[Sutitan]

Im still puzzled as to why more people arent trying out powerglides in ev (actually, I might know. the pain of adapting the PG to the rest of the driveterrain). there have been tons of threads talking about powerglides, and it all seems pretty positive. you have a 2 speed transmission, tq converterless manually shifted auto tranny, which can handle more then enough of the torque that is thrown its way (from a typical conversion). it has a low 1st gear, which would be good to around 50-60mph (depends on diff ratio, tire size and motor rpms, but thats what my calcs worked out to when i checked it out), and a direct drive " 2nd gear", which can provide your 80mph. they are light, cheap, tough, and plentyful. I might have missed the negatives, and I bet your there are a few, but I think powerglides definatly have a place in EV's. the only application I can think of is of "poormansev". Anyways, ill let everyone else chime in on my opinion, but I definatly think you should consider a powerglide.

[etischer]

Originally Posted by dimitri

I'm sure some will come here and argue that they drive in one gear, but they don't go 80 mph and 0-60 in 9 sec all in one gear, and if they say they do, then they are big fat liars . Oh, and they don't get 60 miles range in one gear, not with 16kWh usable pack energy.

Unless they drive a Tesla...

[Propellator]

a quick check shows that
at 2400lb and a cd of 0.34 (which is purely estimated)
you'll approximately make 60mph on a 10% incline and 90mph driving level with nominal motor specs.
Using motor peak specs you'll make 55mph on a 30% incline 75mph on a 10% incline and sadly no more top speed.

I could of course be completely wrong.
Motor specs are from Azure Dynamics pamphlet.
In my calculation I use the rolling friction (not the drag neither the weight) of a 4000lb car, so above values may be on the lower side.

Oh, and I hope I will not completely embarrass myself with my first posting here.

torque in Nm, speed in mph

[SolarJ]

What are the two blue lines one is dashed? Cool chart BTW

[280z1975]

Originally Posted by Sutitan

Im still puzzled as to why more people arent trying out powerglides in ev (actually, I might know. the pain of adapting the PG to the rest of the driveterrain). there have been tons of threads talking about powerglides, and it all seems pretty positive. you have a 2 speed transmission, tq converterless manually shifted auto tranny, which can handle more then enough of the torque that is thrown its way (from a typical conversion). it has a low 1st gear, which would be good to around 50-60mph (depends on diff ratio, tire size and motor rpms, but thats what my calcs worked out to when i checked it out), and a direct drive " 2nd gear", which can provide your 80mph. they are light, cheap, tough, and plentyful. I might have missed the negatives, and I bet your there are a few, but I think powerglides definatly have a place in EV's. the only application I can think of is of "poormansev". Anyways, ill let everyone else chime in on my opinion, but I definatly think you should consider a powerglide.

I've been thinking of a Powerglide transmission in my conversion (being done next year, summer time) but I haven't found any that not in the 1,000+USD range ... I think a good DC motor + PG transmission (lightweight racing one, three speeds, electronicly programmable) + a HV controller would make a killer combo. You could even program the transmission for "city" driving, "highway" mode and then "Light up the tires mode" ... that would be perfect.

If anyone has bookmarked a PG that would fit the 3 (or possibly 3) speed, electronically programmable, please post a link to it. Thanks.

[Propellator]

The blue lines are the wheel torque available at a certain speed considering the gear ratio.
The dashed one for the peak and the continuous for the nominal motor specs.

The other lines show the wheel torque needed to negotiate the incline in percent over the speed achieveable.

[SolarJ]

So my starting weight was 2300 lbs. - the ICE components and tranny removed and I am down to 1550 lbs. It sure is nice to be next to a truck scale. Thats a loss of 750 lbs and I calculate that I will add about 850-900 lbs, thats pretty close. BTW I am pretty sure that tranny and clutch weigh more than 50 lbs. I put it closer to 100.

[dimitri]

So this motor has 250Amp max current, is that continuous or peak? With 60AH cells this is over 4C discharge, which with direct drive you will be doing very frequently. Have you considered impact on LFP cells lifecycle?

Also, with 60 kW power and not so impressive max RPM for AC motor, how does this motor power compare with Warp9, which weighs in 100 lb less?

I push 64kW thru Warp9 at hard accelerations, but I am using all gears so 64kW only gets applied for few seconds and then falls off as RPMs rise. I can't imagine doing it in 3rd gear, it would be murder of batteries and the motor.

Please don't let me discourage you from trying, I am just thinking outloud here it would be nice to see real results from direct drive conversion for once. Like you said, you can always put the tranny back in if need be...
although fitting the monster motor with the tranny maybe tough in Miata.

[SolarJ]

Did some test fitting today. That motor fits like a glove about half way down the tunnel. 2 in at the top should give me enough room for some small motor mounts. Some adjustments will need to happen where the power cords come out but thats not bad.

[Sutitan]

Originally Posted by 280z1975

I've been thinking of a Powerglide transmission in my conversion but I haven't found any that not in the 1,000+USD range

check craigslist, ive seen pgs go for 100$ or so.