elie7

what made you decided not to use magnaflow oval muffler x-pipe #11385 and instead just 2 of #10425 resonator?

jtjr0313

back pressure

E60I

Sorry for sounding stupid, but what does back pressure means for your specific set up (2.50" inlet/ 3" outlet)? Unless I am mistaken, your car has 255 HP and so is mine. If I decided to take that route and want the sound to be similar to my stock's, what can I add? My only objective is to add another set of exhaust tips because I just want the quad looks on my Mtech Kit.

Also, are you getting less MPG on your new exhaust set up? My stock car (2006 530i) is giving me 19 MPG on mixed use and I really don't want it to get worse.

Thanks!

jtjr0313

No such thing as a stupid question... just stupid people who stay stupid cuz they didnt ask the question. Anywho... yes i went with a smaller pipe size and i replaced the resonator with an x-pipe as you can see in the pics. the reason for the smaller piping. i was told that it would help with the backpressure. its only a 255hp engine like you said. BMW optimized the factory exhaust to its max potential. by adding another pipe of the same size from front to back would just be like killing all that back pressure. x-pipe brings all that gas to a central and constricted location creating that pressure and then lets it shoot out. Hence the (X) shape. right now if im not mistaken... your 530i's resonator should be a 2in and 1 out. change that resonator to a 2in and 2out and run a pipe to the back and weld the tip on to that pipe. its basically what was done to mine. but where the resonator use to be i put the x-pipe and the two oval magnaflows. you just gotta look for and muffler or resonator thats made to be quite and not alter the sound. (dont know why you wouldnt want the car to sound beastly but... your choice)

And in regards to the fuel consumption... i havent noticed a change. the only change i notice is when i turn my sprint booster on to aggressive... that baby sucks up the gas like it was a v8... but once its off the car feels like it goes on forever. so no... it still receives around the same gas mileage

Chief Holley

I just listened to your video and wow, that sounds niiccee! It would be a little too much for me though, I want a little more stealthier sound.

elie7

Just wondering where the xpipe picture is located?

jtjr0313

x pipe is right in front of the mufflers towards the front of the car... in the pics before youll see it laying on the ground along with the other parts

elie7

What is the reason for installing the two resonators right after the x pipe instead towards the end, close to tips. Sorry for asking too many questions. I'm trying to replicate same project you did for quad tips on my 530i. I wanted not to make the car not too noisy as much as possible. I like the looks of quad tips on oem bumper.

jtjr0313

real reason is they were put there cuz it would be easier to install... if they would of put the two mufflers towards the back near the tips... the one on the right would not come out straight... and they would have to mess around with the tips a lit bit more then i would of wanted them to. so they just ran the pipes to the back... that way they have more wiggle room to make the tips even coming out of the back. to tell you the truth i bought the two separate mufflers because thats what i wanted them to do, was put them towards the back near the tips. but i saw his reasoning. you dont have to buy two separate mufflers if you are gonna do it the way i did it. you can just get a 2 in 2 out muffler.... what ever brand that makes the sound you like. there is another guy on here.... i cant find that blog though. but he put the x pipe, a 2 in 2 out muffler, and then two silencers towards the back to lighten the sound of the muffler a lil bit. you can try that too.

Rock_Head1956

Stones of steel you got bro! Great job!. Vids like this demystify the art of DIY. Kudos!