# HPEVS AC-75 Data!



## dragonsgate (May 19, 2012)

Just got off the phone from HPEV and was told they have not set a solid price yet but the word is the AC57 96 volt 650 amp setup will be around $5,200. And the 144 volt 500 amp that should be out by Dec. will be at $6,000. These are ball park figures so these are not set prices.


----------



## ruckus (Apr 15, 2009)

dragonsgate said:


> Just got off the phone from HPEV and was told they have not set a solid price yet but the word is the AC57 96 volt 650 amp setup will be around $5,200. And the 144 volt 500 amp that should be out by Dec. will be at $6,000. These are ball park figures so these are not set prices.


I just purchased the first Scott Drive water-cooled 300-450V 600A motor for $3500. The controller is $3600 but includes dc-dc and contactor.

I'll have them for display at EVCONN so everybody can check out the 'vapor' ware.


----------



## dragonsgate (May 19, 2012)

By vapor ware do you mean nonexistent? Not good?


----------



## Frank (Dec 6, 2008)

I'm pretty sure he's being sarcastic, lol.

I won't be at evcon but look forward to results from playing with this impressive appearing new motor.


----------



## Bowser330 (Jun 15, 2008)

dragonsgate said:


> By vapor ware do you mean nonexistent? Not good?


He is being sarcastic because when he first mentioned his bldc motor source people were hesitant to believe him. There are quite a few new motors out there that we the people can't get our hands on to verify or buy so yes those are vapor ware, doesn't mean anything to anyone if you can't get it, right?
Well now ruckus has a great opportunity to be rather successful once he provides data on the performance of these bldc motors. The ruckus bldc motors have a real potential to take market share from hpevs.


----------



## tylerwatts (Feb 9, 2012)

Forgive my ignorance folks, bit new and in research mode. Where could I find more info on these BLDC motors/kits please. Only info I know is of the Scott Drive 100kw Trapezoidal motor/controller kit slated for poor cogging torque and low motor ratings and available only from GreenDrive in NZ.

Any advice/guidance available please?

Also, have wondered about one of these ac75s or even a cooled ac50 powered from a Wavesculpter 100kw controller (or similar) at higher voltage. HPEVS quotes somewhere these motors are rated to 200VAC (or maybe DC) which really broadens their possibilities. I like the idea of a 2 or 3 speed Powerglide auto to broaden the power delivery in a light-weight car (like the Miata in my garage begging me for some TLC!

Regards
Tyler


----------



## dragonsgate (May 19, 2012)

I have been reading HPEV’s trouble shooting manuals and there seems to be a lot of stuff that can give problems or put a car dead alongside the road. As of late I have been wanting to swap out my ADC motor for an AC system. I have driven the DC for over 12 years and 40,000 miles trouble free and am wondering what I might be getting into. I have read the threads here about AC conversions but I would like to hear more from AC owners and hear what they like and dislike about there choice of motors.


----------



## tomofreno (Mar 3, 2009)

dragonsgate said:


> I have been reading HPEV’s trouble shooting manuals and there seems to be a lot of stuff that can give problems or put a car dead alongside the road. As of late I have been wanting to swap out my ADC motor for an AC system. I have driven the DC for over 12 years and 40,000 miles trouble free and am wondering what I might be getting into. I have read the threads here about AC conversions but I would like to hear more from AC owners and hear what they like and dislike about there choice of motors.


 I have about 3 years and 21k miles on my AC50 with no problems with controller or motor. Very nice and reliable controller IMO. Easy to change parameters and datalog with the programming software. Not heard of any problems with them.


----------



## tomofreno (Mar 3, 2009)

ruckus said:


> I just purchased the first Scott Drive water-cooled 300-450V 600A motor for $3500. The controller is $3600 but includes dc-dc and contactor.
> 
> I'll have them for display at EVCONN so everybody can check out the 'vapor' ware.


 What is the O.D. and length of this motor?


----------



## tylerwatts (Feb 9, 2012)

Yeah, Ruckus, do you have any more details about this kit please? Where did you get it from etc please? Is it still a Trapezoidal BLDC motor as the 100kw kit is?


----------



## frodus (Apr 12, 2008)

There's already another thread about the scottdrive controller/motor package:
http://www.diyelectriccar.com/forums/showthread.php/scott-drive-100kw-ac-motor-controller-74638.html

Lets keep this thread on topic about the AC75, I'm interested to hear more about it.


----------



## tylerwatts (Feb 9, 2012)

Yes, sorry all. Am interested in both!

HPEVS AC question then, have any heard of these motors being run up to higher voltage, or is it not needed for AC like it is for DC? Thinking of ways to get more power without too much heat (current). Cooling these concerns me a little.

Thanks


----------



## frodus (Apr 12, 2008)

It's a new motor, so I doubt anyone has seen them in the flesh. The inverters that It's designed to run on are 144V (Not available yet) or 72-96V (1238-6501, 7601). These are lower voltage AC motors. 

IIRC, they have some water cooling options coming up. Not sure if that is included on the AC-75, but I know that there's some motors in the works.


----------



## Coulomb (Apr 22, 2009)

frodus said:


> The inverters that It's designed to run on are 144V (Not available yet) or 72-96V (1238-6501, 7601). These are lower voltage AC motors.


That's right. So if you like, they are "already overvoltaged" (really overfrequencied or overclocked). My feeling is that the controllers that they are designed for do not bring them to their full potential, so it may well be possible to get more peak power from them with higher voltage. Basically, by continuing the constant torque region to a higher motor speed.

These motors have typically been sold, at least initially, as part of a package with the inverter, so perhaps that's why no-one has tried them on higher voltage as yet. Plus, AC controllers for sub-500 VDC are not that common. You certainly can't just put a higher DC bus voltage into the Curtis controllers; their voltage limits are strict, and exceeding them is very likely to lead to failure, either instantly or via drastically reduced life and a dramatic death.


----------



## tomofreno (Mar 3, 2009)

Coulomb said:


> ...These motors have typically been sold, at least initially, as part of a package with the inverter, so perhaps that's why no-one has tried them on higher voltage as yet. Plus, AC controllers for sub-500 VDC are not that common. You certainly can't just put a higher DC bus voltage into the Curtis controllers; their voltage limits are strict, and exceeding them is very likely to lead to failure, either instantly or via drastically reduced life and a dramatic death.


I think no one has tried a higher voltage with them because the AC controllers available that would permit that cost more than people are willing to pay, e.g. Rinehart, Wave Sculptor. If they require that much torque and power they go with DC since it is much less costly. I think HPEVS squeezed in under the door with an AC pkg for $4500. 



> So if you like, they are "already overvoltaged" (really overfrequencied or overclocked). My feeling is that the controllers that they are designed for do not bring them to their full potential, so it may well be possible to get more peak power from them with higher voltage. Basically, by continuing the constant torque region to a higher motor speed.


The 144V (170 max) controller could be used with the present AC50 motor to extend peak torque out over 5000 rpm for higher power. The AC51 (I think Brian has the only one in existence in his Scion) is rewound for higher voltage, so has peak torque out to about 3k rpm with this controller. Both assuming max permissible pack voltage. But yes, the Curtis controllers are the limit. Even the higher voltage controller limits the motors in power. Figure about 148V sagged V (156V nominal) at peak 500A, and combined motor/controller max efficiency of 80% for about 80 H.P. shaft power limited by the controller - about the same as the present 7601, albeit at different motor rpm.


----------



## tylerwatts (Feb 9, 2012)

Yes, I realised most get them as a package. I was only wondering as somewhere (on their website I think) it said all the stock motors were actually rated to 200V. And everyone has huge praise for these little motors and their performance, so I wondered whether the motors had ever been tested/pushed hard. I know current is limitted through them, wouldn't want to dump loads into one anyway, so the next step was since everyone seems to get roughly 100V/~500A AC into them in most instances, how they'd perform with twice the voltage (and hopefully very little difference in cooling issues) in the same applications. I'd expect near double the performance, probably more as you could increase your gear ratios and maximise benefit of the wider power band.

All speculation, and I'm no electrical engineer (mechanical actually...) but it follows simple logic as far as I can see.

Back to topic though, what do people know of this proposed 144V controller please? Is it a new Curtis controller? Why are Curtis not producing higher voltage controllers already, their software is so widely fplexible they'd still operate at the usual lower voltages no problem and not cost much more from what I can tell.

Also, the improved torque of the AC-75, is this due to the larger area/greater leverage radius of the larger motor, as the controller won't be pushing more amps that we're used to in AC50s etc will it?


----------



## Bowser330 (Jun 15, 2008)

It would be very interesting to see how an AC-50 or AC-75 would perform on a dyno with incrementally higher voltages, by using a Wavesculptor200.

100V 350A (35kw)
200V 350A (70kw)
300V 350A (105kw)
400V 350A (140kw)


----------



## tylerwatts (Feb 9, 2012)

Yes Bowser, that is what I was thinking also. Not sure about 400V, but maybe the motors can handle it. I know they're well made. I'd be curious to try those voltages, maybe in 50V increments, with varying current up to 500amps to see any correlation between their torque output and voltage.

But then I can't afford any of that yet! But would love to hook a Wavesculpter to one of these. It'd be monumental on our illusive AC-75!

Ruckus

What of your AC drive sir? Any details? I was keen on the 100 kit until I learned of trapezoidal motors, what is this new setup?


----------



## jeremyjs (Sep 22, 2010)

It was my understanding that the limited voltages are due to the availability/cost of the components needed to make a controller that operates in the 200V+ DC range. If they could make, say, a 250V 500a controller few would buy it if it cost $15k.


----------



## Bowser330 (Jun 15, 2008)

tylerwatts said:


> Yes Bowser, that is what I was thinking also. Not sure about 400V, but maybe the motors can handle it. I know they're well made. I'd be curious to try those voltages, maybe in 50V increments, with varying current up to 500amps to see any correlation between their torque output and voltage.


The reason my sample above was limited to 350A is because that is the max DC amperage output of the wavesculptor200 inverter...


----------



## PStechPaul (May 1, 2012)

I think there are probably more components available for a controller using 300V DC bus and higher, up to 600V, since that is the range of most industrial VFDs. It may be that the higher voltage controllers use IGBTs rather than MOSFETs and they are more readily available, but maybe the HPEVS controller has been designed around MOSFETs which use a bit different drive design. And high voltage high power MOSFETs are somewhat rare and generally rated under 10-20 amps, like this 1200V 3A TO220 part:
http://ixapps.ixys.com/DataSheet/98844.pdf

But they do have a 900V 85A module: http://ixapps.ixys.com/DataSheet/VMM90-09F.pdf
and a 300V 290A module: http://ixapps.ixys.com/DataSheet/VMM300-03F.pdf

It should be possible to tweak a standard VFD to run a motor at a lower nominal voltage and then overclock it as needed. Most controllers probably assume field weakening above nominal drive frequency but my 2HP Fuji/GE AF-300-E11 allows setting base frequency from 25 to 400 Hz and maximum frequency from 50 to 400 Hz. Also rated voltage and maximum voltage can be set from 80 to 240V (twice these values for a 480V unit). 

The motor should not be damaged by overclocking unless RPMs exceed a safe value, and higher voltages (up to about 600V) should also be OK if the motor has been wound with standard magnet wire. However it should be tested using an insulation tester up to 1250 VDC or even 2500 VDC which are standard voltages for insulation breakdown of motors and transformers rated at 240 and 480 VAC.


----------



## tylerwatts (Feb 9, 2012)

Thanks for the info PStechPaul! I'm impressed by those insulation specs! I'm curious also, could a motor (HPEVS) designe for use with MOSFET controllers (Curtis) be used with an IGBT (VFD industrial) controller? I'm no expert but from my limited knowledge I've not heard anything to say it couldn't. I'm keenly following a few threads of guys who've modded VFD controllers for torque and speed control. And I like the options of higher voltages.

Anyway, Ruckus, any news on your high voltage Scott Drive? I'm keen to hear whether it would only be suitable for the chinese trapezoidal BLDC motors or could be used on other AC induction motors such as the AC-75! That would be a killer package!


----------



## few2many (Jun 23, 2009)

tomofreno said:


> The 144V (170 max) controller could be used with the present AC50 motor to extend peak torque out over 5000 rpm for higher power. The AC51 (I think Brian has the only one in existence in his Scion) is rewound for higher voltage, so has peak torque out to about 3k rpm with this controller. Both assuming max permissible pack voltage. But yes, the Curtis controllers are the limit. Even the higher voltage controller limits the motors in power. Figure about 148V sagged V (156V nominal) at peak 500A, and combined motor/controller max efficiency of 80% for about 80 H.P. shaft power limited by the controller - about the same as the present 7601, albeit at different motor rpm.


Wouldnt it be better to run the ac50 on the 144v controller, instead of the re-wound ac51? What would the benefit be of going either way? I would think that having near full torque up 5000rpm would allow one to use a single speed gear reduction easier than a whole transmission.


----------



## Coulomb (Apr 22, 2009)

Bowser330 said:


> The reason my sample above was limited to 350A is because that is the max DC amperage output of the wavesculptor200 inverter...


Err, the _output_ of a Wavesculptor 200 is 300 A RMS per phase. (Note that the addresses within the Tritium web site have changed recently.) With typical induction motor power factors, that equates to about the same or a little higher _input_ current, which is of course DC. Say 310 A with a power factor of 0.86. (Neglecting controller losses, except I used a 5 V drop across the IGBT pair.)

With a nearly unity power factor load, the DC input current could in fact be slightly over 350 A, but we're talking induction motors here, aren't we?


----------



## Siwastaja (Aug 1, 2012)

tylerwatts said:


> could a motor (HPEVS) designe for use with MOSFET controllers (Curtis) be used with an IGBT (VFD industrial) controller?


MOSFET vs. IGBT is just a minor engineering detail in the construction of the VFD (typically, MOSFETs for lower voltages, IGBTs for higher), but it does not affect the basic functionality. Both create "equal" waves.

Things to consider when using low-voltage ACIM with a higher-voltage VFD are at least:
- Lower inductance of the windings (VFD may not be designed for that low)
- Internal motor insulation due to higher voltage used
- Adjustable range of the motor parameters


----------



## Bowser330 (Jun 15, 2008)

Coulomb said:


> Err, the _output_ of a Wavesculptor 200 is 300 A RMS per phase. (Note that the addresses within the Tritium web site have changed recently.) With typical induction motor power factors, that equates to about the same or a little higher _input_ current, which is of course DC. Say 310 A with a power factor of 0.86. (Neglecting controller losses, except I used a 5 V drop across the IGBT pair.)
> 
> With a nearly unity power factor load, the DC input current could in fact be slightly over 350 A, but we're talking induction motors here, aren't we?


To be honest I am not sure what you are trying to say....so help me understand something, apples to apples, If the curtis 1238R references 130V & 650A "peak", then what are the "peak" values of the Wavesculptor200?


----------



## Coulomb (Apr 22, 2009)

Bowser330 said:


> ....so help me understand something, apples to apples, If the curtis 1238R references 130V & 650A "peak", then what are the "peak" values of the Wavesculptor200?


They would be 450 V and 300 A.

The Curtis 1238R can produce a peak output of 650 A RMS per phase. To do this at or above base speed of the motor, it will draw roughly 650 - 700 A DC from the DC bus, depending on the power factor of the motor.
The Tritium Wavesculptor 200 will produce a peak output of 300 A RMS per phase. To do this at or above base speed of the motor, it will draw roughly 300 - 325 A DC from the DC bus, depending on the power factor of the motor.
The Curtis is therefore a 130 / sqrt(2) * 650 * sqrt(3) = 103 kVA controller.
The Tritium is therefore a 450 / sqrt(2) * 300 * sqrt(3) = 165 kVA controller.

Both figures assume a perfect battery, so of course results will be less than these numbers in real life.

I believe that the silicon in the Tritium Wavesculptor 200 is actually capable of a little more current, bringing it closer to 200 kVA, as suggested by the name. However, they are being a little conservative with the specifications. This may be where you heard a figure of 350 or 360 A output. But for now, it is 300 A, and may well stay that way forever.

The sqrt(2) comes from the peak to RMS ratio of voltage and current for AC, and the sqrt(3) comes from the fact that there are three outputs, but either the current (delta) or voltage (wye) will be split by a factor of sqrt(3) at the load (standard 3-phase power formula: power = line voltage x line current times sqrt(3)).

Finally, although VA and hence kVA has the same units as power, the useful power is less than the VA rating. Some of the current into the motor is "reactive", in fact inductive, meaning that energy will transfer between the capacitors in the controller and the magnetic field in the motor. This current has to be borne by the controller, but does not contribute directly to mechanical power. (Of course, if you have no or too little field, you will get no or too little mechanical power out of the motor.) A typical power factor for an induction motor is 0.85 to 0.88; multiply the VA rating by this number for electrical power into the motor. For example, the Curtis 1238-R with a power factor of 0.85 (I don't know the figure for the AC50 or AC75) can deliver 103 * .85 = 87.5 kW electrical. If the motor is say 92% efficient at this power level (again, I don't know the figures for the AC50 or AC75 motors), this allows a maximum of 87.5 * 0.92 = 80.5 kW mechanical from the motor. With realistic batteries sagging to say 108 VDC, this allows some 108/130 * 80.5 = almost 67 kW mechanical output.

With a suitably matched motor, the Tritium Wavesculptor 200 would be able to produce about 160% of this power, or about 107 kW mechanical. However, note that the AC-50 is badly matched to the Tritium, so the Tritium would actually deliver less power to the AC-50 than the Curtis, unless you were willing to run it at very high speed and voltage.


----------



## tylerwatts (Feb 9, 2012)

Gentlemen

Is my understanding correct then tha in principal the Curtis will produce more torque but up to a lower rated RPM, whereas the WaveSculpter will carry the lower torque value (not directly proporional as the % losses increase as more current is shoved through the wiring) to a higher rated RPM say allowing a direct reduction drive versus a geared drive in the Curtis?

Also, Coulomb

Why do you say the WS is not matched to the HPEVS AC motors? What is it about their design? My understanding (though very simple still) was that the wiring format wa the same therefore in general either controller would work with all AC induction motors.

Are the AC motors designed around use with the Curtis controllers then and operate best (highest efficiency, therefore conversion of electrons into motive force) with these versus others?


----------



## Coulomb (Apr 22, 2009)

tylerwatts said:


> Is my understanding correct then tha in principal the Curtis will produce more torque but up to a lower rated RPM, whereas the WaveSculpter will carry the lower torque value... to a higher rated RPM


Yes, basically.



> Why do you say the WS is not matched to the HPEVS AC motors? What is it about their design?


Merely the motor constant, Kv. The AC50 generates too little torque for a given current to be useful. In the process, it generates only a small back EMF, and the Tritium controller has a lot more voltage at its disposal.

I suppose it's like a heater designed for 120 V, when you have say 480 V available. The load is too low impedance to be useful for the supply. If you could "rewind" that heater to have sixteen the resistance, then it is a much better match to your supply.

Same with the motors designed to work with the Curtis controller. It's because the Curtis controller is designed for low voltage and high current. The Tritium controller is designed for higher voltage and lower current.



> My understanding (though very simple still) was that the wiring format was the same therefore in general either controller would work with all AC induction motors.


Well, it would drive it just fine, but the Tritium controller will current limit way before the AC-50 motor has gotten near its maximum torque, and the Tritium will be able to supply way more voltage than the motor will need. So there is a lot of current capacity in the motor unused, and voltage capacity in the controller unused.

Similarly if a motor better matched for the Tritium controller is connected to the Curtis controller. The motor will quickly generate so much back EMF that the Curtis controller "runs out of voltage", and the motor won't load the Curtis controller to its current capability. So now there is current capacity in the controller unused, and speed-at-base-torque capacity (yes, I just made that up, I can't think of a better term for it) unused in the motor. I suppose you could say the motor has "voltage capacity" unused.



> Are the AC motors designed around use with the Curtis controllers then and operate best (highest efficiency, therefore conversion of electrons into motive force) with these versus others?


Well, it's just a matter of voltage and current limits, rather than any synergy or anything else. It is true that if a motor controller's software is optimized for a particular motor, you could squeeze out a few percent more efficiency, but that's a minor effect compared to getting less than half the capacity out of the motor or controller due to basic voltage and current mismatch.

I'm a little surprised that there are so many different AC motors for the Curtis series. I would have thought that one (say the AC-50) would do pretty well with all the various controllers. I still haven't seen what the AC-75 brings to the table that the others don't. Apart from sheer size (and hence maximum torque), there is really only one significant variable, the voltage constant Kv. (There is also the torque or current constant, but these are strongly related, and even have the same numeric value when using appropriate units).

Can anyone enlighten me on the AC-75's advantages?


----------



## tylerwatts (Feb 9, 2012)

Coulomb

Thanks for that info. So it is a case of matching the characteristics of motor and controller to optimise the useable performance of both, fair enough that's great. I guess that explains why rewinding industrial AC motors is sometimes needed.

Re AC-75, I believe you're correct, the motor is getting HUGE and has higher current carrying capacity as well as a higher voltage operation as indicated by the intent to be used with a 144V Curtis. I cannot find said Curtis however, so I wonder if it is being developed for this motor combination perhaps. I believe the drive for this motor is for larger american applications in SUVs and Pick-ups where the torque is desired, adn also to allow direct drive of smaller vehicles like our fabulous Miatas!

As Coulomb says, anyone with any mroe info on the AC-75 and new Curtis combo then please?


----------



## tylerwatts (Feb 9, 2012)

I beg your pardon, first post states only with the 96V controller! Well, there's opportunity then! Anyone with any leads on a medium voltage controller (between Curtis and WaveSculpter) with good current capabilities to serve the AC-75 justice!?

Would a 240VAC industrial VFD controller be suitable? Quite a few guys on the forum are getting serious results from modding these for torque, and speed control. A ~200V controller on the AC-75 with direct reduction drive, perhaps straight into the rear diff, or through beefed up EV Transaxle reduction box would be potent in alot of applications, and offer a very good space saving package (provided the controller isn't huge/can be repackaged).


----------



## few2many (Jun 23, 2009)

Coulomb said:


> Can anyone enlighten me on the AC-75's advantages?


 
I asked on their Facebook page. Bigger frame and higher Torque.


----------



## tomofreno (Mar 3, 2009)

Coulomb said:


> ...I'm a little surprised that there are so many different AC motors for the Curtis series. I would have thought that one (say the AC-50) would do pretty well with all the various controllers. I still haven't seen what the AC-75 brings to the table that the others don't. Apart from sheer size (and hence maximum torque), there is really only one significant variable, the voltage constant Kv. (There is also the torque or current constant, but these are strongly related, and even have the same numeric value when using appropriate units).
> 
> Can anyone enlighten me on the AC-75's advantages?


 More torque, as you said. The 144V controller (170V max) has max current of 500A. The AC31 is perhaps better suited to this controller than the AC50 (higher bottom end torque, with still reasonable running torque), but both would have lower bottom end torque than they can have with the 650A controller. The AC75 was wound to give higher peak torque with the 144V/500A controller, and base speed around 3k rpm. I assume they are targeting mid-size vehicles, say 3k lb, but imo the controller doesn't have enough power for this. The combination will likely perform like the AC50/7501 controller in my car, good bottom end torque to weight, but be unable to maintain higher acceleration at higher vehicle speeds due to insufficient controller power to maintain peak torque out to higher rpm. It needs more power to get 0 to 60 mph time < 15 sec in a 3000 lb vehicle. Will be peppy at lower speeds though, and work fine as long as you don't care about fast 0 to 60 mph time.


----------



## few2many (Jun 23, 2009)

I think I saw sowewhere that the ac75 was for the 96v controller, and an ac76 was for the 144v controller. At least, thats what the two graphs at the start of the thread seem to show. (Found ac76 in another thread).I would also like to see a graph for the ac50 with the 144v controller.


----------



## tomofreno (Mar 3, 2009)

few2many said:


> I think I saw sowewhere that the ac75 was for the 96v controller, and an ac76 was for the 144v controller. At least, thats what the two graphs at the start of the thread seem to show. (Found ac76 in another thread).I would also like to see a graph for the ac50 with the 144v controller.


 Yes, forgot about that. Thanks!


----------



## tylerwatts (Feb 9, 2012)

Hi gents

Again, what is this 144V controller? IS it a Curtis? Where is there info on it please? Curtis do not list one that I can find, and I didn't see info for it on HPEVS website either. Any leads please?

Similarly, where's the info re AC75/76 models? ONly thing I saw was HPEVS website says AC-75 enters production in November.


----------



## Frank (Dec 6, 2008)

1239-8501, soon to be released - Jan. '13 last I heard.


----------



## JRP3 (Mar 7, 2008)

It's been "soon to be released" for quite a while now  I guess Curtis is having some issues with it.


----------



## tomofreno (Mar 3, 2009)

tylerwatts said:


> Hi gents
> 
> Again, what is this 144V controller? IS it a Curtis? Where is there info on it please? Curtis do not list one that I can find, and I didn't see info for it on HPEVS website either. Any leads please?
> 
> Similarly, where's the info re AC75/76 models? ONly thing I saw was HPEVS website says AC-75 enters production in November.


 You might peruse this thread: http://www.diyelectriccar.com/forums/showthread.php/hpevs-ac50-75603.html


----------



## tylerwatts (Feb 9, 2012)

Ah thanks Tom


----------



## Richard Wood (Jun 27, 2008)

Does the AC75 have the same bolt points as on the AC50, such that it would be interchangeable using the same plate? I realise it is a higher diameter.


----------



## tomofreno (Mar 3, 2009)

Richard Wood said:


> Does the AC75 have the same bolt points as on the AC50, such that it would be interchangeable using the same plate? I realise it is a higher diameter.


 Machine drawings for both are on the HPEVS site: http://www.hpevs.com
The AC75 has higher peak torque than the AC50, but you will be limited to the same peak power due to the controller. There is also supposed to be an AC76 with similar peak torque for use with the 144V controller (if ever released), but it also has the same peak power since it has a peak current of 500A. Curtis seems to have a ceiling for peak power for controllers which results in about 60kW peak shaft power.


----------



## epyon (Mar 20, 2008)

So , if i can get the "whole" car to 3,300 lbs and a AC-76 , can 0-60MPH be close to 4.5 or 6.5 seconds ? Will the motor be able to see it's 8,000 RPM or higher ? I'm socking money away for one as I type . Can a double AC-50 motor kit be made just in case more power is needed ?


----------

