Burns, Spintech, Coast Fab, Flowmaster, Borla, or ?????? Laguna Seca Sound

[Payne]

I'm planning to finally drop my Atom off at Six Sigma Racing next week to get a header fabbed. I'm trying to figure out options to make her quiet enough to make sound - 92dB

I'm thinking that I'll run one large muffler where the stock muffler is now, then if I need it, a second muffler down the driver side outside the chassis with a turndown toward the driver (and away from the sound measuring booth on the pass side).

I'm a bit overwhelmed with all my different options. Does anyone have any good, solid feedback about the reliability or power of any of the options?

I'll be a 3" exhaust with about 300rwhp, and spinning to about 9k RPM.

JP

[MadMaxAtom]

I am running a 3" inlet mini Supertrapp muffler with 24 discs and pass sound under 98db. with no power loss. When I run at "quiet" tracks, I remove 12 plates and have passed 91db..with minumal power loss. My main muffler is a stainless 3" inlet/outlet Magnaflow Turbo series. I welded the Supertrapp to the turned down 3" tailpipe from the Magnaflow. This exact exhaust setup was on Max when it made 300+whp,so it is capable of supporting higher HP. Before the Supertrapp,the Magnaflow alone was well north of 110db.



SuperTrapp 544-3003 - SuperTrapp Diffuser Disc Packs - Overview - SummitRacing.com

[Payne]

I am running a 3" inlet mini Supertrapp muffler with 24 discs and pass sound under 98db. with no power loss. When I run at "quiet" tracks, I remove 12 plates and have passed 91db..with minumal power loss. My main muffler is a stainless 3" inlet/outlet Magnaflow Turbo series. I welded the Supertrapp to the turned down 3" tailpipe from the Magnaflow. This exact exhaust setup was on Max when it made 300+whp,so it is capable of supporting higher HP. Before the Supertrapp,the Magnaflow alone was well north of 110db.



SuperTrapp 544-3003 - SuperTrapp Diffuser Disc Packs - Overview - SummitRacing.com

Thanks! That's exactly the feedback I'm looking for. Any idea what sort of power loss you saw from 110db to 98db to 91db with that setup? IE are you leaving 2, 5, 10% on the table? How's it sound?

I'm considering a spintech used for dirt track racing with a supertrapp on the end: Super Stock 1000XP Race Muffler - Mufflers - Race Mufflers - Super Stock 1000XP Series - SpinTech Performance Mufflers

I think it should flow well above what I need for 300rwhp, but I don't know a lot about fluid dynamics, back pressure, etc, etc.

JP

[MadMaxAtom]

When I had Max at the dyno shop,we tuned for 300whp with the 24 discs in place. We then removed all the discs;there was NO change in power...actually about 1whp less..but lots more sound. We then installed 12 discs and the power curve and peak moved down about 600rpms,and the peak lost about 3whp. However,the noise db came down lower than 91db..so well worth it for "quiet" tracks. The muffler you chose is very similar to the Magnaflow chambered unit I am using,so your results should be similar. I have tried a lot of different solutions for noise control,and so far,this has been the perfect adjustable solution. With this exhaust system on Doc, (220whp stage "3" brammo tune) there is almost no difference in lap times between 24 discs and 12. Matter of fact,I usually keep the 12 disc pack in as it really makes the blower whine sound mighty sweet! The overall exhaust note is unique,but NOT annoying like a spec Miata..or rotary powered car.

[Payne]

When I had Max at the dyno shop,we tuned for 300whp with the 24 discs in place. We then removed all the discs;there was NO change in power...actually about 1whp less..but lots more sound. We then installed 12 discs and the power curve and peak moved down about 600rpms,and the peak lost about 3whp. However,the noise db came down lower than 91db..so well worth it for "quiet" tracks. The muffler you chose is very similar to the Magnaflow chambered unit I am using,so your results should be similar. I have tried a lot of different solutions for noise control,and so far,this has been the perfect adjustable solution. With this exhaust system on Doc, (220whp stage "3" brammo tune) there is almost no difference in lap times between 24 discs and 12. Matter of fact,I usually keep the 12 disc pack in as it really makes the blower whine sound mighty sweet! The overall exhaust note is unique,but NOT annoying like a spec Miata..or rotary powered car.

That's the exact info I needed to know. I have a supertrapp on the way from Amazon - $80 shipped, will be here Friday.

Now I just need to figure out an airbox solution to drop the intake below 100 dB...


PM me you're paypal and I'll (virtually) buy you a beer

[MadMaxAtom]

Thanks..just a donate to this site would be fine..

[Richard Buckingham]

I have a 2012 SRA which I want to take to Laguna Seca eventually too (I cancelled my trip this year when I found out it would not pass sound, SRA makes over 100db apparently.

SRA comes with a different muffler than the Atom 3, do you guys think I could use a similar simple bolt-on solution for my Laguna days? Before finding out about this I was going to replace my entire muffler with the Atom3 one to try and make sound (once TMI could figure out how to make that happen that is.)

[Payne]

I have a 2012 SRA which I want to take to Laguna Seca eventually too (I cancelled my trip this year when I found out it would not pass sound, SRA makes over 100db apparently.

SRA comes with a different muffler than the Atom 3, do you guys think I could use a similar simple bolt-on solution for my Laguna days? Before finding out about this I was going to replace my entire muffler with the Atom3 one to try and make sound (once TMI could figure out how to make that happen that is.)

You could do it for sure, but the car would run super rich (less airflow, same fuel) - better than running lean, but not good for sure. Where are you in CA? There are few good shops in socal and norcal that I could recommend to do a muffler and do a tune for the different setup - assuming that TMI doesn't lock down their Hondata tunes, it's super easy to switch between tunes with a usb cable and free software.

(I'll have at least 2 tunes - the low dB and high dB tune, and maybe an e85 tune)

JP

[Richard Buckingham]

You could do it for sure, but the car would run super rich (less airflow, same fuel) - better than running lean, but not good for sure. Where are you in CA?

I'm in LA (in Venice but I keep my car in Van Nuys.)

FYI: I talked to Shinoo at Sector111 he said they tried the Supertrapps at Laguna Seca and they damaged a couple of Atoms exhausts due to high back pressure.

[Norm]

The cars and systems that Shinoo was referring to were Eco's and seem to just produce more heat than the Honda's.