I have a problem with the exhaust Mugen.

I put Mugen exhaust manifolds and cat back Mugen. Instead of the standard catalyst then founded Berk HFC 70mm.

My S2K lost some horse power? Do you blame for this may be the size of BERK HFC 70mm (Mugen header and CAT BACK have smaller diameters of about 65 mm.

Should I replace it with a smaller diameter HFC?

 

My best guess is that where the catback connects to the HFC, that step back down to a smaller diameter pipe is causing turbulence, which is robbing you of a little bit of horsepower. So yes, either switch to a smaller diameter HFC or switch exhausts and headers (because you can do better than Mugen), and that should fix the problem.

 

Now and today continued testing, I assumed Test Pipe and the power of standing still.

Still 232 hp. Almost the same as the oversized Berk. Performance chart is nice, but still lack equal horses ...



Torque 200Nm.

My car has very low mileage. 10 thousand km. (6200 miles) ...

I'm starting to have no idea what is wrong ...

 

what were the numbers with the oem parts on the car, before you added these two mods ?

 

Power without any modifications to 226 HP. (6 thousand km distance).

After installing the K & N intake 236 hp (April 2013)

After installing the Mugen catback 237 hp (May 2013)

After mounting the Headesr Mugen + BERK HFC + + Mugen catback K & N 232 HP (July 2013)

when we got back to the standard manifold and standard catalyst came out 229 HP (July 2013)

Today, after installing Test Pipe 231 hp.

Auto-tuned Hondata has the correct amount of fuel and the correct AFR.

Power stopped at about 230 hp....

 

Gernby has done endless Test pipe / exhaust research for the community. Find his thread. He explains how the worst thing you an do to an S is have different size Header collector->test pipe -> exhaust. He also patented his own test pipe/exhaust based on all his research. The different size piping is probably causing turbulence and messing with your HP numbers as he explains. Gernby's thread and research is invaluable information.

 

But today I set up the correct size Test Pipe. 60mm .. is the same as the exhaust system MUGEN. Power is in place ...