I wanted to get some thoughts on just going the sport cats route and keeping everything else oem. Either Soul or Kline is what im thinking. Is there a sounds difference if im just doing cats between the brands? there is a cost difference; is the soul worth the extra $ for Cats. Thanks

 

Without a sport exhaust like the 3.0s have I dont think your going to be happy with just cats. The stock mufflers on the 3.8 turbos are too quiet. Your looking at over $2000 just to do cats.

 

I agree. I would (and did) start with a sport muffler and see what you think. If you want more sound then you can add sport cats later.

 

I went with Europipe stage 1 as it comes with 100 cell cats as part of it.

 

not looking to hijack, but i am interested in just doing hi flo cats when i install jb4 on my 991.2. not looking for more/better noise, just better flow. who makes the best hi flo cats?
thanks charlie

 

We produce a top quality 991 turbo catalyst.
We use the larger 128mm German HJS 100CPI cores. No CEL and fabricated in the USA. They can also be used with any of our 991 turbo systems at any time in the future, should you choose to expand the system.

SpeedTech 991 Turbo Catalysts

 

I have the speedtech 3" no muffler exhaust and 100 cell cats. Very happy camper. They are awesome.

 

My experience is to do the muffler/x pipe and keep the revs higher. The car howls like a gt3 at you approach red line. Good luck.

 

To be clear: your 100 Cell cats follow OEM geometry and would work with oem muffler? And the converse would be true (OEM cats with Speedtech post cat muffler/pipe)?

On your sport cats does the downstream O2 bung have a built in stand off, emulating a spacer?

 

Correct, our OEM STYLE CATS retain the OEM beginning and ending points with OEM sized tubing to connect to the OEM center muffler. We also produce catalysts with full 3" exit pipes for our full system. Finally, as an additional option, we fabricate an adapter piece that can transition from any OEM sized cat to any of our our full X-Pipe systems. As an example: The adapters pictured below can be used with either the 991TT OEM cats or 991TT aftermarket cats to transition to any of our X-Pipe systems.

To clear, you must specify OEM size exit tubing at the time of order, if you desire to fit to the OEM muffler.

 

That's what I did with a SpeedTech X-pipe, and kept the OEM cats. In NORMAL mode at highway cruising rpm, it's only slightly louder than all OEM. In SPORT mode, with the revs up it does howl like a GT3, with a little turbo woosh in the mix. You also get the cool deceleration gurgles in the SPORT modes, but no loud pops.

I drive in manual mode 95% of the time, so I can keep the revs wherever I want them for the way I'm driving at any particular time.

 

That's a great set-up! It's what I use, as well.

 

Another great choice if you want to keep it on the quieter side and/or or retain OEM emmissions.

 

Fabspeed make excellent High flow pipes with HJS cats

 

Yes, retaining the OEM cats is a consideration for both CPO reasons and some state emissions requirements.