[Mosely]

Sounds like a few of you guys are experiencing this. I thought it was only on cold start at first too, and if you give a tiny bit of throttle on cold start it goes away. BUT, I've noticed that you can hear it more and more just driving around too if you listen for it, which is tough over the general exhaust noise.

I've reached out to fabspeed to see what their thoughts are.

[Fabspeed Motorsport]

This is a very confusing issues. It does not seem to be from the sport cats. It might be the extra exhaust hitting the valve. The sport cat does not change due to temperature but the valve runs off of the vacuum line that needs time to build up pressure. I would look more into that as an issues than the sport cats.

[NO_USER_]

Originally Posted by Fabspeed Motorsport

This is a very confusing issues. It does not seem to be from the sport cats. It might be the extra exhaust hitting the valve. The sport cat does not change due to temperature but the valve runs off of the vacuum line that needs time to build up pressure. I would look more into that as an issues than the sport cats.

Are you referring to the exhaust valves near the muffler? It doesn’t run off of a vacuum line it’s electronic.

[Fabspeed Motorsport]

I am more interested in the valve alone not the controller as much. Does the rattle come back when you open the valve back up?

[Mosely]

Originally Posted by Fabspeed Motorsport

I am more interested in the valve alone not the controller as much. Does the rattle come back when you open the valve back up?

The noise appears to be unrelated to valve opening or closing. Sitting at idle, sport mode opens the valve and the exhaust gets louder but the noise does not change at all. I unplugged the valve in the open and closed position, and it does not change the noise either, so I don't think it's related to the valve. I'm going to get the stethoscope out again tomorrow and listen around to see if I can pinpoint exactly where it's coming from.

[Lukeni]

My bets are still on the wastegate

[Fabspeed Motorsport]

Please give us a call we would love to talk about your issue and hope to help problem solve. Our customer service rep. Brian would love to talk to you about the sound. He is extremely knowledgeable and we would love to help you out with the issue.

[skiparock]

Sounds like you need to go back to original cat to rule out the mod? Then hand keys and car to dealer to figure out?

[Gimmethecash]

I’ve installed the sport cat on my car twice (took it off for a week or two but missed it very badly) and no funny noises other than the increased cold start wastegate noise, easily avoidable by a tiny bit of throttle to hold ~1200 rpm until the cold start cycle completes.

I’ve reused the clamps and left the “exhaust end” gasket on the stock DP.

[XProject]

Any fix for this rattle at cold start?

[DrAnzo2.0]

Originally Posted by XProject

Any fix for this rattle at cold start?

This has me worried as I’m about to install a FabSpeed SportCat on my 2018 M2

[XProject]

Originally Posted by DrAnzo2.0

This has me worried as I’m about to install a FabSpeed SportCat on my 2018 M2

Most of us only have it at cold start. Holding the throttle at ~12000 rpm for 4-5 sec and it goes away. It probably is from the wastegate. Love Fabspeed regardless lol

[skiparock]

Originally Posted by DrAnzo2.0

This has me worried as I’m about to install a FabSpeed SportCat on my 2018 M2

I installed mine 2 days ago and no issue, other then that v clamp was tough to get aligned. Sounds awesome

[Mosely]

OP here, was busy over the holidays but just getting back around to diagnosing this noise. I was feeling around near the wastegate/actuator to see if anything was loose. I took a few pictures down there and this is what I see (first is the downpipe 3 weeks ago, second is the downpipe today, third is the other side of the turbo). What is going on here? Is it rusting over the period of a month (never driven in rain or anything)? Is it leaking? Why is the turbo turning that color? Never seen anything like this.

[pruettfan]

Originally Posted by Mosely

OP here, was busy over the holidays but just getting back around to diagnosing this noise. I was feeling around near the wastegate/actuator to see if anything was loose. I took a few pictures down there and this is what I see (first is the downpipe 3 weeks ago, second is the downpipe today, third is the other side of the turbo). What is going on here? Is it rusting over the period of a month (never driven in rain or anything)? Is it leaking? Why is the turbo turning that color? Never seen anything like this.

All of that looks pretty normal. As exhaust systems and turbos go through heat cycles they change color and that light surface rust is pretty much standard issue. I would ask Fabspeed to chime in but I don't think you have an issue there. Your car was very new when you had the downpipe added but what are your thoughts about the change in sound and performance versus the stock system this rattle problem aside? I am contemplating doing this with my otherwise stock M2.

[Fabspeed Motorsport]

Phil from Fabspeed here.
There is no issue here.
I have had a chance to look over the pictures with my team and this looks normal. The system is T304L stainless steel with the heating, cooling and humidity is going to create a little natural superficial rust.

[Mosely]

Awesome thanks Phil. Still working on pinpointing the sound so I haven't reached out after I last spoke to you guys but I appreciate all the help so far.

[Mosely]

Originally Posted by pruettfan

All of that looks pretty normal. As exhaust systems and turbos go through heat cycles they change color and that light surface rust is pretty much standard issue. I would ask Fabspeed to chime in but I don't think you have an issue there. Your car was very new when you had the downpipe added but what are your thoughts about the change in sound and performance versus the stock system this rattle problem aside? I am contemplating doing this with my otherwise stock M2.

The sound after the install is amazing and it honestly wasn't too bad installing it. I put it on the same day as my break in appointment so I can't compare performance before and after too much.

Just need to figure out what's causing this ringing noise and if it's related or not

[JKen_0115]

Originally Posted by Mosely

The sound after the install is amazing and it honestly wasn't too bad installing it. I put it on the same day as my break in appointment so I can't compare performance before and after too much.

Just need to figure out what's causing this ringing noise and if it's related or not

Hey OP, so the issue has been solved?

[wjjkoevoets]

Originally Posted by JKen_0115

Hey OP, so the issue has been solved?

Mosely

I'm interested in this as well. I'm having some basic maintenance done to my car soon and part of the maintenance will be replacing the downpipe gasket and V-band clamps (I reused the old ones during the DP installation, but that's bad practice). I was hoping this may be related.

[David1]

Originally Posted by wjjkoevoets

Mosely

I'm interested in this as well. I'm having some basic maintenance done to my car soon and part of the maintenance will be replacing the downpipe gasket and V-band clamps (I reused the old ones during the DP installation, but that's bad practice). I was hoping this may be related.

Nope. Clamps are reusable. Just tricky to line it up.

[Mosely]

Originally Posted by wjjkoevoets

Mosely

I'm interested in this as well. I'm having some basic maintenance done to my car soon and part of the maintenance will be replacing the downpipe gasket and V-band clamps (I reused the old ones during the DP installation, but that's bad practice). I was hoping this may be related.

Nope, nothing yet. I'm waiting for my next BMW oil change visit to take it all off and get a better look. I did a ton of listening with a stethoscope and feeling around at start-up, etc, and couldn't figure out what it was. The noise definitely comes from right where the turbo meets the downpipe but no leaks or anything. I'll update this thread when I take it off in July/August.

Originally Posted by David1

Nope. Clamps are reusable. Just tricky to line it up.

The lower clamp that connects the downpipe to the midpipe is a crush gasket. I guess you could re-use it but it works by crushing the little metal tabs around the pipe and likely won't get a perfect seal if you re-use. Whether that matters or not, who knows, but it's only like $25 if you order online.