# Porsche Cayenne conversion ? Am I dreaming ?



## DIGGER11 (Mar 16, 2010)

Hi,
I have been tossing up between a Porsche Boxster and Alfa conversion, but am now thinking of converting a car I actually want to own and drive (nothing wrong with a sports car, but I am getting older and leaning towards comfort over sportiness).

So an early model Porsche Cayenne has me thinking.

Issues I can think of are
1. Limited Range due to weight.
I dont need much range as just to the golf club and back - but would really like 100kms if possible as is 80kms to my little beach house. Would a Leaf pack get me 100kms ?
2. Cayenne is Auto only. 
Not sure what to do here
3. Enoiugh power to move the Cayenne at a reasonable clip.
Can't go over 100kmh - too many speed cameras. Just need enough to keep up with traffic. For the Alfa/Boxster was set on HPEV AC51, but would this be too small for heavy Cayenne ?

Problem is that I really shouldn't spend too much - maybe $30k limit, as otherwise i am going to run into all off the new EV's coming out from the big manufacturers such as Volvo over then next 2-5 years.

Any advice (either +Ve or -Ve ) appreciated.

Cheers
Digger


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## brian_ (Feb 7, 2017)

Since a Cayenne is not the easiest conversion target, I have to ask... why the Cayenne specifically, and not any of the many other medium-to-large SUVs? For that matter... why this type of vehicle? I understand wanting more comfort than a sports car, but there is a wide range of vehicles between a Boxster and a Cayenne.

*Limited Range due to weight.*
It's not just weight... it's also large frontal area, mediocre aerodynamics, and resulting high aero drag. On the other hand, high weight also means high weight-carrying capacity; a large body also means a lot of space for batteries. This doesn't work if you want to use a stock pack for a smaller production car, but on the other hand twice the weight of a Leaf and half the range might work out.
*Cayenne is Auto only.* 
The obvious solution is to not use the original transaxle.
A manual transaxle from another VW/Audi product could work, although none will be direct bolt-in (assuming that the Touareg and Q7 were auto-only as well) because this platform was not used for any other model lines.
A single-speed system could be set up with one or two (for 2WD or 4WD) complete motor-transaxle units salvaged from a production vehicle... the most obvious match would be to build a Cayenne-bodied Tesla Model S dual-motor, but that would be expensive and a lot of work. Any two-motor system means two controllers/inverters, and coordinating them.

*Enough power to move the Cayenne at a reasonable clip.*
It's hard for me to believe an AC51 would be enough for this much vehicle. Perhaps two of them (one front, one rear) would work?


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## DIGGER11 (Mar 16, 2010)

Thanks Brian - good advice,

Reason for the Cayenne (could be Range Rover or equiv.) is that I like large cars and I have a Porsche Macan that I love.

Was looking at a Boxster conversion, but I know I would be happier in a larger car.

Can the original Auto be used at all ? I think AC51 has an idle speed function to keep the Auto spinning - or are the losses too great, or is it electronically controlled and will not work without.

In Aus,all luxury SUV's are Auto which is problematic.


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## brian_ (Feb 7, 2017)

DIGGER11 said:


> Can the original Auto be used at all ? I think AC51 has an idle speed function to keep the Auto spinning - or are the losses too great, or is it electronically controlled and will not work without.


All automatics are now electronically controlled. Regardless of the control system, I can't imagine an 8-speed plus reverse automatic transmission being worth the power to spin up, when it is doing very little for you.

On the bright side, automatic transmissions are moving to the use of electrically-driven hydraulic pumps to minimize parasitic losses and improve start/stop performance, which means that some of them might even be operable without idle rotation (likely with some controller re-programming).



DIGGER11 said:


> In Aus,all luxury SUV's are Auto which is problematic.


Not just there. Manual transmissions are becoming rare, especially in non-sporting vehicles, heavy non-commercial vehicles, very high performance vehicles, luxury vehicles... and especially vehicles which are a combination of those. A small sports car or basic small passenger car are nearly the only places to find a manual transmission now.


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## Egilnajarro (9 mo ago)

Digger, did you get to convert your Cayenne?


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## blackterminal (Oct 14, 2021)

In my opinion dream big. Most things can be done if you are determined and theres pride in doing something that few others or no others have done. What seems to be the right choice for this car would be the Toyota Lexus Hybrid drive unit. potentially just driving the rear end. Im not a fan of the whole lets make whole new subframe and jam a tesla drive in. Using whats there will make less work and less headaches.


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## Hostile Coyote (7 mo ago)

So I'm just wondering. What's the real issue. The thing I've noticed in EV conversions is that most of them are around pre-2000 cars. Back when cars weren't computers with iDrive (bmw), etc. And I get that. It isn't just about converting the powertrain in later model cars. Its about converting all of the other computerised b*llsh*t that seems to be the issue. AmIWrong?


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## remy_martian (Feb 4, 2019)

It's mostly cost of the target cars, I think. Ironically, the older stuff became "collectible" by the Y2k MBAs, so a '70 Chevelle that was $350 is now $7000. A 69 Vette in pieces is $17k, with no engine or trans....you can buy 8 of the '84's for that money.

All of mine in the conversion queue (for me & kids) are post-2k...the stuff I need working in the car I can make work without a BCM in the picture, for example. The GM radio that checks VIN number?...tell me why I'd want to keep that audiophile's prize if it's a P.I.T.A.


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