Working on installing my new Motorsports (Utah) X-pipe and hi-flow cats. The cats are 2.5" in and out. The x-pipe is 2.5" but the factory cat back is 2.25". The hardware kit included a pair of 2.5" TorcTite clamps and a pair of 2.25" TorcTite clamps along with flange gaskets, bolts, etc. I have the X-pipe bolted in and it fit right up. I used the 2.5" clamps to clamp the cats to the X-pipe. The issue is the 2.25" clamps. They will not fit over the 2.5" outlets on the cats and allow the reaction bar and nuts to be installed. I've tried contacting the vendor and the manufacturer for more info but with the holidays and all I haven't heard back yet (glad they are both enjoying their time away from us pesky 928 owners.) Am I missing something? A friend suggested the best install would be to have the cats welded onto the X-pipe locally, then use the clamps to attach the cat-back plumbing. I may do this later but was wondering if I'm just not seeing something about this package that is preventing me from completing the install? Are the cat outlets supposed to be rolled down to 2.25"?

Update-See final post for resolution
Thanks
Mike

 

I would go with cats that are 2.5 in and 2.25 out. And weld them on, those band clamps are Mickey Mouse.

To attach them as is you will a set of step down clamps. Normally included with the install kit when not using cats.

 

Band clamps work fine when properly installed. If you can find an aftermarket supplier of 2.5" X 2.25" cats or clamps please post a link.

Anyone with actual experience doing this install care to comment?

 

 

Mike,
I've slept since I installed mine, and I have CRS, but the way I remember installing mine, I used the larger set on the Xpipe to cat joint and the smaller set on the Cat to cat back factory exhaust and they fit fine.

 

Thanks John. I tried to fit the small clamps on the cat to cat back factory exhaust joint. I could get the bolts through the clamp and into the reaction bar but there wasn't enough of the bolt coming through to get the nuts started. I also tried using a C-clamp to close the band clamp so as to get enough thread exposed and get the nuts started. No luck there. Everyone will be back in their offices today (I hope) and I can make some phone calls.

Mike

 

please keep us updated......

 

I had to take my exhaust off and put the original back on before moving so I marked everything and took it apart. Maybe these pics will help.

 

Thanks. Part of my challenge is I'm reusing the factory cat back plumbing, which is 2.25" vs the 2.5" diameter of the x-pipe and aftermarket cats.

 

I was under the impression from the info on their web site that 928 Motorsports high flow cats were sized to fit the X-pipe on one end and the stock cat-back pipe on the other, i.e. they are 2.5 X 2.25. Not so?

 

The cats I got in the kit from Motorsports SLC were 2.5" on both ends.

 

Mike,

I'm curious... when did you purchase these from Motorsport in Utah?

 

Carl, you have PM.

Mike

 

Hi Mike,
These were just delivered before Christmas.
I have contacted MotorSports SLC to see what is happening.
Just talked with them.
One end of the cat slides over the X pipe and the cat back slides into the cat.
Best Roger

 

No worries Roger. Hope you and the family had a great holiday.

Mike