Anyone put QUADS on a 535i LCI yet????

 

With the magnaflow 10425, you essentially have a straight through system. From the cat to the first two resonators, it is straight through. Those OEM resonators have preforated tubes inside, but I cannot recall if they are also insulated. I doubt it. Then the two pipes go to the center resonator which is also straight through preforated non insulated. You can get the shop to cut the Y section of the center resonator box and have each pipe go the left and right side to the rear mufflers (10425). The 10425 is a straight through preforated insulated muffler. It is essentially a cherry bomb or a "resonator muffler." The reason it is considered a muffler is because it is insulated (4" - 2.5" equals about 1.5" of insulation).

This was my first setup, and it was very loud at the low rpms (1800-2200) or when the engine is tugging (assuming you have the v8). That is called droning. It is stock sound when you go above 3500 rpm. It idles quite loud too with the AC on and a hot system.

Sound level is relative to everyone unless you have db meter. But I prefer not to get into technicals. With the magnaflow, it sound intoxicating at first, but it will get old quick. If the stock sound is rated at a 2, I would rate the the magnaflow to be a 6-7 inside the car cabin (at the low rpm). I got rid of my magnaflow and purchase a pair of turbo tubes from Jones Exhaust. These are channeled (snaking the exhaust gas inside the tube), and it will allow for backpressure, but size is also smaller (1.75"). All the while, it reduces the sound by 3/4 of the magnaflow.

Think about it, if the stocks widest pipe is 3" (after the center resonator Y into a left side 3" pipe, two 1.75" is still more flow than stock, and the channeling plus x-pipe (upstream) will give it some backpressure assumingly equally the stock mufflers.

 

Got one of the videos...removed a lot of scenes, but still made like 5 or 6 appearances.

http://www.youtube.com/watch?v=VIGDrg4vgiU

Got a front and rear at 1:05...few more throughout.

I'm also in the video with a couple of my boys, I'm the guy in the black hat white shirt black jacket, next to my cousin in the blue dodgers jacket.

I'm a little unimpressed, they took way more footage of the car but edited quite a bit. Said they would use the footage elsewhere. Oh wells....

 

Thanks for this write up!
I just ordered the same parts, (minus all hangers) and set up install on Tuesday next week. I'll add more pics and video when it's done.

Parts plus labor will be just under $700.

Edit: I actually got a different set of tips, Magnaflow 35168, but virtually identical. 2.25" in, dual 3" out. (any bigger and it won't fit well under the openings)

 

You're welcome.

 

What is it with this backpressure talk. You don't need back pressure in a system. You need to match the velocity with the diameter so the gases can expel quicker. You DO NOT want backpressure. The whole point is to get ZERO backpressure. If you have backpressure, you will lose HP, if your piping is too big you will also lose HP.

 

What brand and model did you use

 

@ west do you have a pic with a shot of the rear with tips installed?

 

hey db540. the only pic i have is this one. it's not a direct rear shot, sorry:

honestly, the tips aren't all that big. they are pretty subtle.

 

Did you think about bumping it up to 2.5" piping or has the 2.25" given you gains.