Steps and Parts to Achieve Quad Exhaust Look w/ Vorsteiner Diffuser

[MSUGOGRN]

I have been a member here for the past 18 months or so and when I bought my 650 back in August of 2016, I started getting the modding itch. I saw an amazingly modified M6 that had a Vorsteiner diffuser and some sexy 4" quad tips. I decided that is the look I wanted so I went down the path of trying to find an axle or even catback system that works with our non-M6 6'ers. Spoiler alert...it does not exist. I have now achieved the look I wanted after much time and money. Please note: Unless you love drone and headaches, please don't do a muffler delete. You will get the tips you want but the cost of the drone, headaches, and a spouse/significant other that hates being in your car was just not worth it for me (that was a waste of $500).

Below are the parts and steps to achieve a reasonably priced quad exhaust set up with mufflers, a Vorsteiner (or Vorsteiner style) diffuser and 4" quad tips that I am aware of. Please note: You need a 6'er with the M package. As far as sound goes, the M6 mufflers with the 650 sound really nice. A deep throaty sound. I love it.

If there are any suggestions to this thread, please let me know. I put this thread together as I have received various questions via PM and I thought this would be good information for all to have.

All costs assume you live in the U.S. All in, excluding the $1k+ in "wasted sunk R&D $" to find this set up (that includes the muffler delete install and worthless FI Exhaust system that ended up costing me $700...do not buy an FI Exhaust system!), I would estimate I spent $2,200 to get this look.


Step: Buy M6 Diffuser from BMW (part #51128052677)

Cost / Comments: $200 (shop around – prices vary)


Step: Purchase Vorsteiner or V Style diffuser

Cost / Comments: $600 for replica (search ebay for V style or ebmotor.com) - $2500 for authentic. I purchased mine on ebay that was manufactured by ebmotor.


Step: Have M6 Diffuser painted

Cost / Comments: Approx $200


Step: Install Freshly Painted M6 Diffuser & V Style Diffuser

Cost / Comments: The M6 diffuser was easy. I am not including a DIY here. There is one somewhere on our site but I am not searching right now. Again, it is very easy to install. For the Vorsteiner diffuser, fitment was good…not great. I have heard that fitment is about the same for authentic. I installed this myself but it takes some time and finessing. I definitely recommend buying some really strong double sided tape. I believe VHB 3M tape is the best.

Cost should be $0 if you install yourself


Step: Buy M6 mufflers used on our site

Cost / Comments: You just need the axle back portion. Cost should be anywhere from $500 to $800 shipped.


Step: Buy tips (ebay is best in my opinion) - you will need a 2.5” inlet (so it can be welded to the outlets out of the M6 muffler) – you can decide here if you want a 3.5” out or a 4.0” out. I recommend the 4.0” as it really fills in the Vorsteiner diffuser.

Cost / Comments: I have learned many lessons here. You will find that most tips on ebay are about 9” long. In order for the tips to look great after welding them to your M6 muffler outlets, you really need a 4” long tip. Another reason they need to be short is the shop will be cutting a little bit of the muffler outlet pipe but you don’t want to cut off so much that you cut off the vacuum part. If you have a 640, I don’t think this matters but I wanted the vacuum to continue to work.

For example, if you search ebay for this tip: “Blue Burnt Exhaust Duo Layer Straight Tip Polished Stainless”, you will see that the double wall (the actual tip part) is way too long. The tip will stick way out from your rear bumper and look stupid.

You need to find one of those Y style tips that has a single inlet and then Y’s into 2 outlets. The actual tip component of those is only about 4.5” long. Search for something like this: “Dual 4" Quad Burn Style Stainless Steel Exhaust Tips”. Your muffler shop can then cut off the “tip” component and it will only be 2.5” wide at the cut-off which is perfect for welding to the M6 muffler outlets.

Approx cost for tips $100


Step: Have shop install mufflers and tips

Cost / Comments: They will cut off your old mufflers. Weld on M6 mufflers. Note: The pipes on the M6 mufflers are bigger than our non-M6 cars but the shop can do a reducer easily. The shop will then cut off a part of the 2 outlet pipes on each muffler to the right length so that when the newly cut tips are welded to the outlets, there is a nice staggered look to your desire while still retaining the vacuum.

Cost: Approx $500

I hope this helps. Any questions please let me know.

[darms]

Thx for sharing your experience... looks the nutz

[$howtime456]

bump

[Bobby_Drake]

Nice set up.

[SGent]

You have the best setup for a non m6!

[MSUGOGRN]

Originally Posted by SGent

You have the best setup for a non m6!

Appreciate the compliments! I have been very pleased with how those M6 mufflers came out. They sound great and with a good muffler shop, you can really customize your exhaust tips to your preferences with the massive selection available on ebay.

[SGent]

Originally Posted by MSUGOGRN

Appreciate the compliments! I have been very pleased with how those M6 mufflers came out. They sound great and with a good muffler shop, you can really customize your exhaust tips to your preferences with the massive selection available on ebay.

Because your setup is amazing...I am copying it.

Did you use screws to bolt on the diffuser or just the tape?

[MSUGOGRN]

Originally Posted by SGent

Because your setup is amazing...I am copying it.

Did you use screws to bolt on the diffuser or just the tape?

You are bringing back bad memories! You will definitely want to use bolts (not screws) and as many as possible. Use the tape only as a backup but definitely use it. I wish I would have taken some pics of everywhere I had put bolts. The picture I have attached shows circles in red of the areas where I had bolts. The outer 2 on both sides are absolutes (they should already come pre-drilled). The inner 3 circles are ones where I am pretty sure I found a way to bolt them on but I just can't recall. Unfortunately I will not be under my car for a while but when I do, I will check.

[DerBosewicht]

And...
Thank You Sir!!
Again...

[Ptoscano911]

Awesome!

[DerBosewicht]

Can you post a side profile of the rear. I currently have my tips flush with edge of the top bumper, whereas I think yours are closer to flush with the top of the M6 diffuser.

[MSUGOGRN]

Originally Posted by DerBosewicht

Can you post a side profile of the rear. I currently have my tips flush with edge of the top bumper, whereas I think yours are closer to flush with the top of the M6 diffuser.

Hope this is helpful. Not the best picture but hopefully it provides the side profile you were looking for.

[F06msportmia]

Originally Posted by DerBosewicht

Can you post a side profile of the rear. I currently have my tips flush with edge of the top bumper, whereas I think yours are closer to flush with the top of the M6 diffuser.

Here is another perspective, did my mod about 3 months ago:

[DerBosewicht]

Originally Posted by MSUGOGRN

Hope this is helpful. Not the best picture but hopefully it provides the side profile you were looking for.

Perfect thanks.. mine are flush just about the same spot as yours but I guess without the bottom diffuser they look longer. Maybe because I am used to seeing the 3.5 also... but thanks that’s what I needed

[DerBosewicht]

Originally Posted by F06msportmia

Here is another perspective, did my mod about 3 months ago:

Those look lovely how all that carbon came together.

[wazzza]

I went with the EBMotors one as well. Seemed decent for the price. The holes on the two ends were impossible to put a nut through, so I just taped it up with 30 lb. 3M tape. Seems okay for now. I got two bolts on each side though at the side and towards the center. Then obviously, the other 3 that screw in just like the stock one. 5 total, hopefully that will do the trick.

However, the mold is far from perfect and even with a lot of tinkering I couldn't get the panel gap fully sorted out, especially on the left side. Any tips on getting those nasty gaps sorted out?

[jackliu0527]

i just checked ebmotors, man $160 for shipping, has anyone got better shipping deals or what

also is it easier to install the diffuser with the bottom rear bumper inserts off or on? can i install them first and do mufflers later?

[MSUGOGRN]

Originally Posted by jackliu0527

i just checked ebmotors, man $160 for shipping, has anyone got better shipping deals or what

also is it easier to install the diffuser with the bottom rear bumper inserts off or on? can i install them first and do mufflers later?

I installed with m6 bumper insert (I presume that is what you mean by the rear bumper inserts) attached. I think doing mufflers later is ideal so that you can make sure the tips pop out exactly how you want them.

[jackliu0527]

Originally Posted by MSUGOGRN

I installed with m6 bumper insert (I presume that is what you mean by the rear bumper inserts) attached. I think doing mufflers later is ideal so that you can make sure the tips pop out exactly how you want them.

How do you guys put 4inch tips on u r m5 or m6 mufflers? i measure less than an inch gap between the 2 tips, the factory tips are 3inches, so if i wanted 4 inch tips i would require 1inch gap between no? (.5 per tip)

You said something about most tips are 9inches and may require cutting, can you elaborate? I dont quite understand, i wanna get these tips for my 650 which is going to have m5 mufflers as seem below installed

63mm out 101mm would be the correct size if i want voresteiner diffuser ya? anything bigger wont work correct?

[Thewrench86]

I've finally pulled the trigger on an M6 rear diffuser I'm not getting the vorsteiner one, more like the piece F06msportmia has. I'm hoping it looks like that when I'm done. You have same colour car as me and I really like the carbon tips. I however would need to get a y dual tips as I don't want to modify the exhaust just yet. Is that what u have or did u change the muffler?

[MSUGOGRN]

Originally Posted by jackliu0527

How do you guys put 4inch tips on u r m5 or m6 mufflers? i measure less than an inch gap between the 2 tips, the factory tips are 3inches, so if i wanted 4 inch tips i would require 1inch gap between no? (.5 per tip)

You said something about most tips are 9inches and may require cutting, can you elaborate? I dont quite understand, i wanna get these tips for my 650 which is going to have m5 mufflers as seem below installed

63mm out 101mm would be the correct size if i want voresteiner diffuser ya? anything bigger wont work correct?

Your muffler shop should be able to handle it. I think just slightly bending the 2 pipes would work. I do not believe that my shop ran into that issue but they may have and just didn't tell me.

[jackliu0527]

Originally Posted by MSUGOGRN

Your muffler shop should be able to handle it. I think just slightly bending the 2 pipes would work. I do not believe that my shop ran into that issue but they may have and just didn't tell me.

So your muffler shop installed 4x 4" tips on m5/6 muffler? no issues? it seems like they arent even touching each other, you must have had more gaps