M Performance Exhaust Crack

[SanchoDivine]

Originally Posted by horsepower_and_hounds

Yes cuz it will crack again......and again.....and again.....
The only ones that don't crack yet are the latest version with the braces already there from the factory

I have over 35k miles on my v1 MPE and it still looks brand new. I am assuming this is because my flaps are always open so it probably never gets extremely hot. I go over a ton of horrible speedbumps in my neighborhood daily and have been wondering if mine would crack so I can get it replaced with v2 under warranty which will run out in a couple years but it still looks like it did the day I got it.

[jmg]

Originally Posted by SanchoDivine

I have over 35k miles on my v1 MPE and it still looks brand new. I am assuming this is because my flaps are always open so it probably never gets extremely hot. I go over a ton of horrible speedbumps in my neighborhood daily and have been wondering if mine would crack so I can get it replaced with v2 under warranty which will run out in a couple years but it still looks like it did the day I got it.

Has your MPE turned purple yet? If not, then perhaps it hasn't gotten that hot. Regardless, I'm not so sure it's the temperatures alone that cause cracking. My flaps were always open and it still cracked.

[SanchoDivine]

Originally Posted by jmg

Has your MPE turned purple yet? If not, then perhaps it hasn't gotten that hot. Regardless, I'm not so sure it's the temperatures alone that cause cracking. My flaps were always open and it still cracked.

No, mine is still the same color or very similar to what it was when I got it. I haven't tracked my car so that probably keeps the temperatures lower than what would change the colors. Also, unless you disconnected your flaps while open, tuned your ECU to keep the flaps open, or use a valve controller, sport and sport plus do NOT keep the valves open all the time.

[dvq]

Originally Posted by SanchoDivine

No, mine is still the same color or very similar to what it was when I got it. I haven't tracked my car so that probably keeps the temperatures lower than what would change the colors. Also, unless you disconnected your flaps while open, tuned your ECU to keep the flaps open, or use a valve controller, sport and sport plus do NOT keep the valves open all the time.

Your exhaust tubing past the valves will turn purple untuned just in sport plus mode after a couple hot track days. The muffler will turn purple if you track it with the valves closed for sound purposes.

[Tecnniqe]

How does a V1 and V2 look different? Anyone have comparison images?

Also what year did V2 get put onto the vehicles

[jmg]

Originally Posted by Tecnniqe

How does a V1 and V2 look different? Anyone have comparison images?

Also what year did V2 get put onto the vehicles

There are extra brackets from the can to the exhaust tips. I had my V1 swapped for a V2 under warranty on my previous F80 in 2017 so at least that far back.

[CanAutM3]

Originally Posted by SanchoDivine

No, mine is still the same color or very similar to what it was when I got it. I haven't tracked my car so that probably keeps the temperatures lower than what would change the colors. Also, unless you disconnected your flaps while open, tuned your ECU to keep the flaps open, or use a valve controller, sport and sport plus do NOT keep the valves open all the time.

jmg has a CS and with the CS tune, the valves remain open that vast majority of the time in Sport and Sport+ modes. I have a BMS valve controller from my previous 2015 M4 and I have not bothered installing it on my M4cs because I find the valve control logic to be just perfect on the CS.

Further, you don't need the valves to be closed for the rear section to change colour. IMO, driving hard with the valves open is what gets the rear section to change colour. There are still some exhaust gases that flows through the rear section even with the valves open since the channel remains open. Since there is much less exhaust flowing though the rear section, it reduces the flow velocity heating up the exhaust gases as they expand.

[CanAutM3]

Originally Posted by dvq

Your exhaust tubing past the valves will turn purple untuned just in sport plus mode after a couple hot track days. The muffler will turn purple if you track it with the valves closed for sound purposes.

As posted above, IMO, it is driving hard (as on track) with the valves open that changes the colour of the rear section. I exclusively track with the valves open and all 3 three of my MPE turned blue/orange after their first track day.

For sure, tracking with the valves forced closed for sound will heat up the rear section even more. I tried doing that once and the engine started pulling power after a few laps. Valves are meant to be open above 4,000rpm to get the max out of the engine.

[Jbonly21]

Damn, here I thought I have been driving my car hard this whole time. Even after two track day's, stay no purple . Exhaust flap always on open.

[horsepower_and_hounds]

Love the look #gettin it

[jdarwin]

Before my car's warranty expired, I had my dealer inspect my MPE and they found a crack at the top of the muffler - not where most of the cracks have been discussed here. There are no replacement units available at this time but I'm on the list for a replacement. The areas of greatest concern were determined to be fine.

[Jbonly21]

Originally Posted by jdarwin

Before my car's warranty expired, I had my dealer inspect my MPE and they found a crack at the top of the muffler - not where most of the cracks have been discussed here. There are no replacement units available at this time but I'm on the list for a replacement. The areas of greatest concern were determined to be fine.

Interesting can you post some pictures of the cracks?

[horsepower_and_hounds]

From what I was told the exhaust has been discontinued. They don't sell it in europe any longer due to the new TUV sound regulations so sooner or later the warranty supply will run out

[Ef80m3]

V1 mpe bought second hand, zero cracks looks brand new still after 10k miles

[jdarwin]

Originally Posted by Jbonly21

Interesting can you post some pictures of the cracks?

It's on top of the muffler - hairline crack. I'll try to take a pic but it's difficult to access without being on a lift.

[S2000_Europe]

It is more about the Ti than the color, Ti would get blue with the time

Ti exhausts usually have problems if they are not reinforced or the walls are too thin.

I remember when I bought a Ti exhaust from Amuse for my S2000 in 2005. I went to track, Supercharged the S2000 and the exhaust was fine. It weighted 20lbs with a resonator and two mufflers, so you can imagine how things the walls were, while the stock Exhaust weighted 65 lbs

Some friends from UK bought 15 exhausts and 7 of them has cracks inside of the resonator and theirs car where not modified, I was lucky or did not make to many miles (around 10K) as they. In US the same problem, so at the end no one combined Ti exhaust with Forced Induction (FI) S2000.

[bmwfan78701]

Originally Posted by Bmwlmr99

had my mpe repaired, no more issues

Just purchased a very clean 2015 m4 and love it aside from it having this MPE rattle at startup which is simply awful...

For those that opted to repair vs replace, can you provide some examples of what the repair shop did to address the crack and bracing?

Cracks: Concern the weld will weaken the metal around the crack and cause more... Has that occurred to anyone?

Brace(s): Is the consensus two or just one is all you needed?

Lastly, how was the weld performed? Do you have to take the exhaust off the car or do they weld with it in place?

Thanks all!

[WhiteFox]

You can Ti weld the cracks and no issues usually. They crack at the pipe attaching to the side of the muffler as this is thinner than the body of the exhaust. V2 they just welded a bracket so the pipes would not flex. You can get this mod done at a Ti welding place as some owners have done.

Cracks happen with metal fatigue and this is usually caused by extreme heat.

[SpartanGA]

Bought a used V1 (swapped with my stock exhaust). Getting the cracks welded as I type. I will report how that holds up.

[SpartanGA]

Originally Posted by SpartanGA

Bought a used V1 (swapped with my stock exhaust). Getting the cracks welded as I type. I will report how that holds up.

My extended warranty actually covered this and completely replaced with V2 exhaust. It’s an entirely new sound. Incredible and very pleased.

[MNGo4M3]

I have a repaired MPE that was in my vehicle when purchasing. One of the support bars has come loose at the weld point. I took it to my weld shop here, and they are wondering what type of titanium alloy the exhaust is made with in order to get the best bond.

Anyone know the answer by chance or what titanium rods you/your shop potentially used to repair? Searched all over and haven't found it yet…

[horsepower_and_hounds]

The guy that does my exhausts uses TiCon CP1 grade Titanium 1.5/2.2mm rod....size depending on the thickness of tube or wall.