Headers/Exhaust #'s

[Dewey]

So it's been said that the ideal intake/exhaust diameters with regard to backpressure, etc. is 1 3/4 x 2 3/4. Can anyone back this up? What diameter are our stock headers? Exhaust is already 2 3/4, right? Disregard the sound factor, I'm looking for performance only.

[shortdog273]

Nope. Our stock pipes are 2.25".

[ItalianStallion1]

I think it kind of depends on exhaust and also if you have a high flow cat. I have RK Sport headers, with a Car Sound high flow cat, and 3 inch piping in between the cat and headers and from the cat all the way back. I had a Flowmaster before and then I put a rear section Borla, that's the one that goes straite into the muffler and isn't adjustable, and I felt a lot more performance. One thing to note though, the Flowmaster I was using was for a TPI which is obviously a V8 so...

The reason why I went with 3 inch piping was for the sound and also for the future when I get engine work done. I'm willing to go a quarter of an inch bigger and say screw you know. They say you gain it in the top end anyway. For instance when my car hits about 30 MPH it kind of takes off, it's wierd. My midrange almost feels like an 8. But that's probably because of my intake and the big hole I cut underneath it so air can scoop up into it. I don't know, cars are a mistery some times.

[JAM]

What about some of the newer cars with tublular manifolds like my car, are the headers going to give you much more than stock?

[shortdog273]

<blockquote>quote:</font><hr>Originally posted by JAM:
What about some of the newer cars with tublular manifolds like my car, are the headers going to give you much more than stock?<hr></blockquote>

Nope. Don't waste $500+ dollars on headers. If you decide to get headers, wait until pacesetter comes out with theirs for half the price.

[JAM]

Is it worth it at all since my car has tublular manifolds. (looks like headers only heavier) LOL