Nmskull66

Ok so not sure if anyone has ever heard of doing this before or if im the first person to actually do this..? I have a 2001 Firebird with a 3800 all last year i sprayed the car with a dual stage nitrous kit (200hp estimated) never tuned it just ran 110 and it help up until the very last track event of the year. It backfired and I bent a valve so i finally got around to fixing the head (9 months later) so this is what i did and where my problem comes into play.


I used to have a built GTP that constantly broke so i have all these performance parts for a 3800 laying around so I dropped the motor in the firebird, and instead of putting a set of stock N/A heads on the car I put my Built Ported GTP heads on with 1.9 rockers, headers, ported my lower intake very minimal just to remove the roughness, added a direct port nitrous kit where the injectors would have went in the intake, moved the injectors to the heads, head studded it, double roller, etc.

Finished the car started it, it was fine went to drive it and if driving normally the car runs fine. When WOT the car wont shift, Lacks power, misfires. I had my buddy with HP tuners look at it and the minute the car is floored spark knock maxes out.... We added 20% more fuel and removed 8 degrees of timing and it barely made a dent in the problem. Only lower the spark knock to about 10 degrees instead of 15+


Does anyone have any idea on what could possibly be going on?

Any help is greatly appreciated.