LSA question
Thread Starter
Teching In
Joined: Mar 2002
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From: Grapevine, Texas
LSA question Pretty specific. Same cam lift/duration, with different LSA 114,112,110. I am starting to road race, and want to torque curve lower in the power band. I have seen/read two different things. I want to know which one will move the torque curve lower in the power band so I will not have to rev the engine to 6500 everytime to get that torque that I am looking for. Tuning is not the first issue, as I am aware that smaller LSA's have more lope and may need tuning I'd like to handle the torque issue before the drivability issue.
I know (have heard) that adding advance will also lower the torque curve. Not sure if this negates the effect of the LSA, but if you can add in both items (LSA & advance) for discussion, that would be great.
Thanks for your help.
Chris Burton
<small>[ October 11, 2002, 08:16 AM: Message edited by: Chris Burton ]</small>
I know (have heard) that adding advance will also lower the torque curve. Not sure if this negates the effect of the LSA, but if you can add in both items (LSA & advance) for discussion, that would be great.
Thanks for your help.
Chris Burton
<small>[ October 11, 2002, 08:16 AM: Message edited by: Chris Burton ]</small>
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Joined: Dec 2001
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From: new england
Re: LSA question Ok going from 114 down to 110*lsa will bring torque peak numbers up if exhaust system can utilize extra overlap.I dont believe this higher torque number will happen much lower in rpm band though, advancing cam will help with that. Raising your static compression ratio will bring power on at lower rpm though and help maintain it at the higher rpm.I would also look at proper rear gear ratio to match min. WOT rpm usage.Just keep in mind if your exhaust isnt tuned to promote exhaust extraction at key points than extra LSA overlap will only pollute intake charge and cause power loss. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> <img border="0" alt="[Camaro]" title="" src="graemlins/camaro.gif" />
Thread Starter
Teching In
Joined: Mar 2002
Posts: 41
Likes: 0
From: Grapevine, Texas
Re: LSA question My exhaust is pretty free flowing (grots, 3" Y, cut-out always open). And I have 3.73's to keep the RPM's up somewhat.
When you lower LSA to bring torque numbers up, is that just peak torque? So I might gain more overall torque from 114 to 110, and then move that curve lower in the RPM range with advance.
Thanks for your help LS1derfull. Any other opinion/facts?
<small>[ October 11, 2002, 08:39 AM: Message edited by: Chris Burton ]</small>
When you lower LSA to bring torque numbers up, is that just peak torque? So I might gain more overall torque from 114 to 110, and then move that curve lower in the RPM range with advance.
Thanks for your help LS1derfull. Any other opinion/facts?
<small>[ October 11, 2002, 08:39 AM: Message edited by: Chris Burton ]</small>
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Joined: Dec 2001
Posts: 2,298
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From: new england
Re: LSA question Yes mostly peak numbers increase when tightening up LSA, but this is application specific.Flatter torque/power curves are had with wider LSA.Best of both worlds setup imo is slightly too large of a cam with higher compression to tame side effects of cam choice.
