[abhaxus]

So I have been lurking over the last year or so, and purchased my 550i back in February. Thanks to the forums, I've been extremely happy with it. Last month I put a custom exhaust and a BMS Stage 1 tune on it. Was thinking I'd get better mileage (and I do on the highway, about 25 mpg now) but I have too much fun driving in sport+ to get an improvement in the city.

Vids for exhaust note:
Drive by acceleration:

Three stages revving (stock/xpipe/mufflers):

Anyway, I have a few questions which I'll break out into threads if I need to.

1) The new muffler tips I have are toward the inner edge of the cutouts on the stock M-Sport diffuser. Will they fit better on an aftermarket M5 diffuser, or should I just live with it?

2) what brake pads should I buy? OEM spec or something else? Concerned more with pedal feel and stopping power than dust

3) is there any way to get more sound from the turbos/diverter valve without buying the cold air intake from N63intake.com?

Thanks in advance.

[spyroz]

Congrats. on your New N63, If I were you, just enjoy the powerful v8, twin turbo. over the 535 and 528. As for your questions, I don't know what you mean by #1. I guess if you're not happy with the sound, you can upgrade to an M5 muffler or megan muffle as for aftermarket. The M5 diffuser will NOT fit with your OEM 550i Msport muffler, because of the angle of the tips. #2. stick with OEM, and last. I wouldn't spend $1,200 for a air intakes that make no HP or improve on your performance, not to mention it some time give you CEL. A lot of people try to make the N63 intake but so far none are success, that's the way of the MAF system work, too much airflow can cause CEL. But hey, that's your choice. Until someone actually tested the system,tune and map it to work perfectly then I'll buy one...

[lsturbointeg]

Curious as to if you had a custom exhaust system done why didn't you're muffler shop make the necessary adjustments?

[abhaxus]

Originally Posted by lsturbointeg

Curious as to if you had a custom exhaust system done why didn't you're muffler shop make the necessary adjustments?

There wasn't a lot room with the length of the mufflers and tips. It doesn't look awful right now, I kinda think anything with quad tips would look weird with the angled cutout on the bumper. I was just wondering if the m5 diffusers had the cutouts slightly towards the center of the car by an inch or so.

This is before the hangers were welded on, so they are a little higher up now.

[lsturbointeg]

I see what you mean. I'm in the same boat! The tips aren't protruding far enough past the diffuser which can be done but it'll cost me $125. My muffler guy couldn't center the quad tips between the exhaust openings in the diffuser because my QTP motors was almost hitting the spare wheel well