964 cat bypass

[Guest]

Has any one had any experience with cat by passes. I have fitted a G pipe instead of the secondary silencer, fitted a K&N filter and would now like to fit a cat bypass to help release a bit more power and alter the exhaust note again.
I understand that the straight through pipe creates resonense inside the car and a better idea would be to fit the Dansk s/s one without the ceramics, although it still looks like a cat. Has any one done a similar exercise or had any other experiences,good or bad, that they could share with me, I have a carrera 2 tip. Any advice / ideas would be appreciated.

Craig

 

[Dave Wilkinson]

Craig,

I have the Dansk s/s cat bypass/muffler on my car which I bought from Design 911. It has the advantage of having the boss for the attachment of the O2 sensor which some bypasses don't have.

Very pleased with mine. It's difficult to say what effect it has on the noise since I also have a Fabspeed dual outlet exhaust on mine which IS quite loud (108dB at a recent Goodwood test).

Assuming your car is pre-August '92 I'd recommend it. Later cars, as I'm sure you realise, are supposed to have the cat to achieve the MOT hydrocarbon emmision requirements.

Regards

Dave

 

[Guest]

Hi Dave
Thanks for taking the time out to reply.
You were the only one to do so on a subject which I thought would evoke more of a response.
Perhaps the purists out there might be thinking that we shouldn't be tinkering with what Stuggart believes is the norm.
Any your words are heeded and my next project will be the cat by-pass followed by a re-map at Ninemeister. Hope that you approve.
By the way I was looking at your site and was mightily impressed with your motor, it looks terrific. Love the sills, mine is a narrow body so they won't fit, pity.

Regards

Craig

 

[Guest]

Hi Craig,

Mine is a late 91 964 and I have recently fitted a G pipe and cat bypass the G pipe gives it a great sound and the cat bypass allows the exhaust to breath a little more freely difficult to tell if it gives anymore more power but its done now and I am happy the sound if nothing else, recently Mot'ed and told that its the cleanest car he has ever tested just remember she has to be pre-92 to be able to remove the cat bypass without any problems.

Hope this helps

Pete
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964 (91) Tip Guards Red

 

[John H]

My 1990 car has a cat by-pass (no O2 sensor) and a primary silencer by-pass, but the standard secondary silencer fitted. I did not do this, it was like this when I bought it.

Frankly it sounds fabulous, decidedly noisier than standard, but not unacceptable. At speed on a light throttle (ie motorway) the engine becomes almost silent from the cabin. However I was driving a pal's Boxster the other day when he passed me in my own car, flat out in third, and I was amazed at how loud it was from outside the car, this being the first real opportunity I'd had to hear it. Sounded lovely though!

John H