C's Bimmer

Does anyone know what the diameter is on the inlet pipe on the stock muffler on an '07 530? Just to make sure there is no confusion, I'm not referring to the diameter of the tips. This is just for the diameter of pipe leading into the muffler (I believe it's called an inlet pipe). I called BMW and they said roughly between 68mm - 69mm, which equates out to around 2.68 inches, but I don't believe that's right. The woman seemed unsure.

Does anyone know? 2"? 2.25"? 2.5"?

I searched and found that Alpinewhite got a Magnaflow muffler with a 3" inlet, but am wondering if brackets were required bc it was too big.

Reason I ask is because I'm thinking about upgrading my muffler and tips to this:

http://www.performancepeddler.com/detail.a...UCT_ID=MAG14815

I believe this inlet is 2.25".

Thanks!

info@trinityautosport

i'm not sure, but when i had my resonator replaced with straight pipes on my '06, the shop used a 2.5" pipe for the given space. the stock piping, while they were fitting to, measuring, and before welding the pipe on, was just slightly larger, but not too much, in diameter than the 2.5" pipe they were going to use. i don't think it was that much of a difference to be 3". just my experience, hope it helps in some way.

FANTASTIC 5

well, i've got an 07 530 as well, and since my factory muffler is sittin' in the warehouse, it went back there and measured it for you...

inlet pipe diameter is 2.5"

JPJ

I went on Magnaflow's website and it looks like it (or others in that series) only comes in 2.25" I don't think necking down a 1/4" for a really short distance would impact performance though (certainly still a net gain with the better flowing muffler).

alpinewhite

Hey C

my muffler guy told me the same regarding the size of the inlet-- ~2.7". He recommended me with a 3" inlet magnaflow muffler and welded it shut. To be sure, take your car to a muffler shop and ask them to take a look. ImSort0fABigDeal also has the same setup as I did.

alpinewhite

you are right the performace impact. At low rpm, the car lags like a turtle. But when I pass 60mph, accerlation is much easier.

Btw, I might do a ECU chip or intake mods to help solve this problem

KnIgHtCoM

If you got time to measure inlet pipes, you got time to make soundclips!

C's Bimmer

OK...so are we saying 2.5"??? Thanks for everyone's responses. I hate these types of mods without knowing.

PS - Based on the link I showed you and that fact that it needs a 2.25" inlet, is it doable with a sleeve? Any experts out there?
Eurocarfan, Vegastrashed and I started a group buy for the Sprint Booster. That should solve this problem.

alpinewhite

C,
Sprint Booster sounds good, but I rather get 10hp+ from a chip, Per Nerweezy (I rode his car). Plus you get good mileage. He gets 20+ something mpg, while I am getting 18.5 currently. Were you are not interested in chipping before?

info@trinityautosport

sorry to get off-topic and dont mean to jack your thread c. before i had the software downloaded, i would get around 17 mpg, 18.2 at times. after having the chip, gas mileage has changed and i've been getting 20.1 in regular driving in the streets so far.

with the chip, sorry no dyno, but definitely a change. more throttle response, especially in mid and high end. top speed in each gear has increased as well. before at the end of 3rd gear, i would have to shift at about 90 mph. now, i can hold it to 95-96 mph (done when it is safe of course).

also, especially in turns, sometimes i end up with a little wheelspin even when i am not trying to get it. it's somewhat of a difference, but not that much in power. as posted by companies, most i could get out of it is 17hp, but i think less. i think they posted 24 hp out of a 525.