openinverter forum

Fantastic progress! Your comment about the parking brake cable interfering with the battery box is something I found out when I fabricated a wooded box to model the battery boxes. Did you get the extended brake cable from Porsche or somewhere else?
What is the rating of your Tesla charger and your DC-DC Converter? (You may have mentioned it in previous posts)
I will be using a 6.6KW Kia Charger with a TDK 200Amp DC-DC converter. Hopefully it will have enough power for the electric heater and all accessories.

canadasconvert wrote: ↑Fri Dec 11, 2020 6:34 pm Fantastic progress! Your comment about the parking brake cable interfering with the battery box is something I found out when I fabricated a wooded box to model the battery boxes. Did you get the extended brake cable from Porsche or somewhere else?
What is the rating of your Tesla charger and your DC-DC Converter? (You may have mentioned it in previous posts)
I will be using a 6.6KW Kia Charger with a TDK 200Amp DC-DC converter. Hopefully it will have enough power for the electric heater and all accessories.

Re the parking brake, the existing cables were sent to a UK based specialist to copy and reproduce new cables but two inches longer on each side.

Charger is Tesla Gen 2 10KW with Damien brain.

My Chevy volt DC2DC only draws about 30amps max under full load (lights, wipers, fans).

canadasconvert wrote: ↑Fri Dec 11, 2020 6:34 pm Fantastic progress! Your comment about the parking brake cable interfering with the battery box is something I found out when I fabricated a wooded box to model the battery boxes. Did you get the extended brake cable from Porsche or somewhere else?

A quick and dirty method is to add some (steel or copper) pipe at the point where the hard cable shell hits the cabin - moving the cable shells directly outwards. Of course the cable needs to be extended - I used some rather expensive specialty solder and brazed it together.

canadasconvert wrote: ↑Fri Dec 11, 2020 6:34 pm
I will be using a 6.6KW Kia Charger with a TDK 200Amp DC-DC converter. Hopefully it will have enough power for the electric heater and all accessories.

Electric heaters are usually powered straight from battery HV; much more efficient, gets all the heat right there instead of in your DC/DC.


I'm interested in the heating signal - I found one for A/C, any pointers on where the heater is?

-Isaac

You’re brave messing with homemade extended hand brake cables. Not as if you can park the car on a hill and leave it in gear.

I'm interested in the heating signal - I found one for A/C, any pointers on where the heater is?

-Isaac

There’s an analogue 5v check back signal - yellow wire connector B that gives the signal between hot and cold (column E below). It’s a fairly blunt method, but certainly good enough to maintain the existing climate control panel via an Uno and relay.

I was contacted via a Facebook group, by a Porsche magazine journalist who asked to feature the car. I’m supposed to encourage you to go out and buy a copy, but in the interest of open source, the article is below.

The pictures were taken a week before the second Chevy volt pack and battery boxes were fitted therefore to the eagle eyes of this forum, the car isn’t looking its best.

Regardless, it was good to get it featured. The journo got most of the technical information and spec correct.

Very cool! I've definitely seen that magazine at Bares & Noble in the US in the past. Congrats on your 15 minutes of fame. As well to Damien at the end there too!

The Open Inverter community is definitely helping get the word out that conversions are definitely possible, and people here definitely support each other in whatever way they can.

-Matt

Merry Christmas to all. I got a soft copy of the December issue for Christmas. Good article.
I was thinking of mounting the charger and DC-DC converter in the area vacated by the old fuel tank, along with the PS pump, Coolant pump and Vacuum pump. I noticed you have your charger in the Frunk. Any reason for that?

canadasconvert wrote: ↑Wed Dec 30, 2020 12:55 am Merry Christmas to all. I got a soft copy of the December issue for Christmas. Good article.
I was thinking of mounting the charger and DC-DC converter in the area vacated by the old fuel tank, along with the PS pump, Coolant pump and Vacuum pump. I noticed you have your charger in the Frunk. Any reason for that?

Three reasons:

1) There isn't sufficient space in the fuel tank area (the Tesla gen 2 charger is big)
2) The charger has no ingress protection whatsoever. It's meant to be mounted inside the vehicle
3) Ease of access.

I tried the charger everywhere in the car and found that the frunk gave the best options in terms of space, positioning and locality to AC wiring.

Jon was kind enough to knock me up a small Teensy based JLCPCB to handle my CAN BUS drive unit comms and a few other items such as gauge cluster CAN messaging and LV battery tender, IE kick-on the DCDC if the 12v is getting low at any point (when the car isn’t in drive mode).

So nice to have a Cinch enclosure and do away with my amateur breadboard and loose CAN transceiver.


I've also finished off the rear battery box for the medium size Ampera battery module for the second pack. This means I get my boot space back.



The car continues to perform well as a daily driver.

I've read through the thread in detail but don't understand how this is not classed by DVLA as a 'radically altered vehicle' because of the boot floor cutting, etc. How did you get this past the DVLA and what did the insurers say when you told them about the chassis mods?

New Electric Ireland wrote: ↑Wed Jan 13, 2021 1:37 pm I've read through the thread in detail but don't understand how this is not classed by DVLA as a 'radically altered vehicle' because of the boot floor cutting, etc. How did you get this past the DVLA and what did the insurers say when you told them about the chassis mods?

Thanks for your interest, Kevin. The motor mount system bolts into the existing ICE mount points, meaning it's only the boot floor that has been cut to accommodate the battery box. The frame rails and structural elements have not been touched.

I'll continue to be transparent about my experiences with the DVLA, which I think you're aware of having commented on the UK registration process thread.

The insurance process was very straightforward. I used the broker Adrian Flux and provided them with a letter from the garage that supported the conversion and a load of pictures of the car.

Boxster EV wrote: ↑Wed Jan 13, 2021 4:29 pm it's only the boot floor that has been cut to accommodate the battery box.

I suspect that violates the "original or new and unmodified (direct from manufacturer)" requirement... surprised DVLA gave you a pass on that and it will be interesting to see what happens during your evaluation by a third party.

https://www.gov.uk/vehicle-registration ... d-vehicles

New Electric Ireland wrote: ↑Wed Jan 13, 2021 4:33 pm

Boxster EV wrote: ↑Wed Jan 13, 2021 4:29 pm it's only the boot floor that has been cut to accommodate the battery box.

I suspect that violates the "original or new and unmodified (direct from manufacturer)" requirement... surprised DVLA gave you a pass on that and it will be interesting to see what happens during your evaluation by a third party.

https://www.gov.uk/vehicle-registration ... d-vehicles

Well, thanks again for your interest and contribution.

Boxster EV - your build has been so helpful to me thanks for all the detailed work.

One thing I'm working through is an elegant way to select R-N-D. I have the knob from zeroEV and it works well, but I would love to have a more OEM solution like you. Did the Boxster auto shifter already have internal switches that are triggered and send a signal, or did you have to add some internal switches?

On my RX-7 I thought it might have triggers built in to drive the dash illumination but no dice... it must be sending the signal from the transmission or something.

rjmcdermott81 wrote: ↑Wed Jan 27, 2021 2:57 am Boxster EV - your build has been so helpful to me thanks for all the detailed work.

One thing I'm working through is an elegant way to select R-N-D. I have the knob from zeroEV and it works well, but I would love to have a more OEM solution like you. Did the Boxster auto shifter already have internal switches that are triggered and send a signal, or did you have to add some internal switches?

On my RX-7 I thought it might have triggers built in to drive the dash illumination but no dice... it must be sending the signal from the transmission or something.

I’d probably let my detent shifter go since I’m using a Grayhill encoder now. Stick a manual boot over it and it’ll appear stock. Knob not included, open to offers.

rjmcdermott81 wrote: ↑Wed Jan 27, 2021 2:57 am Boxster EV - your build has been so helpful to me thanks for all the detailed work.

One thing I'm working through is an elegant way to select R-N-D. I have the knob from zeroEV and it works well, but I would love to have a more OEM solution like you. Did the Boxster auto shifter already have internal switches that are triggered and send a signal, or did you have to add some internal switches?

On my RX-7 I thought it might have triggers built in to drive the dash illumination but no dice... it must be sending the signal from the transmission or something.

Thanks for the encouragement.

Yes, I just added micro switches to the OEM auto selector. Although I had to re-do them as the first iteration featured cheap Chinese jobbies which failed after a few months. Since then I've used better quality switches.

This more or less demonstrates:

Awesome - thank you! I have switches like that laying around from my 3d printer so I can definitely make this work.

Looks like there are a few of us who are well into their conversions.
I got the Porsche Tesla frame in early January and installed the Tesla motor into the car for initial fitting. It's a tight fit but nothing is rubbing.
Now I need to fit and measure the Tesla drive stub shaft in preparation for cutting to length and welding the cup adaptors for the Porsche drive shafts. I have an '02 Boxster S and was wondering what is the total length of the Tesla drive shaft stub with the cup welded on?
I have also built a wooden template for the battery box that will fit in front of the motor.

That’s some great progress right there.

I can’t easily get access to my stumps, as they’re well loctited in. I’ll take some pictures of them in situ this weekend. Bear in mind my car is the baby 2.7 and will have different drive shafts and adapters to the S.

Have you asked Nev? His Boxster conversion is an S and he’s probably got the dims somewhere.

Are you fitting a Chevy Volt battery?

Maybe the safest way is to measure the distance over the flanges of the original diff. Borrow somewhere a large caliper (how I did it), measure the original distance vs. the flanges in Tesla DU and dimensions the cup adaptors accordingly.

This is how I made mine from Tesla stubs. Original stub at the left.

Hi Boxster EV. I am using Kia Soul batteries. I think they are a little heavier (higher energy density) than the Chevy Bolt ones but are air cooled. I am planning on getting 6 modules between the motor and firewall and the final 2 modules will go under the trunk (boot)

FJ3422 wrote: ↑Fri Jan 29, 2021 10:05 am Maybe the safest way is to measure the distance over the flanges of the original diff. Borrow somewhere a large caliper (how I did it), measure the original distance vs. the flanges in Tesla DU and dimensions the cup adaptors accordingly.

This is how I made mine from Tesla stubs. Original stub at the left.

Good shout. Measuring my thin 2.7 shafts will be no use for S variants.

FJ3422 wrote: ↑Fri Jan 29, 2021 10:05 am This is how I made mine from Tesla stubs. Original stub at the left.

Wy didn't you weld first the chunks of metal to the Tesla stubs and then afterwards on the lathe you brought everything into shape?

Wouldn't that be more precise? Since welding can "move" the parts?

EV_Builder wrote: ↑Sun Jan 31, 2021 11:24 am

FJ3422 wrote: ↑Fri Jan 29, 2021 10:05 am This is how I made mine from Tesla stubs. Original stub at the left.

Wy didn't you weld first the chunks of metal to the Tesla stubs and then afterwards on the lathe you brought everything into shape?

Wouldn't that be more precise? Since welding can "move" the parts?

Sure, that would have been more precise. But I am limited in machining possibilities (just messing around in my 32sqm basement) and had nothing to fix the welded adapter for drilling & tapping the hole-pattern. So I had to do that before mating the parts. Stubs were pressed-in, axial & radial runout checked, welded at the inside, checked again, and finally welded around on the outside. Runout in both directions is less than 0,1mm which is sufficient.

FJ3422 wrote: ↑Sun Jan 31, 2021 1:22 pm Sure, that would have been more precise. But I am limited in machining possibilities (just messing around in my 32sqm basement) and had nothing to fix the welded adapter for drilling & tapping the hole-pattern. So I had to do that before mating the parts. Stubs were pressed-in, axial & radial runout checked, welded at the inside, checked again, and finally welded around on the outside. Runout in both directions is less than 0,1mm which is sufficient.

Sounds good enough indeed!