Rear Diffuser - BMW Forum

silver328is · 10-14-2004, 12:24 PM

I was looking at getting a Rear Diffuser for my 328is but i dont want it to look bad. So i was wondering if the 328is bumper is the same as an M3 besides the Rear Diffuser?

Autotechnica · 10-14-2004, 02:11 PM

Quote:

Originally posted by silver328is@Oct 14 2004, 11:24 AM
I was looking at getting a Rear Diffuser for my 328is but i dont want it to look bad. So i was wondering if the 328is bumper is the same as an M3 besides the Rear Diffuser?

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The M3 rear bumper is not the same as the standard 3 series. However, with a little modifcation to the M3 rear diffuser, you can make it fit your bumper. I have it on mine. All you have to do is clip off the ends of the diffuser slightly. The clips along the top of the actual diffuser won't line up, nor will the 2 holes on each ends for the bolts. Depending on the amount of work you want to do, it can be mounted numerous ways. Some people will just use zip ties and tip up the ends to the mounting holes. Other will put self tapping screws up through the top of the diffuser and into the bumper. It will take a little bit of work, but the fitment looks OEM.

Bry

Cruzin 323is · 10-14-2004, 04:28 PM

oem rear diffuser will fit, but won't look too good... bavauto has a rear diffuser that fits a non M e36 bumper... take a look over there!!

k2c69n · 10-14-2004, 05:03 PM

Quote:

Originally posted by Cruzin 323is@Oct 14 2004, 03:28 PM
oem rear diffuser will fit, but won't look too good... bavauto has a rear diffuser that fits a non M e36 bumper... take a look over there!!

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I actually just picked up the mdiffuser from bavauto, its on sale right now. I have yet to get it painted or mounted, hopefully when all is said and done it will fit and look good. the directions that come with it seem pretty easy. The last thing i need is another headache.

bigred318 · 10-14-2004, 05:10 PM

yeah i saw that it is on sale you should go pick it up it makes the back bumper looks really really good, i like it also better than the stock e36 bumer!

DAvid

silver328is · 10-14-2004, 05:14 PM

i think that it would like better if it were not painted. will the plastic, not painted, change color after a while or would it stay black?

P.S. k2c69n, could you post a pic of the rear end of your car once you get the diffuser on?

jllphan · 10-14-2004, 06:33 PM

Ok ok ok, here's a topic that peaks my curiousity.

The ///M3 rear diffuser is much like the one on my old Porsche. That gives me reason to believe that it's somewhat functional at very high speeds. Therefore, I would be more apt to install the oem piece, as the bavauto piece is solid, and not able redirect airflow.

So, can one purchase the oem piece without buying the whole damn rear bumper, and if so where. Once purchased is the same do-it-yourself cutting necessary.

Probably all questions that can't be answered, but Autotechnica, you probably at least looked into it.

k2c69n · 10-14-2004, 07:36 PM

Quote:

Originally posted by silver328is@Oct 14 2004, 04:14 PM
i think that it would like better if it were not painted. will the plastic, not painted, change color after a while or would it stay black?

P.S. k2c69n, could you post a pic of the rear end of your car once you get the diffuser on?

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yeah, i am going to install it and see how it fits this weekend, I will post pics then, just keep in touch.. if all goes well, im taking it off for the winter and will reinstall it once the snow and stuff melts, no sense of starting outside mods so late in the season.

Deloriant · 10-14-2004, 08:58 PM

Stock Rear

M3 Rear

theogill · 10-14-2004, 10:34 PM

Delorant: That is wicked nice looking!

Autotechnica · 10-14-2004, 10:38 PM

Quote:

Originally posted by jllphan@Oct 14 2004, 05:33 PM
Ok ok ok, here's a topic that peaks my curiousity.

The ///M3 rear diffuser is much like the one on my old Porsche. That gives me reason to believe that it's somewhat functional at very high speeds. Therefore, I would be more apt to install the oem piece, as the bavauto piece is solid, and not able redirect airflow.

So, can one purchase the oem piece without buying the whole damn rear bumper, and if so where. Once purchased is the same do-it-yourself cutting necessary.

Probably all questions that can't be answered, but Autotechnica, you probably at least looked into it.

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I just explained above that the OEM peice fits perfectly without much modification. Everyone chose to ignore my post

n. Anyways, here's a picture of the OEM M3 diffuser installed on my "stock" E36 rear bumper.

Bry

silver328is · 10-15-2004, 10:24 AM

Autotechnica: can you post a bigger pic?

Deloriant: do you have a pic of it on before painting it red?

thanks for all the post, you guys are great

akolang · 10-15-2004, 08:27 PM

hmm so far ive been using the stock rear diffuser from an m3, and now my new one just arrived the one from bav auto and it doesnt fit quite perfectly, had to trim a little, and the color is kinda off from the stock one, not as shiny

anyways its not too bad

jllphan · 10-16-2004, 12:00 AM

Autotechnica: as you can see in my earlier post, not EVERYBODY ignored you. I was curious if you had the actual ///M difuser or one from Bavauto? It looks like the oem unit is similar to the diffuser on my last car and seemed functional at redirecting the air flow, wheras it appears that the unit from Bavauto is solid. Is that the one you have, couldn't tell from the pic.

Back me up here akalong the oem rear diffuser is channeled, right?

akolang · 10-16-2004, 02:10 AM

yea i think so