ok guys.... should i dual out my straight pipes from both headers and put two high flo cats on them, or bring a 3" pipe to the cat and then dual it out going to the back

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crap the pic didnt turn out right ....hope u guys understand what im sayin about it .... i dunno how to explain it really

 

Why bother to split the exhaust after the cat? You would have all the problems associated with dual exhaust, but none of the benefits. I would go with two hi-flow cats if I were you.

BTW, I am running the old cyclone shorty headers to two car-sound cats (one on each side) to two borla XR-1 sportsman race mufflers (one on each side). I want to use a Dr. Gas X-pipe, but I will have to see about cost. I'll use an h-pipe if I can't get the x. Everything is 2 1/2". It is a true dual setup. I was going to put the mufflers under the rear floor pans, but I don't have to clearance. I think I will hang them under the rear axle, as far forward as possible.

I have been planning this setup for two months, it costs about $700-$800 (that includes everything), and is going to limit my ground clearance. It better sound really good and I better feel a power difference or I'm going to be mad.

 

From what i've heard u might be a little mad...

 

I think what camaroman305 has going is a pretty good idea.

When you run true duals, you should use a crossover to equalize flow, increase scavaging, and improve low RPM torque. This doesn't hurt upper RPM HP at all, and it sounds better to.

Using the cat as a crossover would be perfect. It's something you legally have to have, so why not use it to your advantage?

You should match the size of the cat to the area of both pipes, or even make it larger. A 3 1/2" cat is larger than two 2 1/2" pipes.

The area of one 2.5" pipe is 4.43"sq. So two 2.5" pipes total area is 8.86"sq.
A 3.5" cat is 8.95"sq.
Any smaller (like 3" or even 3.25") and it would reduce flow a little. An exhaust only flows as well as the smallest part of the pipe(s) will let it.

So yea, it's a great idea. Good luck getting it to fit though.

AJ

 

hey, I hadn't even thought of using that cat as the crossover. that would be cheaper and easier. You'd probably get the benefits of an x-pipe, while saving the cost of one cat and an x-pipe. Man, too bad I already ordered all my parts (got the car-sound cats--new--off ebay so I can't really return them. at least the price was good).

Good job, camaroman305

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91 Formula WS6, 305 tpi, T-5, cyclone headers, true dual exhaust

[This message has been edited by cort351w (edited November 13, 2001).]