Question of cat location for Kleemann header owners
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From: PDX
1999 C43, 2008 P30 E63, 2014 SQ5, 2024 Model Y Performance
Question of cat location for Kleemann header owners
For those of you C43 (or C55 owners as the case may be) owners that have Kleemann headers where did you locate your cats?
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From: Land of mountains, cheese, chocolate and watches
12' W204 C63 AMG coupe "T-Rex", 12' W451 Smart Fortwo Pulse (99' W202 C43 AMG + Ultima Can-Am sold)
Under the car of course 
Sorry, that is stupid, but I just had to say it
Sorry, that is stupid, but I just had to say it
Thread Starter
MBWorld Fanatic!
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From: PDX
1999 C43, 2008 P30 E63, 2014 SQ5, 2024 Model Y Performance
MBWorld Fanatic!
Joined: Mar 2010
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From: Land of mountains, cheese, chocolate and watches
12' W204 C63 AMG coupe "T-Rex", 12' W451 Smart Fortwo Pulse (99' W202 C43 AMG + Ultima Can-Am sold)
Orgamastic piping
Check this exhaust setup on a CLK63 BS 
One of the photos shows the cross pipe just before secondary cats, or are they small resonators...
https://mbworld.org/forums/clk63-bla...ck-series.html
erh, no looks like the primary cats and the secondary ones are further down
One of the photos shows the cross pipe just before secondary cats, or are they small resonators... https://mbworld.org/forums/clk63-bla...ck-series.html
erh, no looks like the primary cats and the secondary ones are further down
Last edited by DRBC43AMG; Nov 3, 2011 at 05:42 PM. Reason: Completed post
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From: Boston, MA
1999 MB C43 AMG
I got rid of the 2 secondaries and put a Y pipe instead. Then I deleted the resonator and put a 2.5'' straight pipe to the stock muffler. The sound is just amazing, nice deep rumble until 3.500 rpm and then it's a bit raspier. The cold start in the morning are pure happiness 
It's loud but comfortable with windows up on the highway.
I saw some gains immediately the car revs much better and pulls harder in the top end.
It's loud but comfortable with windows up on the highway.
I saw some gains immediately the car revs much better and pulls harder in the top end.
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From: Land of mountains, cheese, chocolate and watches
12' W204 C63 AMG coupe "T-Rex", 12' W451 Smart Fortwo Pulse (99' W202 C43 AMG + Ultima Can-Am sold)
Exactly the same set up I have 
I love it every time I get in the car, except perhaps the neighbours on cold startup It really snarls to life but less when the engine is warm.
I love it every time I get in the car, except perhaps the neighbours on cold startup It really snarls to life but less when the engine is warm.
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From: seattle
1990 300ce supercharged and intercooled
On the installs I have done on that setup I have put the cats after the transmission. When the exhaust reaches the center of the car. Then I put in the y-pipe and hook to the rest of the exhaust system. Some high flow cats and the stock muffler sound great.
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From: Land of mountains, cheese, chocolate and watches
12' W204 C63 AMG coupe "T-Rex", 12' W451 Smart Fortwo Pulse (99' W202 C43 AMG + Ultima Can-Am sold)
Something like this set-up where the y pipe is after the secondary cats? This way probably makes less noise, more emission friendly (?) and needs no cutting. Some hi-flow primary and secondary (if needed) cats is a nice way to free up some extra horses
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From: City with Tall buildings!
C43/55,2k11 Volvo S60 T6AWD,2k Audi B5 S4,95 Eagle Talon Tsi AWD 500+awhp
That pic is how mine is setup as well.
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From: PDX
1999 C43, 2008 P30 E63, 2014 SQ5, 2024 Model Y Performance
I got rid of the 2 secondaries and put a Y pipe instead. Then I deleted the resonator and put a 2.5'' straight pipe to the stock muffler. The sound is just amazing, nice deep rumble until 3.500 rpm and then it's a bit raspier. The cold start in the morning are pure happiness
It's loud but comfortable with windows up on the highway.
I saw some gains immediately the car revs much better and pulls harder in the top end.
It's loud but comfortable with windows up on the highway.
I saw some gains immediately the car revs much better and pulls harder in the top end.
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Joined: May 2007
Posts: 119
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From: Dallas
'99 C43
You should put your new cats where the original secondary cats were. That should work with the new headers and there will be sufficient heat shielding there for the cats. The X-pipe or Y-pipe can be after the cats. I'd use a good flowing Y-pipe to a 3 inch pipe back to the original junction where the resonator outlet pipe connected to the muffler inlet pipe in the area of the back axle. The challenge will be merging the 3 in pipe to the original 2.75 in muffler inlet tube size. Nothing in the aftermarket is 2.75 inches. A good fabricator could build it from a 3 in to 2.5 in reducer....
Here's another thought for you. Put an electric cutout in the new 3 in tube in the area of the back axle before the muffler junction with a 90-degree dump. This would be similar to what's shown on that CLK 63 Black Series exhaust, except you'd just have a single cutout instead of two.
Here's another thought for you. Put an electric cutout in the new 3 in tube in the area of the back axle before the muffler junction with a 90-degree dump. This would be similar to what's shown on that CLK 63 Black Series exhaust, except you'd just have a single cutout instead of two.
Thread Starter
MBWorld Fanatic!
Joined: Apr 2010
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From: PDX
1999 C43, 2008 P30 E63, 2014 SQ5, 2024 Model Y Performance
You should put your new cats where the original secondary cats were. That should work with the new headers and there will be sufficient heat shielding there for the cats. The X-pipe or Y-pipe can be after the cats. I'd use a good flowing Y-pipe to a 3 inch pipe back to the original junction where the resonator outlet pipe connected to the muffler inlet pipe in the area of the back axle. The challenge will be merging the 3 in pipe to the original 2.75 in muffler inlet tube size. Nothing in the aftermarket is 2.75 inches. A good fabricator could build it from a 3 in to 2.5 in reducer....
Here's another thought for you. Put an electric cutout in the new 3 in tube in the area of the back axle before the muffler junction with a 90-degree dump. This would be similar to what's shown on that CLK 63 Black Series exhaust, except you'd just have a single cutout instead of two.
Here's another thought for you. Put an electric cutout in the new 3 in tube in the area of the back axle before the muffler junction with a 90-degree dump. This would be similar to what's shown on that CLK 63 Black Series exhaust, except you'd just have a single cutout instead of two.
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500hp+ IS300
Why run a cat at all? No cats might free up another HP or two. If its emissions your worried about, then the old anti-fouler trick will keep the CEL from coming on.
Just a suggestion, I've been running without cats for over 10k miles without a single CEL. When I deleted them it definitely freed up some power in the higher RPM's... But this was on my C36.
Just a suggestion, I've been running without cats for over 10k miles without a single CEL. When I deleted them it definitely freed up some power in the higher RPM's... But this was on my C36.
