Just got back from chassie dyno shop.

Made 3 dyno runs.
Two were letting the IAT sensor do it's thing and last run was with my IATuner circuit.



I have to pour over the Autotap PCM traces I did during the runs and the dyno raw numbers but in short,

My tinkering and tuning ideas worked !

The dyno that was done in March of this year was best of :

388 RWHP with Torque at 357 ft/lbs , Today it went:
407 RWHP " " 396 Ft/lbs. Clearly in march the lean and low timing had a ill effect to both HP but torque liked it the least.

At the flywheel then with a 17% loss over drivetrain the numbers are:

476 HP with 463 Ft/lbs

Clearly O2s are liars for they reported a bit rich but AFR was 13:1 for all three runs
and reason for knock issue.

IATtuner gave a 10 HP gain at rear wheels with a 15 ft/lb gain of torque.

Once I resolve the knock issue, I see at least another 10 RWHP.

I'll do a full report on team website but at least it shows that just tinkering and fooling the PCM functions can give a decent gain and that oversized injectors can be used and have them in reserve when other mods are added that need the extra juice.

The 3 autotap traces can now be seen on team website at http://teamzr1.com/dyno1.html

Compare run 1 and 3, you can see when IAT was forced to 59 degrees how fewer engine cycles it took over run 1 to get to 132 MPH at redline in 4th gear.

John

Those are very good #'s.

I pulled 306-308 that day with around 315 tq. The car runs 106-107 at the 1/4mile
Although it's less than the LT1 I had with 345rwhp, it is faster by 3/10's

George

the turbo buick guys are working on a "stand alone" wide band 02 that might do a bit better. the "narrow band" o2s can be pretty misleading and can be interpreted as a "gross indicator" of WOT a/f.

13.1 is about right for power I would think. maybe just a tad rich, but it's better to be safe. you migh lean it out but only on really good gas. I'll keep you posted on the wide band thing. this could be a really good aid in tuning.