Loud Miata

[Matt93SE]

I use a single one of these on my 240SX with 2.5" pipe from the header back:
http://www.summitracing.com/parts/MOR-94050/

It's not as loud as the SM guys, and I get a lot of compliments on how the car sounds vs. the rest of the stuff out there. I don't know what it sounds like outside the car (since I'm always driving), but it sounds like a throaty SM to me from the inside.
I'm also usually 3-5dB quieter than the SM guys when I look at sound reading charts. 88-90dB when they're 91-95.

[jimalley]

Thanks everyone for the input and suggestions. I installed an Ultra Flo on the car tonight and I am very happy with the results

The sound control personnel will be happy as well:026:

[StephenB]

Thread hijack Figured I wouldn't start an entire new thread for an exhaust question related to sound...

I am contemplating between the Borla XR-1 oval or Round muffler. I am not sure why they make both styles. For fitment? Is one louder than the other? I don't think that one performs better than the other... this is according to them anyway.

Any experience or advice is appreciated!
Stephen

For reference you can go to the summit website above and plug in the following part numbers that were recomended from borla for a racing exhaust. Oval 40575 and round is 400373 (This round one is designed for rotaries)

[Greg Gauper]

I've been running a Borla XR-1 Oval for several years on my H-prod Honda.
Very happy with its performance. It is very quiet, yet makes very good power.
I usually hit around 89-90db for sound.

Fitment is a bit of an issue for me due to lack of ground clearence. I have to use my old IT tires on the rear to load the car on the trailer, but that has more to do with my trailer ramps than anything else.

I have a small turn down just behind the driver. As such, it is makes the car sound much louder inside than outside. I suspect if I had a traditional rear or side exit it would be much quieter inside.

[TStiles]

I have a small turn down just behind the driver.

Please be careful where you exit the exhaust ... I had a buddy that terminated his exhaust " just behind the driver " on a miata ... The hot exhaust heated his fuel tank , the gas cap pressure relief failed , pressure built and the filler hose exploded , filling the car with a massive vapor cloud @ 90 MPH

Me thinks he was very , very lucky

[Greg Gauper]

Yes I am aware of issues that others have had with exhausts exiting behind the driver.
I run a fuel cell, not a stock tank.
My turn down does not point towards my cell.
I do have a heat shield in front of the cell as a precaution.

[mossaidis]

To add to the intel here...

I run a tunnel dump exhaust, 2.5" ID to 22" long/4" OD Magnaflow resonator to 3" down turn "just behind the driver". I blow 99 db at LRP, 98 db at NHMS and after a 20 minute session you might as well fire off a piston near my head... I won't care (READ: numb).

I will be at the June 18th LRP event with that 99 db exhaust. I hope I can get a similar setup as Greg mentioned before the July 2nd event at LRP. Being that loud, I will never be able to run my car at HPDE's other than at WGI, I will piss off every track neighbor and the annoyance of racing will grow for me.