tajul75

w204 c200

gtracer

wrong section dude.

AMG3.2

At least it was a great post...

Celicasaur

Screw it. I actually really want to know what made this guy sign up to a forum to ask this question...in the wrong forum.

Tajul, i run 3 inch exhaust piping on my car. What appears to be the problem with your car?

tajul75

its my bad. maybe very eager to be the c63 owner

Adi-Benz

why do you need a 3" exhaust on a c-class 1.8?

tajul75

actually theres no problem arise yet. but planning to upgrade more n more. my car is W204 C200 CGI year 2013 model. Now my exhaust system from downpipe(2.5" w/o cat) straight to the end 2.5" piping w 1 small resonator to slow the sound & the end with 2 valvetronic muffler. Done mapping. from dyno result now is 190++WHP & 336++Nm. i want it more such as 250whp is it possible? Planned to change the exhaust piping from downpipe till end. What is the best pipe size if i want to upgrade the intercooler (Tonado @ Rado pls give suggestion).

P/S: admin pls forgive me about this thread. i x know how to transfer the thread to w204 forum @ i need to start new thread in w204 forum. its my bad.

Jasonoff

tajul75

absolutely correct.

krazzdav

Don't do it tajul75; 3" pipes are rarely beneficial unless you are pushing an extreme amount of HP. You will benefit from the back pressure of smaller pipes and actually lose power going with bigger pipes. Your best bet if you want to mod is invest in a nice dyno software simulation program. Im not sure what is out there now but in the good old days (20 years ago haha) when I used to race these programs were very beneficial. You need to "match" all your components to get the most out of your setup.

Fatz

3" pipes could yield better or worst performance depending on the engine and it's tuning and how the engine/car is driven. Assuming a stock setup and "as designed for" driving, at best performance would remain the same. There could be some "seat of the pants" improvement precipitated from, or aided, by the fact that "you" did it. Worst case is you would go beyond some limits the MB engineers accounted for and performance would decrease.

Larger pipes have more capacity for exhaust volume but results in a reduction of exhaust velocity. The longer the exhaust hangs around the more power there is required from the engine to move it on the next exhaust stoke of a cylinder. The larger pipe will also have a bias toward enhancing the lower frequency content of the exhaust. The stock size is generally arrived at based on performance across rpm range and probably using some "expectation" around "how" the car will be driven.

Also, in general, the pressure "seen" by the engine will be dictated mostly by the size of the smaller diameter section of pipe, and it's relative distance from the exhaust port/s of the engine.. So adding larger pipe, say from the cats back, primarily only affects the exhaust tone with some secondary negatives, IMO, of slowing the exhaust flow rate (velocity) some. Sorta like those nasal strips, unless you're clogged up or needing to pump more air in a given time frame (athletes competing) through a smaller than required air passage, they're not needed. Your unaltered nose is just fine.

Celicasaur

I agree with everything you said ^ but what I don't understand is why the E, CLS, SL....(all of the models with full throttle from factory) have near enough 3 inch piping throughout.

I spoke to Kleemann about this also and Claus was adamant that 3 inch piping is optimal for the M156.

But yeah, a carefully crafted 'stepped' exhaust would be the best system.

Fatz

Of course I don't know why, but it could just be a matter of product positioning by MB. I would have no doubt that a tuner like Kleeman could tune the car to get the "extra" out of it without reducing performance due to other parameters of the car. Just installing the larger pipes, I think, would be a 50/50 proposition.

I have much respect for Kleeman, even though I wish they built a supercharger for my 550, and would certainly follow their lead/recommendations. Perhaps the CLK550 is an example of where, due to the CLK impending obsolescence, MB tapped into more of the engines capability and did not do a CLK55 in those last couple of years. Since business is business, there was probably not enough left on the table to generate enough demand and make it profitable for Kleeman to build a supercharger for the M273.