Hey everyone,

Now that my intake system is completed, I'm working on an exhaust system from the down pipe back (cat-back). I was originally going to do a 4" from the downpipe to the y pipe but I sided with 3"all the way with 3.5" tips. My current mock up will be made of aluminized steel, I didn't want to spend a lot of the first version. It will require 2 exhaust flap actuators and a new harness to control both valves. the system will have a muffler with internal X-pipe to equalize the pressures and sound.


*****************Update*******************

8/22/2022

This will be VAVLE-LESS exhaust, I wasn't able to find a good flowing valved muffler without adding extensive amount of weight. The photo of pipes, mufflers and flex pipes don't represent the new system.

I may have to make the drive up there to hear it in person.

Wow. I’d be interested. Looking for a cat back exiting to quad tips.

This was such a pain to remove, good thing I have access to a lift to help. There's no turning back now!

The suspense! Did you post your intake yet?

Update....

I ran out of argon while making my Y-pipe, so I'm currently running 1 single 3" pipe to the back of the X3 mean while I get more gas. I'll be able to work on it again on Thursday night as my shift work shift begins early Sunday morning. On the plus side, it sounds pretty dang good, quite a bit of drone but I'm sure that'll go away once I install the muffler. The burbles are be excessive for me. I pops all through out the rpm range. If you guys are interested I can make a video of that.

808ron wrote

The suspense! Did you post your intake yet?

The heat shield is currently in production queue, I have the aluminum tube, also waiting on the IAT mount to come in, followed by welding together the components and then they'll be sent of to be powder coated by a local shop. It'll take approximately 1 month before I can ship any out.

Subscribed.

dcchris311 wrote

It will require 2 exhaust flap actuators and a new harness to control both valves.

Are you going with the two of stock g01 flap actuators, part # 18308623424 ?

Or something else?

dcchris311 wrote

This was such a pain to remove, good thing I have access to a lift to help. There's no turning back now!

Do you by chance took close up shots of the exhaust system you took down, around the areas of the stock hangers and flaps, that you can post?

And close up shots around the underside where the exhaust was in?


Thanks.

dinan5m3 wrote

dcchris311 wrote

This was such a pain to remove, good thing I have access to a lift to help. There's no turning back now!

Do you by chance took close up shots of the exhaust system you took down, around the areas of the stock hangers and flaps, that you can post?

And close up shots around the underside where the exhaust was in?


Thanks.

dinan5m3 wrote

Subscribed.

dcchris311 wrote

It will require 2 exhaust flap actuators and a new harness to control both valves.

Are you going with the two of stock g01 flap actuators, part # 18308623424 ?

Or something else?

Yes, I'll be using OEM flap actuators. 1 from the oem exhaust and the other from a BMW supplier.

dinan5m3 wrote

dcchris311 wrote

This was such a pain to remove, good thing I have access to a lift to help. There's no turning back now!

Do you by chance took close up shots of the exhaust system you took down, around the areas of the stock hangers and flaps, that you can post?

And close up shots around the underside where the exhaust was in?


Thanks.

If you're asking in regards to your other post about the axle, then yes they are exactly the same mounting points. The M40i exhaust is just a 1 piece so you'll need to cut it to make it work. I don't have other photos but I'll take some more when I go to finish the exhaust.

dcchris311 wrote

Yes, I'll be using OEM flap actuators. 1 from the oem exhaust and the other from a BMW supplier.





If you're asking in regards to your other post about the axle, then yes they are exactly the same mounting points. The M40i exhaust is just a 1 piece so you'll need to cut it to make it work. I don't have other photos but I'll take some more when I go to finish the exhaust.

Okay, thanks.

You are way more resourceful than i am...

I'm trying to see how i would use 2 flaps in G01 where it only has 1 stock flap at the driver side. I believe our stock flap system is either open or close. I'm learning that the F97 X3MC actuator actually supports also the partial open.

One option i'm considering is use aftermarket control box that controls dual exhaust vale remotely, to override the stock.

You and i are both trying to fit in exhaust systems not directly made for our cars. You are going total custom made! Me on the other than looking to fit in DINAN's F97 axel back system...

It's done!! Just no muffler installed, I wanted to see what it sounded like without it. It sounds pretty damn good, and very very little drone. I installed quad tip, full 3" to the y-pipe and then it splits to two 3" dual exhaust and exits via quad tips. I don't have the hangers installed, so that's why they look a bit low and sagging. I'll post a video tomorrow of a fly by and interior driving.

Assuming you can get the fitment centered and OEM looking that will be a sweet mod.

Looks awesome.

Delicious, waiting for the video!

Looks great - looking forward to seeing the video as well!

Here's a quick video. I'll be posting more videos the interior at highway speeds, launches and just driving.

dcchris311 wrote

Here's a quick video. I'll be posting more videos the interior at highway speeds, launches and just driving.

Sounds good! You doing clamp bolt on or weld?

808ron wrote

dcchris311 wrote

Here's a quick video. I'll be posting more videos the interior at highway speeds, launches and just driving.

Sounds good! You doing clamp bolt on or weld?

The current setup has more clamps than actually being welded. The production version will have more welds and a couple of clamps.

Following. Very interesting. I live near you OP.

Dobie Dog wrote

Following. Very interesting. I live near you OP.

Maybe we'll get together sometime, I see that you have a dobie! I had one but cancer took him way to soon... I'll get another dobie companion in the future.

Here's a link to the video that has the cold start, WOT passes, interior sound clips from a launch and highway speeds.