modifications > ETS Extreme Exhaust Modified

Why did you modify the ETS Extreme Exhaust on your RS?

The ETS Extreme exhaust system has options to eliminate the mufflers as well as any "normal" resonator. I opted to eliminate both. Smooth bends, larger piping, and less backpressure mean more power and torque. The funky extra tube in the middle of the exhaust is a fancy Helmholtz resonator to eliminate harsh resonance discovered by ETS during prototype testing.

Fast forward from 2017 when I installed the ETS Extreme Exhaust to 2021, and a handful of folks started complaining of the loudness of my exhaust at local Autox events (not to mention how bad I was beating them!). There was never a threat to losing any race site because there aren't any noise restrictions in places where I race. However, I wanted to see if there was an option to make the ETS Extreme exhaust system lighter and not as loud, yet not cause any negative effects. It turns out I could do all of the above!

Sound Test results:
I placed my iPhone 6 inches from the ground, 6 ft behind the exhaust, and in between the (2) exhaust tips.
- Cold start ETS Extreme exhaust with Helmholtz resonator = 108.1 dB max, 98.3 dB avg.
- Cold start ETS Extreme exhaust with Magnaflow muffler = 107.0 dB max, 97.2 dB avg.

I had no way of measuring the exhaust noise while driving under a load. Therefore, I will report back at the next Autox in September. I took my RS for a quick drive. No drone at all. WOT is definitely more quiet compared to the unmuffled ETS Extreme exhaust setup I had before.

Date Completed:



- Magnaflow 4" round center/center 3" inlet/outlet muffler #14419 (Amazon)
- Friend with welder, argon, 308 wire, and talent
- Scrap 304 SS for patching resonator branch
- M6x1.00 nut
- Sweet Tea (optional)


- 3/8" drive ratchet, 6" extension, 15mm socket
- 13mm combination wrench for V-band clamp
- 10mm combination wrench for mid-pipe hanger bolt
- 10,000 lb 2-post lift (optional, but highly recommended!)
- 9,000 lb 4-post lift (optional, but highly recommended!)


1. Cutting/grinding/welding took about an hour. Removal/installation took 15 mins. I took my time because of taking pictures for this website.
2. I recommend doing this swap on a cold engine/exhaust. Otherwise you will get roasted a few times in cramp quarters.
3. Leftover parts = Helmholtz resonator tube section, Mid-pipe section.
4. Reversible back to ETS Extreme stock only if pieces are welded back together and a hole is drilled for the resonator.
5. Weights:
        ETS Midpipe with Helmholtz resonator tube = 16.5 lb
        ETS Midpipe with resonator deleted and Magnaflow muffler added = 15.2 lb
        Total weight removed = 1.3 lb.