OK, here's the problem...

My buddy, Chris89Formula has just rebuilt his engine, here are the specs:

1989 165 ECM MAF
4 bolt block 355 ci
forged crank, 5.7 rods, 8.5:1 forged pistons
LT4 HOT CAM. 1.6rrs
Vortec heads, SDPC Vortec lower, Superram runners and plenum
42lb FMS Injectors, Racetronix 255 high pressure pump, Vortech FMU
Paxton SN93 charger, MSD 6AL BTM box
SLP 1 3//4 headers and full SLP catback NO cats
No EGR or AIR pump.
Centerforce clutch, Gforce rebuilt T5, spohn torque arm
3.73 gears, MT Drag Radials 275/40 17

Here is the problem, this engine makes poor power, I raced him in my g/f's factory SLP equipped 350 formula and we ran dead even until we both let off at around 130mph..... Her car runs between 13.99 and 13.80. His idle is up and down in RPMs but the air fuel ratio is steady under load...

With tunerpro scanning it, the O2 sensor frequently goes to 4.44 volts and the idle suffers badly, but under load the o2 reading is between 850 and 900 mv. Timing is set at 6btdc. I have no idea about total timing under load, This is the third mail order chip that he has had. Two from ed wright and one from PCMforless. No dyno in the Atlanta area that we can find "burns" chips. Everyone has concentrated on the flash LS1s. His car is drivable but suffers from very low power for what he has. The car will not spin the tires unless it is linelocked.
It seems like everything is right as far as air, fuel and spark but I cant put my finger on why the power isnt there.... Could it be the low compression or the vortec heads? A combination of a few things???

Any help or ideas?

Later, Kevin
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Also, he sees about 4 psi on the boost gauge. Doesnt overheat and shows no spark knock on the ECM.

 

mail order chips, that's a factor for sure. the more wild your combo is the less the chip companies can do for you, only way to tune YOUR motor is to tune YOUR motor, they are all different and it's a matter of time before people realize they aren't buying anything really, that they couldn't have done themselves.
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and i wasn't trying to be an *** just the facts of life, other will say the same. best of luck on your freinds project