I just read the article in this months magazine comparing Burns and Supertrapp mufflers. I was thinking there may be a real advantage of using the Supertrapp as far as adding discs for track use then removing discs for street use for a car used both places. This would seem to be easier then changing mufflers. The Supertrapp seems somewhat expensive but probably not compared to having two systems. Engine I will be using is a 3.4 liter V-6 What has been others experiences.
My opinion is that the SuperTrapp makes promises it doesn't keep. On paper it looks great: tunable, compact, stainless, rebuildable... but in practice it seems to have pulled off the engineering feat of being restrictive AND loud.
At Laguna Seca they have a very restrictive 92 dB limit. My mid-engine Mini with its 2.2 liter Honda barely passed that with only three baffles in. Of course if you add up the cross-sectional area of three baffles, it meant that the car was breathing through a soda straw. Oh, and the huge back pressur pushed the end cap out of the housing, not to mention that the bolts retaining the end cap extend into the interior, guaranteeing that they'll bind up and snap off.
Yeah, that's my take on them... will never use another.
Just get a quality, high-flowing fairly quiet muffler like a spintech prostreet & call it a day...
Supertrapps were designed back in the 1970's. The first ones had a long J bolt and a cap to hold the discs in place, you can still buy that exact unit as a universal muffler. Like this:
The only real change they have made is the bolts around the perimeter and those bolts will seize in a skinny minute.
Had three on dirt bikes, with enough discs to make decent top end power they make ear bleeding noise. Take out enough discs to shut it up, everything's corked off, might as well run a turbo muffler. On top of that, they spooge the fender and/or body exhaust cutout with exhaust carbon. Nope, no more.
David Vizard did a pretty extensive db/power test on supertrapps (How to tune BL's A-series Engine)- basically came to the conclusion that they are crap. Buy a good "turbo" style muffler and get better power with less noise on the street and the track.
I don't know from a power perspective, but i've NEVER heard a supertrapp sound good, and they're all loud as berkeley unless you stuff them.
There's a miata locally with a supertrap, and it is the MOST god-awful racket i've ever heard.
Stainless? really. Every one I have ever used here int he rust belt was rusted. The little nuts and bolts are useless. Just get a good free flow muffler. Size your pipes and muffler to the motor. There was a long discussion about this quite some time back. I experimented with cherry bombs on a 4age and found any larger then 2 1/4" and it got really loud.
I liked the sound on my old SHO. The bolts vibrate loose...that was a PITA. As far as flow vs not-flow the car dyno'd 5 to the wheels higher with just the trapps swapped for the stockers, in street mode (4 baffles IIRC). Car was a bit more quiet than a fellow SHO club members ride with flowmasters in the 4 disc config.
The only part that made it all strange was the Yamaha V6...they just sound odd. That said, a ton of folks loved the sound and an equal amount hated it.
I used to be an engineer for a sister company to Supertrapp, and they sponsored my autocross car. I dyno tuned my car on their chassis dyno. It was a stock class '89 Civic si. Up until the time I had the supertrapp system installed, the car still had a stock exhaust on it. Adding a mandrel bent, 2" exhaust and ST muffler resulted in a gain of 2hp. Subsequent tuning of the ST muffler added another 6hp. I don't have any bias towards ST, as the current owners screwed me over and they didn't develop the technology, but I don't know of any other system that can add 8hp and reduce weight as much as that system did on my car. Just food for thought.
Did you test against other brands/styles?
No we didn't.
Teh E36 M3 wrote: Did you test against other brands/styles?
I didn't either, but my point was that it made HP on a Stock '89 SHO 3.0 motor. They're well known for breathing well from the factory. The Fella with it on his 2.2 liter may have had a bad unit construction-wise, but I don't think it was the back pressure caused by a 2.2 that moved that endbell out.
Interesting comments?! SuperTrapp Industries, we will have been in business for 40 years next year, we didn't get that far by making something that didn't work when applied to the proper application, just as well-we have also come a long way and learned a lot and improved a lot over the years.
Although we are predominantly motorcycle related, we do a substantial amount of business in automotive applications. Please, if you have questions, make a posting on our forum, or send us an email or call. We have done a lot of different applications, but if it is something we have not done or seen, we'll be honest enough to tell you that also.
KB58-you didn't have enough discs on there to flow, creating the large amount of back pressure. It also appears that in the photo, the disc screws are way overtightened. Comparatively-I run 8 discs on my daily driver Caprice with 305.
Tozovr-thank you for your honest observations.
Bravenrace-also-thanks for your honest observations-regardless of history (we've all had those!). I also, ran a Stainless Superlight on my 91 Civic with great results.
Thanks,
Jeff-SuperTrapp Industries.
Thanks for your comments, Jeff.
KB58 mentioned that three discs was the only way he could meet the 92dB sound limit.
I stand by my less than stellar experiences with the motorcycle SuperTrapps I have owned.
FWIW, I have had similar experiences with Flowmasters: way too loud for the HP increase. I realize there is no perfect solution to the issue of exhaust noise, everything's a tradeoff. But in this age of the ever shrinking pool of autocross venues and ever tightening OHV noise regulations, sometimes sacrifices must be made. So far, in my current situation (NA13B rotary), the DynoMax has been the best compromise between HP and sound.
Am I the only one who finds it odd that someone from Supertrapp would use the word backpressure?
i put a 3.5'' inlet (massive discs) supertrapp on the back on my civic (didnt feel like building a new exhaust...got sick of the LOUD turbo exhaust on the car when i took the turbo off), and it works...i think.
quieted it down quite a lot, and it looks hilarious hanging off the back of the car.
i love the looks it gets when i pull through the pits, or while parked in grid for track events.
i'm leaving it when i put the turbo back on..just adding more discs.
I have no dyno results (neither real or butt-dyno). The system seems simple and effective enough. I simply love the sound they produce on my bmw 3.2L m-coupe.
I've got one with 8 disc on my ST civic and it works great. I'm at 94db's which is perfect for auto-x and it makes pretty decent power.
I do wear ear plugs if driving it for more then 20minutes at a time though 
But it does sounds berkeleying wicked at full song
To expand on mycommnet since we have the eyes of the Mfg. For racing we always found that the units rusted. The nuts would back off causing non scheduled pit stops and with a 4age you had to reduce the number of plates t so few that it was being choked off.
Now my disclaimer.
the 4age is very sensitive to pipe diameter from the header to the muffler. As stated above anything above 2 1/2 and it made ears bleed. below 2" and you start to loose the high end 2 1/4 was a good compromise
Since this was in a 4age in a MR2 the exhaust system was very short. Header to about 12 inches of pipe and then the muffler. This setup was very sensitive to small changes. Probably not a fair test of a supertrapp. My situation is not a typical installation where you have 5-6 feet of pipe with bends in it.
I was doing alot of enduro type racing with scca 4,6 12 and 24 hour events. Under the conditions that we had the units mounted to the 4age they would literally shake them self apart. The answer was to finally get the db set correct and once past tech weld the units together. This solved the problem of trying to deal with little hot nuts bolts and plates. Add in a pair of gloves and the exercise could really get you steaming mad at the design of the supertrapp.
So in fairness to supertrapp My application was not typical. The issues with rusted nuts and the things coming loose and falling apart on the track could also have been a result of a very short exhaust system. Virtually all the vibration and lots of heat from the motor was transmitted to the supertrapp. For all intensive purposes we had the unit mounted directly to the collector flange with a short piece of pipe to extend it to the rear bumper.
If they could come up with a better way to deal with the plates and the spacers and the small nuts and washers. Keep them from rusting, keep them from backing off I would give them another try. The idea of a large central locking nut with studs that align the plates I think would be much better but probably more expensive.
I love the look and sound of the units for the street / autocross and sprint racing they probably are great. My specific application they were less than stellar. If supertrapp could eliminate the little pieces and make the assembly more idiot proof (yes I can be an idiot) they would have a much better product.
JTW wrote: ... KB58-you didn't have enough discs on there to flow, creating the large amount of back pressure. It also appears that in the photo, the disc screws are way overtightened. Comparatively-I run 8 discs on my daily driver Caprice with 305....
That's correct, absolutely agreed that there aren't enough discs on there to flow... yet Laguna Seca would have kicked me out had I added one more disc.
About the disc screws... with safety-wired bolts (the ones that hadn't frozen and snapped off the heads) there was no reason to make them tighter than barely snug. Regarding the bolts that broke, the threads did have the SuperTrapp-recommended antiseize, but due to the muffler design that exposes the threads directly to hot exhaust gas, it's all but guaranteed they'll bind up - and they did.
About your daily driven Caprice and its 8 discs... what dB level does it emit? On racetracks that can be a real showstopper, not like on the street where you can let off.
dean1484 wrote: If they could come up with a better way to deal with the plates and the spacers and the small nuts and washers. Keep them from rusting, keep them from backing off I would give them another try. The idea of a large central locking nut with studs that align the plates I think would be much better but probably more expensive.
Buy the stainless unit and safety-wire the bolts, it's the only way to keep it from disassembling itself, but then binding will cause them to break when removed, so...
As you and others have already pointed out, the proper design would be a single central stud in order to keep the threads away from the hot internal exhaust gases, and either safety-wire the nut or use a all-metal self-locking type.
Jensenman, those old 3M steel dirt bike mufflers were loud, they just don't have enough volume internally to absorb sound-agree with you there. As also stated by a few others, the much larger SC Elite mufflers with substantially more internal volume absorb sound much better. Volume dictates a mufflers ability to absorb sound, bigger the muffler, lower the sound. Dean, did you have the 'Disc Only' units? Those as kb stated, are not stainless and prone to rusting, especially when high heat is applied-burn the paint right off, left with bare metal that has been subject to the acidic nature of exhasut gasses? On the Civic I had the Stainless Superlight, which utilizes the 4" discs, inside of a large diameter muffler body, but they are failrly short and have a small volume, short core. I used 10 discs on that, idle was good, it was on the loud side-when you got on it. The Caprice; stock 305 rated at a whopping 170HP, using a 24" long SC Elite with 8 discs (no Cat) at idle is about the same as stock, WOT it is still pretty quiet. On this muffler, I have played with the number of discs/closed end cap vs. open end cap (emmission testing) and when initially assembled I used liberal amounts of the anti seize in the threads of the muffler (not on the threads of the screws) and have not had a problem with the screws galling. However, I do only use 3 screws and upon changing disc configurations have probably used different holes at different times? Shouldn't really matter as not using a hole only leaves it open and prone to the damaging effects of the exhaust gasses? Current configuration has been on for just over 10K, overall about 15K. The Civic I put about 25K on, never touched it after installation. Sold the car, new owner took it apart and changed to fewer discs-no problems. It would be nice to have a simpler center bolt installation that still looked good however, just to make it easier to alter, 6 screws can be time consuming (why I only use 3). Track sound testing and the street are completely different as kb stated in one of the last post, you can back off the throttle on the street as you go by Mr. Johnny Law, but if you back off on the track-you loose!?
I've got one on the CRX. It passes sound and the car is fast. Works for me...
Tranks for all the information and opinions, give me a lot to think about.
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