I'm trying to figure out how I'm going to do the exhaust on my car. I'm assuming that running a completely open exhaust will be too loud for my track's 98db limit, so I've looked into these race mufflers: Flowmaster Race mufflers, silencers, and exhaust race accessories

Does anyone have any experience running a single race muffler similar to #15430S or #15430 ?? Are these generally quiet, or do they have minimal effect at reducing noise?

Any help is appreciated!

 

Although I haven't experienced it myself, most everyone agrees that one muffler isn't enough.

I have two Coast Fab mufflers (one right after the header collector, one at the tail) and they do a good job keeping the noise at a good level (NOTE: I haven't measured noise level).

 

The Flowmaster mufflers don't do that great of a job on a rotary.

Start with a spiral-flow style in the resonator position, either Moroso SS or the BHR version. Supposedly the BHR one is more rugged. Haven't run that one myself. Then see how much more you may need in the back from there

 

Thanks guys, I appreciate the advice! I will post pics of progress in the next couple weeks.

 

Should have stated that I have a resonator muffler in the front with it split at the back with two smaller dual mufflers/tips Originally were all Coast Fab mufflers, but I replaced the big resonator one with a spiral flow type and saw an impressive change in sound readings. Currently working on trying to delete the dual rear mufflers for a few more pounds of weight savings.

 

point the tips downwards as well.

 

The plan is to have it remain as a single exit 3" exhaust all the way out to the passenger side. I ordered a Moroso SS muffler (part # 94055) to get the ball rolling and intend to put it right after the header. While I know I'll likely need a 2nd muffler, I figure I'll build it with 1 for now for maximum weight savings, and can easily add a 2nd muffler at the rear if it ends up testing above 98db next season.

A turndown will be a last resort as I'm personally not a fan of how it looks.

 

 

To each their own... not my cup of tea

 

Greddy ti-c is great option lightweight and sounds good

 

... having a facepalm moment here ....

Turndowns never seemed to make much difference for me, not sure why not

I originally split mine at the back to have more muffler volume capacity. It's all 20 Ga T321 piping so the weight difference is more in the extra muffler than piping

 

Or have the pipes turned in toward the infield away from the mics. That will help a lot!

 

92db

 

My main motivation for this exhaust is the weight savings, and the issue with saving weight in the exhaust is still remaining quiet enough for the tracks I run at. The racing beat race exhaust at 25.5lbs is far too heavy for what I would like to run.

 

Here's what I saw at Laguna Seca. The Goodies company is in San Jose and the make the tips to put on your exhsust. Give them a call to find out what kind of noise reduction you can expext. The day I drove there, the limit was 92 db, so I'm sure they could help you or at least give you some suggestions


Here's the Goodies website:

http://goodies-speedshop.com/


Here's an example from the gotbluemilk photographer:

http://www.gotbluemilk.com/web130825...s/image12.html

 

my entire exhaust system; custom manifold, custom midpipe with 6# race cat & center resonator, and custom split dual rear mufflers/tips weighs less than the OE rear muffler assembly. The cat goes bye-bye for 2014, and if I can get away with deleting the rear mufflers sprinkled with a dose of ingenuity, the entire system engine port to rear bumper should be below 30#. You can't get anywhere close to that with off the shelf components.

 

I sometimes run no mufflers at all. Just header to a 3" exhaust out the back of the car. Very loud. Certainly over 100db. But it's super light!

 

I've been down high 80s low 90s dbA @ 100 ft with straight tips out the shrouds, sometimes lower, sound is not an exact science due to all the variables


.

 

that certainly makes a difference,


edited, now that I think about it, the tips I tried were only 45 deg down, not 90 deg


.

 

Try to point the tip away from the sound meter.

Awhile back I tried to pass a sound test at a local track here with a 94dB limit. I had AEM Intake, OEM exhaust manifold, Agency Power dual resonated test pipe and Espilir catback which was 2.5" that split to 2.25" with two glasspack type mufflers and I blew the sound meter at 99dB at 50ft.

The crazy thing to me was that at 7000RPM going past the sound meter, it was 88dB, 8000RPM was 93dB and 9000RPM was 99dB.

Now I have a Racing Beat header, Racing Beat straight midpipe and HKS Hi-Power single exit and it's a shitload louder. I just don't go to that track with the 8, I co-drive my dad's Miata there.

The only thing you'll find out is that every track is different due to how sound bounces off of stuff, how far the meter is away from you, what type of meter they use, how dense the air is etc etc, so you just won't know until you try.

 

The only track that remotely comes close to enforcing sound rules in the Toronto area is Canadian Tire Motorsport Park (formerly Mosport). Trial and error will be in order for the spring I suppose...

 

I feel sorry for you guys with noise restrictions when the F1's come to melb you can hear them from miles away!

 

forgot to mention that intake noise plays into your overall sound reading too, it contributes more than you'd think

 

burns stainless 17" muffler is 3.3 lbs according the last email I got from them. Run two of them and some thin wall tubing and you're golden.

Play with titanium or aluminum if you're into experimenting. Vibrant makes aluminum mufflers. Just make sure to keep the aluminum downstream as it gets HOT.

 

TI should be able to take the heat but i would not mess around with aluminum at all. The burns stuff is Very nice.

Team has some good input on this subject. A proper built low noise set up that is lightweight is going to be more money then you would guess.