[spielnicht]

Finally got my hands on a nice set of M5 mufflers from a member here. As I wait for the BMW body shop to call and let me know my stock M5 diffuser is done being painted, I'm trying to figure out the last pieces before I take the car over to the muffler shop.

For those that have already gone through this, 2 questions for you:

1. How did you manage to install the M5 diffuser before taking off the original mufflers? This is the obvious first step so the shop can install the M5 mufflers, but how did you manage this?
   
2. Beings that the valves are on opposite sides of the 550i muffler, I'm assuming that you'll need longer vacuum lines. I really doubt the muffler shop has these on hand so I want to have them beforehand. Where would I get these from? Anyone know the diameter and length requirements?

[txoid]

I don't know if you need the adaptor under the bumper for the 550. I assume you have the insert.

If it's a good muffler shop, they should know what to do.
Make sure the tips are where you want them. Some shops leave them too far in or too far out.
Remove the tips or wrap them with tape so they don't get scratched. Remember to remove the tape after installation.

I wouldn't buy anything expensive for the vacuum lines. Autoparts stores should be able to help.
The hoses are easy to get from o'reilly. Ask for the 1/8" ID rubber vacuum hose. They sell it by the foot and is behind the counter. Should be about 50cents per foot.
The adaptors/connectors to add your extensions are cheap.
http://www.oreillyauto.com/site/c/de...1168&ppt=N1171

[spielnicht]

Perfect, thank you! I'll check with my local NAPA store to see what they have but at least I know what I need now if I have to order it online.

Originally Posted by txoid

I don't know if you need the adaptor under the bumper for the 550. I assume you have the insert.

If it's a good muffler shop, they should know what to do.
Make sure the tips are where you want them. Some shops leave them too far in or too far out.
Remove the tips or wrap them with tape so they don't get scratched. Remember to remove the tape after installation.

I wouldn't buy anything expensive for the vacuum lines. Autoparts stores should be able to help.
The hoses are easy to get from o'reilly. Ask for the 1/8" ID rubber vacuum hose. They sell it by the foot and is behind the counter. Should be about 50cents per foot.
The adaptors/connectors to add your extensions are cheap.
http://www.oreillyauto.com/site/c/de...1168&ppt=N1171

[Ickdeep]

Originally Posted by spielnicht

1. How did you manage to install the M5 diffuser before taking off the original mufflers? This is the obvious first step so the shop can install the M5 mufflers, but how did you manage this?
   
2. Beings that the valves are on opposite sides of the 550i muffler, I'm assuming that you'll need longer vacuum lines. I really doubt the muffler shop has these on hand so I want to have them beforehand. Where would I get these from? Anyone know the diameter and length requirements?

Its super easy to install the diffuser, just need patience. I took off my rear bumper in order for the tabs to line up perfect (ebay). It does look kinda funny with a M5 diffuser on stock mufflers.

Cant help you there. I have a 535 so I just wired my valves open.

[txoid]

I have a 535 with the valves working. I ran a vacuum line from the engine to the rear. Purchased the valve and wireless remote. Now I can open and close the valves when I want.

[spielnicht]

Thanks for everyones' input. I got everything installed and working this past weekend.

For the tubing, I don't have an O'reilly close by and neither Advance Auto nor AutoZone had anything good. They both carry just very thin vacuum tubing that looks like it'll break in a week. I ended up getting this from Amazon (http://a.co/9WlVpCc) and it's very thick, durable and made to resist high temperature. Might be an overkill, or might not, but it looks professional grade and puts my mind at ease.

As for the tubing connector, I went with the Dorman Help! 47300. It's working, but construction leaves little confidence in durability. I've located some brass ones on Amazon (http://a.co/4QIIeFR) this week that I've ordered and will be replacing the Dorman's with when they arrive.

As for the diffuser installation, surprisingly I was able to do all the pre-work of installing the comfort access before taking the car into the exhaust shop. The original stock 550i diffuser fits back onto the car with the newly installed M5 comfort access adapter, thus giving me time to visit the shop and install the M5 mufflers. Once I got to the shop, they cut the original mufflers and called me into the bay to swap the diffusers. Took less than 2 mins.

All in all, very happy with the setup. I'm amazed by how good it sounds now at startup, cruising and foot-down. It really sounds like a V8 now.

The only complaint I have (just one), while there is no true "drone", you definitely get the "humming" at low RPM. It's subtle, but noticeable when the engine is hovering around 1K RPM. It's much more noticeable in Eco mode, but I rarely drive with it. Again, not too bad in comparison to even high-end aftermarket exhausts I've tried in the past on other cars (Eisenmann, Remus, etc.). For the price you pay for this setup and amazingly great sound you get, it's still a win-win. I'm sure Dinan has worked to eliminate this "humming", but then again their mufflers don't sound anywhere as good or loud when your foot is down as the stock M5 mufflers on the 550i, not to mention would have cost me 7x as much

[lsturbointeg]

AWESOME! post some pictures