Hey guys, i got a 95 firebird formula a4 with the following mods, intake hooker shorties borla cutout !cat 3.5 driveshaft 12 bolt 3.73 gears 2800 stall tb bypass recently did full tuneup and underdrive crank pully. Put my car on the dyno today for the first time (dynojet) and pulled 260hp and 290ft/lb. torque. I was expecting in the 270 range so i was kind of pissed off. I also expected at least 300 torque. The power curve waqs very flat and didnt break up at all. The motor temp was around 180-190 so it wasnt hot. Is this about right or am i missing something here. Its kind of odd also because ive raced more than my fair share of ls1 with intake/ehaust, 6 speeds and autos and have came out victorious on all but one who had long tubes and gears. What gives, my car sure feels a lot faster than what my car is putting out.

Thanks, Heath

 

It could the dyno, I would expect more power with your mods

 

Yeah I know man..I feel your pain!!!I dynoed at 230rwhp and 281 rwtq with K&N intake,TB bypass,180 temp,Flowmaster catback,vortech elbow and !maf. I feel your pain man. I was expecting a lot more out of my car too but I dunno.

 

Your #'s are a little low. But i'm pretty sure that running through a 12 bolt will lower your hp to the wheels. There is more drivetrain loss i think. But i'm not sure and i'm sure someone that does will chime in.

 

Did you have the cutout open? The only mods that improve horsepower/torque that I see are the shorties(questionable by some), cutout(could be a decent HP gain), intake(maybe 7 hp) and pulley(maybe 5 hp), but none of them are big HP improvers. I would think that you would be a little higher than that also. Was the dyno SAE corrected?

Dan

 

Drew your are correct. A 12 bolt does cause a bit more drivetrain loss. Thats the catch you lose a bit of power for the more durable rear end.

 

cutout was open and no, the numbers were not corrected. Im wondering if it waould be worth it to upgrade to some hooker longtubes?? i hate these stinkin hooker shorties. they blow!! no power diff. at all in my opinion.

 

i even cut a little off the collectors like everyone has been saying. How much power do u think the 12 bolt robbed? does anyone know what the corrected numbers would be, I live in atlanta if altitude has anything to do with it.

 

like the others said.. the 12bolt will pull some power away...
upgrade to some longtubes

 

Definitely upgrade to the Long Tubes. Also, are you an A4 or M6, and lastly, was it a dynojet or a mustang dyno?

 

hey dude....the stall and 12 bolt decrease rwhp.

 

If you can list the temp., dew point, barometric pressure, and altitude i can tell you your corrected #'s.

 

My numbers in sig are not SAE corrected, they are the actual numbers. But SAE corrected I belive they are 270 rwhp 314 rwtq. I dont have headers either. Something is DEFINITLY wrong, check your ignition and fuel system maybe?

 

I feel your pain, man. I just had my 396 stroker dynotuned on a Mustang dyno and the results were: 345.7HP @ 6000 RPM and 333.2 ft.lb @ 5000 RPM. I have a 4k stall TC, built TH400 and 10 bolt 4.10 gears, so I know I have some big rwhp losses, but the car pulls strong. I hope that I can get it to the track before they close for the season to see what it can do.
In the meantime, I think I have a bad spark plug wire and some fuel issues to correct. The car is always running in closed loop and drinks like a fish.

 

I dont know if anyone has told you this but mustang dynos suck...a dynojet is the way to go as it will tell you the real tail of oyr hp. dynojetx usually dyno 12% more output than mustang dynos. why? because mustang dynos create a negative inertia effect(they say its so it would be just like driving on the road, which is bs IMO) so figure a dynojet would give you about 387.18 rwhp and 373.18 ftlbs of torque. if you ever get a dynojet dyon done, let me know if i was close