Porsche Boxster with Siemens and DMOC

[johu]

Very well!
Set fconst=1000 and fslipconstmax=fslipmax to disable the constant power region.
To use it later set roughly fslipconstmax=2*fslipmax and fconst=1.5*fweak

[joromy]

Temperatures stayed very nice. Ambient was 15C which helped, but after 20 miles at 60-70 inverter only hit 36 and motor read 65 (that sensor is suspect, reading too high).

What is temperature showing when it stay overnight? It should show same on inverter motor and ambient.
I have used the Siemens (and Ford) motor lot's of times, and the temperature is always showing to high.
I think the sensor is degraded by age?

[Isaac96]

Motor reads 39 when inverter is at 24 (after sitting overnight).

I've changed tripmode to autoresume, and noted that fslipconstmax was 5 - much higher than my fslipmax of 3. That may have been my issue.

I'll test more later -- my charger keeps acting up, need to deal with that.
-Isaac

[Isaac96]

I've been driving the car daily since my last post.

I added 100 points of boost, that seemed to improve smoothness. The performance is quite nice, even in field weakening.
And temperatures have been very nice, with the inverter staying under 45 degrees at all times and the motor reading no more than 65 (so it's probably at 45 too). This is even with rather hard driving.

I haven't yet implemented that boost-per-gear setup, it isn't really necessary at this point and I'm perfectly okay with shifting. The syncros do a good job of preventing grinding.

Yesterday, on the way home from school, I began noticing a 'clunk' when going from foot on pedal to foot off pedal. This rather concerned me but I let it be for the night (had to charge at 120V which takes about 10 hours after the commute).

So this morning I got in the car and drove down to the corner, where there is a stop sign. I hit the gas (gently) and the motor revved up -- but the car did not move! Shifting into a different gear had the same results. Ouch.
I'm fairly sure the motor-transmission adapter decided to give out. It looked very strong but seems to have disliked the motor's power. I've only put about 400 miles on it, so that's pretty terrible reliability.

So here I am, looking at a Tesla unit once again. With some Zero-EV Porsche 930 driveshaft stumps and a Johannes board, it should be fairly easy.

If anyone has some bulletproof adapter ideas that will prevent a drivetrain swap, I'd love to hear about them.

-Isaac

[johu]

Nice the electronics are sorted, not so good you blew you coupler with it
Can you upload a picture of your coupler? Maybe the MEs here will spot the weakness and propose something stronger.

[Jack Bauer]

How about this baby :
viewtopic.php?f=12&t=437&p=4733&hilit=siemens#p4733
Yours for shipping cost. Running an identical one in the E39 since last summer.

[Isaac96]

Nice the electronics are sorted, not so good you blew you coupler with it
Can you upload a picture of your coupler? Maybe the MEs here will spot the weakness and propose something stronger.

Here it is installed (pre-breaking):

And on the floor:

This is one of those EV West splined blanks, welded to a Porsche clutch disk. It fits beautifully on both sides but apparently couldn't take the strain.
I'll upload more pics once I get the sucker out of there.
It's quite likely that the weld between clutch disk and splined blank just broke. Which is rather weird, it was done pretty darn well by a professional.

How about this baby :
viewtopic.php?f=12&t=437&p=4733&hilit=siemens#p4733
Yours for shipping cost. Running an identical one in the E39 since last summer.

Damien, I really appreciate the offer, but that's almost exactly what we've got in there right now. Thanks anyways!


I'd prefer to avoid the drivetrain swap but if I can't improve the current system then it'll have to happen. SDU would be pretty fun


-Isaac

[Isaac96]

Finally got the transmission down (or rather my dad did) and diagnosed the issue.
It's quite an issue.

Ouch.

Time for a SDU! I've got a place that'll sell one fairly cheap so all set in that area -- and will likely buy some Zero EV Tesla to Porsche CV stubs.

Anyone know what to do with a shaftless motor? I could build a new rotor theoretically....

[arber333]

Not enough meat/splines on the shaft i gather. Maybe it even oscilated a little before braking... It makes a lot of rotating mass.
I have used gas engine clutch disc centers in similar way in my Mazda setup. I went through 3 discs in about 120.000km! Luckily disc centers are a lot weaker than transmission shaft end and it just broke the splines or spring holders on clutch disk.

What i have now is lovejoy coupler with 2 splined centers welded on the transmission side which increased the spline surface. As of then i didnt have an issue besides seeing how banged up lovejoy coupler is getting .

Oh and to all of you using transmission i really recommend you put an inspection hole on the underside of the TX bell so you can quickly inspect your coupler... just saying.

If you can get a machine shop to make another coupler for you i suggest you make an extension in two parts with some clamping method that can grip the smooth part of the shaft right up to the bearing seal. Then bolt that up to your transmission part like prop shaft. I bet larger crosssection will transfer more torque and make easier to fit. You need to take care everything is in center with transmission though! Maybe make a fitting step in the old coupler before you drill any holes.
Maybe you can even get one off the shelf since you are in california?
Something similar:
http://www.waltergear.com/psc.htm
https://www.marinepartseurope.com/en/vo ... -9704.aspx
https://www.nauticexpo.com/prod/reggian ... 09182.html

[Isaac96]

It's quite likely that the motor was slightly misaligned... the adapter plate is not exactly a work of art. It might have been fine with a clutch but did not work with the tight interference fit coupler. Ah well. I'll think about the clamping method, Anne Kloppenborg (sic?) of New Electric Netherlands did that at one point.

Here is the next phase of this vehicle though, and the direction I wish I'd gone in two years ago.

This was cheaper than the original price of the Siemens + DMOC.

Time to order a SDU board! I hope I get one of the new slim ones

Incidentally, when I went to flip the unit over in order to get at the phase bolts, it leaked what looked like some cooling oil out of the black "T" logo thingy at the top (bottom) of the photo. Is that normal? It looks like a standard air vent to me.

-Isaac

[arber333]

Here is the next phase of this vehicle though, and the direction I wish I'd gone in two years ago.
This was cheaper than the original price of the Siemens + DMOC.

Damn that was fast!
I whish i was in CA. I still want to work on Mazda coupler.

Is that model S SDU or model3? I remember model3 front drive is ACIM as well.
You have driveshafts also?

A

[Boxster EV]

Excellent. look forward to following this. I'm sure you wont look back.

[Isaac96]

Damn that was fast!
I whish i was in CA. I still want to work on Mazda coupler.

Is that model S SDU or model3? I remember model3 front drive is ACIM as well.
You have driveshafts also?

A

Yup, 4 hours of driving and here it is. It's a model S small rear (fits better in the space needed).
Driveshafts will (hopefully) be the originals, with a pair of these https://zero-ev.co.uk/product/tesla-dri ... 64-993-vw/ -- these only fit on small or large rear units.

Excellent. look forward to following this. I'm sure you wont look back.

I'm taking significant inspiration from your build... was considering the custom subframe as well, but my battery configuration doesn't allow it. I'm the one following here

-Isaac

[Isaac96]

Today I tore out the inverter, the reservoir, and the cooling hoses. It'll be really fun getting the motor out -- it is sandwiched between battery boxes and can't go straight down because the battery support bar is directly under it. So it'll have to be slid back and out just like the transmission was.

The drive unit fitment is looking better and better. It looks like the Tesla diff is offset a little to the left, meaning the unit can be moved to the right -- exactly what I need to make the sucker fit on the original transmission mounts.

What should I do with the Volt inverter? It's going to be pretty useless for now unless I get more bad ideas, and if I want to power something small I have a Prius gen2 inverter with a control board on the way.

[mdrobnak]

Hold onto it for something that you can use 1000 A in.

[Isaac96]

Hold onto it for something that you can use 1000 A in.

Right, I've been thinking about a Tahoe/Suburban/Escalade hybrid transmission (2ML70)... It's basically a GS450h alternative with zero information and much less supply.

[Isaac96]

The Tesla SDU will fit. Barely.

But that's settled, so now it's time to play the waiting game for some Zero-EV 930 stubs (they say 40 days). It'll be at least another week after they arrive before the car is on the road, since I am also waiting on a SDU board from Johannes. But at that point it will just be a matter of welding in mounts and wiring up the unit.

In the meantime, I've just removed the manual shifter and cables and begun to reimagine all the LV wiring.
What was once a bunch of terminal blocks and a maze of wires is being replaced with some real fuse boxes and distribution busses, along with circuit breakers and strategic relays. And my 3-year-old wiring for the charger and charger controller is coming out next; goodbye wire nuts, hello terminal blocks!

I'm moving the DC/DC HV wires from after the contactors to before the contactors, since the powered-off draw is apparently about zero and it simplifies the system to be able to power on the DC/DC at any point. This will also make the 12v battery a little happier since the DC/DC can now be turned on at any point.

These are all the things I should have done a while ago but didn't really have the time or motivation for, and also that trunk was a total mess, full of inverters and coolant tanks (both of which are going under the car now).

My custom BMS was complaining about a couple of cells being out of balance, turns out it was just a poorly seated connector. I should really rework that system. Maybe next week.

-Isaac

[Isaac96]

12V wiring is in the process of being revamped. New fuse blocks are installed, each with 12 slots. 1 ignition block and 1 permanent 12v block.
An 8-gauge wire runs from the DC/DC to each block through a 40 amp circuit breaker; that ought to be plenty of capacity.

The DC/DC works beautifully with its HV sourced from before the contactors. It gets CAN and logic 12v as soon as the ignition is turned on, and produces power about a second afterwards.

Now to re-wire and properly insulate all the 12v things... (The goal is to return the trunk to its OEM state, minus the DC/DC sitting in the corner; this means hiding all the relays behind the floor carpet the way Porsche did.)

Always more work to do.

[arber333]

12V wiring is in the process of being revamped. New fuse blocks are installed, each with 12 slots. 1 ignition block and 1 permanent 12v block.
An 8-gauge wire runs from the DC/DC to each block through a 40 amp circuit breaker; that ought to be plenty of capacity.

The DC/DC works beautifully with its HV sourced from before the contactors. It gets CAN and logic 12v as soon as the ignition is turned on, and produces power about a second afterwards.

Now to re-wire and properly insulate all the 12v things... (The goal is to return the trunk to its OEM state, minus the DC/DC sitting in the corner; this means hiding all the relays behind the floor carpet the way Porsche did.)

Always more work to do.

Good to hear that. Please do not forget to add maybe 20A fuse to DCDC HV input side to guard your HV wires. Either from - or + side. You can use it as a service disconnect too.
However i use 350A Chevy Volt fuse as disconnect located between packs so i can break the circuit if i work on my cells...

[Isaac96]

Good to hear that. Please do not forget to add maybe 20A fuse to DCDC HV input side to guard your HV wires. Either from - or + side. You can use it as a service disconnect too.
However i use 350A Chevy Volt fuse as disconnect located between packs so i can break the circuit if i work on my cells...

Will do! I do have a disconnect before the DCDC but I'll add a 20a fuse as soon as I can get one. Hmm, maybe the small one out of the Leaf contactor box will do? (probably not.)

[Isaac96]

SDU board arrived today! Thank you Johannes!

And now it's installed in the inverter. That was not an easy task, the current sensors are quite a pain when one only has a 120w soldering gun.

And my MX150 connectors arrived, one for Tesla and one for Chademo controller. Time to wire up the inverter! I'll start with just the basic; 12v, start, etc. Need to get more wire...

C25 on the SDU board is missing, looks like it's 1uF; I'll just solder one on there. Might be a good thing to check in QC. Looking at the SDU/LDU update thread, the other v7 boards might be the same? I'll check the CPL file and see if there's a screwup.

EDIT Yes there was a screwup. C25 is missing in the BOM. Johannes, expect a new BOM with C25 added (1uF is the correct value).

[johu]

What was I thinking, I actually spotted that but forgot to just whack one on. Have already added it to the BOM but thanks anyway
It's just the filter cap for the temperature which is quite low impedance, so shouldn't cause a functional issue. Heavy software filtering is used anyway.

[Isaac96]

I thought as much. I don't have any of the same but a 0.1uF should do, just to fill the spot

[Isaac96]

And just like that it's been 3 weeks again.
Spent a few hours testing and playing with the inverter (just powered up with 12v, no motor attached). I temporarily jumped the HVIL DISABLE and got it up and talking, checked the default parameters and all look good.
I ordered MX150 connector and pins, made up a harness with all the wires I need.

12V rewiring is mostly done. I'm looking at an iBooster for the front end (thanks to Lars) so if that pans out I'll redo the front end wiring.

Trying to position the SDU perfectly has been taking up lots of time; jack it up, check all directions, move it a bit, check again... Only 3 mounts to make but they've got to be perfect. The rear end is going to be in the way of a rather important chassis bar so that needs to be replaced or the motor moved. At least we have the Tesla to Porsche stumps from ZeroEV now, they're gorgeous.

I'll be doing some 90v testing with the SDU assembled; need to get some sort of coolant in the inverter first as I've heard about all the burned up inverters which have occurred.

And in the cabin; removed the shifter and all those cables, which will be replaced with a F-N-R switch ($1 from a salvage yard, needs a nice knob.)

With luck and lots more work, shouldn't be more than a couple of weeks before we're on the road again. This is what, revision 3 now? This one should last...

-Isaac

[Boxster EV]

And just like that it's been 3 weeks again.
Spent a few hours testing and playing with the inverter (just powered up with 12v, no motor attached). I temporarily jumped the HVIL DISABLE and got it up and talking, checked the default parameters and all look good.
I ordered MX150 connector and pins, made up a harness with all the wires I need.

12V rewiring is mostly done. I'm looking at an iBooster for the front end (thanks to Lars) so if that pans out I'll redo the front end wiring.

Trying to position the SDU perfectly has been taking up lots of time; jack it up, check all directions, move it a bit, check again... Only 3 mounts to make but they've got to be perfect. The rear end is going to be in the way of a rather important chassis bar so that needs to be replaced or the motor moved. At least we have the Tesla to Porsche stumps from ZeroEV now, they're gorgeous.

I'll be doing some 90v testing with the SDU assembled; need to get some sort of coolant in the inverter first as I've heard about all the burned up inverters which have occurred.

And in the cabin; removed the shifter and all those cables, which will be replaced with a F-N-R switch ($1 from a salvage yard, needs a nice knob.)

With luck and lots more work, shouldn't be more than a couple of weeks before we're on the road again. This is what, revision 3 now? This one should last...

-Isaac

Thanks for the update - a good read.

Really interested to hear how you get on mounting the ibooster. I'm keen to go that direction too but haven't really assessed how well it'll physically fit in the frunk.

I have two annoying things on my 986. One is the power steering pump noise and the other is the vacuum pump kicking in. Hoping to improve both this summer.