[rickd]

After the first track day, I noticed that the exhaust has melted the plastic spoiler. I did get the Dinan resonator delete that might have heated things over stock. I just bought a carbon fiber diffuser and don't want to melt it as well. I measured 1" from the top of the exhaust to the molding.

Can someone throw a tape on theirs and let me know what you have?

It's a 17 M240i

Thanks,
rickd

[capt_and]

I’ve had the same problem. After a few track days, my m perf diffuser is melted where the tips were curling up. You could tack weld the pieces together so there’s less movement. I have an aftermarket exhaust so the tips are adjustable, I angle them down a little bit.

[cxp213]

How is the diffuser and the exhaust tip making contact? Is the stock (or MP) diffuser is catching air and being pressed onto the exhaust tip which then melts due to heat?

[rickd]

Originally Posted by cxp213

How is the diffuser and the exhaust tip making contact? Is the stock (or MP) diffuser is catching air and being pressed onto the exhaust tip which then melts due to heat?

It's not touching, there is a 1" gap between the bottom of the exhaust to the top of the spoiler.

I'm going to see if there is a way to angle it down like capt_and mentioned. I don't see how because the rubber hanger isn't adjustable?

[XutvJet]

There's definitely contact going on. When you drive hard and shift hard (especially in the 6MT), there will be a lot of movement of the motor and exhaust. Remember, all those components are sitting on, supported, and otherwise hanging from rubber mounts and hangers.

Does the Dinan midpipe remove OEM flex section? That certainly won't help things if it does. Also, the reduced weight of the Dinan midpipe and muffler may actually contribute to even more exhaust system movement.

[rickd]

Originally Posted by XutvJet

There's definitely contact going on. When you drive hard and shift hard (especially in the 6MT), there will be a lot of movement of the motor and exhaust. Remember, all those components are sitting on, supported, and otherwise hanging from rubber mounts and hangers.

Does the Dinan midpipe remove OEM flex section? That certainly won't help things if it does. Also, the reduced weight of the Dinan midpipe and muffler may actually contribute to even more exhaust system movement.

It looks like I can fix it by installing a couple of washers under the mount that holds down the rubber grommet hanger.

Got it installed this morning!

[Dylan86]

That's from rubbing and contact with high heat, this wouldn't happen from simply exhaust temps. You can see where the pipe has melted into the diffuser, and made a lasting "impression"..

You'd be surprised how much the factory exhaust can move.

[cxp213]

That's definitely from sustained contact with heat source (exhaust tip). I wonder at what point the contact happens, maybe under braking.

[CP911]

Too much curb action?

[capt_and]

Originally Posted by cxp213

That's definitely from sustained contact with heat source (exhaust tip). I wonder at what point the contact happens, maybe under braking.

For whatever reason, whenever the exhaust gets heated up (track temps not highway temps), the tips curl up. I have a picture of my car going down a straight with the right tip clearly higher than the left and touching the diffuser.