Tighter LSA's
 

Why are alot of you guys running as low as 109 & 107 on your lobe seperations? Is it just for more torque at mid rpms?

Definitely not an expert on the subject, but... I have a tight LSA, running a large HR with the stock computer. I'm sure my cam on a 112 or something would pull well into the 7k+ range. But I wanted a peak at 6800ish, with a big cam to match the top end I have.

112 was done for emissions and because people did not think the computer could handle tighter LSAs because older injection systems could not. If emissions is not a concern and the computer can handle it then the question should be why do so many folks still use 112-114????

I always thought one reason was because the higher LSA's had better idle quality opposed to a lower LSA, more of a stock feeling I guess. However I have read both sides of that story.

a few issues ago of engine masters had a good article on lsa. identical cams with exception to the lsa. they ran a 106, 110, and i think a 112 or 114. the 106 brought power on earlier and made more peak but they said with the lower cranking compression of the wider lsa they might be inclined to run the wide lsa with a higher compression due to the better idle.

Yes wider LSAs make for a better idle, but if that is the only reason you want to go wider, just go smaller.

If you go 108-110 you are in between a happy medium of the two trains of thought on the subject. As with almost everything somewhere in between the extremes is probably where you want to be.

tighter your lsa it makes the curves alot "peakier," more midrange, and brings your peak rpms down. Wider LSA will make smoother curves, and make peak hp (possibly more) at a higher rpm. A wider LSA will "tame" a larger cam, but will make it lazy in the midrange (poor performing car at the track). Unless you're OutlawZ (114lsa) and spraying a large amount of nitrous (350+ i think), no reason to run more than a 110. I plan on spraying a 200+ and my LSA is tighter than most NA cams.

Such things are said without a proper frame of reference. What are you using for a base starting point and then saying "tighter or wider".

http://www.babcox.com/editorial/ar/eb90252.htm

we'll say tight is 100 and wide is 120. I was speaking pretty generally, not really anything specific, the original question is pretty general I think. The answer to his question is because a 107 lsa will make more average power than a 112 lsa, given the same lobes and ICL on your average LT1.