Ale-Superbike

HELLO I WOULD LIKE TO ADVICE, SEE THAT FOR A GOOD DRAINAGE IS CHANGING HEADERS, CAT / CATBYPASS, MUFFLER, BUT I WANT SOMETHING NEW. I DO NOT WANT TO CLIMB ON THE CAT, BECAUSE I WANT Reprogram the ECU. SO WHAT DO YOU THINK OF A DISCHARGE IN PICTURES LIKE THIS? WEIGHT IS CLEAR, more straightforward:

Dennis C

Huh?

Tippy

I don't follow either. The second pic looks like a 993 but I could be wrong.

kiesan

You and me both Mr. Ale. Carry on.

onefastviking

With coolant pipes ? Naw, I'm thinking it's an early 6cup.

Ale-Superbike

My English is not 'the best. The photos are of 996, I would like to change the complete exhaust to my 996 3.6 x 51. I do not put the cat. These discharges in the picture what do you think? Lose 'hp low?

Dennis C

I think it will be loud!

nick49

In most modern motors a little back pressure is good. It keeps the intake charge from following the exhaust out the combustion chamber during the overlap event of the cams and keeping midrange power losses at a minimum. That doesn't mean you can't have a less restrictive and lightweight exhaust system, which if tuned properly can add power and concentrate it in the rpm range most necessary for the cars intended purpose.

By losing the cats, some restriction and weight will will be lost as well. Some things to keep in mind designing your system, are simpler is generally better. Fewer welds, mean fewer potential areas to crack. A bend increases static pressure, just like adding length. Fewer bends are better. Make bends as large of radius as possible. There is plenty of information regarding exhaust pipe length for maximum torque. Ideally, exhaust systems can be made to help scavenge cylinders that have just fired by creating a low pressure area to help pull out the exhaust charge. Sounds fun! Let us know what you come up with.

Torontoworker

Discharge?

(I'm sure you'll all appreciate my self-censorship as far as what picture I *could* have posted... )

Tippy

Ah, I see. Exhaust looked like a 911 system, block looked like any air-cooled engine, and then the piping going to the heads I had never seen before.

Ale-Superbike

Uppppppppp .