Porsche 911 - will a Nissan Leaf drive train do it justice?

[mcgousha]

Success!

[tom91]

Great Success

Did you try a cheeky little test drive?

[mcgousha]

Would have loved to, but just running it like that highlighted some issues with the brakes so I will need to do a bit more work on them before I try running it with the wheels on the ground.

[JaniK]

Good job! Electrified porsche is certainly different!

Porsche+nissan= Ni-che
Or Por.c-San

Sorry I just had to share my stupid mind

[Cookie6000]

Class!!
Well done. You're making cracking progress Shane. Hope to catch up with you on my build and have an all-German, all-Leaf powered drag race between the Porsche, the Grey Goose and the Audi some time

[mcgousha]

Thanks Fiachra, seems like you're making some pretty great progress too. Drag race sounds like a great idea.

It was really cool getting the motor running in the car for the first time, even if it was just up on jack stands.

I had to make a few last minute changes to the wiring. Mainly due to me rushing to buy the relays in time for next day delivery and then finding out they were still expecting too much power from the inverter signal wires. Fortunately I still had the relay board from my Arduino powered precharge circuit so I was able to repurpose that for this set up.

So the wheels spun, I couldn't do it for too long as the gearbox didn't have any transmission fluid in it, so it was making a lot of noise, definitely need to get it filled up before the next run.



Next steps will be to try to get everything buttoned up and the brakes working so I can try driving the car out of the garage....and back in again.

[mcgousha]

I was all set to just drop the car off the jack stands and see if I could get it moving given that the motor is now able to turn the wheels. Common sense kicked in and I figured before doing that I should try to resolve the issue I had with the brakes from when I first drove the car into the garage.

The issue was that the brakes just didn't work...at all, when you press the pedal it just goes right down to the floor and the pads don't engage on the discs.



I decided to investigate further to see if there was an easy fix, but it looks like the master cylinder seal has blown and there is a puddle of brake fluid inside the brake booster. No easy fix for that, so I have ordered new parts which are starting to arrive.

I thought I had a work around by getting the handbrake working by replacing the cables, but the old cables were in such bad condition that the rust had fused them to the wheel carries and I ended up breaking part of the mounting system for them when I tried to get them apart. More new parts ordered....and still no brakes.

I have come to terms it will be another week or two before I can run the car on the ground, but I have now filled the gearbox with ATF and replaced the driver seat in the car so at least I can now sit there and push the accelerator and get the car to make all the right noises:-)

[mcgousha]

I finally managed to get the brakes working enough that I felt I could risk trying to drive the car out of the garage, and decided to just go for it.

I got 6 12v lead acid batteries hooked up to the inverter for about 75vDC and switched the power on and pressed the throttle pedal. I could hear the motor start and the car started to slowly move backwards, gradually picking up speed. It was as I reached my planned distance out of the garage and pressed down on the brake pedal, I realised that all the work I had done on the brakes hadn't actually fixed the problem enough, but as the motor was behaving itself, it wasn't a major problem and it slowed down quickly when I let off the accelerator.

I ended up doing that a few times as I was having fun:-) There were a few knocking clanking sounds which revealed a bunch of things I hadn't tightened down properly in my excitement to drive the car, like the brake caliper on one of the wheels, but once those were bolted down properly, the inverter, motor and gearbox all sounded really healthy.

I made a few attempts to steer the car around the place, but the unassisted steering was way to heavy with the small steering wheel and wide tyres.

Based on the initial run, I am keen to try and drive a bit further, but I will need to get the brakes and steering sorted before I can take it any further.

I've got a TRW Zafira power steering pump now, so I need to decide where I am fitting that and do some measurements between that and the steering rack. I can then get a couple of hydraulic hoses made up joining the ends of the two different systems together.

I also need to go around the car and give the calipers some attention so I can bleed the brake system properly.


Check it out here, if you get bored of me talking about brakes fast forward to 4:50 to see the car rolling.

[Zapatero]

Hi,

i watched one of your videos and figured that you're using this brake underpressure switch, that i use too:

Dracarys 28146




I'm having lots of issues with the valve. I'm running it with a relay, too. But Very often i have to wriggle on the valve to restore the electrical contact again. Especially when cold. I already have the second valve but it's not any better. Worked well in the lab, but not on the road. Do you have better experiences?

Cheers, Philip

[johu]

In Touran and Polo I'm using this pressure/vacuum sensor: https://www.ebay.de/itm/Drucksensor-VW- ... SwY4NebpuS

It outputs an analog signal. The lower the pressure, the lower the voltage.

In Touran I have a microcontroller that reads the voltage and controls the pump via a mosfet (with hysteresis)

In Polo I use a simple voltage divider to divide the voltage of the needed vacuum (I think it was like 2V) down to 0.7V to control a simple BC547 npn transistor. I also put a large capacitor between base and emitter which adds some hysteresis. The transistor controls a relay, the relay controls the pump.

[arber333]

Please put that posts about vacuum switches into hardware post. Good job!

tnx

[JeanVapeur]

Hi Shane,
it's not easy to find place for the battery (your last video).
Is there place for the inverter at the place of the old Gearbox?
So you have more room to play with, in the back...
And what is with the old Fueltank, 64L more?
Happy Easter!
Peter

[damian.lo]

Hi,

I'm using like Arber said this one:
https://uk.farnell.com/multicomp/psf109 ... PSF%20109S

Of course with relay, otherwise contacts inside will die shortly. The best is, that with hex-wrench You can adjust vacuum level, so You don't need to take maximum vacuum, which pump does, but adjust to exact level, which You had original (or You do more). Measure also pump current according to vacuum level

[mcgousha]

Wow, a while since I last posted an update.

A lot of the work over the last few weeks has focussed on the battery side of things.

With the 40kWh 2019 Nissan Leaf stripped down I went on a bit of a spiral of analysis trying to figure out the cleverest way to fit the modules in the space I had where the Porsche engine was. This was getting me nowhere as any option was going to require a lot of fabrication and getting metal is a total pain at the moment.

With a view of trying to keep the project moving forward I went for the simplest set up that seems to fit, 2 stacked rows of 12 modules.

I started with the box so I could get it fitting in the car while still relatively light and build mounts etc. from there, but I hit a problem with the metal I had. While waiting for new metal to arrive, I switched my focus to building out the pack itself so it can sit in the back of the garage while I work on the box and then just get dropped in once everything is ready.

It was really cool seeing the pack take shape, though I did end up with a bit of a challenge getting the BMS wiring all correct.



I'm hoping I'll be able to test the BMS wiring properly later this week. Fingers crossed I got it right, otherwise I may end up with a puff of smoke from the LBC.

[Isaac96]

Very nice!
Yeah the Leaf BMS is quite scary to use... I killed two by putting a maintenance switch mid-pack and leaving a charger connected - the voltage across the middle of the pack became 400v and poof went the optocouplers. So don't do that I guess?
-Isaac

[Speedy]

How's it going @mcgousha? Long time no see update

[mcgousha]

It's going good Speedy, thanks for asking.

Real life has been taking up a lot of my time recently, I am one of the lucky ones who has been kept very busy with work during this pandemic craziness, but I think I'm back on top of things so hoping to make more progress on the car over the next few weeks.

[mcgousha]

And on that note, I figured I should give an update of what I have managed to get done over the last couple of months.

With the battery pack more or less complete (bar tidying up some BMS wiring and getting the main positive and negative terminals wired in) I've basically been following two threads, one to make the car actually roadworthy and the other to build out the battery box and get the pack safely installed into it.

With the first thread, I can do most of the things needed to get the car back to a good place, with the exception of the drive shafts. I got to see enough driving the car around the drive way that I am happy with the lengths of the drive shafts I welded together, so I took the rear suspension apart and took these out of the car and shipped them off to an engineering firm that specialise in this sort of thing. It took a few weeks, but these are now back and look really good, I'll have a new video on those shortly. They look even more robust than the Porsche stock ones so should be able to take any power I can throw at them.

I have also bought components to replace a few parts of the suspension set up that are looking a bit the worse for wear. The OEM Porsche parts are ridiculously expensive, but fortunately there are some really good parts suppliers out there offering comparable quality at a much better price. And other parts are available direct from the OE manufacturer but non Porsche branded. These will be going on the car shortly and should reduce the number of items that the MOT inspector can fail me on:-)

[VortexEV]

Perhaps I should start by saying I have very limited knowledge of EV's but I am trying to learn using different forums, I have read this thread and watched the Youtube video links, I am interested to understand if this setup can achieve the sort of power you initially wanted. I really want to have a go at doing an EV project, I have built many IC projects over the years but feel EV has to be the way to go. I am considering using a kit car as a base rather than a conversion so hopefully no Can bus issues for me to consider. The Nissan Leaf setup was proposed by the kit car manufacture but I felt that this setup would not be powerful enough (but now wondering again if it would be) I also looked at using a Tesla small motor as this should give the desired power if we can get enough batteries in it, so I would be very interested in your thoughts on power to be achieved and potential reliability by over working the Leaf.

[mcgousha]

@VortexEV

To be honest a lot of this is still theoretical and is one of my drivers for the project, I want to see what this combination of components is actually capable of, and what can be done to get them operating at their max. There will be some headroom in the specs for each component, but I expect they is isn't the same for each part. I expect the inverter will reach it's limits before the motor does.

Based on testing done by others before me the Leaf motor has been pushed to just over 300bhp (220KW) successfully (the 1998 911 was rated at 300 so this is my goal) It is worth noting that the one I have seen the most information about (Arlo posting on Endless Sphere) had to build his own inverter power stage in order to achieve this. I believe he used 1200V 800A IGBTs which is undoubtedly an upgrade on the Leaf's standard inverter specs. This will have allowed him to send more power to the motor than would be achievable using the Leaf inverter.

Johannes mentioned at one stage that he reckons that by upping the voltage slightly (additional cells in the battery pack wired in series) I can probably get around 160KW out of the Leaf Motor and Inverter, which would be a good start.

I want to see what I can get it to do with the stock inverter first, before adding additional voltage or stronger IGBTs.

I think out of the box, the Tesla motors will produce more power. It's also worth looking at the packaging of the motor and inverter to see which is most likely to fit in the space you have.

[johu]

Yes well summarized. My source for the 160 kW claim was the GT86 build here: viewtopic.php?f=11&t=326&hilit=gt86&start=100

Somewhere he mentioned 136 kW with a stock 24 kWh Leaf pack - a rather beaten up one at 70% SOH I believe. So just upgrading to a stiffer pack would already deliver some extra power. We will see because right now he is doing just that

So stock Leaf is 395V max. The inverter consists of 600V modules which should hold up to like 430 or 450V unless the protection kicks in. So another 10-15% added. That's about the most squeeze you can do.

[Evkiwi]

Hi mcgousha

Love following your build...very inspiring.

Please forgive me for going slightly off topic in your build thread but I have a question in regards to what you, Johannes and vortexEv are discussing. From what Ive read its the inverter that holds the leaf motor back from making more power. Ive also read that the prius gen3 inverter has a better power stage than the leaf inverter. Could we use the prius inverter to get more out of the leaf motor?

Keep up the great work

[celeron55]

The prius gen3 is better in terms of voltage capability but worse in terms of current. I wouldn't expect it to be able to perform better with a Leaf motor than a Leaf inverter, except maybe in a specifically high rpm focused system with a silly high battery voltage.

[SciroccoEV]

Current Leaf still uses the EM57 motor, but the top of the range model with the big battery is available in 217PS form.

[SKB123]

What inverter was used on that honda CRX that did the 300hp?