Well, in 3 seconds flat if you don't count opening the vacuum cap packet. I don't know why this simple method escape my mind but after thinking through how the electronic vacuum switch work then everything makes sense. The electronic vacuum switch turn on the vacuum to close the lower exhaust flaps when 13V pass through it. When the electrical current is gone the electronic vacuum switch release the vacuum through a lower opening metal hose as shown below.



Plug up this metal hose then you will maintain vacuum ALL THE TIME and the lower exhaust flap remained closed regardless of RPM change or if Sport button is on or not. You do need to run the car with Sport button off first for 2 seconds to create the vaccum then your are good to go. This is super easy to do and you will pass 92 db sound limit at Laguna Seca. Sorry I did not think of this earlier but I will bring the packet of vacuum caps for those needed this Thursday at Laguna Seca

Of course those of you want to control the exhaust note at your finger tip can still venture the mod as follow: https://www.6speedonline.com/forums/...inger-tip.html

Here is picture of the vacuum caps. $2.37 with CA tax LOL



Put the cap on the button metal vacuum release hose and you are good to go. You can install the cap without removing the electronic vacuum switch unit. Ignore my Jerry rigged wires for the other mod lol.

No more need to connect vacuum hoses together or any other cumbersome method just to track at Laguna Seca! I believe this method can be apply to other none GT3 models if you have similar vacuum switch.

 

wish it was that easy on the 997S's. We don't have that setup. Last LS trip I showed all the GT3 guys your last mod suggestion (the hose disconnect to plastic male to male fitting). No such luck thogh with the 997. Guess I'm back to lifting this trip until I figure something out for Aug? Thanks again though!

 

Now I am really curious on how none GT3 model control exhaust note. Should operate on the same principle right?

I will take a look at your exhaust on Thursday

 

Doctor, you operate on cars or people equally well. Bravo.

 

mike, good find. save a cap for me.

 

Thanks landjet. My patients like it better if I practice on my RS rather than them

I am painting it white as we speak

 

Seriously what do you do for a living?! Your like a mad scientist and a electrical engineer wrapped up into a mechanic. So awesome how easy this solution is! lol LOVE IT

 

lol

I am far from a scientist and more like a hobbyist. I love tearing things apart since young. I lost count how may time I took my TV apart while parents away and got shocked many time by the vacuum tubes ... you heard that right, vacuum tubes lol. I am a doctor so I can patch myself if I get electrocuted

 

While this is a an option to potentially pass sound not having the valves open in the exhaust will effect engine performance above 5000 rpm.

So yes this may help sound but it will hurt performance as the valves are designed for a specific reason to work a specific way when the engine is under load at a specific RPM.

As an option for our clients who are running at SECA and dont want to loose performance we do offer a turn away tip extension which redirect exhaust and does not effect the performance of the engine but still allow you to pass sound.

 

Yeah, I documented 8.2 lbft of torque and 9.3 hp loss and 17.2 lbft loss of torque at 4300 RPM by muting the exhaust on this write up a while back: https://www.6speedonline.com/forums/...nd-buster.html

I don't want to stick a "diversion pipe" and I seen plenty of flying projectile from similar Jerry rigged diversion pipes on the track. I may be forced to use it when I install sharkwerks race exhaust

 

LOL sure there are a lot of home brewed diversion pipes out there ,if you ever get out to a Porsche club race you will see the contraptions people install on cars to get them to pass sound. Pretty funny stuff.. Some of those cars look like they are right out of a Mad Max movie.

All things equal, we would only sell a properly made extension that would divert the sound away from the sound tower

 

With all due respect, there is no way for a 997 GT3 / RS to pass 92db sound at Laguna with just a "turn away tip extension". With that setup you would simply have to short shift and cruise at part throttle out of turn 5. Personal experience.

 

I have about 5 customers who run this set up and havent had any issues passing..They are close and one of them was at 92db ... Now taking into consideration that weather greatly effects sounds at Laguna maybe they are just lucky?

 

I've got 986 s with techart headers / exhaust that's not going to make the 92db and I have a couple track days coming up at LS. any ideas?

 

No one with OEM exhaust be it 996 or 997 GT3 or none GT3 pass sound at Laguna yesterday. There were a mad dash to Home depot for some Jerry rigged diversion pipes and they still did not pass sound! Everyone had to lift at turn 5. The simple cap on the vacuum switch worked perfectly on both 997.1 and 997.2 GT3 ... my toggle switch was FANTASTIC without a single black flag !!