Advise on rear diffuser and tips for 640xi gc

[Msane]

I have recently upgraded my rear diffuser to 650 msport oem and welded new tips to my current exhaust. They stick out too much so I'm looking into the Megan exhaust to fix this. Wanted to know if anyone has been in a similar position will I need a more aggressive diffuser as well?

Here are some pics of my 2014 640xi gc
I did search but allot of posts Are older appreciate any tips thanks!

[AccordTR]

Originally Posted by Msane

I have recently upgraded my rear diffuser to 650 msport oem and welded new tips to my current exhaust. They stick out too much so I'm looking into the Megan exhaust to fix this. Wanted to know if anyone has been in a similar position will I need a more aggressive diffuser as well?

Here are some pics of my 2014 640xi gc
I did search but allot of posts Are older appreciate any tips thanks!

Diffuser will help but those tips are really far out. They should have been set back a bit more.

[jackliu0527]

My setup, M5 competition exhaust with V style diffuser

[itzjoker]

Why spend almost $2k on Megan axle backs just for the tips? Just have a shop chop them off and weld them back on shorter. They do stick out a little but I think if you get a different diffuser then you can get away with how it is.

You can get a V-style diffuser (like jacklui's) for ~$700, then you'll also need an M6 oem diffuser. You're looking atleast ~$1,000 to get that style diffuser.

A diffuser like AccordTR's will run $300 shipped from Aliexpress (2 month delivery time). I'm finally receiving mine this week!

[doggboy]

Originally Posted by itzjoker

Why spend almost $2k on Megan axle backs just for the tips? Just have a shop chop them off and weld them back on shorter. They do stick out a little but I think if you get a different diffuser then you can get away with how it is.

You can get a V-style diffuser (like jacklui's) for ~$700, then you'll also need an M6 oem diffuser. You're looking atleast ~$1,000 to get that style diffuser.

A diffuser like AccordTR's will run $300 shipped from Aliexpress (2 month delivery time). I'm finally receiving mine this week!

I agree with most of what you said, but you can get Megan axle back for under $600 if you buy the ones for the M6.

[itzjoker]

Originally Posted by doggboy

I agree with most of what you said, but you can get Megan axle back for under $600 if you buy the ones for the M6.

Ahh well that changes alot lol. If you're doing it for sound as well then go for it. They sound great on a 650i, not sure about 640i.

[doggboy]

OP, if you are looking at replacing the exhaust I would hit up 2dogs from the thread below to see what he did. It is custom, but it sounds great!

https://www.6post.com/forums/showthr...t=exhaust+tips

[Msane]

I just did a resonator delete which helped with the sound but now this gives me an excuse to purchase an exhaust.

Apparently the y shaped tips I have were cut the most they could and the exhaust pipe as well so not much room left, I purchased the tips from a e90 n55 user but realized their exhaust is probably different then f06 too late.

I found Megan exhaust for m6 with larger inlet which won't be an issue for the muffler shop. I had a v10 m6 with eisenmann race in the past I know I'll never get that sound but the burbles are entertaining.

I'm going to try the exhaust first and worse case if it doesn't fit then order the Ali express diffuser and just wait it out.

Thank you all for the quick responses!

[doggboy]

You can also get the factory M6 diffuser for under $200 brand new if you look around, then get the carbon center diffuser on ebay. Total will be around $500 and I think it looks better than the all carbon piece from ebay/alibaba.

Something like this..

[AccordTR]

Originally Posted by itzjoker

Why spend almost $2k on Megan axle backs just for the tips? Just have a shop chop them off and weld them back on shorter. They do stick out a little but I think if you get a different diffuser then you can get away with how it is.

You can get a V-style diffuser (like jacklui's) for ~$700, then you'll also need an M6 oem diffuser. You're looking atleast ~$1,000 to get that style diffuser.

A diffuser like AccordTR's will run $300 shipped from Aliexpress (2 month delivery time). I'm finally receiving mine this week!

Mines actually not the $300 one lol. It's a 2 piece one with much better fitment and build quality. Closer to $1000. The cheap ones on eBay etc fit like crap.

This is the one I have. The center piece is separate from the body molding piece. This allows for more flex to make make it fit tight. 1 piece ones, $300ish, have zero flex and usually don't fit great.


https://www.ebay.ca/itm/122001828863

[itzjoker]

Originally Posted by AccordTR

Mines actually not the $300 one lol. It's a 2 piece one with much better fitment and build quality. Closer to $1000. The cheap ones on eBay etc fit like crap.

This is the one I have. The center piece is separate from the body molding piece. This allows for more flex to make make it fit tight. 1 piece ones, $300ish, have zero flex and usually don't fit great.


https://www.ebay.ca/itm/122001828863

My bad, didn't look closely enough! Hope mine will fit...

[AccordTR]

Originally Posted by itzjoker

My bad, didn't look closely enough! Hope mine will fit...

I tried a cheaper one and sent it back. Seems kinda hit or miss how it's made and how it will fit. Maybe you'll get lucky. If not maybe try the one I listed. It's definitely more money but fits great.

[Msane]

I'd rather pay more for the oem one and easy install but those aftermarket ones look more aggressive.

I ordered the Megan exhaust for m6 will have muffler shop fit next week and update here after. If that doesn't fit then I can always look into the m6 diffuser but preferred the more subtle look for a 640.

Megan prices have dropped for 640/650 they were 460 shipped although due to covid can't deliver in 2-3 months that's why I decided to get the m6 one on sooner.

[BMWF06]

Originally Posted by AccordTR

Diffuser will help but those tips are really far out. They should have been set back a bit more.

I don't understand why people like that sticking exhaust. Honestly I think it looks stupid 🤷*♂️ especially on car like 6er

[Msane]

Originally Posted by Easy18893

I don't understand why people like that sticking exhaust. Honestly I think it looks stupid 🤷*♂️ especially on car like 6er

I actually hate the look it drives me crazy. The y shaped tips don't have much space on the 640 stock exhaust to sit flush on msport diffuser. I don't think there is a way around that except for new mufflers or aggressive diffuser.

[sixfiftyay]

i had heatsync performance mufflers installed and am very happy with them. they come with 3.5 or 4" tips and are under $300 shipped. they fit perfect with the oem m sport diffuser and sound great. definitely worth checking out.

[rxryanm.]

Originally Posted by sixfiftyay

i had heatsync performance mufflers installed and am very happy with them. they come with 3.5 or 4" tips and are under $300 shipped. they fit perfect with the oem m sport diffuser and sound great. definitely worth checking out.

Vids??

[Bigjule1111]

u are dead on doggboy.. that's exactly what I did on my 640 xi .. 170$ oem.bmw valance ..the center oem m6 diffuser.400$ used .. m6 mufflers 350 and cheapie 4 inch tips from Amazon, I believe 30 a piece plus $80 to get them welded . I promised a few members to post a video of how she sounds ..I'm definitely going to see if I can get around to it this weekend

[sixfiftyay]

Originally Posted by rxryanm.

Vids??

here you go.

View post on imgur.com

[Msane]

Originally Posted by sixfiftyay

here you go.

View post on imgur.com

Originally Posted by sixfiftyay

here you go.

View post on imgur.com

[img]

View post on imgur.com

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That sounds amazing for a 640!
I already have my Megan exhaust on the way otherwise I would've definitely gotten this.

[Bigjule1111]

Thanks for sharing ..sounds great .. u keep both flaps open ?

[sixfiftyay]

Originally Posted by Bigjule1111

Thanks for sharing ..sounds great .. u keep both flaps open ?

i had to have them removed with the muffler swap.