What exactly is the "e81 upgrade" ??

That kit was for a 957 CTT right? Is the 957 intake any different than that fitted on the 958 turbo engine? Has anyone done this to a 958 CTT?

Interesting thread..

Lot of DIY'ers - but not a lot of modifiers for performance. There are a few who have done some impressive things with the 955/957 series. Not so much on the 958.

If your fix of the coolant pipe is a new style bolted pipe and housing then I would recommend water pump, t-stat, and serpentine belt.

The new thermostat housing (which has the two pipes coming out of it) was redesigned with pipes that bolt in. They are not coming out. If you look at the thread on the topic - there are photos. If you're replacing this - you'll R&R the water pump and the thermostat in order to replace the housing. To me putting the old ones back in would seem penny wise and pound foolish. Doing the labor twice when one of them fails really isn't that appealing. You also need all new seals for the thermostat, and it's not trivial to remove it from the housing in an undamaged condition.

Also curious - do you have an AllDataDIY subscription? If you're serious about DIY on a Cayenne you should. It will avoid having to ask questions like this - there will be step by step directions on this procedure.

The confusion comes about since you started out the thread with a performance modification. Sorry.. And cell phone pics work just fine for DIY's.

As far as how many serious DIY'ers there are here - have you looked at the Cayenne DIY subforum? That should answer that question for you.

Subscribed to thread. I would be interested in a 40hp gain, for sure.

As I understand it, there's an E81 'powerkit' available for the 957 Turbo V8 and one for the 958 Turbo V8 that includes H/W and S/W (tuning) specific to each gen. It's most of the engine enhancements that are done to the Turbo S models, although the factory power rating on the E81 Turbo motor and the Turbo S motor for a given gen are not exactly the same (Turbo S a little higher IIRC). This powerkit was available as a factory option or added after the fact, available through Porsche's Tequipment program. The E81 powerkit includes the larger front brakes of the Turbo S model as well.

I'm not certain but I believe Porsche might have discontinued the 957 and 958 E81 kits already, although they might still be located as NOS somewhere.