It's come time in my turbo project to hook up the wastegate. Do you guys think that I should run it back into the downpipe or vent it to the bottom of the car?

I've got a 3.5" downpipe and I'm looking for 6-800 hp. Would it hurt me much to run it back into the down pipe. It would be easiest to put it back into the downpipe, but if it's gonna cost me a bunch of HP to do it another way.

Thanks,

 

It will cost you HP to run it back to the downpipe, but from an emissions standpoint (which is probably rather moot in your case) it isnt legit. From a sound standpoint, when the wastegate is open it will be extremely loud. After riding in a DSM with one on a 2L motor - I refused to ever dump the WG. I found the volume annoyingly loud, and it sounded like the car was about to blow up. But that's just me. I'd personally say run them together. But then again my car will have some appearance of being emissions compliant.

How much HP will be lost? Hard to say. You will probably loose more HP by the backpressure in your 3.5" exhaust, so I wouldnt worry about it, but then again I'm not out for every HP I can get.

A really good advantage of having the WG dump is it becomes more effective at venting and it makes it harder for the turbo to boost-creep.

 

Any body else have an opinion?

 

Ive never ran one back onto the downpipe , always dump under the car, never really hear any noise, Ive done alot of cars this way.

 

When I had mine dumped to atmosphere on my single setup it was very loud and annoying. I say back into the exhaust

 

thats because in all of yours they dont even have any downpipe to speak of, so the noise of the wastegate is masked by the loud noise from the open DP.

 

Any addition of turbulance to a pipe will reduce flow. Maximum Boost reccomends venting the WG back to the down pipe at the shallowest angle you can get it at, as well as doing it 18 inches or more away from the turbo. SleeperZ28 vented his back to the downpipe pretty close to the turbo and was still able to make 1000+ Hp, so does it really kill performance, no... Just follow the above guidelines and you'll be fine. I too tried venting to atmosphere once and it totally killed the sweet sound of the turbos spooling, it turned it into a really bad annoying ride. You spend enough money for those damn turbo's, ya better be able to hear them!

 

I'm pretty sure I can get the narrow angle, but I'm not sure i can get the 18" Of the downpipe that is. Hearing the turbos more would be much cooler, but I've run an open downpipe off of my old turbo setup and still could hear it fine. I'm just worried about wasting 50 hp in a dumb move since I only have a 3.5" downpipe.

Here's some pics of what I've got. I'd end up splicing it into the first seem after the white connector(its PVC just used to hold the pipes togther, its welded now). Sorry I don't know how to make the pics show up, just the links.

 

anybody else have any comments?