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      08-16-2017, 03:43 PM   #1
Matticus91
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Lightbulb New Project: Electric Exhaust Cutout

I decided a while back that I wasn't totally thrilled with the Berk Street, yet I didn't want something waking the dead everywhere I drove. I thought about trying a catless DP with the OEM exhaust, and honestly just didn't want to deal with the annoyances of going catless.

Enter plan Numero Uno: An OEM axle-back exhaust with an electric cutout.

It's not a "new" idea or something super abstract, but I have not seen it done much. I really didn't mind the sound of the stock exhaust with the golf-tee mod, and it's nice to have some real peace & quiet when I'm on my multi-monthly road trips from DC to NJ. With that said, I also love the obnoxiously loud sound of these engines when they're less restricted.

My plan is to weld in an electric cutout in the 10" straight section of the OE exhaust that's just past the axles when under the car. The cutout comes with a turn-down that will just get pointed right at the ground. The wiring will go up through one of the many convenient grommets in the body to a power source, and the cutout will be remote-controlled.

Here's the cutout I plan to use: Link

And here's an image of the section in the exhaust I plan to utilize:

20170806_193455 by Matt Steele, on Flickr

That section is a perfectly straight 9.5/10" and is free and clear of any components under the car. So I'll have plenty of room to fit the cutout and it's motor.

The next stage is to do the OE BMW PE Exhaust mod, but I will only cover the larger hole section so the smaller perforated pipe is in-tact: Link 1 - Link 2


So with that mod and the cutout closed, it will sound like this, but a little quieter.

Finally, I'll be finishing the project off by either cutting off and replacing the stock exhaust tips or completely working them down and repainting them. I am a fan of the black finish because of how clean they appear even when dirty. The stainless ones just get so damn nasty so fast.

That's it! Thoughts and input welcome. I've already sold my berk street and acquired an OE exhaust. Next step is to order the cutout kit and parts to seal up the internals on the OE exhaust.

EDIT: Finally finished the cutout, made a DIY, took pics, and a couple videos! All details in this DIY thread: http://www.1addicts.com/forums/showt...9#post22336099

And here are a couple quick videos of the setup, I'll make another with some better footage of the audio at some point.

Valve Operation:


Quick Sound Comparison:
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Last edited by Matticus91; 10-23-2017 at 09:44 AM..
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      08-19-2017, 04:45 AM   #2
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Good luck Matt. Sounds like a fun project and I hope it turns out the way you want.

Where you say "it will sound like this" is just the way my car sounds and I'm very happy with it.

I understand you liking the black tips better, a lot of people do. Personally, I prefer the PE tips over the stock black ones but of course that's very subjective.

Looking forward to seeing and hearing the finished product.

Last edited by Esteban; 08-20-2017 at 05:25 AM..
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      08-21-2017, 06:30 PM   #3
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Good luck on the build! I hope it goes as smoothly as you make it sound. The color of the tips isn't as important to me as the size relative to the opening in the diffuser. I like when the dual tips really fill out the cutout and leave little room around the edges. Looking forward to seeing pictures and hearing it on video once you are done.
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      08-21-2017, 07:57 PM   #4
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Yeah, that's the way to go. I never understood "enthusiast" exhausts when they're quieter than a straight pipe but still loud enough to call out your position to cops every time you open the throttle. I mean, you've already lost the stealth game, why not just open it up all the way?

Cutout gives you two options, stealth or kill mode, and that's the way it SHOULD have come from the factory.
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      08-21-2017, 08:38 PM   #5
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Following.

My plan is to do something very similar, but as a quad exhaust setup.

IE: leave the OEM location exhaust outlet stock standard, but have the right-hand outlets connected back to Y splitter at the midpipes (straight piped) and controlled by an inline electronic butterfly.
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      08-22-2017, 10:15 AM   #6
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Quote:
Originally Posted by Esteban View Post
Good luck Matt. Sounds like a fun project and I hope it turns out the way you want.

Where you say "it will sound like this" is just the way my car sounds and I'm very happy with it.

I understand you liking the black tips better, a lot of people do. Personally, I prefer the PE tips over the stock black ones but of course that's very subjective.

Looking forward to seeing and hearing the finished product.
Thanks Esteban! Visually I think the stainless/chrome ones look best when clean, but I never seem to be able to keep them clean haha.

Quote:
Originally Posted by Mr. Pharaoh View Post
Good luck on the build! I hope it goes as smoothly as you make it sound. The color of the tips isn't as important to me as the size relative to the opening in the diffuser. I like when the dual tips really fill out the cutout and leave little room around the edges. Looking forward to seeing pictures and hearing it on video once you are done.
Thanks! I hope it goes well too haha. I think the PE conversion will be pretty straight forward, I have everything I need for that already and just need to make sure I take my time and do it right. The electric cutout install will be more complicated, specifically with ensuring I line everything up properly before welding.

I understand your point on filling the exhaust opening with the tips - I share the same preference there. I do have a slight concern about heat however so I typically look for at least 3/4 inch gap around the tips.

Quote:
Originally Posted by The Wind Breezes View Post
Yeah, that's the way to go. I never understood "enthusiast" exhausts when they're quieter than a straight pipe but still loud enough to call out your position to cops every time you open the throttle. I mean, you've already lost the stealth game, why not just open it up all the way?

Cutout gives you two options, stealth or kill mode, and that's the way it SHOULD have come from the factory.
It's a balance I suppose, people are either looking for OEM quality sound, a bit louder without reducing daily comfort, or "wake the dead" loud. I'm going for the slightly louder than stock option with the PE mod, and then the "wake the dead" version at the flip of a switch!

Quote:
Originally Posted by xQx View Post
Following.

My plan is to do something very similar, but as a quad exhaust setup.

IE: leave the OEM location exhaust outlet stock standard, but have the right-hand outlets connected back to Y splitter at the midpipes (straight piped) and controlled by an inline electronic butterfly.
Honestly ideally I'd like to grab the 1M rep rear bumper with dual exhaust openings and run a similar setup, but I can't afford that whole conversion right now. Dual exhaust means changing quite a bit under the car with the battery tray/etc. to make it all fit. If you start this project please make a thread! I'd love to see you make it happen


For all: I've acquired the parts necessary to do the PE conversion. Now it's just a matter of cutting open the can, making the changes, and finding a shop that will weld it back up for me at a reasonable rate. Once that's complete I'll start the cutout install if I'm happy with the PE mod results.
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      08-23-2017, 11:56 AM   #7
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Quote:
Originally Posted by xQx View Post
Following.

My plan is to do something very similar, but as a quad exhaust setup.

IE: leave the OEM location exhaust outlet stock standard, but have the right-hand outlets connected back to Y splitter at the midpipes (straight piped) and controlled by an inline electronic butterfly.
This is what I am going to do as well. In the very near future hopefully!
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      08-23-2017, 11:57 AM   #8
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Quote:
Originally Posted by Matticus91 View Post
I decided a while back that I wasn't totally thrilled with the Berk Street, yet I didn't want something waking the dead everywhere I drove. I thought about trying a catless DP with the OEM exhaust, and honestly just didn't want to deal with the annoyances of going catless.

Enter plan Numero Uno: An OEM axle-back exhaust with an electric cutout.

It's not a "new" idea or something super abstract, but I have not seen it done much. I really didn't mind the sound of the stock exhaust with the golf-tee mod, and it's nice to have some real peace & quiet when I'm on my multi-monthly road trips from DC to NJ. With that said, I also love the obnoxiously loud sound of these engines when they're less restricted.

My plan is to weld in an electric cutout in the 10" straight section of the OE exhaust that's just past the axles when under the car. The cutout comes with a turn-down that will just get pointed right at the ground. The wiring will go up through one of the many convenient grommets in the body to a power source, and the cutout will be remote-controlled.

Here's the cutout I plan to use: Link

And here's an image of the section in the exhaust I plan to utilize:

20170806_193455 by Matt Steele, on Flickr

That section is a perfectly straight 9.5/10" and is free and clear of any components under the car. So I'll have plenty of room to fit the cutout and it's motor.

The next stage is to do the OE BMW PE Exhaust mod, but I will only cover the larger hole section so the smaller perforated pipe is in-tact: Link 1 - Link 2


So with that mod and the cutout closed, it will sound like this, but a little quieter.

Finally, I'll be finishing the project off by either cutting off and replacing the stock exhaust tips or completely working them down and repainting them. I am a fan of the black finish because of how clean they appear even when dirty. The stainless ones just get so damn nasty so fast.

That's it! Thoughts and input welcome. I've already sold my berk street and acquired an OE exhaust. Next step is to order the cutout kit and parts to seal up the internals on the OE exhaust.
This is definitely the way to go IMO!
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      08-23-2017, 01:32 PM   #9
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Hey man, just stumbled across this and had to comment. I had the stock bmw exhaust and did the PE mod and it was too quiet. I then bought an afe muffler delete and that was too loud. I decided last week to delete the resonator and add a valve in its place. Cost me 150$ including the valve and welding and I couldn't love it any other way. Valve closed for the neighbors and valve open for straight hell when I go for a canyon run. Also added a brand clamp to the muffler and midpipe connections for easy removal rather than using 2 bolts.
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      08-23-2017, 01:54 PM   #10
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Quote:
Originally Posted by rominun View Post
Hey man, just stumbled across this and had to comment. I had the stock bmw exhaust and did the PE mod and it was too quiet. I then bought an afe muffler delete and that was too loud. I decided last week to delete the resonator and add a valve in its place. Cost me 150$ including the valve and welding and I couldn't love it any other way. Valve closed for the neighbors and valve open for straight hell when I go for a canyon run. Also added a brand clamp to the muffler and midpipe connections for easy removal rather than using 2 bolts.
That's a pretty solid setup! So you're running the OE exhaust with the resonator deleted and then the cutout?

Where did you run the power line for the cutout?
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      08-23-2017, 05:37 PM   #11
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Good luck!
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      08-24-2017, 12:04 AM   #12
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Quote:
Originally Posted by Matticus91 View Post
That's a pretty solid setup! So you're running the OE exhaust with the resonator deleted and then the cutout?

Where did you run the power line for the cutout?
My muffler is the OE exhaust with the bmw PE mod where you weld the holes shut on the big holes inside the muffler. I routed the power line for the cutout up along the gas tank and above the fuel pump to the inside of the car.
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      08-24-2017, 12:06 AM   #13
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FYI, the muffler is a 3 inch, not a 2.5. Here's the cutout that i purchased.
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      08-24-2017, 09:12 AM   #14
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Quote:
Originally Posted by rominun View Post
My muffler is the OE exhaust with the bmw PE mod where you weld the holes shut on the big holes inside the muffler. I routed the power line for the cutout up along the gas tank and above the fuel pump to the inside of the car.
Quote:
Originally Posted by rominun View Post
FYI, the muffler is a 3 inch, not a 2.5. Here's the cutout that i purchased.
Great info thanks! Did you just run the power to an add-a-circuit in the fuse box? That's what I'm planning to do with mine once I get it in the cabin.
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      08-24-2017, 09:37 AM   #15
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Quote:
Originally Posted by Matticus91 View Post
Quote:
Originally Posted by rominun View Post
My muffler is the OE exhaust with the bmw PE mod where you weld the holes shut on the big holes inside the muffler. I routed the power line for the cutout up along the gas tank and above the fuel pump to the inside of the car.
Quote:
Originally Posted by rominun View Post
FYI, the muffler is a 3 inch, not a 2.5. Here's the cutout that i purchased.
Great info thanks! Did you just run the power to an add-a-circuit in the fuse box? That's what I'm planning to do with mine once I get it in the cabin.
I actually ran it to my rear D.C. Plug. I will be running it to the battery with an inline fuse but just been lazy :/
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      08-24-2017, 09:48 AM   #16
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Quote:
Originally Posted by rominun View Post
I actually ran it to my rear D.C. Plug. I will be running it to the battery with an inline fuse but just been lazy :/
Sweet! Just ordered the cutout you linked and the rest of the stuff I need. I'll probably end up leaving the resonator in place and sticking with my location for the cutout. I don't want to lose the resonator for fear of any drone that will pop up.
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      08-24-2017, 11:26 AM   #17
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Quote:
Originally Posted by Matticus91 View Post
Quote:
Originally Posted by rominun View Post
I actually ran it to my rear D.C. Plug. I will be running it to the battery with an inline fuse but just been lazy :/
Sweet! Just ordered the cutout you linked and the rest of the stuff I need. I'll probably end up leaving the resonator in place and sticking with my location for the cutout. I don't want to lose the resonator for fear of any drone that will pop up.
Yeah my drone is kinda loud when the valve is open but i like the placement of the valve and I'm eventually going single turbo so that means 3" all the way through
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      08-28-2017, 09:51 AM   #18
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Quote:
Originally Posted by rominun View Post
Yeah my drone is kinda loud when the valve is open but i like the placement of the valve and I'm eventually going single turbo so that means 3" all the way through
Nice man. I ordered all the stuff I need and hoping to have them by today! If so I'll be starting the work tomorrow.
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      08-28-2017, 10:25 AM   #19
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Quote:
Originally Posted by Matticus91 View Post
Quote:
Originally Posted by rominun View Post
Yeah my drone is kinda loud when the valve is open but i like the placement of the valve and I'm eventually going single turbo so that means 3" all the way through
Nice man. I ordered all the stuff I need and hoping to have them by today! If so I'll be starting the work tomorrow.
Sounds like fun! You're doing the welding yourself?
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      08-28-2017, 11:55 AM   #20
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Quote:
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Sounds like fun! You're doing the welding yourself?
Nope that's the one thing I can't do. Going to take everything off the car, cut the spot for the cutout, and cut the can/wrap the internals for the PE mod. Then I'll bring everything to someone (haven't picked a place yet) to weld it all back together. Then I can just install the axleback and route the wiring, and it'll be done! Should be fairly straight forward.
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      08-28-2017, 01:40 PM   #21
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Quote:
Originally Posted by Matticus91 View Post
Quote:
Originally Posted by rominun View Post
Sounds like fun! You're doing the welding yourself?
Nope that's the one thing I can't do. Going to take everything off the car, cut the spot for the cutout, and cut the can/wrap the internals for the PE mod. Then I'll bring everything to someone (haven't picked a place yet) to weld it all back together. Then I can just install the axleback and route the wiring, and it'll be done! Should be fairly straight forward.
I can weld, but not very well. It was well worth the 100$ for someone else to weld it. It would've taken me all day lol
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      08-31-2017, 10:55 AM   #22
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Cutout was welded in yesterday morning! Just need to attach the valve and turndown, and route the power to the cabin for connection to the fuse box.

I had them weld it in to the straight section that I originally planned on. It fit perfectly and I had them angle the cutout so it goes to the side of the car and down slightly. I'll be able to further direct the exhaust down and out with the turn-down, directing the exhaust away from the underbody completely.

Before:
20170830_110843 by Matt Steele, on Flickr

After:
20170830_112055 by Matt Steele, on Flickr
20170830_112055 by Matt Steele, on Flickr
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