I don't know if this question has been answered before...but why hasn't anyone tried the following design from Sharkwerks for the 997.2 TT on our 996 TT? Here is the link for reference.

http://www.sharkwerks.com/products.php?pid=329

 

HI,,Proromotives exhaust is like that but it is connected where they cross by having the back side open of one pipe and the front side open on the other pipe,,they are still individual though..
I have asked several times why anyone else doesnt use/copy this type of configuration...

 

Hi there,
The reason this design works on the 997.2 cars is because the cats are a separate piece to the muffler. On the 996tt, the whole exhaust is one large piece (with 2 cats and muffler).

You could build a system like this and replace the cats or maybe cut and weld to stock cats but it's a lot more work. Also it would probably be a lot louder. The .2 cars are notoriously quiet so our system isn't outrageously loud. Hope this helps.

 

HI,,So in your opinion or testing
Does this type work better for Performance then the typical merge X-pipe collectors that most use ?
Sound is probably alot different..
Thanks

 

Thanks Dan for the quick reply. I think your design would be an interesting new thing to the 996 TT market especially since there are already a TON of X-pipe designs (including my own custom piping) out there, it would make sense to build one like your .2 product for the 996TT. I would imagine sound-wise it would not be too drastic compared to the straight pipes out there and not too much louder compared to the X-pipe design - but I may be wrong.

Just curious why this design has not been used on a 996 TT. Hmmm....Maybe I might want to try it...hopefully someone will talk me off the cliff if this is a bad idea...

Brent

 

IMO, This design is just longer straight pipes which would sound similar to regular straight pipes on a 996TT, the gases just have to travel a longer distance to get out. It would be shade quieter than short straight pipes, but still way too loud and way too much drone for the majority of users, so there is not a real good reason to do it on the 996TT. Mixing the banks at the center will improve the sound, but again, IMO, way too loud and too much drone for most people. Also, mixing the banks on this design sends exhaust gasses from each bank which are travelling in opposite directions into a head on collision - very bad for flow IMO.

 

Thanks for the clarification John. You mention that exhaust gases from each bank collide if you mix the banks. I am assuming then, the popular X-pipe designs including yours still have exhaust gases colliding and thus will still have issues with flow compared to straight pipes, but this is the compromise between sound and flow. Is this correct?

 

7 years ago my 01 TT had that set up... now its a X design

 

This is how I would describe it -

I would not use the term collide with our "X" design. A more appropriate description would be "blend". As the gases come around into the "X", they are pointed downward where they are faced with a "Y" splitter formation, much like the throttle body plenums. The exhaust gasses can take the path of least resistance and go either right or left. There is no "head on" collision or slamming against each other - it's a blend of the two banks. Also, we make the "X" passage approximately 1.5 times the volume of a single pipe and the engine is only firing one cylinder at a time, so as the exhaust pulses arrive at the "X" they have more room than they do in the standard pipe they travelled through to get to the "X" and they can choose the path of least resistance after the "X". Another pulse is right behind it and does the same. It flows very well. Nothing will beat a short straight pipe for ultimate flow, but a well designed "X" pipe can be relatively free flowing.

It is important to get the "X" right for the proper blend of performance and sound. Too much blend and the flow can be restricted, too little blend and you lose sound quality and the system becomes more like a conventional exhaust. We experimented with this and found what we determined to be the best best sounding system that provided very good flow. When you take into consideration the fantastic sound we are achieving with our "X" design, there is little reason to use straight pipes, unless you like it very loud with a lot of drone and/or you are looking to shave a few pounds of weight for track times.

 

Fact is no exhaust makes the most power. Any pipe passed the turbo is costing power. I would guess it around a foot or so. Do yourself a favor and read up on it and not someones butt dyno or a vendors claim, Look at the race cars that are turbo'ed. There is no clean and easy way to cross the exhaust on our cars and the only benefit is the sound.

 

What I can't understand is why nobody proves their design by means of measururing backpressure. Backpressure = bad. The more backpressure the slower the spool. When I used to build exhausts and design turbo headers, we just put in an 1/8" bung and measured.

In my opinion, I can's see "blending" banks after the turbo being anything that will encourage scavanging. The pulses were already timed in the header. (flame suit on)..

 

HI,I agree fully with Evil and Tim..
I still have to say because I think > the EB X merge collector is the best I have seen,,the smooth complete bends into the center and the volume in the center ....
But still love my 100 Milltek....

 

I have always known this.

I did my X-Pipe for fear of sound. Now that I have it, I don't mind going louder and the design I was referencing seems interesting but there is no market for it for the 996TT. I guess it's a black and white thing. Either go short straight pipes to the rear bumper or go X-pipe/muffler.

 

Straight pipes have to be the worse sounding things ever on our cars. I am going this route..




Lets see how it sounds

 

In my opinion. if your looking for the best of both worlds, the best setup would to have electronic "cut outs" in place of the cats. Put a hobbs switch and an electric over ride button on the dash to control when it opens. Have it setup to open at say, 2800 rpms so around town and at cruise, you can short shift and send the exhaust through a big muffler. Then let the hobbs switch or your over ride button open it(or close it) for performance.

Other than that, I can't see any reason why you should "blend" the exhaust gas again. That being said, it seems "blending" helps with the tone/drone so perhaps that there is a tiny plus side.

I have a GMG exhaust on my car now. I will weld in a bung and test the back pressure. I will then build my own exhaust and measure again. If anyone wants me to test their "x" design, let me know..

ps - I don't and won't sell any of this stuff. I just own a Tig welder and love to fab stuff..