Did you install a 6" X 14" canister center muffler or a smaller diameter center muffler? Also what muffler did you have at the rear exit?

Trust me this is truly a stock quiet setup but for stock cam and motor setup. I cant comment for non stock stroked or cam'd motor Evo's. But the rattle really sucks. Hopefully the new version is fixed. Also I'm skeptical about the stainless steel grade used. I think its a lower 400 series ss and not a 304 ss.

Best way to describe cruise and idle sound is stock quiet. During acceleration depending on your throttle it will sound stock quiet or similar to a 3" downpipe testpipe with stock catback setup. That's if your accelerating close to 0 vacuum or less than 5 psi area.

But remember I have a high flow cat. But soon I will remove that also and probably put another center muffler.

 

I can't believe a cut-out would yield 30 more whp - I'd guess 10 - 15 at most. Easy way to test since you have one - take a log with your stock exhaust and then take a log with your cutout and use VDR to show you the difference.

 

I already have a couple times in the past...that's where my numbers are coming from. Actually, torque at higher boost was up about 40.

You will get about 15whp simply from replacing a hi flow cat with a test pipe. My cutout is in my downpipe and it is bypassing a hi-flow cat, stock cat-back piping and stock muffler.

 

So if I am understanding you correctly, the TP is worth 15+ whp over the HFC, which would imply the catback at best is worth 15 - 25 whp (over open exhaust - no mufflers / resonators / etc.). Interesting and exactly what I was hoping to find out.

I wonder how a 3" catback compares to an 'open' exhaust ? I can accept a 15 - 25 whp loss, but the idea of losing 40whp due to the exhaust is too much for me to stomach ...

 

Well, it's going to be different on every setup, of course. Peak numbers will vary, but most of your loss will be under the curve. Depending on how much boost you are running and if you are maxing out the turbo, the absolute peak HP numbers may not be that different (for the stock turbo), but the amount of early torque and area under the curve will be.

Let me find some runs that I did. I hate running with my cutout open, so I only saved a couple. I think I have one at lower boost on 93 and one at higher boost on E85, where I got a little induced knock, so it effected the comparison, but you will get the idea.

Higher boost on E85...some knock with cutout open, so that is why the midrange dipped down, but you get the idea:


Lower boost (I think on 93). I have this posted in the VDR thread with screenshots of the LogWorks log as well here.

 

^^ Very informative and just what I was looking for, thank you! I guess if you had just used a test pipe and the stock catback it would have been very close to the cutout - within 10 hp above 6000 rpm.

What turbo and cams are you running ? Thanks again!

 

for you guys running the stock catback... what power differences did you see going back to stock from your 3" catbacks?? i'm considering this muffler if not maybe going back the the stock catback but i will be getting a BBK, cams ported IM and EM and a 65mm TB soon.

 

I don't know about that...the stock catback is pretty restrictive. I don't know how far off you would be with a test pipe and stock cat-back, but I would imagine it would be somewhere in the 20whp on stock turbo. Removing two restrictive parts in an exhaust isn't necessarily going to have an additive effect.

I am running the stock turbo and old gsc 272/264 cams (the original GSC cams from way back).

 

Just got my VT in the mail today from Jeg's. I poked at the valve to see if I heard any obvious potential for rattling and I couldn't see that. I guess I'll just have to try it and see. I took a picture with my phone of the valve. Does this match what others have seen for tolerances and design? There's a rope-like edge to the flapper that would seem to be designed to keep it quiet? I guess now that I look, that same feature is in the initial pictures in this thread.



As far as a sound clip, due to demand I'll be setting up a pay site with before and after clips

 

looks the same as mine does. there is a surprising amount of drag on the valve. doesn't feel like an idle could open it.



jeggs told me yesterday that they don't expect the corrected mufflers until 6/22nd.
i'm going to talk again the manufacturer Monday to see what can be done, I had the muffler welded on, and if I send it back I'm basically mufflerless for ten days or so.

 

Got mine in. I bend the flapper a bit so it didn't contact the inside of the muffler. Bad move. it still rattles and is probably louder because of it. Either way I'll be returning it when the time comes because it rattles like CRAZY. Still real quiet. My camera can't really pick up the sound. Tried a vid. Didn't work.

 

I can't believe Jegs is knowingly continuing to sell defective mufflers. When I ordered, I assumed that they would only be shipping the redesigned ones. If they aren't going to get those until 6/22 and the one I got is one of the original ones, then I'm going to expect them to do an exchange and bear the return shipping costs. It doesn't even seem worth it to try to install it now with this version.

 

Okay, slipped it on (it's a very easy swap on a Buschur catback) and fired up the car. It was obvious as soon as the motor started to idle that this was a definite no-go. It clacked extremely loudly. Think of a motor with horrendous rod knock. That's what this sounded like, except coming from the rear of the car. Definitely not a livable noise at all. Keep in mind my car has big cams and a high idle, though any level of that sound would drive me nuts. Hope the new, improved model solves it.

 

Mine isn't that bad. We should have compared them.....

 

What cams do you have and at what RPM do you idle? My car has a very strong pulsing at idle, even at 1200 rpm.