What would be more beneficial for a turbo application, a single or dual exhaust? What would be an optimal size of the exhaust piping? I'm just wondering. Thanks

 

Single exhaust, 3"...I believe

 

3" is the important part... my guess is that whether it's single or dual outlet has a minimal effect.

 

I agree with Derryck, as the exhaust splits into two separate pipes pretty far downstream, so splitting one 3" pipe into two 3" pipes won't make any difference. The diameter of the downpipe is probably what matters.

 

Can you run a turbo on stock exhaust until you have the $$ to get an exhaust?

 

Sure you can, you just wouldn't spool up as quickly or make as much peak power.

Now, is the exhaust too restrictive for the turbo for the long haul and would there be detrimental heat build up that would lessen the turbo's life? Please run it like that for a year or so and report back we need all the data points we can get. ; )

Now that I have the smart ass out of my system, other cars, Miatas - DSMs, etc. do it and the people never seem satisfied with their performance until they replace the exhaust.

On one hand if you are going to spend the big bucks for a turbo it only makes sense to replace the exhaust at the same time since an exhaust is relatively cheap. On the other hand since you've already spend the big bucks for the turbo there may not be much left for an exhaust.

Now the big question, is there a 3" exhaust available or will you have to custom fab one?

 

PM Yiannis who has done exactly what you've proposed -- added a turbo without upgrading his exhaust. Based on the dyno numbers he showed me, I think he's losing about 25rwhp on low boost. But he's still pushing 260rwhp through the stock pipes, which ain't so bad... :-)