External wastegate muffling

[Pyro15D]

I did a search on this forum and SF and I haven't found an answer. Is there an exhaust system that takes the external wastegate and reroutes it back into the exhaust system, or is that a custom fabricated sort of deal? I would like to convert my 7m to run a t4 v-band turbo, but the only thing that is holding me back is the fact that the external wastegate just vents to the atmosphere. I don't want car to get really loud when the wastegate opens, but I do recognize the benefits that running a t4 v-band turbo gives. I think I have heard of people adding little mufflers onto the wastegate, but I would prefer to run it back through the exhaust if I could.

 

[Albert]

Yeah run it back into the exhaust. Custom fab ordeal

 

[Pyro15D]

Damn. I guess I need to get a welder. Someone could stand to make a few bucks if they made a downpipe that was built with an external wastegate in mind. I'd sure buy that! I guess it would be a bit more difficult with all the external wastegate positions and such though. Maybe if you made the header and downpipe a matched set...

 

[mark1987supra]

Well the issue is that
1. Not to many companies make a full bolt T4 setup for a 7M.
2. With that being said to get a setup with V-band DP to match up with whatever turbo you choose. (Exhaust turbines vary in size) Vary on what turbo you decide to go with.
3. Depending on turbo size you WG able to bleed off enough pressure and fast enough to be controllable.(IE 1 60mm WG or 2 40mm WG's for a big turbo or 40 or 50 for a small to medium sized turbo)
4. To match the above 3 together you basically need a custom setup, or to talk to the manufacturer for a custom setup based off of their off the shelf units.

 

[SC61 MK3]

Any decent exhaust shop should be able to do it. Just get everything installed and drive it over. Should only need the wastegate flange and they can make the bend for you

 

[Insidious Surmiser]

when I switch to a T4 I'm planning on getting a small borla muffler for the WG dump tube. Don't really care to re-circulate.

BTW I did have mine recirculated once before.... and the shop did an atrocious job. Absolutely killed the power the car was making.

 

[Poodles]

Not just any muffler shop can work with stainless (properly to where the weld won't rust)

 

[Insidious Surmiser]

good to know

 

[Pyro15D]

Well I might just have to go with the extra muffler then. You brought up something else I never even thought of. I didn't know you had to size waste gates for the turbo application. Yet more things I need to think about...

 

[mark1987supra]

To small of a wastegate can cause boost creep due to not being able to bleed off enough exhaust pressure to retain a set boost pressure.

 

[Pyro15D]

That makes sense. What happens with too big of a waste gate then? Doss the boost fluctuate because it bleeds off too much or something?