Dave951M

Has anyone tried the supertrap on a 951? What do you think of it?

Sean951

I use a supertrapp. It's tunable, light, rebuildable and sounds great. With the 12 disks and cap on my 3' exhaust it is capable of flowing 400hp. Take the cap off and you have an open pipe that is still packed with a perforated core. It is only loud under full throttle. Cruising is a deep tone with a turbo whine.

Dave951M

Tnx for the response. Which model did you use? I'm seriously considering going that direction on my 951. It looks like a good way to "uncork" it for track days.

booster

Why would you use a Supertrap on a turbo? are they not setup so you can adjust your back pressure and if so why would you want back pressure on a force inducted engine.

Dave951M

All mufflers are restrictive to a point. I am trying to determine if a supertrap with just a couple of disks is about as restrictive as a normal street muffler but still has a good sound. The neat feature of supertraps is the ability to remove the disks and have essentially straight pipes. I've seen them on normally aspirated engines, just wondered about a 951. The original plan was to take a second cat back exhaust pipe, cut it off and make both a "free flow" muffler section and a straight pipe. When track use is on the agenda, change to the straight pipe, use the free flow for street use. A supertrap might be the easiest way to accomplish this.

keith

Hey Dave.

I don't see why you wouldn't just get a straight through muffler and be done with it - It would essentially be the same as the uncorked Supertrapp... - I guess I don't understand why you would want to put the disks in a Supertrapp on a 951, and by that reasoning, why have a Supertrapp at all?

The Ansa OEM replacement is straight-through, and Borla, Magnaflow, etc. all offer a straight-through SS muffler as well (and less weight). The common thinking on the turbo is that you want as little restriction as possible after the turbocharger. I would think that running disks in the Supertrapp would actually inhibit spool-up and perormance...

Your thoughts?

Dave951M

Keith-

The reasoning behind this is that all mufflers are restrictive to some extent. I liked the idea of being able to "adjust" the restriction. The question more accurately put should be how restrictive are the supertraps in the "uncorked" state? After spending some time with Summit tech support and others, I'm thinking the best bet near a straight pipe is the single chamber Flowmaster. I will have to trash the adjustable idea if I get this one. I'm checking into a guy near here who knows how to bend 3in pipe to plumb the entire system, including a "test pipe". One response I got from a "race" shop is that turbos need backpressure. Sure, that holds true for normally aspirated engines but not turbos from any data I've been able to gather.

keith

Dave - the single chamber Flowmaster is not a straight-through design, is it?

booster

I don't know of any performance turbo engine that needs back pressure.

86944turbo

A turbo motor requires an exhaust with the least amount of restriction. Remember the 935 with the flames. Dumped the exhaust right from turbo to atmo. Turbo'd motors do not use scavenged gas to pull exhaust from the combustion chamber. The turbo needs to be of sufficient size and proper calibration to perform this task, along with ideal amount of valve sizing and overlap. I use a very large Flowmaster muffler. In tests on race track that require decibel levels that cannot be attained W/O a muffler, this muffler was used with a negigible difference in lap times. The increase in the lap time could be attributed to the weight of the muffler. Larger mufflers have a tendency of having less restriction, particularly in the case of the Flowmaster (very large open chamber). The cat must die! Adding a free flowing exhaust after the cat, produces more noise than H/P. You are still faced with the bottle neck. The stock cat pretty much ends the party at 350 or so H/P. The exhaust on my vehicle is 3 1/2" stainless, with the front half Jet Hot coated (to prevent the adhesive on the carpet to melt). The car is loud and has a resonance that sets off car alarms more often than a hoard of Harley's. It is not like any other 4 cyl. I've heard.

sprbxr

I just installed a Flowmaster. I noticed a few things:

1. Louder than stock straight through muffler. Not too loud though.

2. Turbo spool up is better than with the stock pipe. I ran the car with a straight pipe and the seat of the pants feel was not much different than with Flowmaster.

3. The Flowmaster is alot light than the stock pipe.

4. The Flowmaster came with a bunch of cool stickers. 8)

Justin
86 951 with a bunch of various parts