Quieter (<93db) track muffler options for header/single hi-flow cat
 

I have JRSC + EL Tomei header (catless) + Invidia front pipe with one high flow cat + Invidia Q300 = well within sound limits of any track. Starting to hear a little rasp and I know that it's only a question of time until muffler packing is gone. Will keep the header/op/catted fp.

Q300 lasted 22 track (HPDE) + 8 ax days without a significant change in sound, except after initial break-in. Let's say 2hrs/track day + 1hr/ax day comes out to >50hrs of hard high rpm driving. Also 10-15k street miles. Even now, the rasp is not loud and only comes up when getting on power around 3-4k rpm, then disappears or gets overpowered by other sounds - engine, tires, wind.

Few notes:
- Larger cans such as stock or q300 help with aero.
- It's OK to save weight but not critical.
- Dual or single exit is ok but would prefer dual.
- Don't mind putting on silencers for tracks with sound restrictions if that makes them well under 93db at high rpm wot.
- Know that published db numbers may not mean much as it's all about how it's measured. I have seen cars with loud exhaust redirect the exhaust pipe slightly to stay within sound limits because of where the track measures from.
- Wouldn't mind buying another q300 every 1-2 years but would appreciate a little more character from the exhaust note, just not too loud.

Keeping an eye on the ACE muffler that's in the works, thanks @CSG Mike for heads-up.

What tail end are you using on track with aftermarket headers and at most one high flow cat that isn't too loud or that can be made quieter with silencers for tracks with sound restrictions?

Responses:
- Q300 (one of the quietest, lasted 20+ track days until it got some rasp - good cost/benefit ratio)
- TRD (not good as it blows packing fast on track)
- JDL (should work)
- Fujitsubo Authorize R (should work)
- Blitz Nur-Spec VS (should work, OP ordered this to try next)
- Perring 2.5 resonated (should work, louder than Q300)
- ACE (should work, baffled/not muffled, in development)
- Other?

I changed my catback for the same reason, and gave a TRD a shot because it was cheap (used) and in good shape (previous owner had a stock car and babied the car a lot, no track time).

At first the car was very quiet, I would say around the 90db. I did feel a slight loss in power, probably due to the fact that the car was tuned with a 2.5" full exhaust and now it has a catback that barely makes it to 2". After 2 track days, the car is louder, probably all of the packing is done for and Im affraid I wont pass the sound check at Calabogie in a few months.

So in all, even tho many people say its very quiet and has a nice sound (which it does), stay away from the TRD, you will run into the same problem as with the q300 and probably lose some power as well.

JDL may be a good option

Thanks, have you used or heard this JDL muffler - any comments on sound, ideally with EL headers and single hi flow fp cat?
https://jdlautodesign.net/shop/ft86-dual-exit-exhaust/

Not cheap (that's ok, just sayin'), heard others comment on good JDL quality (header materials/weld), no information on loudness (db) and no silencer option on a custom tip design. Would much appreciate more feedback.

I'll have the setup you're mentioning soon. They're in the process of building my exhaust atm.

Fujitsubo Authorize R - no issues
Blitz Nur-Spec VSR - no issues

-alex

I have a full JDL 3" (ultra quiet over-frontpipe and resonated mid-back) with a Nameless header (EL catless) and it's a touch brash WOT but not really raspy. Quiets down a lot around town and part throttle.

Not the best driving but the only video I have with sound so far...

https://youtu.be/PWg-_jNCSjs

Can't speak about the exhaust systems but my JDL header is magnificent, one of the most beautiful, best crafted piece on the car... too bad you can hardly see it most times. Quality from JDL is top notch.

My Q300 also got loud. I will cut out the round resonator in the midpipe that came with the Q300 and replace it with the 18" Flowmaster Super HP-2 muffler http://www.flowmastermufflers.com/?page_id=11167


I'm also adding Magnaflow 14156 Race resonator ( https://www.magnaflow.com/products?partNumber=14156 ) in series with the Flowmaster.


I wanted two different types of mufflers to cancel out different frequencies. The whole setup is 12.8 lbs, but you deduct the weight of the resonator that will be removed.

It looks like there are several options at $900+. I am currently looking at the proven Invidia Q300 vs ~$100 more for the Nur-Spec VS.

Factors impacting decision:
- $$$ - mufflers with stuffing have limited lifespan since stuffing burns out with track use, so expect to replace every 1-2 years max to maintain <93db
- aero-friendly design
- no ETA on the ACE baffled muffler
- lack of re-packable muffler options (used to have one made by BOE on Lotus Elise)

I'll probably order one of the two and swap when enough stuffing gets blown out of my current Q300 for the rasp to become loud.
I may also look for a muffler shop to cut open my old Q300 and repack it. Wish I knew what Q300 looked like from the inside, to tell the muffler shop where to cut.

If money is no issue, I would do the Burns 2-Stage muffler in a heartbeat. Re-packable and lightweight. I considered doing that, but can't justify the price for a daily driver.


http://www.burnsstainless.com/2-stage.aspx




Not instead of the Q300, but in addition. You can move the existing resonator in the midpipe or get rid of it alltogether.

Brilliant, thank you. I wish somebody would sell it, will ask around for custom work. Would be well worth it for me to have a re-packable muffler for track.

That's an insane price. On all the older cars I used to play with where a nice exhaust = a custom exhaust, I always used "Thermal Research and Development" mufflers.

How do you pull them apart to repack them? How much will that add to price to have a couple of Vbands on both sides? etc

A quality muffler is going to take thousands of track miles to fall apart. I bet in the time it'd take you to replace one, even 2, TR&D muffler, you'll still be money ahead and will have likely moved on to a different car.

Re-pack is $35 http://www.burnsstainless.com/sm-repack-3.aspx


Or you can get different repacking options like the Bristol Core http://www.bristolcore.com/product_p/14415.htm


The outer shell on the Burns muffler is fixed with 3 small hex bolts. You remove those and the outer shell slides off, exposing the packing. That's how you replace it. I had it on my CRX years back and IIRC you weld the front part to the 2.5' piping and the rear part is a slip fit designed to over 2.5" pipe.


Burns Stainless is $$$, but they are also extremely well built and most importantly, they work very well for their versatility, size and weight. Here's an article from Grassroots Motorsports testing them out https://grassrootsmotorsports.com/ar.../sounding-off/