Wastegate came in the mail today. It's from an 87 audi 5000. For those of you that don't know, these cars came with external wastegates that are pretty high quality. I just measured the valve and it's about 1 1/8" with the flange insert. I think the actual valve is about 1 1/4" across. Now I just have to modify the backing plate on my S4 turbo. I'll be venting to atmosphere for that scare the neighbors effect. Best part, it was only $50.00 shipped to my door.

 

so its about a 30mm wastegate? hmm..what kind of manifold are you going with? custom tubular?

 

:-o sounds nice

 

I got one for free .

I'm just going to get a TiAl 40mm I think . Might as well do it right the 1st time . Though the Audi gate is nice you can't repalce the spring and whatnot as you can with say a TiAl , or Deltagate .

 

So you going to mount this on the back of the turbo? Then you'll still need to port the hell out of the stock wastegate port to get any improvement. Since a ported S4 wastegate with a larger flap has been proven to control boost, a small external wastegate may be a lot of work for little gain. Just a thought.

 

yeah you'll actually have to fab a manifold (or try and modify the existing one...hah) to put the wastegate on there. putting it on the backing plate is like enlarging the space AFTER the bottleneck, when its the bottleneck that needs to be widened.

 

Yeah, port the stock hole as big as I can make it, weld that divider plate in like a thread awhile back and come up with some kind of route for the pipes. I have a boat manifold shop in cleveland that can work with cast iron, so it shouldn't be much of a problem. When I go to a 60-1 I'll make my own manifold and run two of em. 30mm on each runner should be plenty and all for $100.00. Oh and I think the stock spring in those gates is 7 psi. But I have a boost controller, so it doesn't really matter...I can set it as high as I want.