[CitrinF30]

I'm currently running BM3 Stage 2 93OCT AGG tune.. at the moment I'm fully catless but I'm looking into putting a high flow catalytic in just after the downpipe in the mid pipe area.

I'm wondering if anyone's got any feedback on this, how much power loss will I notice with a ultra high flow, what brand to get etc..

Thank you! (Car is a F30 335i xDrive)

[n55david]

Originally Posted by CitrinF30

I'm currently running BM3 Stage 2 93OCT AGG tune.. at the moment I'm fully catless but I'm looking into putting a high flow catalytic in just after the downpipe in the mid pipe area.

I'm wondering if anyone's got any feedback on this, how much power loss will I notice with a ultra high flow, what brand to get etc..

Thank you! (Car is a F30 335i xDrive)

that location is realistically too far back to heat up to the proper temp to actually do what its supposed to. either change the downpipe to a catted version or go about it different.

are you doing it for sound deadening or for emissions reasons?

[thejeremyman9]

Originally Posted by Phantom10R

that location is realistically too far back to heat up to the proper temp to actually do what its supposed to. either change the downpipe to a catted version or go about it different.

are you doing it for sound deadening or for emissions reasons?

The further back the cat is located, the longer it will take to heat up, but it will still work. I recall a few threads a while back where people installed cats in other locations. Usually this was paired with a cutout so that you could have a catted exhaust when close and a catless open exhaust when open.

Having said that, i too would recommend just getting a catted DP.

[mike@x-ph.com]

Originally Posted by CitrinF30

I'm currently running BM3 Stage 2 93OCT AGG tune.. at the moment I'm fully catless but I'm looking into putting a high flow catalytic in just after the downpipe in the mid pipe area.

I'm wondering if anyone's got any feedback on this, how much power loss will I notice with a ultra high flow, what brand to get etc..

Thank you! (Car is a F30 335i xDrive)

Whats the reason to add cats in the midpipe? It makes more sense to replace your catless downpipe with a catted one

[CitrinF30]

Originally Posted by Phantom10R

that location is realistically too far back to heat up to the proper temp to actually do what its supposed to. either change the downpipe to a catted version or go about it different.

are you doing it for sound deadening or for emissions reasons?

Would this still apply even if I have the HF Cat mounted right after the downpipe?

Mostly for legal reasons.. tired of being bothered by police for not having a Cat.

[CitrinF30]

Originally Posted by mike@x-ph.com

Whats the reason to add cats in the midpipe? It makes more sense to replace your catless downpipe with a catted one

I just want to add one high flow right after the downpipe, and mostly due to buying a catted downpipe is a much higher cost then putting in a high flow cat. Especially after just buying the catless DP not long ago.

[Randy Johnson]

Your best option is the vrsf catted downpipe for $400.

[thejeremyman9]

Originally Posted by Randy Johnson

Your best option is the vrsf catted downpipe for $400.

Cheapest option

[Logicoeur]

Sell the catless dp. Buy a catted Dp. Prosper.