exhaust sizing for a turbo system

[Anonymous]

About the piping. Run the charge pipe fromt he back turbo over the timing belt on the passenger side. The firewall will need to be pressed in about an inch to fit a 2.5" pipe through the space between the back corner of the UIM and the firewall. Then it goes beside the radiator into a dual chamber air to air intercooler. And the front turbo would be easy, but you would need to move or do somehting with the fans.

As for the ports, the 1st gen exhaust manifolds are oversized by a minimum of 1/16" all the way around, and the smae goes for NAPA gaskets. However the ports aren't the same on top and bottom, they are a bit more rounded on top. Hard to explain.

That weld looks sooooo much better than mine

[pocket-rocket]

That is how he had his turbo on the car before Aaron, flipped front manifold on the rear. Besides, you want the turbo mounted as high as possible so the oil drains back easier. If your system doesn't drain back easy, oil will coke on the bearings, and other nasty things happen. Makes me wonder how the Porches do it with the turbo's so low (if the stock ones go were RUF puts theirs).

[Anonymous]

Yah I figured he did it that way.

About the turbos, doing it with a twin turbo setup and they would sit plenty high enough for the oil lines to go back to the pan. Just do it liek a 300ZX setup, except piping would be different a little.....

[dykz34]

Why use twin turbos when a single, bigger one will make more power?

[blk92z34getrag]

Wouldn't two smaller ones spool up faster and give a better powerband? It would probably net the same power too wouldn't it?

[dykz34]

Yes, they would spool up quicker... but smaller turbo's will not make as much power in high RPM/high PSI situations because they cannot flow enough (they plateau). That's where a nice T4 would love to play.

[skalor]

It's a common misconception that twin turbos spool faster than single turbo systems. It's A/R ratio that will tell when a turbo will spool or not. Just look at the TGP as an example...the lag that a TGP has is actually from the computer. If you were to hook up a manual boost controller on a TGP, full boost would be instant. The T-25 on a TGP has a 4 psi wastegate actuator and it will spool to 4 psi then the computer will slowly ramp the boost up via control of the wastegate actuator solenoid.