HF Catted Downpipe Question

[M3 SRRY]

Hello all,

Im wondering if a HighFlow catted downpipes provides any valid gain to performance or sound especially matched with the AA single mid pipe and a remus backbox. Ive read that the stock cells are properly efficient just as the top mount intercooler and doesn't really need any aftermarket replacement but could there be minimal gains with a redesigned cat as well as pipe diameter for increased sound even though they are still catted?

Thanks.

[ck_M3]

I went with catted DP’s, matched up with a non-resonated single MP from AA, and stock muffler. Up’d my tune to Stage 2, and I feel there a bit of a gain; not huge, but enough to be noticeable.

The sound however became too loud for my ears, so I ended up swapping pipes with someone to be resonated.

Don’t expect the gains to smack you in the face, I will suspect it to be even more noticeable if and when I go E85

[TopJimmy]

Just some gain in sound.

[M3 SRRY]

Originally Posted by ck_M3

I went with catted DP’s, matched up with a non-resonated single MP from AA, and stock muffler. Up’d my tune to Stage 2, and I feel there a bit of a gain; not huge, but enough to be noticeable.

The sound however became too loud for my ears, so I ended up swapping pipes with someone to be resonated.

Don’t expect the gains to smack you in the face, I will suspect it to be even more noticeable if and when I go E85

Would you mind posting some sound clips when you have time?

[Info@mad-us.com]

Originally Posted by M3 SRRY

Hello all,

Im wondering if a HighFlow catted downpipes provides any valid gain to performance or sound especially matched with the AA single mid pipe and a remus backbox. Ive read that the stock cells are properly efficient just as the top mount intercooler and doesn't really need any aftermarket replacement but could there be minimal gains with a redesigned cat as well as pipe diameter for increased sound even though they are still catted?

Thanks.

Opting for race cats with significantly fewer cells than the factory downpipe, such as our 200-cell race cats, can certainly result in improved sound and gains. As you generate more power, the performance gains are likely to become even more noticeable.

[mike@x-ph.com]

Noticeable increase in sound

Power wise:

On upgraded turbos, they are a must, in my opinion

On stock turbos, the gains will depend on how much PSI you are pushing.

The power increase would not be noticeable on base maps but will make a significant difference on custom maps.