[RarlyL8]

Brian,
This is very interesting.
I have a OEM heat exchangers + test pipe + 1-in/2-out muffler on my ‘83. I measured 86dB at idle about a meter from the tailpipe. Any idea what your idle dB is for comparison? I used an iPhone app called “db Meter Pro”. Do you think this would tame the idle sound even with a 2-out?
What’s the rough opening rpm? Just wondering what the sound would be like at interstate cruising in 5th gear.
How would this compare to HP/torque gain from SSIs?

The only thing that may change the static dB level in your current system is the premuffler part of the active exhaust. The premuffler is a bit more quiet than a test pipe. With this system the main muffler sets the baseline for how loud your exhaust is at idle and cruise.

The valve opens at about 6" of vacuum so there is no RPM setting involved. Your right foot controls when it opens. Drive like there is an egg under your accelerator peddle and the valve will not open, stab the throttle and it opens. This is demonstrated in the video posted above. The engine is revved quickly from idle to 6000rpm and the valve stayed shut so the exhaust was stock quiet. The throttle was then stabbed to 6000rpm and the valve was open creating the sport sound. While cruising the valve is closes so the sound would remain the same as it is now.

It well documented that our premuffler shows the same gain in HP when installed on a Carrera as SSI exchangers and a dual inlet muffler. This is not a fair comparison however as SSI primary pipes are not optimal for the 3.2L engine. Our premuffler has oversized inlets, F1 style merge collector with 2.5" straight through to the outlet. The active exhaust valve is sized to give the best HP gains regardless of the main muffler used. We also have a tuned tailpipe that knocks the sound level in half for those who prefer a less aggressive acceleration note. You have the ability to tune the sound level to your liking. A lot of R&D went into this system, much more than just a pipe with a valve on it dumping exhaust. Several styles and brands of valves were tested as well for longevity, heat tolerance, and durability to fully close and open every time for years of enjoyment!

.