cam and I believe it is around 112. I know for a fact it is installed straight up and does not have an adjustable chain. My exhaust is a disaster because I hate loud. I have QTP headers, a custom Y-pipe with high flow cats and a normal merge, and a SLP dual/dual exhaust. Very restrictive, but it does what I need it to.
I never thought about advancing the timing on my cam. Thank you for that! Maybe that in conjunction with some heads and intake. I'll run it by my mechanic. Any other ideas?
I never thought about advancing the timing on my cam. Thank you for that! Maybe that in conjunction with some heads and intake. I'll run it by my mechanic. Any other ideas?
The "recipe" to 500 rwhp with heads and cam - post # 9 - Exhaust
Advancing your cam can help, as long as you already know how it installed. If it is already advanced, your only options are to move to a smaller cam/tighter LSA/both, or increase the compression ratio.
I am also of the opinion that you might benfit from a slightly smaller cam to meet your needs. Cylinder pressure is torque, and closing the intake valve sooner builds more cylinder pressure. Advancing a cam helps, but if you have to advance more than ~ 4 degrees, the next smaller cam is probably the ticket.
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Very good info in this thread. Thanks guys
I thought about summoning his help for a new cam earlier today. I just searched that thread and that seems to be exactly what I am looking for! Although, I am a little wary about running LSK lobes. I wonder if doing some road racing or autocross would be too hard on the springs. In any event, I think I have the information I need. I think a cam swap and some heads and intake are in order for the summer. I love the top end pull I have on my bigger cam, but I think I can get better street manners and torque from a better combination of heads and cam without compromising top end. I am very excited for this summer and a new setup for my car!
Also if your thinking about possibly changing the cam check out Patrick G's thread "Torque comming out of my ears" the dyno graph is on page 15 and shows it compaired to a much larger cam. That's an amazing grind that was used in a m6 car with about the same gearing as you.
Very good info in this thread. Thanks guys
I thought about summoning his help for a new cam earlier today. I just searched that thread and that seems to be exactly what I am looking for! Although, I am a little wary about running LSK lobes. I wonder if doing some road racing or autocross would be too hard on the springs. In any event, I think I have the information I need. I think a cam swap and some heads and intake are in order for the summer. I love the top end pull I have on my bigger cam, but I think I can get better street manners and torque from a better combination of heads and cam without compromising top end. I am very excited for this summer and a new setup for my car!
I thought about summoning his help for a new cam earlier today. I just searched that thread and that seems to be exactly what I am looking for! Although, I am a little wary about running LSK lobes. I wonder if doing some road racing or autocross would be too hard on the springs. In any event, I think I have the information I need. I think a cam swap and some heads and intake are in order for the summer. I love the top end pull I have on my bigger cam, but I think I can get better street manners and torque from a better combination of heads and cam without compromising top end. I am very excited for this summer and a new setup for my car!
https://ls1tech.com/forums/dynamomet...is-tuning.html
Last edited by printmanjackson; Jan 26, 2010 at 02:22 PM.
