1G Another Open 02 Dump Question

[chanley talon]

All right I been reading. I read that an open o2 dump will not increase power just noise. But , I have one question. What if you have a 2.5-inch turbo down pipe and you're running 25 psi? Wouldn't the 1.5 open dump pipe help flow and increase the power capability? If you add the 2.5 plus the 1.5 opening, that is a total of 4 inches flowing under high boost. Seems like that would make more power than trying to squeeze back through the 2.5-inch collector. Am I wrong or is the dyno the only person who is going to know?

 

[pauleyman]

It is like a bigger exhaust but it is not the same as a 4 inch exhaust. I haven't had one in 15 years but on a stock downpipe and 2.5 inch cat back it felt similar to a 2.5 inch downpipe. Spool was better with a 2.5 inch downpipe as a dump tube does nothing until its open.

 

[chanley talon]

I was thinking it would allow you to make more horsepower once vented to atmosphere.

 

[gsxeclipse102]

If your exhaust is restrictive it can increase hp once the wastegate opens. If your running a 3 inch downpipe/full exhaust you prob wont notice much gain.

 

[turboglenn]

I can say this in the 500 horsepower range when I rerouted my open dump back into the downpipe I lost 37 horse I like the quietness but I'm thinking about dumping it again. Really all depends on your setup how you're utilizing it and where your restrictions are

 

[bling5tatus]

3" exhaust doesn't become a restriction until something like 600hp worth of exhaust flow coming out of the engine/turbo. If you're not running "low" boost you won't hear the vented dump until you're on kill throttle position in high rpms.