911tuning X design custom exhaust
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911tuning X design custom exhaust
As already mentioned in the X-Pipe exhaust thread, I have finished my exhaust project and would like to share it with you.
Mark of 911tuning. com is a great guy to work with. I called him with my ideas and we discussed what I wanted and what is possible to do. The final result will be presented here to show you the great product that he has delivered to me. I will be posting the pictures during the next days just like I find the time to do it.
It all began with my 996 TT that I bought as a Gemballa GT 600 with 37.000 km on the clock. I won’t get into the details of what they have really delivered to their clients. Let’s just skip this part.
I bought some parts from Markski (4.5” intercooler, 2nd fuel pump, injectors, tune) and we got the car to life. It was a totally different animal after that parts exchange and re-tune. The Gemballa exhaust however was quite restrictive. My logging data showed this bottleneck and the first attempt was to work on the cat section and make some room for the exhaust gases (deleted the secondary cat section). We need to run cats here, so a no cat solution is not possible and for environmental reasons I also want to use the cat – just not as restrictive as mine was.
The result was better, but still not good enough. That was the decision to go for a new exhaust and the first step was to choose a cat that has a sufficient flow and the least possible restriction. The result was a HJS 100 cell PE foil cat that I bought in parts (5” cat section and the cones). Mark agreed to implement these cats into his design, so this really is a custom design. I shipped the cats to him and this is where the story began.
I will start this documentation with some pictures and a video of the sound that I had before:
Mark of 911tuning. com is a great guy to work with. I called him with my ideas and we discussed what I wanted and what is possible to do. The final result will be presented here to show you the great product that he has delivered to me. I will be posting the pictures during the next days just like I find the time to do it.
It all began with my 996 TT that I bought as a Gemballa GT 600 with 37.000 km on the clock. I won’t get into the details of what they have really delivered to their clients. Let’s just skip this part.
I bought some parts from Markski (4.5” intercooler, 2nd fuel pump, injectors, tune) and we got the car to life. It was a totally different animal after that parts exchange and re-tune. The Gemballa exhaust however was quite restrictive. My logging data showed this bottleneck and the first attempt was to work on the cat section and make some room for the exhaust gases (deleted the secondary cat section). We need to run cats here, so a no cat solution is not possible and for environmental reasons I also want to use the cat – just not as restrictive as mine was.
The result was better, but still not good enough. That was the decision to go for a new exhaust and the first step was to choose a cat that has a sufficient flow and the least possible restriction. The result was a HJS 100 cell PE foil cat that I bought in parts (5” cat section and the cones). Mark agreed to implement these cats into his design, so this really is a custom design. I shipped the cats to him and this is where the story began.
I will start this documentation with some pictures and a video of the sound that I had before:
Last edited by GT996; May 2, 2013 at 02:17 PM.
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This is the first start after the winter period. I cycled the car a few times with no ignition/fuel and then started it. Hence the little hesitation at the start and some blue smoke, which it doesn't do on normal starts.
This video ist just for reference before/after.
Andreas
This video ist just for reference before/after.
Andreas
Last edited by GT996; May 2, 2013 at 08:27 AM.
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Gemballa exhaust detail pictures. The cat sections are 200 cell plus 300 cell = 500 cell. Kinda choking....
The 2nd cat has been cut out already.
The 2nd cat has been cut out already.
Last edited by GT996; May 2, 2013 at 08:52 AM.
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Glad you got the exhaust on 
now show some pics lol
now show some pics lol
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2001 996TT 3.6L and stock ECU
9.66 seconds @ 147.76 mph 1/4 mile click to view
160 mph @ 9.77 seconds in 1/4 mile click to view
50% OFF ON PORSCHE ECU TUNING BLACK FRIDAY SPECIAL
2001 996TT 3.6L and stock ECU
9.66 seconds @ 147.76 mph 1/4 mile click to view
160 mph @ 9.77 seconds in 1/4 mile click to view
50% OFF ON PORSCHE ECU TUNING BLACK FRIDAY SPECIAL
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The HP ratings on the cats are coming from the DMSB and FIA homologation and the corresponding classes. 350 HP is the rating for each cat cell and this is only a value for which a linear backpressure response is given.
Of course you can push more gas thru the cat, but beyond 350 HP the backpressure may not raise linear with more exhaust gas and also the catalytic efficienty will be degraded.
I was talking to the product manager at HJS Germany and he gave green light for 750-800 HP with these cat cells. This exactly matches my needs.
They are expensive. I learned here that this is the only valid sign for good catalytic converters, so I am happy that I have the best catalytic converter money can buy.
Oh ... and Markski is using the best available cats as well
Andreas
Of course you can push more gas thru the cat, but beyond 350 HP the backpressure may not raise linear with more exhaust gas and also the catalytic efficienty will be degraded.
I was talking to the product manager at HJS Germany and he gave green light for 750-800 HP with these cat cells. This exactly matches my needs.
They are expensive. I learned here that this is the only valid sign for good catalytic converters, so I am happy that I have the best catalytic converter money can buy.
Oh ... and Markski is using the best available cats as well
Andreas
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Thank you. Unfortunately I recently was lying more in front or behind of my car than driving it. It looks like this when clean and on it's tires:
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That front bumper and rear decklid look great! Did they ever figure out what happened to Uwe Gemballa? I remember that it was a crazy story about smuggling money or something along those lines!
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Installation of my shiny new catalytic converters. The cones have been welded to the cores and the cats have been polished. I also got a 2nd O2 probe plug before my cat for 2 purposes:
- ECU independent O2 measurements with seperate O2 sensor (to be installed later)
- backpressure measurements
- ECU independent O2 measurements with seperate O2 sensor (to be installed later)
- backpressure measurements