Acropora

Bruce, that VES is fantastic. Would like to hook that puppy up to my B&B's sorta like Scott's setup. Maybe have it open only at WOT or via a switch somehow. This one might be activated by a wire? http://www.atpturbo.com/Merchant2/me...egory_Code=BCS
Or maybe bite the bullet and get this http://www.atpturbo.com/Merchant2/me...egory_Code=BCS

Bruce SEA 993

So far I have seen the ATP VES valve but it is 3" DIA. The cable operated valve is from JC WHitney and I am wondering how hard it would be to route the cables from somewhere in the drivers seat to the engine compartment. The other set is electricaly operated and would be a little easier to route the wires.

JC Whitney valves:
http://www.jcwhitney.com/autoparts/P...roup?Ntt=valve

The electric valves:
http://www.quicktimeperformance.com/...ct_detail&p=38

So I am looking at the QTP electric valve with a gasket and a flange on either side bolted together. The flanges will have the halves of the connector pipe already welded to them and then weld the assembly into the muffler. the muffler inlet and outlet pipes will have the corresponding holes cut out of them to feed the exhaust to the bypass.

So basically, it is a LPMM with a valve to vary the loudness.

Just trying to hook up with a buddy in Sacramento as I don't have a welder buddy here in Seattle. Any Rennlisters in the area up for a little fab work?

FisterD

I would be up for helping with the fab work. I am about an hour away from Sac, so that may not help you too much.

Bruce SEA 993

Thanks Fister... I will call if we need help or someone else to hang with. My buddy works at the rocket shop (Aerojet) and so if the tools in his garage are not sufficient, we can always use the "lab".

He is a 928 owner but doen't spend any time on the 928 list...dunno why.

C4S_fan

Bruce: I owe you a reply and apology on this thread... I remember we were going to sync up on this project, but I had a few issues pop up and it completely slipped my mind. I have a friend who I talked who whose interested in helping me out. I've PM'd you my phone number..

K24madness

Thinking this through I believe the best location for the valve would be where the 90 degree bend is after the turbo (sorry NA guys) and go straight into the exhaust TIP. In this case the 3" diameter pipe would be perfect!!!

Ther shortest part from header to tip would be prefered.

brucec59

Digging up this old thread...

Did any of you guys ever do the electric-butterfly-in-bypass-pipe mod? I'm thinking of doing this myself. I really want a better sounding exhaust, but I cannot have a really loud exhaust all the time.

TIA.

Bruce SEA 993

Bruce 59,

I bought the butterfly valve and it was too big to fit. I sent it back (20% restock fee...rats!).

Then I looked again at the LPMM muffler and I welded in a curved bypass in the same place. It turned out great and I realized that it was perfect for use all the time. I thought I would use it at the track and switch back to the stock muffs for everyday use.

There is very little addional noise in the cabin except when you stick your foot in it. With the windows open (as you would be at the track) you can really hear it. I followed my car with my wife driving and I was in her convertable. It sounded great!

Another thing I realized was that for any valve to work the way I wanted it to, which was to be REAL loud with the valve open and quiet with it closed, it would have to shut off the flow to the muffler forcing all of the flow through the bypass. The valve would have to be in the inlet of the muffler rather than in the bypass. Had I fabricated the valve the way I thought I was going to do it, which was in the bypass, I would have been real dissapointed and I would end up running the valve full open all the time.

That is what I know. There are a couple of threads on the mod from about a month ago.

Cheers

Bruce SEA 993

Here is the thread with the sound and videos:

https://rennlist.com/forums/993-forum/285005-gtg-in-seattle-updated-with-sound-and-videos-good-comparo.html

brucec59

Thanks for the info, Bruce. So, you're saying the QTP valve/motor assembly was too big to fit between the inlet and outlet pipes on the muffler? Bummer. I saw the videos in that other thread, and I love the LPMM sound. I'm just not sure I can hang with it all the time. I guess I need to hear some of these in person. Thanks again.

Bruce SEA 993

Yeah, the QTP is way to big...plus, the valve would be open 100% of the time and it would not be that loud.

If there was a way to block the inlet to the muffler rather than putting the valve in the bypass, it might be a lot louder and then the valve idea would work.

Right now I am much happier with the curved LPMM and have no intention to go back. The car is not at all too loud when cruising.

Cheers

Toga

Bruce, my BMW525i has a valve that opens at engine start for about a minute to by pass the cat. I suppose it closes at a certain t°. I checked in my manuals but don't find it on the diagrams. If you're interested, I could ask a BM dealer to see how big it is and if it is electrically operated.