Hey guys, I have the mp90 sidemount non intercooled, I'm running a 2.9'' pulley thats showing between 5.25 and 5.75 psi on the gauge, I'm using 92 octane fuel, tr6 plugs, I have a ls1 cam as well, My buddy is doing the tuning with efi and we tuned it the other night it was about 73* outside, The iats at cruising were between 105*-120*. at the end of a run they were between 175*-200* (closer to 200* for the most part) temps would quickly drop back to cruising temps after i let off.

We were able to tune for 19* of timing and it would pull it and showed the best performance with 19*. Is this abnormal for the temps? We both figured it was kind of high timing especially for the amount of the heat the charger was producing. He has it set so if the temps were any higher it would durastically drop timing off.

We were able to tune to 21* and still no knock but it did not seem to pull as well and the little calculator on the efi tuning showed less power. it consistantly showed best power at 19*

I have a 4x4 crew cab z71 with the 5.3 its loaded so its heavy. best we did that night is 2.3 0-60ft and a 6.48 0-60. I am going to fab a water to air intercooler to fit right after the charger before the intake and try to get the temps as close to ambient as possibly with the least amount of pressure drop.

From what I read If I could drop these temps to close to ambient after a run with the pulley I have it should wake it up quite a bit. I know guys have ran 2.8 or even 2.7's on this charger.

Does the timing seem right for these temps and this boost? truck seemed to run great

 

A base setting of 19* would be fine with that little boost, but if you log a pull I can guarantee that the computer is pulling timing as your IAT's climb, especially if you have a stock IAT retard table. So when it gets to 200*, which is very very hot, it may only be giving it 5-7* of advance. You need meth or a bigger charger

 

my buddys truck has a isky 212 cam in a stock 5.3 and we are running 19* timing on 93 oct on 10PSI. IATs are only 120-130ish tho.

Do you have a log of the pulls?

If its got the stock timing table in the IAT section your prolly running about 5-8* timing total.

a good W/A IC setup would wake it up pretty good!!

 

Timing tables are not stock, He has modified them as we have gone along, He has done quite a few tunes and also has his own turbo truck he tunes, As for only pulling 7-8* of timing when it gets hot, he set it up to command the timing and it pulled all the way to 21* through entire pull and showed no knock. He just knocked it down to 19* for safety and it pulls best at that setting, Also we were only seeing a max of around 190* briefly after thinking about it. so it would climb to that height depending on the run.

 

How does he have the IAT timing table setup?
and whats the AFR?

 

Try and post a log of the runs

 

That's allot of timing for that much heat.

 

Thats what im thinking..
maybe its what they are commading and the IAT table is pulling it all out??

 

You can get detonation without knock. Just a FYI.

 

200* IATs cant be good for the pistons either.
Meth kit and a Intercooler would do wonders on that thing