ok guys, im planning on rebuilding my engine in a couple of months and adding a couple of go-fast goodies and i need some opinions on how i should set up my exhaust. my engine is a 302, and when i rebuild it im adding edelbrock aluminum heads and intake manifold, bigger TB, and an aftermarket cam (if i can find one that will fit my truck). for the exhaust, i was planning to go with long tube headers and true dual exhaust (2.5" piping) with a crosspipe and maybe 2 chambered flows on each pipe (or maybe 1 chambered if they'll give me more power). i would like to run with no cats, but there arent any shops around here that will do that for me, so ill just put in some high flow cats. im basically looking for the most power throughout the entire rpm band, i dont care how it sounds, my main concern is horsepower and torque. emmissions isnt a problem, we dont have inspections down here. should i go with long tube headers, or shorties? what about mufflers, 2 or 1 chambered flows? im open to suggestions, thanks a lot!!!

 

any ideas are welcome!

 

If it were up to me I would either suggest Gibsons or Thorley's. The Thorley's are a tri-y design that promotes low end torque, a great asset in a truck. Other then that I think it is simply a matter of personal preference.

I think the sites are:
www.gibsonperformance.com
and
www.thorleyheaders.com
Just go onto their sites and see if theu have applications for your truck.

When it comes to going with no cats, what I would do is simply have them install every piece as a seperate component. In other words put a flange between the header and cats and then one between the cats and muffler. Then if you want the cats off you can simply remove them.

Also be careful running true dual 2.5' pipes. That really doesn't give you a whole lot of backpressure. It might be OK with the right headers but be careful.

Good Luck,
Bones

 

i think you're right about the pipes. im thinking of going with 2 1/4" pipes instead. thanks for the input! nayone else have any ideas?

 

I would go with long tube headers, 2.5" pipes, 2 cheap cats, and dynomax racing bullets. This would make your truck sound bad A$$ and you wouldn't have any power loss.

 

i found the headers i want, cerama-coat dynomax long tubes. jegs has them for 215 and they already come with jet-hot coating inside and out. fordman, you dont think 2.5" pipes are too big? please keep the suggestions coming!!!

 

i got to agree,.....2,5 inche dual pipe sound awsome......I haven't heard dynomax racin bullets, but my friend has a 357 V8 wiht JBA headers, 2.5 inch pipes with two 6 inch glasspacks, and at idle I can barely hear myself think./..

Later

 

well the dynomax headers i have my eye on have 2.5" collectors and i think that will hurt my low end torque with 2.5" piping. thats why im thinking about the 2.25 piping with the crossover pipe. any other suggestions? thank you all for the input!

 

302.....well...I would have ya still go wuth 2.5, you may lose a little low-end, but not enough to harm anything...but I doubt you will lose any.... 2.25 would be good, but they wont be as deep I dont think.......but either one will be good...,although I still sAY 2.5 inch pipes would be the better bet

later

 

i know what u mean, i also think that 2.5 piping will sound deeper and meaner. but remember i dont really care about the way it sounds, my main concern is power through all rpm's. i think that with a 2.5" collector and 2.5" piping it will give me some real good top end, but lose low end (lose backpressure). im hoping someone with experience can tell me for sure. thanks again!

 

For the record I have a 4.6L V8 and it is equipped with a very restrictive set of cats, 2.5 inch single pipe out the back. If I run my truck with no muffler I can feel a HUGE difference between mufflers and not. Now, keep in mind mine is a single pipe, not dual. If you go with 2.5 you are going to want a header/muffler combo that will provide adequate backpressure. Please don't qoute me because I am not an expert. What I would honestly do is take it to a performance truck shop and get their opinion on the matter.

What you could do is run 2.5's and then end them with an adjustable muffler. That is what I did on my truck. I'm very happy with it. It is made by Supertrapp. And they are not easy to find. Their web site is www.supertrapp.com

Hopefully that will all help. Good luck and take your time.

Bones