Black51

Alas, most of the rest of us do also, except police!

Voith

I'm interested in that too. Is it worth doing it or not?

Paulyy

sweet, now i dont need to scare people down the road when i give it a little squirt...

toddk911

+1

Although it is not that loud and only at WOT full boost and at that point I am not worried about it. lol

But if the muffler kit gets people to go with wg dump, then that is cool.

Here is mine with windows open:

http://www.youtube.com/watch?v=TRTGqxiUeac

dirtyTurbo

Can you tell about your setup? Mine is much different than that, or maybe its just the video.

toddk911

In terms of exhaust it is just a 3" cat back and flowmaster 40 muffler with wg dump.

dirtyTurbo

Huh. Mine is more night and day with it open and doesn't differ much with throttle position. I'll make a video at some point

Baptizo

I'm somewhat familiar with the concept after having an O2 dump on a 1g DSM - it did help with the mid-top end performance.

I'd love to find out how this setup helps a 951.

pudges951

I have been contemplating dumping the wastegate for the last couple of months, this might just convince me to do it. I do want to know difference in numbers, as well as sound difference.

TurboTommy

The exhaust flow interference caused by the wastegate flow tie-in into the main pipe results in higher pressure before the turbine to operate at the same pressure ratio.
Therefore, get rid of the wastegate flow and you'll have less back pressure on the engine.

alxdgr8

Mike, do you have any audio clips or videos comparing this?
I'm not sure how effective what looks to be a maybe 6-8" long straight-thru glasspack style muffler is going to be at giving a significant dBA reduction over a straight dump.

I like the idea, but it would be nice to know how effective it really is. I would be interested if it really works.

Mike Lindsey

We don't have any video or audio. When we tried re-producing sounds on the web, your volume, speakers, etc... can change the sound, so it seems pointless. It never sounded like it actually sounded.

It's quieter then just dumping open, but not as quite as tying back in. Think in the middle. It would be a similar change in dB that you would get runing a exhaust with and without a muffler. It is a blow through. If you did chambered to be even quieter, then you destroying the preformance you're trying to gain. If you want totally quiet, try ear plugs.

We can do a 18" version versus this 12" but it will require a bracket be welded on the main exhaust pipe for support. This version attaches to stock exhaust hanger mount for support. If someone thinks they would want a 18" version, we will go ahead and build some (take 2-3 days), and put on the web site.

toddk911

Mike: Do you have any data on quicker spool up or over all gains from the dump?

Like TurboTommy said this obvioulsy reduces back pressure which we know is always a good thing, but just curious how much performance is actually gained.

Mike Lindsey

Let's try this from a common sense approach.

We don't know exactly how much of your exhaust (percentage wise) is flowing though the
wastegate versus the primary tube. 10, 15, 20% maybe more? We believe most cars when at WOT (and under boost), your wastegate is probably wide open. If you're running a dump to atmosphere set-up now, you can simply verify that with your own ears. There is no questions that it's open and seems to be the case on any level of build so far we have listened to. We find typically if using a DP WG, that your WG is starting to open once you reach 1/2 the total boost setting with the throttle WOT.

So based on that knowledge, if you're tied back in, you're adding that percentage of exhaust back into
your primary tube. That means you're putting more through the same pipe which is going to increase the
back pressure. So dumping to atmosphere has the same net effect as putting a larger primary tube exhaust system on the car without actually putting a larger primary tube exhaust system on the car.

So a stock exhaust may act like a 3", and a 3" may act like a 3.5", and a 4" might act like a 4.5" etc...
Even a 5" exhaust is going to have back pressure. The more HP (air to move), the more back pressure. And if you dump to atmosphere on the WG with whatever size you have, you improve the flow and reduce back pressure even more.

This product is all about doing something with the sound you get when you do dump to atmosphere which some might not find to their liking.

User 41221

Do you get much in the way of residual exhaust fumes in the car from having it exit directly under the car? Just curious.