Hello Chaps,

Are there any manufactures that make a 200 CEL Sport (Secondary) Catalytic Convertor for the 2011 and newer 958 Cayenne Turbo?

Looking online the only could I can locate is Cargraphic, and I’m not willing to spend $2k+ on this mod.

Don’t want bypass pipes as I’ve heard they are too loud.

My CTT is my daily driver and I don’t want to make a noisy entrance / exit anywhere, just want a bit more performance without added noise.

Fabspeed (and I think FVD) makes bypass pipes I believe, correct? Heard 1-2 sounds clips, sounds VERY loud versus factory! Is that a correct assessment based on those of you who have done this mod? Any before after clips or decibel readouts before and after?

Not 100% opposed to bypass pipes, just don’t want to go to all the effort of installing pipes only to end up sounding like a Cummins Turbo Diesel (not that there’s anything wrong with that, if that’s your goal)!

Thanks in advance for the feedback.

Primary cat bypass pipes are louder. Secondary cat bypass pipes are perfect with a barely noticeable difference when inside the vehicle, but a nice, deeper and slightly louder tone outside the vehicle. I have a 957 Turbo S where I did this mod with Fabspeeds and, since our DFI engines are nearly identical, assume the result would be comparable. For my taste, it was still not aggressive enough so I added a Cargraphic rear muffler too, but if you're looking for not much more sound, it's probably per perfect for you.

You're not going to find good quality, inexpensive, 200 cell secondary cats because the HJS cats or similar are expensive themselves with the platinum that's in them.

Did you see these

http://www.hhrproducts.com/porsche-c...ry-cat-bypass/

I spoken to people that have used them, and they have said they are great.

This ^. I have the 2.5" secondary cat bypasses from HHR (non-resonated).

I was also worried about drone/cabin noise, but it's so subtle that you hardly notice it unless you're at WOT.

- There's high idle at startup, but it dies down to 600rpm after 30 seconds - it's intoxicating to hear.
- Normal driving you won't notice any additional sound, even with the windows down.
- I cruise often between 70-90 on the hwy, zero drone.

It's so subtle, that I am even on the market for an axle-back exhaust now.

Be careful! You may end up like me - I started off with a couple things for additional hp (HHR cat bypass + Fabspeed tune), now it's left me wanting to do so much more!

my understanding on this mod is that its purely for sound....little to no additional power comes from replacing the secondaries. Is that correct?

GBXSport, there's multiple dyno pulls that show 30(ish) hp gains.

For me, noticeable mid-range torque, some higher end boost.

Not many individual upgrades will be noticeable at the 500hp level, but this is one of the few. Overall drivability is improved, both around town and highway use.

https://rennlist.com/forums/porsche-...u-upgrade.html

Try a search in the Cayenne DIY section to see if anyone has done a Primary Cat Removal / Replacement DIY. I haven't so can't help you much with what's involved there.