PowellSixO

Have you thought of maybe trying a set of high ratio rockers? It will get you that added lift, and make the cam seem a little bit bigger. Plus if you're running stock rockers, it can be a good way to upgrade your valve train. Just an idea.

blsnelling

iTrader: (4)

But that wouldn't increase the duration, LSA, or overlap.

BlackPanther6.0

im in the same boat you are, ive had the btr stage 2 truck cam, which was an absolute torque monster, had no chop at all.
then i went to a howards 218/224 .604 112 cam, had more chop and i didnt feel i lost lowend, the dyno actually showed improvement all over the power band.
now im on the btr stage 4 truck cam, it chops decent. lost a hair down low very minimal but runs really good up top.
now im thinking of swapping cams again, im thinking of the TSP 228/232 112, the Tick Performance ls2 SNS stage 1 cam, which i had in a 2006 gto and sounded really nice, thats what i might end up going with its a 227/231 if i remember correctly.

here is a little idle video of my truck

blsnelling

iTrader: (4)

I still haven't changed my cam and am looking at this again with some new choices. I think I was looking to big last time. What are your thoughts on these?

madmann26

iTrader: (7)

So in short,

The more overlap you have, the more it's going to chop.

The caveat of having a cam with large overlap is that it's going to bleed off some compression and the rpm range will be higher.

As cams get to 0 overlap, you can definitely hear them. My cam is a -1 overlap and it chops plenty.

Idle tuning can be a little more difficult with higher overlap cams causing you to run a higher idle to compensate.

blsnelling

iTrader: (4)

That is true if the greater overlap la created by increased duration. If duration stays the same and the LSA is decreased, overlap increases and dynamic compressing actually increases. To that end, I believe I should achieve my desired idle by decreasing the LSA, along with a conservation duration increase to bump overall performance. I do have 4:30 gears and a 3200 stall to mitigate any bottom end torque concerns.

GREENSIERRA

Lol
My cam has 32.7* of overlap.
As a tuning newb it wasnt easy to get it to idle well but with some time I got it driving like its stock.

stock48

iTrader: (16)

Sorry I just saw this. What you want for that like said above is similar duration to what you have but on a 108 lsa with a milder lobe. I've done a bunch of them and they pull really hard in the midrange and have the nasty idle. You need to be really careful with the milled heads and PTV clearance. The 1218 spring makes it more sensitive if you spin it up.

blsnelling

iTrader: (4)

That sounds reasonable and would result in valve overlap of 2. Is that little of overlap really going to lope?

stock48

iTrader: (16)

Yes it will have a nice lope. I have a 227/230, 108 that is really nasty sounding and makes killer tq but ptv will get tight with heads milled. 224/230, 108 would be safer. At that you'll only have .060'' or so PTV on intake. The tight LSA's have a crisp quick chop to them. Even 218~222 range on a 108 chops pretty good.