On Pole

Are the flaps open or closed when the rod in the picture is extended?

340Elise

They are open the way you show them in the picture (meaning in sport mode). They are naturally open and are closed under vacuum.

Hope this helps. If you need interior shots of the valve within the exhaust piping, I can provide that for you.

On Pole

Thanks, mine are stuck open then. I would like to fix them myself, anymore info would be helpful.

Md11skipper

Check your vacuum connections

340Elise

Did you take the pic with the motor running or not? If you shut off the motor, they could go to this state automatically without vaccum. When you start the car, the sport button always defaults to off, which means the valves should close. When you hit the sport button, then they should switch to closed under vaccum. I would check them this way with the motor running and hitting the sport switch; see if they move.

If not movement then make sure the rubber vacuum lines nre connected to each of those round drums. If so, then you may want to trace the vacuum lines and see if they are plugged in at the source. Finally, there is also an electrical connection to check on the right side of the engine bay. You may need to do a search to find info on its exact location.

If it is plugged in, then check your fuse box!

Or you could just go with straight pipes and get ride of all three mufflers and over 50 lbs of weight in the process. The sound? Yeah it's a bit loud, but better than any other exhaust that I have ever heard. Think of it as the Sharkwerks center delete on steroids, lots of them!

On Pole

Thanks for the good info. I have been driving the car for the last 6k miles with the flaps stuck open and it's not too loud for me. I have a Sharkswerks center by pass pipe. Will I loose power if I by pass the side mufflers?

KJinDC

On Pole... did I see you on the shoulder of I-95 South Friday morning?
If that was you, the new car looks good. And Omar is enjoying your old car.

-KJ

On Pole

Yes that was my car on the side of I-95. I let a friend drive; we were getting a warning for no front tag. Omar got FTD at a resent Autocross.

When the exhaust flaps are open, does the engine exhaust by-pass the side mufflers completely?

rmag

Jon - Are they actually "stuck" open as pointed out (car off). Mine have done that a few times. I just grabbed the rod and moved it up and down a few times to free up the movement.

On Pole

When the side flaps are open the exhaust does bypass the side muffler almost completly. For me, why keep the side mufflers if I have never used them in the past? I'm going to try the Fabspeed side muffler bypass pipes. I love weight savings too.

I found this video that shows how the stock 997 GT3 exhaust system works.

http://www.youtube.com/watch?v=J0Q5Szx021s

MJones

Video actually shows how the resonance intake runners perform....watch the flaps

On Pole

The exhaust note from the Sharkwerks 997 GT3 Bypass pipe is worth every penny!!! I have since lost my great exhaust note by installing Fabspeed Side Muffler Bypass pipes. The Fabspeed pipes do save a good deal of weight, but they don’t have a Cup Car exhaust note. The Fabspeed Side Muffler Bypass pipes sound a little louder than a stock 997 GT3 with the sport button depressed.

Weight or Exhaust note

TRAKCAR

How do they sound with the center bypass I have already? Same great sound just louder or does it change / boom too much?

Surely this is why I the GT3's have tilting sunroofs, if I close it the rear exhaust sound is not quite as crisp :-).

I have'nt remembered to change my 1 CD since I bought the car over a year ago and I seem to have no FM radio reception on my 9 mile daily commute.. I do drive by a big hospital..