SilverSmoke

Just out of curiosity, how much spark on average is everyone running with a good head/cam combo with all supporting mods on an LS1 engine?

I know for me I'm around 22* and the car seems to be happy in that area. If I drop the spark down lower my MAP does increase up until around 11* where the car has some trouble running cleanly. If I increase spark, the MAP doesn't do much.

CamaroSS22

iTrader: (1)

It really depends on how radical your setup is. 22 sounds like a factory number, I run 25-26 on mine, but my cam is 26x/27x duration. Usually the more radical the came, the higher your idle timing is going to be. You dont want to go too high or else the engine wont have any in reserve to handle sudden loads, and you dont want to go to low or the flame propagation will be too low and it will idle like crap.

06X6spdGTO

iTrader: (6)

17-23* depend on application (Cam, SCR, Manual/Auto, Rear Gear, etc)

printmanjackson

iTrader: (1)

27* on mine.

SilverSmoke

Do you find that on higher compression cars the spark get's a bit lower?

Just curious if the rule of thumb on MAP increase is gospel, or just a general idea to what to shoot for.

06X6spdGTO

iTrader: (6)

Honestly I start by commanding around 22* timing at idle and the car to start and idle fine. Then log with the VCM scanner and use the VCM scanner controls to adjust timing while im logging to find the "Sweet Spot" i guess you could call it.

soundengineer

iTrader: (16)

you can push the idle timing around with the scanner controls in HP Tuners...
push it till you get the best vacuum at idle.. dont go way past where it seems to bottom out at...have to find where a little timing stops making a big difference..

*most* cams above 224@0.050 like to be 26*~29* at idle...
anything with any serious amount of overlap is going to want to be in that range for sure...
cams with 0 overlap are in general happy anywhere from 14*~24* at idle..