Tried to pass sound at a local track and failed miserably.

Their limit is 94dB. My totally stock GT4 blew a 100.7. Thanks for that Porsche.

Any simple yet effective ways to make this thing quieter? Gotta keep the environmental wackos happy.

 

100.7 with exhaust button off? Wow.

How do they measure dB at a track? (I've never encountered this before)

 

How's the check done? Is the checkpoint on a straight or safe spot where you can put in 6th with PSE off or clutch in / neutral briefly? Or you can put on a silencer.

 

Holy smokes thats loud! I was looking to do a track day at laguna next month.....

 

Guys gotta do mech33's PSE bypass
I'm waiting for my GT4 to test it out.

 

That is loud for stock. - surprising it is this loud

 

Solution

 

Any throttle at all in 4th gear tracking out of turn 5 at Laguna blew sound for me at 94 db. Normally 3rd is the gear I'd be in all the way thru 5. The exhaust starts opening up around 4000 rpm and is in full song at 4500. I made it thru the day with maintenance throttle holding 4200-4300 rpm til the bridge where I went back to 3rd and accelerated into turn 6 (that was weird) I still beat my best time ever in the track prepped CR PDK I had by a half second! I not surprised the GT4 hits 100 db and it will only get worse with mods.

 

Better solution: https://rennlist.com/forums/991-gt3-...nd-checks.html

 

That seems like a giant pain in the A$$ how about just a Fvcking toggle switch (Labeled Laguna of course) in the car that lets you keep the god damn valve closed.



Any aspiring Porsche GT4 engineers know if keeping the valve closed at full revs does anything bad to the engine? (dunno like hot spots in the exhaust or unexpectedly build up pressure) Is it just for sound or does it increase flow?

 

Do not force the valves closed 100% of the time unless you want a melted bumper and potential other damage from retained heat. It has happened.

Mech33's solution is the best option out there. Everything else is a compromise

 

Ok that's all I needed to know. So just avoid Laguna then.

I didn't know if there was a good reason the valve opened other than aural pleasure but now that you've confirmed it makes sense why guys don't have a toggle button.

 

You can still pass with turnaway pipes and sound diffusers. That won't damage anything. Mech33 solution is much more elegant

 

I did do a whole day at Laguna with the valves forced closed... not sure if I melted anything...

Contact Alekshop if you want to purchase one of these pre-made... I believe they are making a few of them. But you'll need to modify the GPS coordinates for other tracks.

 

Who makes the best turn-away pipes and sound diffusers in the SF bay area?