Time to get back on the spanners / Electric Porsche 928 project (Ep.9)

[@billhill4479]

" Why not do it once and do it right ". Lol. Famous last words. Because you haven't done this conversion before, you will have to learn everything about how the Porsche works so that you can marry it up with the MG system. While there will be a few challenges with this, you have the two known systems to start with which should make it easier. This will involve trial and error and making mistakes along the way of course. Anyone that's ever built a car has always come out the other end with a list of things they would change if they had their time over again. At the end of this project, you will have an intimate knowledge of the Porsche controls and also how to merge an MG with most ' modern ' cars. That will be a very good position to be in. Given that you've suggested that this will be the first of several projects, I reckon keeping this one a bit simpler is the right move. The best thing about this is that we, the armchair experts watching on, will get to see the trials and tribulations of both projects as they progress. I'm really looking forward to it.

[@inCARnationAustralia]

You're right. That was unrealistically optimistic. Probably do it once and make a huge number of mistakes. Do it again and make fewer, but still plenty. I'm going to try to keep the MG and Porsche systems as separate as possible. I hope they'll share little more than just just the 12V battery. So 40-year old Porsche for wipers, washers, lights (upgraded to LED), interior lights, hazard, elec.seats, elec.windows, central locking and that's about all. Oh, and mandatory stuff like seat belt warning light. Those are all things the MG does better, plus there are a hundred other MG systems I won't use at all - like rain-sensing wipers, cruise control, cameras, radar, folding mirrors, blind spot alert, all the autonomous safety, proximity sensors, rear drive assist, lane keeping and heaps of others. Hopefully I can retain the infotainment though - it's be so nice to have practical console driven bluetooth, DAB, satnav, carplay. And a proper modern electric A/C system in a 928 would be just glorious! The KERS system may not work without ABS data though, which would be a real shame. Yet to be established.

[@richardvoller8183]

Hi Stuart Watching from the Uk and really enjoying this project. Will be fascinating to see how things develop. Thanks for sharing this journey in such an entertaining fashion.

[@stanlomax4615]

I like your cautious multi-prong approach to start. Don’t commit to anything until you have contemplated all options. You are exhibiting evidence of full frontal lobe utilization, which is a welcome thing to see. I am pulling for you from the endless mountains of northeastern Pennsylvania. May 2024 see a fully functional EV928.

[@inCARnationAustralia]

Thank you Stan for the vote of confidence. I actually laughed. Plenty of mistakes yet to come though. Yes, 2024 is the plan. Matt is more confident than me. And maybe one day I will discover the beauty of the Pocono and Route 6. Looks like a lovely area.

[@JamieJones1985]

You sharing the can logs from the MG? Be useful for getting the parts working stand alone. Damien Maguire working on charger at the moment

[@inCARnationAustralia]

Yes the guys here in Sydney are working actively with Damien, although having a little New Year pause at the moment. But yes.

[@markedwards4879]

To be honest, I think that the model S route with batteries at the front makes sense - that’s what I was thinking about for a while. The MG transplant is also a good idea but maybe you should do that in a different car. Mixing the MG and Tesla components seems to make both more complicated.

[@inCARnationAustralia]

I do agree Mark. And "a different car" might be another 928, maybe? I foresee lots of issues and bottlenecks when trying to mix MG and Tesla technologies (battery -> controller -> invertor -> motor). Regarding batteries in the front, once I get the 928 stripped and corner-weighted we will have a better idea about where the 16 (or possibly fewer, Nick is only using 5 in his VW conversion) Tesla modules might fit. Personally I think it would need most in the front but some still in the rear. Which isn't really a problem, but I would like to have a slightly rearward weight balance. And I think it'd be good to keep some space in the front for P/S, brake accumulator, AC components. A lot of the other stuff can go rearward - BMS / charger / invertor / DC-DC convertor / 12V battery. Even the cooling pumps and reservoirs.

[@markedwards4879]

@@inCARnationAustralia Hey Stu, I think that it would be interesting to see how much space the removal of the fuel tank gives you in the rear when the drive unit is installed. I suspect that there would be some space there that could be interesting to use. The MG power plant to get would be from a wrecked XPower if you could find one, but that would be a massive effort to get the 928 to be AWD. As for the rear weight bias, I’m pretty confident that the original 928 was a touch heavier at the front. One consideration with the batteries at the front however would be to make sure that they were in a very substantial enclosure with some decent contact or/fuses. The last thing that you want is to be in an accident that causes a short circuit and subsequent fire straight in front of you.

[@lappy65]

@@markedwards4879I thought the 928 had a 50-50 balance by mounting the gearbox with the differential at the back of the car.

[@adriancnolan]

I would have guessed you'd like a Perth to Sydney road trip with the donor model S towed.

[@pieterschaar5613]

Tesla S route looking like more sense in the long run, MG easier to make work right now but in the end, will you be happy with the lack of oomph and making MG work with S motor frought with potential issues and the $4k freight cost of wrecked S vs all the time/effort and bits needed to make them work together will pale in comparison Thinking through process and askng the experts for advice will hopefully steer you in right direction Keep up this great series

[@inCARnationAustralia]

I'll keep watching for a Tesla Model S closer to home. Funny how they go for more than the plethora of crashed Model 3 and Y. Those S battery packs are popular!

[@CrazedCrittic]

Yes!!!! Looking forward to the next one Stu. Tesla battery also flows more current (peak) than the MG pack and the cooling is time proven.

[@inCARnationAustralia]

Indeed. So using the Tesla SDU motor with the MG battery not likely to yield much improved performance over the MG motor. And switching to Tesla battery (if we could find a place to fit all those modules) would mean the MG motor controller also a bottleneck to current flow. Lots of fun times ahead.

[@tomcat7525]

No one ever said it was going to be easy, very challenging to say the least. How long before this is done to your satisfaction? I never imagined a conversion would be this difficult. What was that old ad jingle. Electricity makes life easier 🙀

[@inCARnationAustralia]

Major milestones as I see it at the moment (some consecutive, some concurrent) - Porsche denuded of petrol stuff, repairs to suspension, brakes, tidy up, corner weighted, ready for electrics - MG entire electrics from battery to motor removed from car and demonstrated working in workshop - Motor mounts and battery box(es) designed and test fitted to Porsche - MG electrics reconfigured to fit in new layout, loom extended, all components weighed and weight balance established - MG electrics fitted to Porsche - enough to turn the wheels How long? I'm not speculating. Matt says "2024". That'd be nice.

[@larssandvik1347]

Nice!!!!!

[@gazfish]

Trying to reverse engineer the MG would seem to be more effort than letting experienced guys buy their known parts and then customer building the max battery config that would work.

[@Mark-Cantor.1961]

Hi Stu, I have a question for you if you have time. I’m looking at buying a 1986.5 Porsche 928 which appears to be well maintained. I have read up about it and know the difference between it and a standard 1986 model. I’m just wondering if they are in fact rare, and I should expect to pay a premium for this model over others. Like you. I have a long term love ❤️ for 928s. I would really appreciate any thoughts you could share with me on these Porsches. Cheers Mark. 🧋😎

[@inCARnationAustralia]

Hi Mark I don't know enough about the 'organ pipe' 928s to comment. Sorryl. But Bruce Buchanan would know the answer. Suggest you contact him. [e-mail]