[cpct]

Originally Posted by marc02228

That was my thought, too. But I am not sure, if it can handle the torque, even though most of it should be transferred by the motor/Gearbox adapter.?



I ordered the EMUS BMS a couple days ago. Good to hear, that it works well.
What diameter are the connecting holes for the cells? How long are the cell units (A/B)? I am not sure if it fits to my A123 Modules. Maybe I have to cut off the connecting holes and connect it by cable or connect the cell units by some L-bracket or so.

I can't check right now, but the holes are at least M6 (the thread size on our ThunderSky cells) and the dimensions according to the manual are 50 x 30 x 17 mm The modules are designed to fit prismatic cells mainly so some "hacking" will be needed for your setup.

An L-bracket seems the best for warranty

[kerrymann]

Originally Posted by marc02228

That was my thought, too. But I am not sure, if it can handle the torque, even though most of it should be transferred by the motor/Gearbox adapter.?

Make sure all the torque is taken by your motor mounting. The transmission is designed to hang from the motor and react all the torque their. That small ladder channel that goes to the rear axle won't take any real torque. If you are unsure I would add a rod from one of the front motor 3/8" bolt holes tangentially to the frame. I went with direct mounting as these motors have virtually no vibration but only time will tell if my choice was a good one.

[marc02228]

Cell testing is done, half of the packs are assembled.

yesterday I connected the rebirth adapter to the motor and flywheel and run it at 24V on the soliton.
There seems to run rough. It's not vibrating, but you see it, when you take a close look or try to mark it with a pen. I don't know, why this is.

I guess, its time to post some pictures...

The motor is the Kostov Alpha.

[marc02228]

This afternoon, I took out the fuel tank.
Wasn't that hard, as I assumed it would be.

I removed the rear subframe and took it out. The only problem was that the nut of one of the lower arm of the suspension, which originally is welded to the arm wasn't welded anymore and is REALLY hard to reach. So it took some time to get it out and to get the screw fixed afterwards.

Now I am waiting for my motor and controller to be back, which are at a machinist, who hopefully fixes the rough running flywheel.

[giless]

Great looking battery packs. How much are your boards? Am looking at a similar conversion with an RX8 but I think I will be needing 6 or 7p A123 cells.

[marc02228]

Thanks.
The Boards were around 30 Euro each.
You could use a copperbar to connect 6 or 9 in parallel, but I am not sure about the resistance, then.

Originally Posted by giless

Great looking battery packs. How much are your boards? Am looking at a similar conversion with an RX8 but I think I will be needing 6 or 7p A123 cells.

[zeroexcelcior]

Originally Posted by marc02228

Does anyone know, how many pulses per turn the original Miata tach expects?

From what I understand, for all four stroke ICE, a tachometer expects half the number of cylinders to fire per revolution of the crankshaft, so two pulses per turn for your conversion (stock inline four) but get a second opinion just to be sure.

Best of luck.

[Batterypoweredtoad]

A generic motor mount with a stud protruding from each side would work fine in the Miata stock mount holes or in holes drilled in the front crossmember. I would use some sort of cushioned mount as several people here have reported a whining or singing noise when direct mounting their motors. I don't think the power plant frame will give you any issues.

K11 Alpha? With a pack that can feed it? I am excited to see what this thing will do! Please get it to a dyno or dragstrip as soon as you can and post the results and log files.

[marc02228]

Some progress, again.

I cut holes for the battery boxes into the trunk floor and where the fuel tank used to be. So I can split the pack into smaller packs to get the best weight distribution possible and for some additional space.

With the motor connected to the adapter plate I noticed that the flywheel can be turned almost 2mm without any turn of the motor. When I assembled motor and adapter plate I measured a gap (for the feather key) of 6.5mm and the motor has gap of 6.1mm so I tried to make a feather key myself but it apparently didn't work out.

Now I gave motor and adapter to a relative to make a CNC feather key. So I still can't work on the motor mount.

Some other thing I noticed is that the Rebirth adapter plate doesn't fit the manufactured mounting platforms of the Kostov Alpha. No matter, which 4 of the 8 holes you take, the motor is attached twisted and not parallel (the platforms) to the subframe.

So If you use a Kostov Alpha I would definitely not take the Rebirth adapter. It looks good, and is is really good manufactured, but bad engineered.

Now I tried to setup the Audi vakuumpump I bought for the conversion. Seems to work good, but the vakuumswitch I bought can only put out a current of 100mA which is not enough for a 12V relay. Tried a 20A relay, too. But it doesn't work either (even though it just takes 70mA). Maybe the initial current is to high?

Just ordered another vakuum switch. I could use an even smaller relay to drive the power relay, but I don't wanna do this in the circuit of the vakuumpump for the brake.

Today the EMUS BMS was shipped. The motor shall be back the next couple days and battery boxes should be done until the weekend, too.

Does anyone knows how the fuel (and oil pressure and temp) gauge works? Does it need a signal 0-12V or a varying resistance to the ground or whatever?

[marc02228]

After three weeks, I am finally back home, to continue working on the car for 3 days.

The new feather key works great. No slackness anymore between motor and hub.

The clamp (part of the motor mount) looks really good, too. Now I have to figure out, how to connect it to the subframe or the original motor mounts at best.
Any Ideas?

BMS arrived, but some components of it are still missing.
Batterie boxes aren't done yet.

I figured out, how the original fuel gauge works.
It has two magnets. One, which puts the gauge back to zero, if 12V is connected and the other magnet has to be set by the sensor/BMS.
If both magnets are the same field strength, it will stay in this position.
I set up a small circuit to get it driven by the BMS but still have to order the parts and test it.