I've been thinking long and hard about getting headers and exhaust for my 305 TPI. I already have a Flowmaster muffler on it so I'll just replace the stock intermediate pipe with a mandrel bent 3" pipe. As for the headers, I was thinking about 1 3/4" ones. What make should I go with? Money is tight, so SLP is out of the question.

To all the people who've already made this mod, what kind of gains should I expect from headers and exhaust. I've never taken my car to the strip so 1/4 mile times are pretty useless. I was wondering about the seat-of-the-pants difference it would make. What I mean to say is if I were side by side with another car in a race to 80-90mph, how much further ahead would I be with the mods? Thanks for your time

 

Headers and exhaust will probably give you around 25hp. Which would equal out to 2.5 car lengths of a lead in the 1/4 mile roughly. You'll definately notice the power increase, and besides any mods besides exhaust won't really benefit your car with out a free flowing exhaust.

 

Amen to that

and also you can make your car sound so much better if you get the right stuff

 

SLP is the only outfit making 1-3/4" primary shorties at this time, and even they don't recommend them for a 305. Unless your near-future plans include a 350, 1-5/8" will be fine (and would be an improvement over stock manifolds for a 350 as well).

I made most of my other mods at the same time I did the exhaust, so I can't tell you how much difference the exhaust itself made for me.

 

I can't decide whether to keep the IROC or not but i guess i'll end up modding it after all. As my first car here, it has a lot of sentimental value. 2.5 car lengths in the 1/4 mile sounds good to me. It's enough to put a good whooping on the typical ***** and punk bitch.

Hey rx7speed, did you see my earlier post for you on the general tech/engine board? It's about RX7s. It would be cool if you could reply to it. I need to arm myself with as much knowledge on these cars as i can before I go out to buy it.

 

oops sorry I got behind and was reading too much of the other forums

I am putting my post in that place now though

 

2.5 car lengths huh? 25hp sounds right, but does that equal 2.5 car lengths in the 1/4?

Does that mean I'll beat my best friends 96Z if I get headers and exaust? I raced him before I had CAI and I don't think he could've been more than 3 car lenths ahead of me. Just curious. Maybe I'm wrong. -Brian