legacycentral bbs

So my SS I have now came with a 3" DP and matching exhaust all the way back to a Greddy 4" end pipe/can. It also has an exhaust leak between the downpipe and mid pipe flange. At idle you can hear the gasket fluttering against the metal. When I get on the throttle it's ridiculously raspy and annoying. Sounds like shit, really. Even my wagon with stock open downpipe sounded way better than this.

Do you think fixing that leak will give me both better performance and sound better? I almost just wanna rip the thing off and run open DP again honestly

Thoughts.

I think fixing the leak will help with both. I was in the same situation, and the added (small amount of) back pressure helped with my spool up. Plus I love how a non rattly aftermarket sounds most of the time.

Yes, fixing a bad exhaust flange will definitely improve sound, and possibly even performance.

I am also in favor of ripping it off and going open downpipe, I'm gonna miss mine when I get an exhaust put on this month...

The 4" tip looks so good in the back though, but I also think open DP sounds heavenly. I'll probably unbolt it and see how it sounds and then maybe I'll pull it off. Or maybe I'll go buy the $12 gasket... Lol. I just hate how Honda raspy sounding it can get. I hope the gasket fixes that.

Yes, do the gasket. If its still too loud and you want to keep the 4" tip, put a resonator somewhere in the middle.

Sounds like a good plan, Stephan.

I heard that running open downpipe could cause head gasket failure due to the engine sucking in air with such a short exhaust.. any thoughts about that?

I've heard other things, such as burnt valves and whatnot. None of it specific to Subaru. I figure, with a turbo you've got stock manifolds, plus the back pressure of the turbo, plus the down pipe that's like 4ft long. Its definitely a lot different than running open header on a small block Chevy.

Someone correct me if I'm way off-base.

I don't think anything, other than some eardrums, would be adversely affected running an open downpipe. Even open headers on a n/a engine isn't that bad. No manifolds, on the other hand, is a good way to burn exhaust valves.

Yeah, there's no issues with running an open down pipe.

I agree, if fixing the leak doesn't help, put a resonator in.

So I replaced the DP to midpipe gasket and the leak is still there. I still hear the gasket fluttering. So my next move I guess is to replace the uppipe and downpipe gaskets. Sucks cause it's kind of a pain to do but whatever.

Why don't you put the car on jack stands and try to find where the leak actually is.

I did, but I can't figure out exactly where it is...

An easy trick is to place (or have an assistant place) a shop rag over the tail pipe and look for any place you can see or hear more exhaust forcing its way out.