Leigh2

While we're on the topic of Laguna I have a problem. I'm planning to run the August POC event as well and my exhaust is well over the 92 limit. Any ideas??? I'm thinking that I'll have to find a stock exhaust system somewhere for the event.

mikymu

??

Bob, are you trying to keep the lower exhaust flat open or close? You need to maintain vacuum in the line to keep the lower exhaust flap close which lead to lower db. If you disconnect the hose you will lose vacuum which will cause the lower exhaust flap to open.

That's a straight pipe out from the cats right? You will blow the sound booth away at T5 of Laguna Seca. I won't be surprise if you get caught at 110 db or more. You need some sort of side mufflers.

Carrera GT

How what ? Cap?

Short of a cone suppressor and Supertrapps, what can be done to muffle a GT3 with the center bypass?

mikymu

Yup, a simple cap on the vacuum switch will do the trick as shown below. I will quote my intial post to help explain:

"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. 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"

Carrera GT

Not once you remove the center muff with the bypass ... : )

Bob Rouleau

Another Mikymu thread copied to DIY. Congrats!

mikymu

That's my exhaust setup whe I run Laguna. I have sharkwerks center muffler bypass and it pass sound as long as you divert the exhasut to the side muffler first with the simple hat trick (cap trick)

Thanks Bob

Carrera GT

But the vacuum controls the position of a butterfly valve diverter in the center muffler section, so once that center muffler is replaced by a "delete" pipe, there's no option to control the valve diverter position or the rest of the exhaust system.

mikymu

The lower exhaust flaps are located on the side muffler and not the center muffler as shown on the picture and video below. You will pass sound with center muffler delete as long as you keep the side mufflers.



http://www.youtube.com/watch?v=3Bwyqg3NrTA

Carrera GT

Gotcha! Ok. Now I'm awake ... : )

mikymu

lol

Don't stay up too late tonight

Larry Cable

I'm having trouble identifying "where" in the engine compartment this connector is mikymu... looks like it might be on the right hand side as you look at it ... any clues ... prior to my "sailing" event there on Monday?

p.s do you also need those wires connected to the plug to the right of the vacuum line?

drl

Great thread. Thank you guys.

stujelly

Big time, saved my bacon this last monday there in my 2011 gt3 rs. I ran all out and never got so much as a warning.

Thank you again mikymu

Larry Cable

this mod is good for about -5Db @ Laguna. I got meatballed yesterday at 95.x db in 4th going past the sound station, popped into Monterey and picked up a vacuum cap, voila passed at 90.y Db ... this was with a SW center bypass btw ...

Thanks man!