where are the Porsche cayenne expo builds?

there's a guy on AudiWorld who claims to have the ability to restore the tune on a 8spd Aisin (yrk2.7t@curbside), or alternatively you can find a salvage TCM w/same part number on ebay or something.. put it in, get it fixed, then put your original back..
I'm probably going to get mine finally fixed in the next few months, then use the money to buy a stage 2 tune, dpf/scr/egr delete, get the TCM fixed and then put on a front runner roof rack so I can carry a full sized spare and mount my ham antenna.. and still have some cash to burn.
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I would highly advise against getting the 'fix' - this is not reversible. Also you will probably have issues plugging in a used TCM / ECU as they are programed to each car based on options selected. The TCM / ECU hardware may look the same, the software is not. Then, as I said above -
. Issue with 'tunes' is that I have never seen one that addresses both the engine tune & transmission.
. Then there is the issue of whether the tune is for Pre or Post fix.
 
theres several people whom have swapped TCM before, got fixed and put the original back, no question its the original software.. I know things are a bit different tooling wise for you Cayenne guys, but I've got a computer right here that can code my TCM appropriately, infact its been recoded to use the Cayenne shifting behavior so I know its the same TCM you guys use and it works just fine being coded 'wronglly'.. as long as the model number matches entirely the factory coding should be good to go.. The guy claiming to reflash grabbed imags off pre-tuned vehicles and just puts em back down ontop post tune, the problem is he dont have any of my specific model TCM on hand for a direct swap, so I'd have to loose the vehicle for a few days while overnighting it back and forth.. Ive been waiting for more feedback but I've found a few who claim its just as it used to be after sending it to him.

As far as tuning the ECU, pre-fix or post fix dont matter.. a tune with all emissions deleted is the same, they dont have to come up with a special post-fix tune because they didnt change any hardware that I wouldent be throwing away (just a post-scr nox sensor is all they put in, to make sure AdBlue is working).. this is not my first rodeo, Ive had a handfull of TDI's and this is my second one impacted by #dieselgate.. they can be unfucked if you know what your doing, I can give you names of people whom have done it.. at least for 2nd gen Touareg's and Q7's
 
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Spare tire size

We will be carrying two spares. Our C has the OEM swing-out rear wheel carrier but it may be limited to about 30" or 30.5" and we are going 32" (we have removed some lower plastic and are ready to modify the wheel well liners if needed). So, we will definitely be able to have a full size spare on the roof, but it may work better to have a 29~30" on the rear carrier. To those of you who have actually driven your Cayennes with a smaller wheel: what issues are we likely to run into if we run a slightly smaller spare? Will some computers complain? Might we lose the PSM or PTM? I strongly suspect that by the time we're on our second spare we'll be heading cautiously for a tire repair shop, not continuing on into the wilderness.
 
its applicable because you have two diffs now running @ 100% duty cycle with no reprieve, there is a reason why your user manual says: "rolling radius of all 4 tires must remain the same or within 4/32-inch of each other in remaining tread depth."

not to mention TPMS, ESP, ASR, ABS, EDL and other things are all operating off ABS sensors that check for wheels spinning at different speeds... so the vehicle will throw a bunch of errors and warnings and end up in limp mode within a few hundred feet of moving if one tire is not the same size as the others.. Know someone who swapped 2 big front tires on and went for a ride around the block to check clearances, he left the original rears on and it came back with every light and buzzer going off that it had, he thought he'd have to tow it back..
 
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The Cayenne manual talks about replacing tires and staying within 30% of the tread depth for handling reasons. I understand that the differential would be working a little more and that may affect all of those electronic things. In fact, that is specifically what I was asking about because while I can guess as well as anyone else, I was looking for direct experience. Still am.

And is it common in this community to talk about differential action as windup? To me they are VERY different things. I've driven things with locked differentials and I know what windup is. In fact, the Wiki article is pretty clear about it. With differential action there's nothing to unwind... it's the whole point of a differential. Common conflation or not?
 
The drivetrain is still wound up just now its wound up at the differential and not the tire, typically when your driving at speed in a straight line your diff is not doing anything.. its basically fixed, if you turn one side might start spinning very slightly faster, the diff will start doing its job but it wont be much work and wont be for very long before it goes back to rest.. the harder and faster you turn the quicker the diff starts moving, but you dont drive constantly turning tightly at high speed for long times..

now you put a smaller wheel on one axle and go out on to the road at 60mph, the bigger the difference in OD's the faster that diff going to be engaged, and its never going to stop.. when your driving at 50mph in a straight line the diff's acting like your driving 50mph turning tighter than your vehicle is physically capable of even at lower speeds.. now you have non stop friction and limited source of lubrication that was not designed with 100% duty cycle at high speed in mind.. so you overheat your diff.
 
If you guys go on rennslist, you’ll see that the problem isn’t the differential, it’s the transfer case when the tires are different sizes. That’s when they start getting all explodey.


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