Custom Race Exhaust Advice
#1
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Thread Starter
Custom Race Exhaust Advice
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!
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!
#2
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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).
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).
#3
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iTrader: (25)
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
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
#5
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iTrader: (25)
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.
#7
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Thread Starter
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.
A turndown will be a last resort as I'm personally not a fan of how it looks.
#11
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iTrader: (25)
... 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
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
#14
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Thread Starter
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.
#15
Mr. Örange
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 ![Smilie](https://www.rx8club.com/images/smilies/smile.gif)
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
![Smilie](https://www.rx8club.com/images/smilies/smile.gif)
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
Last edited by TANKERG; 10-14-2013 at 08:27 AM.
#16
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iTrader: (25)
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.
#20
BECAUSE RACECAR
iTrader: (10)
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.
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.
#21
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Thread Starter
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...
#24
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.
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.