80 Hp increase minimum

[olddog]

When I purchased my car the engine had 1500 miles on it. A 5.0 stroked to 347 cid. Edelbrock performer heads, aggressive hydraulic roller cam. Mass Flow EFI system. The previous owner said the builder estimated 400 hp. Putting all the engine specs into my "virtual engine dyno pro" and "dyno2000," both software packages estimate 400 to 450 Hp at the flywheel.

My first impression, when I drove it, was that it was putting out about 300 hp maximum. The engine light was coming on. By the smell of the exhaust and the black sooty side pipes, I new it was running way too rich - which we all know will kill Hp. Well the seat of my pants is not an accurate dyno, but with 3.50:1 rear gears, you could stomp it at any rpm in 1st gear, and it could not break the tires loose (P295 50R 15 BFG T/A).

I've been working my way through the EFI system. The engine light code was caused by the right O2 sensor plug being loose. That helped a little. The fuel pressure was 43 psi and should have been 40. Correcting that made some improvement. Today I cleaned the mass flow meter - it's a hot wire type, and wow! What a kick in the pants. I was not expecting the tires to light up just stepping on the throttle at 1500 rpm (the cam lopes until 2000 rpm)

I figure a 240 lb passenger is like a 40 Hp reduction. The power increase is like taking two passenger out of the car, hence my 80 Hp increase. Sorry if I bored anyone to death, but it was exciting to me.