Secondary Cat Bypass?

[X5 AFICIONADO]

I am thinking in doing a Bypass in the second cat in a 2002 3.0.....
Anyone knows any side effects this might have?

I all ready did thismod in my father´s Cayenne and I am very happy with the results, a much throatier sound.

[powers1]

Originally Posted by X5 AFICIONADO

I am thinking in doing a Bypass in the second cat in a 2002 3.0.....
Anyone knows any side effects this might have?

I all ready did thismod in my father´s Cayenne and I am very happy with the results, a much throatier sound.

You will have a less restrictive engine and a gain of power of +/- 1.5%.......
This on a 3.0i!On a 3.0 D,you will get more as the turubo will spin faster.......

[X5 AFICIONADO]

Powers1,
thanks for the info

[vinuneuro]

Originally Posted by powers1

You will have a less restrictive engine and a gain of power of +/- 1.5%.......
This on a 3.0i!On a 3.0 D,you will get more as the turubo will spin faster.......

Yea, on the diesel going to larger diameter tubing starting with the downpipe would do wonders as far as reducing backpressure. Does anyone know if exhaust diameter is the same across all the engine models? What is stock diameter?

[powers1]

Originally Posted by vinuneuro

Yea, on the diesel going to larger diameter tubing starting with the downpipe would do wonders as far as reducing backpressure. Does anyone know if exhaust diameter is the same across all the engine models? What is stock diameter?

The ideal exhaust system for the 3.0D(as tested on Rollers!),is to replace the kat with a downpipe with a slight increase in diametre from the 51mm (2.0")std to 57mm(2.24") piping all the way to the rear Mufflers where in my case I am installing the 4.8is which have an std entry pipe diametre of 63.5mm(2.5").
Therefore:-
3.0D=2.0"
4.8is=2.5"
4.6is=????
4.4..=????
3.0..=????