Repetitive cracking on Fabspeed exhaust

Here's an issue that has me seriously stumped and very frustrated. I was hoping to get some thoughts on this. Quick summary: I installed a Fabspeed race exhaust (gen 1) on my 07 Cayman S in May 2012. System cracked on the inlets to both mufflers in less than a year and had to be replaced with a new system (Gen 2) in June 2013. Come October 2014, lo and behold!! Cracks again, this time on the exit side of the muffler going into the tailpipes. Cracks are away from the weld area and circumferential all the way around. I'm exploring repair options at the moment, including warranty repair (again!!) through Fabspeed.

Odd, did you confirm the rest of the mounting area is properly unloading the weight? Otherwise, perhaps an issue is dissimilar expansion traits and a design flaw. (metallurgy pro please comment?)

Yes, I had a professional install the new one to take me out of the list of variables. Also, there are cracks on both mufflers in similar locations, not just one.

Maybe you have bad engine/trans mounts causing to much flexing in the system

Is this similar? Not sure if this is the same problem I noticed on mine. If you bought it new, you should contact Fabspeed. Edit...Logged on to my computer to see your pic. Looks about the same. Interested to hear your next step.

Yes speter20 , very similar. Always away from the weld. Your picture is exactly what my Gen 1 system did (cracked on the inlet to the mufflers). This time around the cracks are on the exits and a bit further up into the cup. Both systems were bought new from Fabspeed. When the first one was sent back, it was completely butchered on one side during the weld "repair" and the other side wasn't done at all. After significant negotiations and an idle car for close to a month, I paid a significantly discounted price for a Gen 2 design. I did send Fabspeed an email on Friday and am waiting to hear back. Given that this is my daily driver I had to drop it off for an evaluation and repair yesterday. These are not just surface cracks. I will have the engine/transmission mounts checked as well but there were no obvious indications of any issues there. Given the location of the cracks this time around any purely mechanical flex would likely have damaged the muffler mounts before causing issues on the exits. I'm suspecting bad welding practices and/or a thermal fatigue issue in the heat affected zone. The exhaust is so loud by default that you don't discover these cracks easily or until they've caused a very obvious issue. I will post updates on the situation.

just from looking at the pictures you posted, i would say the cracking is due to the heat cycle. with the crack going all the way around the can, something is expanding/contracting faster/slower than something else. if it were stress related, the crack would originate from the point of high stress and stop at a point of lower stress. without knowing how the can was made, i would fair a guess and say the wall thickness is too thin for the heating/cooling cycle of the exhaust. i'd like to think the manufacturer would stand up and replace it. keep us informed.

Metalengineer, I'm more or less convinced it is a heat cycle/thermal fatigue issue and I had brought this up with the manufacturer last time. I did not get any straight answers to my questions on the factors that drove the design change from the Gen 1 system (eliminated the flex couplings and split the mufflers into a two piece design). At that time, I was hoping it was a welding issue because that would mean a replacement system might not have the same problem. A fundamental design flaw on the other hand makes a warranty replacement pointless because this will happen again within a year. Visually it looks like the cup is drawn but I'm not sure if they account for thinning during drawing. Thank you everyone for taking the time to respond.

Is this fixableis my question? Sounds like its possible it may happen again. My other side looks fine by the way.

We apologize that you system cracked - it was very odd that is cracked once, let alone a second time in what seems like the same place? Please shoot an email to [email removed] - we can get this corrected for you.

In contact with Fabspeed to try and resolve this. Obviously, I'm not the only one with this problem. My mechanic confirmed that the cracks are through and through. Speter20, I didn't realize you're currently in this situation as well. I assumed you had experienced this in the past.

Yes. I'm not the original owner. Bought used on this forum. Cracks just showed up within last few months. Saw your post while I was thinking what to do. Really like the race exhaust so emailed them to see what could be done.

Hi Speter, I know this is an old post but I'm experiencing the same issues. Could you please elaborate what happened at the end?. Did you get them repaired from Fabspeed, cost? Thanks for your reply. I greatly appreciate it. Thanks.