When adding cams, such as gsc s2s, how should you change your timing map to adjust for the aggressive cams? And also would you need to adjust your afrs to get the car running properly, or is the biggest part getting the idle down?

yes cams will change most everything.

idle is not easy nor difficult just get desired AFRs in and adjust timing to suit.

for S2s i am not certain on an "average" idle timing value maybe some of the more experienced guys can chime in...

Most of the time idle timing is increased a few degrees when cams are installed. In addition, the base idle rpm is also usually increased. I've see idle timing from 7 degrees to 15 degrees.

I run my revolver cams at 11 degrees and 1000 rpm idle.

It is all personal preference.

What???? I am runing a 25 PSI peak boost and cannot take more than 5~6* of timing. Even at 6000 RPMs I cannot run more than 8* without knock. By 8000 rpms I can run 14 maybe 15*. All this is on 93 Oct. Peak load (1 byte load) is about 280 @ around 4000 rpms.

To me 8* at peak at 25 psi sounds a lot or maybe my car just hates timing. Even with a 2 knock count timing gets pulled 1*.

25 pisi isnt low boost lol. i was running on my old set up 15psi small *** t25 umm i think 11-13 * @ peak tq, and twenty somthing by 7500... lol. but i rather boost over timing. now i have a new dsm and 16g but not touching it till i get my wbo2

OK. I misunderstood JOT comment. For low boost maybe 8* at peak torque is OK. But for higher boost you will need to run lower timing. That makes sense now.

Anyways I still think my car hates timing or we had really bad pump gas in PR. Anything that can be done to make the car take more timing on a cammed evo on pump gas (no meth).

I have a simular setup to you. My car does not like more than 4 to 5 degrees up top.

If you want to add timing you need to run lower boost and/or run richer.

You mean 4 to 5 at peak load. Not at top right? 4 to 5 at top m,akes no power.

i'm lost, but if he can get 4 or 5 at peak load he is walking on water too.

I run 4/5 at peak load and 12 up top, but I am on a 2.3, that takes a little more timing than the 2.0.....understandably too!

That is my pump gas map! I run a good bit more timing on e85!

Yeah, I meant peak load. Up top I am at around 14.

Yeah I am able run around 4/5 degrees during peak load at 26 psi on 93 pump gas, but it's a 2.3l....peak load hits around 3600-3800 RPM.

good lord, 3 or 4 degrees at peak load. how much load is that?


I may need a lot of help, -1 at 3500 rpm and 280 load or more

Depending on the road (up hill, down, or flat) load for me at peak is beteen 290 and 320. Average is about 310 ish.

Boost is 27psi tapering to 25 and holds till redline at 7700.