[pocoyo_3]

I have been trying to understand why there seem to be differing opinions on the noise of our cars. I realise that noise / drone / rasp is a subjective thing, but I did want to see if there was any correlation to the following:

(1) Presence of secondary cats (xDrives have them, rear drives don't)
(2) Presence of Performance Pack or other tune
(3) Exhaust flapper mod (such as golf tee mod or via PPK)
(4) Manual or automatic (if this makes a difference)

Mine is a rear-drive manual, and I don't recall what it sounded like before the Performance Pack install, but at the moment it drones loudly at 2000 rpm under load. I had a performance exhaust on it at one point and that was unbearable). However, I have been in an xDrive with the Performance exhaust and that was cultured (and sounded great).

I'm looking to hear other people's experiences and thoughts.

[mashimarho]

Originally Posted by my325i

I have been trying to understand why there seem to be differing opinions on the noise of our cars. I realise that noise / drone / rasp is a subjective thing, but I did want to see if there was any correlation to the following:

(1) Presence of secondary cats (xDrives have them, rear drives don't)
(2) Presence of Performance Pack or other tune
(3) Exhaust flapper mod (such as golf tee mod or via PPK)
(4) Manual or automatic (if this makes a difference)

Mine is a rear-drive manual, and I don't recall what it sounded like before the Performance Pack install, but at the moment it drones loudly at 2000 rpm under load. I had a performance exhaust on it at one point and that was unbearable). However, I have been in an xDrive with the Performance exhaust and that was cultured (and sounded great).

I'm looking to hear other people's experiences and thoughts.

I'm hoping you aren't refering to your 06 e90 325i.

I've noticed xi vs i, sedan vs coupes, tune, cats, resonator, exhaust (of all sorts), and how old the car is.. These makes some sort of difference.

I don't have the exhaust flapper in my situation because mine is always open due to the exhaust I have.

[pocoyo_3]

No worries, it's not the 06 325i. That was my last car. Which exhaust do you have, and how loud is it?

[evo335xi]

Secondary cats keep drone and raspiness to a minimum. I have them on my xi manual with downpipe and corsa mufflers still but have toyed with the idea of putting resonators in place. I have 0 drone very quiet cruising.

[pocoyo_3]

You're lucky if the secondary cats keep it that quiet :-) Drone is not fun.

[SRT14PimPin07]

I personally have BMW performance exhaust with AR catless DP's and Jb4 as a tune, mine is auto and a coupe so no extra cats. I have very very light minimal drone, only when RPM's are low and I put a lot of load on the engine. For example, going up a steep hill.

[pocoyo_3]

Unfortunately mine drones annoyingly at 1800-2500 rpm in 3rd or 4th gear under load, such as going up a hill. My car is stock (I even had PPK uninstalled). It's to the point where others riding in my notice and complain about it as it's loud enough that you can feel it through the floor. Rear passengers have it worse. I'm considering trading the car for something else.

Does anybody have any suggestions on what I can do to reduce drone.

[evo335xi]

What is done at the moment? Flapper intact?

[pocoyo_3]

Flapper intact. The car is completely stock.