[dyingbreed]

I have a 1978 Trans Am with the base 185 Hp, Pontiac 400 engine (which allegedly has a few upgrades, including a "mild" cam). Trust me this motor is basically stock, I don't care what sales pitch the seller tryed to pull over on me. In the future I plan to have this motor built to approximately 350- 400 Hp. Anyway, the exhaust is shot!! I figured since it needs replaced, I might as well do it right.
I was planning to put on a set of Hooker Super Comp headers running out through a "true" dual exuast system, using 2.5 inch pipes. I'm not quite sure at the present time, if I'll use Flowmaster or Dynomax mufflers.
I have heard alot of talk about headers and larger diameter exaust pipes "robbing" a car of horse power and/or torque, especially from low end launch. I guess my big question is what will I loose with headers and 2.5" exhaust system on the current 185 HP motor? What gains, if any, should I expect? (basically a PROs vs CONs question).
Some people have said I would be better off using the existing stock exhuast manifolds with 2.5" dual exhuast, instead of the headers. Others have said a 2.5" exhuast system may be too large and Should I possibly go with headers and a 2.25" dual exhaust. Hell, I don't know!!!! I can only assume when the engine is rebuilt to 400 Hp, it would probably benefit from the larger exhuast and headers.
This project is soon to be under way and I just want ot make sure I'm heading in the right direction with the exhaust system.
I would most appreciate any advice or exhuast set-ups which have worked well for some of you with the 400 Pontiac motor.
I should mention that this car is not raced in any way. It's just a summer car, which only sees about 1500- 2000 miles a year. I do want to make sure, in the future, that I'm able to dust a mustang or one of these little compact "rice burners," should one pull up next to me!!!!!!

Thanks in advance.

[dyingbreed]

I have a 1978 Trans Am with the base 185 Hp, Pontiac 400 engine (which allegedly has a few upgrades, including a "mild" cam). Trust me this motor is basically stock, I don't care what sales pitch the seller tryed to pull over on me. In the future I plan to have this motor built to approximately 350- 400 Hp. Anyway, the exhaust is shot!! I figured since it needs replaced, I might as well do it right.
I was planning to put on a set of Hooker Super Comp headers running out through a "true" dual exuast system, using 2.5 inch pipes. I'm not quite sure at the present time, if I'll use Flowmaster or Dynomax mufflers.
I have heard alot of talk about headers and larger diameter exaust pipes "robbing" a car of horse power and/or torque, especially from low end launch. I guess my big question is what will I loose with headers and 2.5" exhaust system on the current 185 HP motor? What gains, if any, should I expect? (basically a PROs vs CONs question).
Some people have said I would be better off using the existing stock exhuast manifolds with 2.5" dual exhuast, instead of the headers. Others have said a 2.5" exhuast system may be too large and Should I possibly go with headers and a 2.25" dual exhaust. Hell, I don't know!!!! I can only assume when the engine is rebuilt to 400 Hp, it would probably benefit from the larger exhuast and headers.
This project is soon to be under way and I just want ot make sure I'm heading in the right direction with the exhaust system.
I would most appreciate any advice or exhuast set-ups which have worked well for some of you with the 400 Pontiac motor.
I should mention that this car is not raced in any way. It's just a summer car, which only sees about 1500- 2000 miles a year. I do want to make sure, in the future, that I'm able to dust a mustang or one of these little compact "rice burners," should one pull up next to me!!!!!!

Thanks in advance.