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ok. when picking a cam you get to pick your LSA. i understand that a smaller lobe separation gives you more overlap and better top end power. but, will a larger lobe separation give better low end power? on a given cam will it even make a noticeable difference?
i daily drive my car so im not all that concerned with the high end and would like a lower power band.
basicly a tighter lsa (more overlap) will make a smaller cam act like a bigger cam. a cam with a 112lsa will have a power band a few hundred rpm higher than the same cam on a 114lsa.
for daily driving most people are going with a 224, or 228 with a 114lsa to have good driviblity for the street, these cams are making good power from around 3,000 to 6,500 rpm to give you a good idea
yeah, thats what ive been reading. i know a lot of guys go for the lower LSA for that choppy idle and sound, and i also know it helps up top while taking away from the low end. but if you go for a higher lsa (leys say 114 as opposed to 112) will you get better power in the lower RPM range? or will it be insignificant?Quote:
Originally Posted by mark21742
in my opinion I'd say just a few hp gain with the tighter lsa, but if you have a good tuner (or take a month of beating your head against a wall tuning it yourself like I did) you can still have great a great DD with your choppy idle.Quote:
Originally Posted by grouch0jr
I went with a 220/224 112lsa and love it, slightly choppy with good power all the way to redline
The cam I have has pretty good all around power, but it does lack slightly in the lower end (not much though). I just went to the beach this weekend and got 23.6mpg untuned with a 6 spd car and the cam is on a 111+2. The driveablility is awesome, except when the car is cold it can be cranky and when the ac/defroster are on it can act up a little.
if you are running HPtuners, go in to your target idle speed and raise your cold rpms up 25 rpm, and your A/C on up 25 rpms acrossed the temp range.......that made a huge difference in mine. right now I have cold idle set at 950 and warm down to 725Quote:
Originally Posted by 01ws6er
do you DD your car? your cam is a little bigger than what i was lookin at.Quote:
Originally Posted by 01ws6er
230/236 .573 .580 114LSA 110 ICL.
Daily drive it when ever the weather permits. Ita all about your tolerance for a camshaft. And, of course, your tune.
no hptuners here, it's mail order tuned but it definately still needs a real tune. July is when I'm going down to Frost to have it tuned.Quote:
Originally Posted by mark21742
No, but I drive it every day pretty much. I DD'd it for almost a month and it was extremely easy IMO. On my way to and from the beach this weekend it poured it's ass off and the car was fine, I just slowed down a bit cause the roads were flooded.Quote:
Originally Posted by grouch0jr
whats the 111+2 mean?Quote:
Originally Posted by 01ws6er
111 is the lsa, the +2 means the cam has been ground so when your marks are linedup on your crank and cam gear the cam is already advanced 2°Quote:
Originally Posted by grouch0jr
oh, for timing, got it.Quote:
Originally Posted by mark21742
for cam timing.....if you advance the cam it raises your rpm band and where the motor makes peak hp, also can give I slightly bigger peak hp number.....if you retard the cam it will lower your power band and give you slightly bigger tq numbersQuote:
Originally Posted by grouch0jr
To add to that: Subtracting/adding your advance/retard from the LSA will give you your ICL. IE: Mine is a 111 LSA with 2 degrees of advance ground in. 111-2=109, hence my ICL is 109. You need that number if you do your cam the right way and degree it, which I did not :hide:Quote:
Originally Posted by mark21742
Lowering the LSA actually brings peak power down the rev range not up it.Quote:
Originally Posted by grouch0jr
Do a Google on it.
lower lsa = more overlap which gives a choppy idle and more exhaust reversion back into the cylinder at low rpms, but pulls more air/fuel into the cylinder filling it better and increasing high rpm cylinder pressure for more top end power.Quote:
Originally Posted by HSVGTS300
higher lsa = less overlap giving smoother idle and less exhaust reversion at lower rpms, but lower cylinder pressure at high rpms for better low end....
I think you mistook lsa for overlap .
lsa and overlap are related....Quote:
Originally Posted by mark21742
yup. take two camshafts with same duration, lift, and advance......one wth a 112lsa and one with a 114lsa. the cam with the smaller 112lsa will have a larger overlap and the cam with the larger 114lsa will have less overlap.Quote:
Originally Posted by grouch0jr
just remember everything being the same lsa goes down, overlap goes up......lsa goes up, overlap goes down
Acrually I think you have it backwards advancing the cam makes everything happen sooner. Closes the intake valve sooner which builds more cylinder pressure and increases torque. Also has the effect of lowering the powerband.Quote:
Originally Posted by mark21742
Then retarding the cam pushes everything to a higher powerband.
Lower LSA's build more torque esp in the midrange and makes for a peaky torque curve.Quote:
Originally Posted by mark21742
Larger LSA's make torque over a broader range for a very flat torqe curve.
damit lol guess I'll have to go back and do a bunch of reading again......it not the first or last time I've been wrong lolQuote:
Originally Posted by 9T8W66