befast

Are we talking pipes from the headers to the outside, with nothing in between? I am more curious than anything. I think those cup cars sound great.

redridge

straight pipes!

Meister Fahrer

aka bypass pipes.
It's an amazing sound, I had people chase me down telling me how great it sounded.
However very loud, not practical for a DD.

However, the RSR's in ALMS have some kind of muffler.

AudiOn19s

Even with Bypass pipes you still won't sound like the 'Lizard cars. There's just something different in the tone of the GT1 block cars from the M96 cars. The GT1 derived cars still have a higher pitched song to them then the M96 cars do.

M96 still sounds great with bypass pipes..just don't expect it to sound like a GT1 platform car.

Andy

befast

I knew it! Gay pipes are the problem.... and that I would need straight pipes!

All joking aside, I would never expect a 996 to sound exactly the same as a cup car because of the difference in the engine. But just so I understand, straight pipes run straight from the headers to the back? Is there a carbon-monoxide issue potentially?

AudiOn19s

JimB's old 996 race car was setup this way. I believe I remember him stating that they gain'd 17hp on the X-51 3.6 with this setup BUT the car lost miserable amounts of torque below 4500 (not really a concern for a race car however). Go here for a picture: http://76.162.35.35/photo_player_flash.html

Carbon-Monoxide won't be the issue...the issue will be that the car will be soo loud that you'll bleed from the ears. Seriously muffler bypass pipes by themselves are noisy enough that I don't even enjoy driving on the street with them because you can't have any fun without drawing all the wrong attention.

himself

I run bypass pipes on my DD. They're loud, but not too loud IF you are aware of your throttle input in sound sensitive areas. Just don't go WOT every start. I'm sure lots of people run Fabspeed pipes without mufflers - and not just at the track.

On a positive note, you don't need a horn any more. Just blip the gas and you'll get more attention than a "meep-meep."

-td

befast

Anyone in the Westchester area running the muffler bypass on a 3.4L 996? I would love to hear it in real life, as opposed to the couple of YouTube videos.

IrocMan

Running a 996 without cats is virtually impossible because of the OBD II, so you would have to get rid of the ECU and use something programmable like a Motec, which will never work as good as a Motronic and is only adapted for specific applications like racing.
The bore/stroke ratio is different on the GT1, valve timing is very different too so you will never get the same sound... forget the GT1.
You can probably target the GT3R except it will never take the RPM...

redridge

Just disconnect your muffler.... and there you go, instant bypass sound.

JimB

Actually it's easy. You just leave the pre-cat sensors in the pipe and hang the post-cat sensors in clean air.

To hear what a 996 with straight pipes sounds like from inside the car you can go to my very out dated web site www.jimbreakey.com and click on 996 racecar for sale. Scroll down a little and click on virtual test drive. I think it will still take you to a YouTube video from Daytona a couple years ago.

A 996 with straight pipes sounds pretty good but nothing like an RSR or even a cup car.

Tippy

I have been preaching this since day one. 15 minutes and you will know EXACTLY how it will sound.

JimB

I would agree if you disconnect the mufflers and put some kind of 90 degree pipes on to direct the exhaust out the back. Just taking the mullers off and dumping the exhaust sideways behind the bumper cover won't do it.

befast

I think that's great idea: I will try just disconnecting the mufflers to get a sample. My cans have to be swapped regadless, so I might as well experience the bypass sound while I figure out how the replacement works. Two birds with one stone! For a 5-10 minute test, would it be an issue to run without the bypass pipe or will the exhaust gas quickly melt stuff?

On another note, why the heck are bypass pipes running as much as $500+ w/o tips? It's just a pipe, no?

redridge

if its just 5-10 sample... it should be a no issue. BTW the bumper are heat shield lined.

Agreed, straight pipe prices are crazy.... you can go to pep boys and get a cheap pipe w/o the tips.