so, I got to thinking. With a LOT of searching around and looking at other builds of other makes and models, has anybody routed a DP through the wheel well area through the A-Arms and stuff? Ive seen this a lot on mustangs, etc.

Just trying to think of ways to route a 5" DP without too much hassle.

 

Im necking my DP to a 3.5 and gonna ovalize it under the K member....and it its too big I may go to 2 3 inch ones. It has been done on a 3rd gen.

Jay

 

I've thought about it, but haven't tried it. We don't have much room in the back of the wheel well, but tons in front of it.

 

im routing mine out the side of the front bumper just in front of the tire almost done!

 

I'm tired of the noise and smelling it. I have mine run to the back of the tranny, 90* to 90* to get to the pass side and turn back again, its dumped somewhere around the pass butt and as soon as I get some pipe I'm going to the axle with it.

This is through 3" - a single 3" its not ideal but you can make good power with less than an ideal setup. If I put even a straight through muffler on it I get spool problems, so I'm just going to run open 3" out the back.

 

eric bazaan on here made 750 at the wheels w/ a s400 with logs, anda 5" into a 3" setup.

 

Jose had a customer with a 88 making 1000+ rwhp on a 3" downpipe, you don't need a 5" downpipe, I know you won't be making that much power.

 

that kit was a gt4088 with a 3.5" DP IIRC, 1079hp at the wheels on 23psi. I know that setup VERY well. I should be at least 850 at the wheels. I have everything to hold at least that much and more. I do have the turbo kit completely done though, with a 5" dumppipe at the front tires. Might just stick with that, but definately needs a muffler on it.

 

I remember when it was made, back then, was a 3" downpipe, he may have stepped up later, but I know for sure they made ~900 on a t76 and 1000+ on an 88.

 

This is mainly theory/opinion but you should try to run ~10% larger diameter DP than turbine exit. Ramp up as soon as possible at no greater than 7 degrees rate of change of pipe wall to avoid seperation.

So a 3.5"DP on a typical 76/T4 should work well.

I wouldn't dispute +700rwhp with a 3" DP, but I also wouldn't think at first glance that would be an optimal DP diameter either. It would likely be harder on the combo than an otherwise optimized exhaust. But I'm no expert

-Scott.