High flow cats anyone?

[solo the lad]

anyone ever put high flow cats in their N52 z4? Curious as to what the sound/ performance difference was if any at all

[3002 tii]

Originally Posted by solo the lad

anyone ever put high flow cats in their N52 z4? Curious as to what the sound/ performance difference was if any at all

Only worth it if you’re getting rid of primaries. If you’re keeping factory headers, then you can even get rid of the secondary cat entirely.

[deemo319]

After screwing up my exhaust system I rectified it by adding high flow secondary cats and a resonator.

After having it on the car for about two years I heard some sound’s yesterday that I have never heard before. Which reminds me that I need to get a sound clip or two.

[Our03z4]

I have no back box and no secondary cats but I do have a magnaflow muffler. The combo sounds perfect, not too loud, no drone and it does nice little pops like my m54 5spd use to. Wouldn't change a thing, even my wife likes it...which is saying a lot.

[solo the lad]

Originally Posted by deemo319

After screwing up my exhaust system I rectified it by adding high flow secondary cats and a resonator.

After having it on the car for about two years I heard some sound’s yesterday that I have never heard before. Which reminds me that I need to get a sound clip or two.

Do you have the N52? I've been curious about removing the secondary cats, my muffler has already been removed but I would like to get some more pops and crackles

[deemo319]

Originally Posted by solo the lad

Do you have the N52? I've been curious about removing the secondary cats, my muffler has already been removed but I would like to get some more pops and crackles

I have a 3.0si. With the secondary high flow cats resonator my car now sounds like I wanted it to. It gurgles, with subtle pops, and crackles along the rev range.

[solo the lad]

Originally Posted by deemo319

I have a 3.0si. With the secondary high flow cats resonator my car now sounds like I wanted it to. It gurgles, with subtle pops, and crackles along the rev range.

Lovely. So you've left the resonator in then?

[deemo319]

I took out the factory exhaust system (large and heavy) and added

1) Schmiedmann Hi Flow cats
*these help the overall sound to a certain
extent. I was surprised when they arrived
and found that they are well made with
very nice welds and a high polish.

2) MagnaFlow 4x9 Resonator part #11378
*it’s very small and very cheap with very
good quality!

3) Different Trends Exhaust Tips (part #
DT-24017AC) t
* These are huge but they do fit within the
factory exhaust tip’s cutout. They are
double-walled with high polish and
measure 2.25” and 3.5” out