what size downpipe should i use if i want to run 10 lbs boost on a turbo z24?
 
well on my turboed sunfire 2.2 eco i run on about 10 with a 2.5 in down pipe and cat to a 2.25 cat back...so really dont go to big because you want back pressure...
 
2.5" seems rather standard size to use.  I ran a 2.5" DP and then stepped it up to a 3" system down by the cradle.  You dont want any restriction after the turbo.
 
 
3" turboback... NO BACK PRESSURE.... well a lil
ECOtec DOHC
 
 
SweetnessGT wrote:nick bucci wrote:well on my turboed sunfire 2.2 eco i run on about 10 with a 2.5 in down pipe and cat to a 2.25 cat back...so really dont go to big because you want back pressure...
Incorrect, you want zero backpressure after the turbo.  The turbo itself is a restriction in the exhaust system.
-Chris-
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