I have a 95 Z28 and, I would like to convert in into a 3' true dual system. However, I already have a Eibach Pro-Plus kit on the car, lowering it 1.3 inches. I'm worried if I go with the true duals it will not give me a great ground clearance. Any thoughts on this problem.

 

If you're like me, you'd get the duals custom-made, which would get you better clearance than any aftermarket y-pipe. BUT if you can't afford that route, then a y would be better suited to your needs.

 

I asked one of my buddies about this and, he suggested oval pipes. I never heard anything about oval pipes. As anyone else?

 

do you plan on getting long tube headers too?? these will sit about 1/2 to 1" lower depending on the make ( SLP tuned length say they drop 1" ish) The main problem is the axle you can dump or run over or under.

 

I plan on going with the Kook's 1 7/8" headers. I'm going to run them over the axle.

 

you should manage it, just be steady over any bumps areas. You might have to drop the panhard support bar some with a relocation bracket to get over the top with 2 pipes, but 3" is fine

 

I would stick with a 3 inch Y-pipe and call it a day. But thats just me.

 

^^ x2

3" true dual all the way back is going to be WAY more flow than you need, you'll end up spending more money than you need, and you'll get 0 benefit over a good 3" Y-pipe and cat-back. I'm not quite sure what the allure of true duals is, but a good Y-pipe setup can easily support over 500 RWHP...Oh yeah, and the Kooks 1 7/8" stepped headers are going to be way more flow than you need as well unless you're running over 415 CID or revving the car to 7000 RPM. A 1 3/4" primary is almost perfect for a 330-415 CID motor to optimize the exhaust scavenging wave.

 

I think the allure is the sound

If you do go with a single 3" as crb and slvr suggest i am unsure if it will support upto 500hp, correct me if im wrong but i went through this whole process when designing some 2.5" true duals for my friends pontiac gto

Ok, so a rule of thumb is that per hp your car with flow 2.2 cfm of exhaust gases So say you are around 350-400hp makes 770-880 CFM exhaust. And a typical cylindrical pipe will flow 115 cfm per inch squared. 1" diameter pipe will flow 115 CFM thus support 52 hp.

Here we have a 3" pipe, x-sec area = 7.06" squared. Thus flows 805 CFM, just enough from the single pipe to support 360hp

With 2.5" true duals we have combined X-sec area of 9.8" squared which supports 1130CFM, ie ~510HP which is the limit we had for costs etc on my mates GTO
( his pics are here if your interested in looking: http://www.hsv.org.uk/topic.asp?t=724822&f=69&h=27)

Anyhow planning my exhaust for the 'maro im gonna go with single 4" (1445 cfm - 650hp) or dual 3" (1625cfm - 740hp)

The 1 3/4" primary headers are ok however as they flow 360cfm each pipe which is likely more than the heads on the motor anyway

hope this help

 

im gonna have to agree with 95slvr on this one. plenty of guys pushing 450hp have 1 3/4 prime headers with a 3inch y pipe n cat back. the setup has plenty of flow n just the right amount of back pressure. just because the pipes r bigger doesnt mean they're better.
you see it alot with those mustangs. 3inch H pipes n dual exhaust all that sound but no performance