2009 957 Cayenne GTS undertray
#1
2009 957 Cayenne GTS undertray
When I picked up my car it was a good example with a full service history, a bit rare for the age. What I didn't find out was that likely in the last major service the engine and gearbox undertrays weren't replaced. It was pristine under with no dirt and even the stickers gleamed so the undertrays hadn't been off for long. In my neck of the woods, replacing the trays won't be easy. Nil stock at Porsche and no wreckers offering them up.
I have elected to go with an off road undertray as that is where the car is being outfitted for use. This was always the plan but I had hoped to at least have the originals to consider when settling on the off road tray. I have chased down some pictures of the factory GTS undertrays and I note that there seem to be two ducts in the factory trays. Has anyone got any views on their importance when using an offroad style tray. Cars like OTIS have a pedigree so what ever they are using seems to stand the test of time. No doubt there may be some special needs for the 4.8 GTS so I'd like to capture any of these when I get the undertray set up.
I also have a touareg diesel and the trays, while basically the same have different ducting according to the photos. So it seems little help there.
Thanks
I have elected to go with an off road undertray as that is where the car is being outfitted for use. This was always the plan but I had hoped to at least have the originals to consider when settling on the off road tray. I have chased down some pictures of the factory GTS undertrays and I note that there seem to be two ducts in the factory trays. Has anyone got any views on their importance when using an offroad style tray. Cars like OTIS have a pedigree so what ever they are using seems to stand the test of time. No doubt there may be some special needs for the 4.8 GTS so I'd like to capture any of these when I get the undertray set up.
I also have a touareg diesel and the trays, while basically the same have different ducting according to the photos. So it seems little help there.
Thanks
#2
After a day plunging through the parts numbers it seems that the engine under tray in Plastic is the same for the Cayenne and the Touareg. Porsche also have the 2mm steel version. Both have the same front diff cooling arrangement.
The gearbox under tray seems to be based on the same core moulding for both with the Cayenne Auto trans version having a NASA duct rivetted to the right rear of the tray for added cooling to the center diff. One can only assume that this is due to the higher output and the potential for greater loading through road speed.
So it would seem that making allowance for additional cooling when using an off road design may not be necessary but can't hurt and maintains the basic design intent.
The gearbox under tray seems to be based on the same core moulding for both with the Cayenne Auto trans version having a NASA duct rivetted to the right rear of the tray for added cooling to the center diff. One can only assume that this is due to the higher output and the potential for greater loading through road speed.
So it would seem that making allowance for additional cooling when using an off road design may not be necessary but can't hurt and maintains the basic design intent.
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rosskuhns (01-23-2024)
#3
"the engine under tray in Plastic is the same for the Cayenne and the Touareg."
I can't help with the ventilation insight, and I'm in a similar place with a missing piece or three, but thank you for reminding me of this small but significant factoid. Many parts are interchangeable. When I go on the hunt for some things, I sometimes forget this.
Do you have information on that aftermarket piece you decided on? Also, what's this 2mm steel version that Porsche option?
I can't help with the ventilation insight, and I'm in a similar place with a missing piece or three, but thank you for reminding me of this small but significant factoid. Many parts are interchangeable. When I go on the hunt for some things, I sometimes forget this.
Do you have information on that aftermarket piece you decided on? Also, what's this 2mm steel version that Porsche option?
#4
The aftermarket option is a locally made one piece tray, advantages are much better protection for off road, disadvantages weight and faffing around whenever it needs to be removed. It doesn't offer the same level of cooling duct placement as the GTS factory unit, hence my questions. Freight is a killer and this undertray is no longer being made but at one time the maker shipped a bulk order to the US so it is held in some regard by users.
Porsche offer a 2mm pressed steel engine tray that is used with the plastic transmission undertray. Certainly better than the plastic option but not for any heavy impacts. It would be a more sensible option for dirt road / track users who don't expect to make heavy impact under their vehicle.
It becomes a bit of a battle of choices between maximising the factory cooling design that is required 24/7 and improving underbody protection that is crucial but occasional if at all.
Porsche offer a 2mm pressed steel engine tray that is used with the plastic transmission undertray. Certainly better than the plastic option but not for any heavy impacts. It would be a more sensible option for dirt road / track users who don't expect to make heavy impact under their vehicle.
It becomes a bit of a battle of choices between maximising the factory cooling design that is required 24/7 and improving underbody protection that is crucial but occasional if at all.
#5
In the end I went for the OE steel engine undertray and the OE Porsche transmission undertray. While the plastic transmission undertray component is the same as the VW Touareg, the Porsche version adds a metal air guide to direct cooling air toward the transfer case output flange that VW do not include. Interestingly the rivett holes to fit it are seen on most VW sourced parts. While this may not be essential at sub Autobahn speeds it was proving a bit of an issue with the available bash plates so I've taken the compromise approach.
#6
Parts received. The Eng undertray is steel
Steel undertray
The Transmission undertray is the stock item, for which the plastic component is identical with the VW touareg undertray but Porsche have added a cooling duct.
Porsche cooling duct
You can see where the rivett holes are in the VW tray for the cooling duct
Steel undertray
The Transmission undertray is the stock item, for which the plastic component is identical with the VW touareg undertray but Porsche have added a cooling duct.
Porsche cooling duct
You can see where the rivett holes are in the VW tray for the cooling duct