[Simon.bmw]

Hi everyone, i recently installed a magnaflow 14815 on my car, the sound is fairly good. but i think im loss a bit power for my set up on low rpm.. and i find that it is really loud on low rpm.. i dk whether it is normal or not?
my set up like this...
my installer use to 90 degree pipe and weld them together to get this set up.. is there anything wrong with it??
my low rpm is really loud.. and why i feel i loss some power for doing this?.
thank you.

[jc5988]

not enough back pressure will cause loss of low end tq, especially with smaller engine and auto tranny, tq loss will be more sensitive.

also prepare for drone after it breaks in, i had terrible experience with their universal muffler.

you should get a full cat back magnaflow system.

[Alpineweiss e90]

Originally Posted by jc5988

not enough back pressure will cause loss of low end tq, especially with smaller engine and auto tranny, tq loss will be more sensitive.

also prepare for drone after it breaks in, i had terrible experience with their universal muffler.

you should get a full cat back magnaflow system.

Your first and last sentence contradict each other. If loss of torque is a result of lack of back pressure, how would a better flowing catback system help?

The back pressure theory is a myth. Our car has many adaptations, one of them being for the lambda (O2) sensors.

Drive around for a few hundred miles, the car will adapt to the change. Or you can have a shop, dealer, or someone with access to INPA, or another BMW diag tool, to reset all your adaptations....throttle, octane, knock, lambda, vanos, etc.

Btw I have no drone and I also have a 14815 on my n52. And OP, my setup is similar to yours except I cut right behind the resonator and then welded a pipe directly to the res.

[Simon.bmw]

thanks for ur words, i will let it go for a while, and see whats going on..

Originally Posted by Alpineweiss e90

Your first and last sentence contradict each other. If loss of torque is a result of lack of back pressure, how would a better flowing catback system help?

The back pressure theory is a myth. Our car has many adaptations, one of them being for the lambda (O2) sensors.

Drive around for a few hundred miles, the car will adapt to the change. Or you can have a shop, dealer, or someone with access to INPA, or another BMW diag tool, to reset all your adaptations....throttle, octane, knock, lambda, vanos, etc.

Btw I have no drone and I also have a 14815 on my n52. And OP, my setup is similar to yours except I cut right behind the resonator and then welded a pipe directly to the res.

[AddictedToBavarian]

14815 was the same for me. Loud on low RPM.

[Simon.bmw]

Originally Posted by AddictedToBavarian

14815 was the same for me. Loud on low RPM.

lol..any idea? i dot want it too loud in low rpm...

[mapleridge]

others have felt a loss initially after installing a new exhaust but after adaptations it seems to pick back up. how long ago did you install it? Pictures of the finished product?

[Simon.bmw]

Originally Posted by mapleridge

others have felt a loss initially after installing a new exhaust but after adaptations it seems to pick back up. how long ago did you install it? Pictures of the finished product?

3 days ago.. lol..
pics would update later..

[mapleridge]

As a follow up. I put my aftermarket exhaust on the Dyno. I thought I had lost torque and power but I had gained in both. I think the added noise and the fact that you aren't really speeding up plays tricks with the mind.