At what discharge temps does the PCM pull timing and how much?
I've noticed that since I've added my 2.8 to my 4# lower that it seems to make no difference weather I run my 16* or my 18* tune. It still only run high 107mph.
With the 4# lower I was allways high108 or low 109mph even on slicks.
Is my PCM pulling timing or is it simply to hot of discharge temps to make a difference?
IAT2 temps can get well over 145 in the TOP of third gear. I've seen 150* in third gear @ 115+mph.
What should I do? The truck is mainly a track truck but I do use it for cruising also when the weather is nice. Should I add a supercooler? or a Ported blower?
A ported blower would put me close to beaking point of a stock block right?
A supercooler would take advantage of the current boost by cooling the dischage temps right?

Here is my current mods: 4#lower, 2.8upper, JL cold air, Denso plugs, 100mm idlers, Monster Box TD convertor, JL traction bars, JL saftey loop, JL dyno tuned Pred..404/508 with out the 2.8upper.

 

Sounds like your heating the charge up right much. I think that w/ ur current combo, plus an apten or whoever you use, your temps will drop significantly. Larger heat exchanger may also be in the works. I run an Apten and a 4lb, 14-16psi dependant on weather, and my temps dont reach that high. If you ported, you'll be adding boost no doubt, but its a much cooler air. I think back in the day they were posting results of the apten, and an apten w/ a 4lb was cooler than a stock unported eaton @ stock boost. Correct me if im wrong guys, i THINK i read that.

 

But would a supercooler work just as well for the track?

 

porting the supercharger has been shown over and over again to lower those temps.

 

Well if you are worried about this, here is an idea. Ditch the 2.8 (I am assuming that this is equivalent to a 2lb upper?) and add a ported blower. The ported blower would lower the temps, and many have claimed that they have gained 1-2 PSI. I think that this would solve your problem.

 

Just out of curiosity, was your tune adjusted for the additional 2.5 psi of boost?? I run non-ported Eaton with a 6# lower and stock upper with 21 degrees of timing, other mods are similar, and run 109-110mph in the 1/4.

Jason