Supersprint X-Pipe - Page 2

pride355 · 13th March 2003, 10:38

Quote:

Originally posted by HIPAD
Pride355,

I don't understand why would the torque decrease and the horsepower increase when you remove the cats? Shouldn't both horsepower and torque increase?
Since there aren’t any cats in the way of the exhaust gas flow, I think it makes the gas flow much smoother. Wouldn’t that result in better horsepower and torque numbers?

In US spec M3s, cats are too close to the engine which results in decrease both in hp and torque. However, on the other hand too much flow means no back pressure, so at low rpms torque numbers decrease and at high rpms hp numbers increase but you make a compremise there.

So the best combination is achieved with enough resisdance with the cats to increase torque at low RPMs and then free flow silencer and rear muffler to increase hp in high RPMs.

Have you read the articles I posted on exhaust system??

pride355 · 13th March 2003, 10:56

Quote:

Originally posted by johann
I think that if you change to race cats (metal cats) you'll get the sound you are looking for. You also get some extra power as a bonus.

Cheers,
/Johan

Johann, I agree with you. My friend used to have racing cats on his E36 M3 EVO (the fashion rot M3 before supercharged) and I liked the exhaust note very much; deep and loud. It was better than my EVO's exhaust note which had SS resonators and SS cat-back.

I shall spend my money on race cats instead of rear muffler. I really believe OEM E46 M3 muffler is one of the best mufflers in the market.

pride355 · 13th March 2003, 11:01

Here is the Euro spec M3 exhaust system on E46 M3:

You can see that actually there are 4 different parts.
1- headers
2- cats (SS has race pipe or race cats for this section)
3- X-box; small silencer (SS has connecting pipe or centre silencer for this section)
4- Rear muffler

HIPAD · 13th March 2003, 20:04

So the best combination would be the X-pipe plus the race cats.
How much torque would you lose if you install a straight pipe in place of the cats? Is it significant?

pride355 · 14th March 2003, 18:14

Quote:

Originally posted by HIPAD
So the best combination would be the X-pipe plus the race cats.
How much torque would you lose if you install a straight pipe in place of the cats? Is it significant?

Tell you the truth I really don't know how much torque you would lose with straight pipes in place of cats.

On the other hand; I believe the best combination would be SS X-pipe (actually centre pipe; in order to correct myself) and race cats as you suggest.

Phoenix · 14th March 2003, 21:13

i decided to go with SS headers, met racing catz, mid pipe with no resonator, and titanium exhaust and get rid of the ACS which i lost some hp with. I'll let you know how this setup is once its installed in a couple of weeks. By the way what are toque numbers on the dyno suppose to be with a stock M3?

M PWR · 14th March 2003, 22:40

Phoenix,

I don't think you'll need met cats.. since you're changing the headers..

M PWR

pride355 · 14th March 2003, 23:32

Quote:

Originally posted by M PWR
Phoenix,

I don't think you'll need met cats.. since you're changing the headers..

M PWR

NO, I think you are Wrong. Phoenix, you have the perfect setup; WELL DONE

Only downside is it is VERY expensive. How much will you pay??

SS headers should be close to 2000 $
SS Metal cats should cost approx. 1600$
Centre pipe is relatively cheap; should be around 500$
And eisenmann titan. is around 2500$

Can't say much; YOU DO THE RIGHT THING

Best alternative for your setup is Metal cats + centre pipe IMO (if you have euro spec car already)

Waiting for your dyno results

M PWR · 16th March 2003, 03:34

Pride355,

Phoenix has a U.S spec car.. so again I think what I said is right.. If it was a euro me too will think its a perfect mod

M PWR

pride355 · 16th March 2003, 03:54

M Pwr,

Do you know what US spec cars have in place of euro cats?
If they have only straight pipes (which I don't think so), euro headers or SS headers on a US spec car decrease torque because there would be no back pressure since you eliminate the cats by changing the headers, and by putting race pipe and connecting pipe the only silencer would be the rear muffler.
I believe you'll have more hp but at low RPMs torque numbers would be significantly low due to lack of back pressure. Also in the States, passing the emmisions would be a problem.

If I had an US spec M3, I would have put SS or euro headers with race (metal) cats. With this setup, you'll gain both hp and torque.