How to make it sound like a Flying Lizard?

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.

straight pipes!

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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.

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

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?

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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.

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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

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.

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...

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

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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.

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

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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.

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?

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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.

I agree with the temporary bypass for a 10 min fun Yesterday evening I tried a ride with the pair of GT3 headers and cats, and nothing else. Goodness. Since it's half an hour to put in place I will do it again and make a movie. The car isn't faster but it gives such a feeling of power... what a fun. The most impressive is the deceleration in 3rd gear above 6K. I had to put everything back in place because this morning my wife wanted to take the 996, but it gave me some ideas. Jim, have you tried it (the post sensor to the air) ? From what I know a lambda sensor won't run correctly at ambient temperature it needs to be hot. According to Bosch the ECU will switch to a conservative mode, but maybe that's some BS to avoid this kind of DYI. So if you succesfully experienced it, please let me know, it will give me some other funny ideas ! I took a look at the mufflers and think that a pair of stainless steel valves (like a very big waste gate) will make a funny device to control the bypass. Like each time the pressure before the cats meets 500 kPa, it opens the bypass. It could be 100% mechanical, a bit tricky to setup, but wonderful once it works.

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We ran my racecar like that for a couple of years. We had the post cat sensors right above the engine. Maybe that was hot enough.

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My car sounded close enough to Fabspeeds site with just removing the cans. It will get you in the ballpark, and people in general, will know if they will go down the road of bypass pipes in about 5 minutes of driving time for free.

interesting. I don't want to try that on my 996 because I don't have any tool to reset an eventual panic or conservative mode... even if I have the feeling that nothing bad would actually happen. The other nasty way to get rid of the post cat sensor is to give it a 0.9x volt signal that makes the ECU believes that everything is perfect.

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I agree that trying things on a race car is much different than trying them on a street car. Personally I would never remove the cats from a street car.

Pep-boys mod is fugly - and the pipes *might* fall off when they get hot/cool down a few times. The connecting clamps aren't perfect. Maybe for the track only. An even cheaper mod is to cut the pipe off your dead 3.4/3.6 muffler and face it backwards... -td

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TD - what did your wife say when you stole the clothes dryer hose???

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Curious. you put headers from a GT3 on a 996? I was told by several vendors that they don't fit. Let us know. Thanks!

I did the Pep boys pipes as my track pipes for a few events but hated the crimp bends and trying to attach them inside of the factory clamps. So I went out and spent a whopping $20 and made a MUCH better solution. I purchased a Mandrel (sp?) bent 2 1/4" U pipe from Jegs, cut it in half and then shortened to my desired length. I then took it to a Muffler shop who expanded the end slightly for me so it would slide right over the factory cat pipe rather than trying to do the inside mounting with the factory clamp. I then used two traditional clamps to hold the pipes in place and I feel this is a MUCH better solution to the pep boys style pipes. I still don't have tips on them but could throw something on there if I wanted to. However I put the mufflers back on for street use so there's really no need for tips. The biggest benefit of my setup is it's soo much more securely mounted than the pep boys style pipes. Trying to use a pipe that fits inside of the factory clamp and is not suppored anywhere else is just asking for them to work loose and come off (ask me how I know). Andy

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I was told the same, and it's what I was telling to Porx in the "ebay headers" thread. Since the engines are different it made sense to me that they wouldn't fit. I was even certain than the distance between cylinders was different. But since we told about this, and that I have a pair of GT3 headers it took me half an hour to install them on the 4S. The first surprise happened when I measured exactly 115mm between cylinders, the same than on the GT3 intake. I have a whole GT3 cup engine that I'm rebuilding; what I can do next week-end is to check directly on the GT3 heads and see the difference, maybe the exhaust conducts don't exactly fit - that's more than possible. Or maybe also the GT3 headers I have are not GT3 (I realized I never tried to mount them on the GT3 heads). It will be easy to check that they fit the GT3 headers. I can do that tonight, and will post pictures here. [EDIT] I can't wait to get that mystery cleared so I'm going back home during lunch time and check the headers.

Andy, it will be probably better... because the pepsi pipes look like the car is an old beetle with 911 body panels and large wheels

So here we are. The headers I have, supposed to be GT3 headers aren't actually GT3 headers At least the heads in the box are truly GT3 and you can see that the headers wouldn't bolt on them.

So Paul you are right : GT3 headers definitely don't fit regular 996 engines and what is sold on ebay for cheap (and advertised as GT3) is pretty similar to the header above (branded fabspeed but probably built at the same plant). Now, to make things clear I removed the right header from my car and compared to the 'fabspeed' header. It's the same, except that the blender is a straight 3:1 and it's made of stainless steel :

So... if you are looking for the 'lizard' effect I do think that these cheap headers some found on ebay, that are very similar to (and actually probably the same than) the stainless header above, are a good start. 1) they help singing like a bee . Above 3500 RPM they sound a bit more metallic than the OEM headers. Maybe a bit louder too. 2) They are very easy to install. It takes me 35 minutes to replace the OEM pair by this one. I would be careful with the cheaper one, maybe you will need to adjust them. I can see on mine that the surface has been adjusted, the bolt pattern has been reground probably after welding to make sure it fits correctly. But maybe the cheap one are just this good, I'd like to get the info by someone who gets them. 3) Easy to put OEMs back in place if you decide to put the car in its original configuration. They probably don't make more HP as everybody agrees, but I don't think they can be responsible for a loss of power at high RPM. They probably lose torque under these 3500 rpm where they start making a difference. I finally keep these ones and work on the cats and mufflers now.

So what about glass pack mufflers? It's basically a straight pipe with fiberglass backing and lots of tiny inlets along the inside. Has anyone tried this on their Porker?

Here is a clip of Roger's 996 race car. He is running a x51 engine with stock x51 headers and coast fab mufflers. Sounds very good and not nearly as loud as straight open exhaust. http://www.youtube.com/watch?v=78jWBohTFqE

I run headers to custom pipes to platinum 200 cell cats then out 4.5 inch tips and it's loud but I love it. Not for everyone, I know, but it's a very mean sound with HP to back it up!