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Heading to Laguna, lots of homework already done- appreciate the thoughtful work, however..
AWE Switchpath, Grimmspeed's product- these are elegant solutions, but downside is cost and requiring competent install. The_Dead_Cow said :

" I pass 96db @ 50' with McMaster high temp plugs in the valved pipes $50"

Does anybody have experience with this? It seems cheap and easy. Just unscrew the plug when you finish your track day, right? Any advantage to the electrical/exaust module defeat ? Even clever contributors describe the install as a PITA..Either way, "running quiet" in our cars heats up a valve or a plug, produces some back pressure thus stealing a few ponies, whatever.

Thoughts/ Wisdom?
 
Yes, read all that. Good stuff. I was just thinking exhaust plugs with a wing nut to install/remove is cheaper than anything else @ 50$..Lots of other expenses to pay to play, so trying to efficiently squeeze out the dollars on other stuff. Is there a part # or size to order up, or just call McMaster and work it out?
 
Yes, read all that. Good stuff. I was just thinking exhaust plugs with a wing nut to install/remove is cheaper than anything else @ 50$..Lots of other expenses to pay to play, so trying to efficiently squeeze out the dollars on other stuff. Is there a part # or size to order up, or just call McMaster and work it out?

The high temp expandable plugs are tapered. McMaster lists them by the large & small diameter of the taper. I can't remember exactly the size but I did measure the ID of the exhaust pipe and made sure the diameters at each end of the taper were larger/smaller. I think the pipe is 2.75" dia with .060" wall, so the ID should be 2.63".

https://www.mcmaster.com/high-temperature-expanding-plug

Trade size 13.5 should work.

Keep in mind I got this idea from another member on here before the other solutions were on the market. The Grimmspeed units are the actually a little cheaper.

https://www.grimmspeed.com/exhaust-valve-simulator/

If I were doing it again, I'd try the Grimmspeed units.
 
Increase in back pressure sounds like a good reason to spend at least miata money- that suggests that more back pressure is generated by forcing open the exaust valve with plug installed, rather than switching it open with electrical mod- is that true? I get that if I run the whole track "quiet" the car is subject to more minutes of back pressure than "running quiet" for only a short segment of track per lap. OK, Grimmspeed.
 
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Increase in back pressure sounds like a good reason to spend at least miata money- that suggests that more back pressure is generated by forcing open the exaust valve with plug installed, rather than switching it open with electrical mod- is that true? I get that if I run the whole track "quiet" the car is subject to more minutes of back pressure than "running quiet" for only a short segment of track per lap. OK, Grimmspeed.
Glad you got it... if you were in my hood I’d even let you use mine just so you can see how easy it is.
 
Increase in back pressure sounds like a good reason to spend at least miata money- that suggests that more back pressure is generated by forcing open the exaust valve with plug installed, rather than switching it open with electrical mod- is that true? I get that if I run the whole track "quiet" the car is subject to more minutes of back pressure than "running quiet" for only a short segment of track per lap. OK, Grimmspeed.

The Grimmspeed device just fakes out the car and the valves stay closed because they're not even plugged in (i.e. no flow thru the 2nd muffler opening). The plugs block flow thru the 2nd muffler opening regardless of what the valve does. Either way the majority of the flow thru that outlet is blocked. No need to overthink it.
 

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