Slickdvl

I’ll have some pictures up later.
What you need
10mm socket and wrench
25mm torx
small flat head
needle nose pliers
pair of diverter valves - comes with 4 worm gear clamps
two small worm gear clamps 6-12mm
Small ratchet tool with socket attachment (7-8mm?)

i used forged diverter valves - kept the spring it came with until I get a tune - they include a blue and yellow for higher boost.

Loosen lug nuts. jack and support. Remove the wheel.
remove all the screws holding the fender liner - there was more than 10 of them including 1 in the front air dam and 2 under close to the jack stand point. There’s 2 10mm plastic nuts to remove as well. Pull away the fender liner.
Driver side - you will need to remove the plastic air trim behind the intercooler. It slides to the left of you are facing it - however there’s two little nubs that hold in from sliding on top and bottom. As you slide it you will need to pull the nubs away a little. I used a rubber mallet to help loosen as there was a lot of debris on the bottom. Be careful not to pull too hard on the plastic - I ended up snapping a piece off.
note: you don’t need to do this on passenger side.
Once everything is out of the way, you now need to get The two pinch clamps off, I wedged my screw driver into the pinch portion and twisting and prying it off - same with the needle nose pliers. Once the two clamps are off you can pull out the small tube in the middle and twist and pull the valve away from the pipes. I had a little oil in the pipes, no big deal. Replace the diverter valve making sure to put the new clamps onto the pipes and then putting on the new diverter. Tighten clamps. I used a small ratchet tool with 7mm attachment to tighten, as well as flathead. You can use the small 6-12mm worm gear clamp on the center small nipple however it’s not necessary.
Driver side, replace the plastic intercooler trim.
replace fender liner.
replace wheel

John Young

Awesome DIY write up. I realized after another post that the 3.6L TT has the same valves. Did you notice better boost response and more consistent boost through the shifts after? Any partial vent to atmosphere or you did full recirc? Thanks.

timmyz06

What are the pluses to go With Forges BOV? They seems to be full recirculation, more consistent opening? Can you hear them? Nice write up!!!

Slickdvl

Hard to say - it did feel good last night on a short drive to the store. I was expecting to see the notorious kinked line - however I did not encounter it. Full recirculating as our cars have stock. I primarily bought these in preparation for a tune which will require better valves and a spring that can support the psi. The forge valves came with a yellow (16-23?psi) and blue (24-?psi); so I plan to replace the original spring when the tune is added.

Slickdvl

i bought them on the recommendation of a member, build quality looks good and they came with 2 springs for higher boost application. Also, this was specific to Porsche Cayenne and one of the small nipples came with a 90 degree bend already ... I believe because there’s a common kink on one side that it was meant to alleviate. Full recirculating as stock - couldn’t really tell a difference. No I didn’t hear them, I don’t you should when they recirculate

timmyz06

Do you have any kind of CAI? Can't find anything for the 3.6TT

dbv1

Those aftermarket valves usually need regular servicing, stock valves never do. Is this the case here?

Slickdvl

correct, however the stock valves are known to have issues on tuned applications and failures.
im not too worried as I barely put 2k miles a year on my car.

how to service:

Slickdvl

no - intakes are not as available for our cars as they are for the 955/957. I have BMC filters installed for better flow.

Slickdvl

Went for a long trip to family’s today - car felt really good - pulled very nice and easy. Weather was good to for it. Not sure if the diff and tcase fluid helped - but it definitely picked up nicely.

8202632

I have a question. Thinking about doing this. For all of you with a 958 turbo, when braking, do you feel that the pedal travels down faster and there is somewhat a loss of pressure as it downshifts. Kinda hard to explain. My normally aspirated cars have a very firm pedal feel and it's very linear. But my turbo s feels like there is some sort of pressure loss as the car slows and requires me to push the pedal down harder and further . Didn't know if it was related to a vacuum leak or maybe the diverter valves. Or maybe it's normal. I have had the fluid flushed recently, so that's not it. Could anyone shed some light on what to look for or maybe confirm how your pedal feels? Also at a complete stop, if i forcefully push down on the pedal, it continues to sink. My other cars, no matter how hard i push, the pedal is firm. So maybe a master cylinder?

deilenberger

The continues to sink - normal. Mine's done it since I got it. Thing is - it does this if you're stopped. If you pressed it that far down under normal braking you'd be into the ABS.

Also worth considering - the turbo has a camshaft driven vacuum pump for the brakes - on the starboard side of the engine. There should be no real pressure loss - but you also have to remember that you probably have adaptive braking on your turbo. Do you have adaptive cruise? Under hard braking at speed the pedal is purposely hardened up, allowing you to brake harder. In a potential collision, the pedal is really hardened up and the brake pads are moved into contact with the rotors to minimize freeplay in the brake system. It won't apply the brakes for you - but you will be notified with a very loud squealing noise and a big red warning on the multi-instrument-display on the dash. The brakes are capable of fully automatic behavior if you're using the adaptive cruise. Last time I was in LA with my CTT - I really got into adaptive cruise on the freeways, which can go from 70mph to a crawl in 1,000 feet. Adaptive cruise handled it fine. Even my wife (who normally makes hissing noises if I did that sort of braking) seemed to trust it.

deilenberger

Timmy - take a look at the stock intake. How big are the filters in comparison to the intake throttle body? Look where the filters draw their air from. You have a CAI of way oversize proportions on your Cayenne right from the factory. All the aftermarket stuff will do is lighten your wallet.

8202632

So I noticed something with the brakes today. I do not have adaptive cruise. When on a hill, my hold light turned on and the brake pedal was as firm as a rock. Felt like my other cars. To delienbergers point it must have something to do with the adaptive braking. Wish it felt that way all the time but all must be good!

John Young

Since you are one of the few actually tuning the cayenne- @Slickdvl any report on how the forge diverters are doing? Or are you still waiting on some parts to get the Cayenne going?

My stock ones are leaking- so time to upgrade. I noticed the Agency power, Kraftwerks, KXX all look suspiciously the same as Alibaba housings- and some look like similar springs etc. So leaning to the Forge DV, GfB, or even Perrin universals.