[matthieu149]

I have been reading a lot about electric car for the past year, and I have learned a lot with this forum, I would like to thank you for all the great information that is already written here!
I live near Montréal, Québec, Canada, where the climate is normally cold and snowy, but I will not drive my electric car on winter.

I am studying mechanical engineering, and I have been working on car and mechanic as a hobby for a few years now. I have restored a 1992 Honda Prelude and build a home made CNC router.

I feel ready for converting the 1985 Mazda RX-7 I recently bought for this purpose!

I planned to do this project mainly for energy efficiency, durability, to reduce my ecological footprint and for personal accomplishment. I want an EV that is small, light weight, good handling and relatively powerful. I'm hoping to exceed the performances of the original 100hp Wankel engine!

My budget is around 20 000$, I plan to do complete this project within one or two years, I want to do things right and learn a lot!

Here is what I planned, for now (September 2nd, 2012):

• Warp 11 Motor
• Evnetics Soliton 1 controller
• GM Powerglide transmission (2 speed automatic with manual valve body)
• 3.2 Volt 100Ah LiFePo4 battery (80s1p) or 3.3 Volt 20Ah A123 LiFePo4 pouch cell (90s5p)

The GM powerglide will be converted to run without a torque converter and to shift manually. The bellhousing will be cut to shorten the assembly.
Something like those will be done:
http://www.kansasev.com/evglide-powertrain.html
http://3.bp.blogspot.com/-2dMIr1FwLKs/UDOMlIi3pvI/AAAAAAAAGcE/TaaQ4fp3_2U/s1600/BMW+M3+motors.jpg

My calculations tell me I should be able to do 110 km (68 miles) with 80s1p of the 100 Ah cell and 120 km (75 miles) with 90s5p of the A123 cells using 300 Wh/Mile.
Constant speed drag calculation give me bout 230 Wh/Mile at 100 km/h (62 Mph).

I used an Excel spreadsheet I have created, I considered air drag, tire rolling resistance, 1000 W of accessories, 80% DOD and a "battery to wheel" efficiency of 74% (94% controller, 88% motor, 90% transmission).

The car weight 1085 Kg according to the registrations and the GVWR is 1305 Kg.
377 kg have been removed yet.
-Engine and auto trans assembly : 216.4 kg
-Cooling system : 31.7 kg
-12V Battery : 15.9
-Exhaust system : 39.2 kg
-Fuel system : 63.3 kg
-Spare tire: 10.6 kg

I am considering Thundersky, CALB, GBS, Sinopoly and A123 battery.

Other components have not been selected yet.

I plan to design most of the project with CATIA V5, which I am quite familiar with. I want to be sure everything fits properly before starting to cut/weld the car chassis.

I have already contacted the SAAQ (The authority that registered cars in Québec), they provide me with a list (which I am not allow to share) of things required in order to register the converted car.

This thread will be my conversion built thread, I will post some photo as the projects go on!
I would like to have your advice/opinion on my project. About what I have planned and the results of my calculation and discuss it!

If some of you live somewhere close to Québec, Canada, I would like to have more specific advice for EV products dealers near me! For those from Québec, if any, your experiment with the registration process would be greatly appreciated!

Thank you!

EDIT 1 : Parts planning have changed (initially plan to use HPEVS AC50 and Curtis 1238).
EDIT 2 : This thread will be my conversion built thread.
EDIT 3 : Parts planning have changed (used to be kostov 9 or 11", Soliton 1 or jr and OEM manual transmission)

 

[Yabert]

Welcome to the forum Matthieu

Don't expect miracle performance with the AC-50 in an overweight car. Despite the torque advantage, you will regret having only 2/3 of the original power.
67 hp in a 1200 Kg car is the worst power to weight ratio of all todays car..., but if it's just to move around, this power will be enough since you probably need only 20-25 hp to cruise on highway.

Oh! and I personally know 3-4 guys who had many difficulty with the SAAQ... I hope things change. Good luck!

 

[matthieu149]

Thank you Yabert!

I am still uncertain of the acceleration I want, more is of course better!
But I like the better energy efficiency, and the regen capabilities of an AC system. I might also prefer to have a brushless motor, for durability and maintenance-free.

Any personal experience about the AC-50 performance would be great!

Here is the photo of my car, as promised!

 

[Batterypoweredtoad]

I would really recommend a Soliton 1/Kostov 11" or Soliton Junior/Kostov 220V 9" before the AC system. For the same or lower price a DC system will crush an AC system in power. The cheaper of the two DC systems (Soliton Jr and Kostov 9" 220v setup) will make more than 30% more torque than the AC system and carry it much higher in the RPM range. That means longer in a lower gear and much improved acceleration. It also matches the personality of a Rotary engine waaaay better than the shorter powerband AC system. The durability is not a worry with either system. The AC system may not have brushes, but changing brushes is a very simple job and it will probably never need to be done for the life of the car. The added AC system range from regen is minimal and the efficiencies are a wash. AC system has the ability to do reverse but you will have a transmission so that is unneeded. One day maybe someone will produce a cheap AC system with decent performance, but as of right now it doesn't exist.

 

[Yabert]

Nice car!... dismantle the rear spoiler will help the aerodynamic efficiency...

About acceleration, you can compare with other car using AC-50 on http://www.evalbum.com/mtrbr/HPGC
You can probably expect 12-15 sec for 0-100 km/h.... so, not exactly like a RX7 (sport car)!

About drive systems efficiency, you are not quite right. Let compare for example:

-AC-50: Controller efficiency 94%, motor efficiency 89% = 83.7%.... 110 lbs-ft, 67 hp for 4500$

-Kostov K9 + evnetics Jr: Controller efficiency 98%, motor efficiency 87% = 85.2%.... 145 lbs-ft and over 130 hp with proper battery pack for 3700$

It's sad to say, but old DC technology will be the winner in cost / power ratio until the ac systems price drop.

About regen, just remember than you live in a really flat region!..
No big advantage.

 

[matthieu149]

Wow!! Thanks you for all you advice! That's exactly the kind of information I expected to have by posting here!

I have already looked about a few DC systems, but I really taught the AC system would be great despite it's low power!

Might be more suitable in a chassis that does not "need" to be sporty to be nice!

Kostov motor and evnetics controller have already caught my attention earlier...

Looks like I will do some more research about it!

Thank you!

 

[tido]

hi mathieu,

I've contacted the saaq to make this kind of project legal and it is very complicated. Do you know an electric engineer willing to put his name on your project? They will not accept it if you don't. I have a list of requirements but the saaq told me not to post it since it is not completed. I could show it to you in a private conversation. PM me if you are interested, I have this at home...

 

[tido]

Do you live on Mortagne? I think I saw your car last weekend and said to myself that I would have liked to convert this one... I was moving my brother pretty close to this location....


BTW sorry I didn't have time to read the complete post before my first reply. I was at work and just got off the phone with Yabert concerning my future DC motor and he told me I should look at your topic.

 

[dougingraham]

I am also doing a 1985 RX-7 conversion. Couple of comments.

I don't think the AC-50 will be powerful enough to equal stock performance. I don't think it will be bad, just not what you hope for.

You can't use the flywheel that is on the 12A engine. It is counter weighted to balance the engine. If you were to mount it to the motor it would shake everything apart when it spins. I had to get a lightweight aluminum flywheel that didn't have the counterweight. I bought this from Mazdatrix but you can also find them at Racing Beat and I am sure other places as well. You should talk to Canadian EV before you order their kit. It doesn't look like there is enough stuff there to connect to the flywheel. It may be that this kit is intended to connect the motor shaft directly to the splines on the transmission eliminating the clutch and flywheel. I can't tell from the picture.

I have owned my RX-7 for about 11 years now. I haven't driven it in 6 years. When I started the conversion I quickly came to realize that it was not in as good of shape as I thought. I had stopped driving it because it would smoke badly about a minute after started for about 15 to 20 seconds. It didn't do this every day, only about 1 in 3 days. What I found was that the brake reservoir was dry and so was the clutch. So both those systems needed to be completely fixed. I also found one area of the car that had a bad rust problem. If you pull the rear wheels off there is a reinforcement plate that is spot welded to the sheet metal in the wheel well. The center of this plate looked a little crusty and what I found was that this was rusted all the way through to the inside which you can see if you remove the storage boxes behind the seats. I picked at it with a screwdriver and eventually had a hole 2 to 3 cm wide and 10 cm long. I've cleaned these up and reinforced with fiberglass and it does not look like it will be a problem. I am pretty sure this was caused by dirt collecting under the plate, rubbing away the paint and then holding water when it got wet. The point is that you can spend a lot of conversion time just fixing stuff that is broken on a 27 year old car. It might not be worth it. I think I would have gone looking for a better car if I had known how much time I would spend fixing stuff. Since your car is running at least you know that the brakes are fine. One thing I would recommend is before you start take the car to a car wash and bring a jack and some jack stands. Clean everything you can underneath and in the engine compartment. Even if you do this I suspect you will be dirty up to the elbows every time you work on the car. I had 1/4" of dried mud on top of the fuel tank as an example of an area you just wont be able to clean.

I chose to use the GBS 100AH batteries. I made a battery box that fits where the spare tire, fuel tank and muffler were in the back. I can put four rows of 9 cells back there easily but for weight and balance reasons I am only going to install 32 cells. There will be an additional 22 or 24 cells under the hood. I fabricated an insulated battery box out of foam and fiberglass. I might put some sort of heating element in the bottom of the box for those really cold days.

I am using a WarP9 and a Soliton 1. This is assembled on my workbench and running right now.

Good Luck!

 

[matthieu149]

I think I'll go with a Kostov 9" 220V and the Soliton 1.
Then, considering the GVWR of the car, the power will only be limited by the amount of batteries!

Thank you for your flywheel advice! Be sure the whole drive train will have be dismantled and measured twice before I ordered anything! And for sure I will call CanEV!

About the age of the car, I am confident that the chassis is in good shape, even though the rear reinforcement plate you are talking about will need to be repaired on mine also.

I have already restored a 1992 Honda prelude that was more damaged, so I am not afraid to weld and to get dirty!

I chose a car as old because in Québec there is almost no way to register a 1997 or earlier car. And in my area a 15 years old car that are in great shape and at a reasonable price are either very rare or not not the kind of car I would convert. 2500$ for a slightly rusted 1985 RX-7, it's a good deal for me!

dougingraham, do yo have a built thread or a web page? I would be interested to know more about your project!
Thank you!

 

[dougingraham]

ougingraham, do yo have a built thread or a web page? I would be interested to know more about your project!
Thank you!

I have a picassa photo album I update from time to time. I have a google doc that is more or less a journal which includes what I worked on that day. Here are the links:

The Photo album.

The journal.

I hope you find the photo album of some interest.

I have a big pile of stuff I still need to weigh. The list of stuff I have weighed as I removed it is at the very end. The one thing that surprised me most was the weight of the exhaust system.

 

[Yabert]

I think I'll go with a Kostov 9" 220V and the Soliton 1.

From 65 peak hp systems to a potential of over 150 hp..... Impressive change!

Really interesting album Doug. Do you have an explication to share about "Replacement armature for the WarP 9"

 

[MN Driver]

I'm not sure how well a Soliton 1 will go with a Kostov 9" 220v. I have my doubts about that motor would be able to handle 1000 amps for long. It's wound for higher voltage instead of higher amperage. I'm thinking it would take 280v better than it would take something near 1000 amps. There was another thread on this talking about dual motors where plamenator suggested running higher voltage and running out to higher RPMs rather than pumping gobs of amps. With a Soliton 1, I'd see if you can fit the Kostov 10". I'm personally looking to max out the voltage and go with a Sol Jr and Kostov 9" 220v.

 

[Batterypoweredtoad]

According to this graph http://kostov-motors.com/files/productattachments/6ff70418861d3230f01fc0340802fb1f_S220E01.pdf

200V on a 220V K9 will carry 500A (130ft lbs of torque) to 4250rpms. Assuming a fairly constant rpm/volt relationship at 500A you are getting 21.25 rpm/volt. That means if you want to take that torque all the way out to 6000 rpm you need around 282 volts under load. That should be easy to achieve with a performance oriented pack and a Soliton Jr. You would have a 6000rpm power band instead of the 3000rpm powerband of the stock motor.
http://kostov-motors.com/files/productattachments/6ff70418861d3230f01fc0340802fb1f_S220E01.pdf

 

[dougingraham]

From 65 peak hp systems to a potential of over 150 hp..... Impressive change!

Really interesting album Doug. Do you have an explication to share about "Replacement armature for the WarP 9"

The first one had excessive runout at the end of the shaft. About 0.004" (0.1mm) and the spec is for about half that. I just got the replacement into the motor and measured it at 0.0008" (0.02mm) so I am now very happy. I was seeing about 0.010" (2.5mm) at the edge of the flywheel so I couldn't use it. This was both radial and axial so there would have been pretty terrible clutch chatter and it probably would have worn out the pilot bearing and the front transmission bearing in very short order. Netgain made it right and I have nothing but good things to say about them.

 

[crashedup]

hi im from terrebonne. Not far from montreal. where do you live?
I have a vw corrado that im thinking of doing a conversion with!
would be great to meet up one day and talk

 

[matthieu149]

Next week, I will start to remove ICE components (engine, exhaust, cooling system and fuel system). I will measure the space and weight available.
If weight and space allow it, I'll go with the 11' and the soliton 1, otherwise I will go with the 9' and soliton JR.
Battery weight will of course be important, I would like to match my battery max discharge with my motor size!

If my battery pack cannot supply enough amp to max out the 11', would the additional low end torque worth the additional weight?

 

[dougingraham]

If weight and space allow it, I'll go with the 11' and the soliton 1, otherwise I will go with the 9' and soliton JR.
Battery weight will of course be important, I would lite to match my battery max discharge with my motor size!

If my battery pack cannot supply enough amp to max out the 11', would the additional low end torque worth the additional weight?

It looks to me like a WarP 11 will fit but without a lot of clearance. The WarP 9 fits fine although it it extends farther into the engine compartment than I was estimating.

The 12A motor produced 105 hp (78 kW) and 105 ft-lbs (144 N-m).

The 13B motor produced 135 hp (101 kW) and 135 ft-lbs (185 N-m).

A Warp9 can produce 105 ft-lbs at somewhere around 600 to 650 amps and over 150 ft-lbs at 1000 amps. At 1000 amps and 192 volts a Warp9 will be producing approximately 170 hp at the shaft. At 600 amps and 192 volts will produce approximately 120 hp. That is estimated, probably someone has better numbers but those are going to be representative. With that in mind I chose a WarP9 rather than the WarP11 for my project. I am concerned that the stock drive train will be stressed even with a WarP9. The WarP9 should be plenty for this car as the performance should be a bit better than with the 13B engine unless the car gains a lot of weight from too many batteries. I am using 54 or 56 100AH cells which will end up adding only a few pounds over the stock weight of the vehicle. I ended up with a Soliton 1 rather than a Jr because you can turn down the current on a Soliton 1 but you can't turn up a Jr above 600 amps.

I am about 90% confident that a WarP 11 will fit, but the extra weight and the weight of the extra batteries to get the higher currents and the fact that the drive train wasn't designed to handle that power level it seemed more prudent to use the smaller motor.

I think the AC50 and 650A Curtis would also be excellent in this car although it is on the high end of the weight scale for that setup.

I think the additional low end torque of the WarP11 would be wasted destroying clutches and smoking the tires.

 

[Tesseract]

...
A Warp9 can produce 105 ft-lbs at somewhere around 600 to 650 amps and over 150 ft-lbs at 1000 amps. At 1000 amps and 192 volts a Warp9 will be producing approximately 170 hp at the shaft.....

Just a quick correction/FYI. Our hydraulic dyno has two WarP-9 motors in tandem and each delivers approximately ~240lb-ft of torque at 1000A. There is some variation from motor to motor, so call it 230-250lb-ft of torque at 1000A.

The WarP-9 requires ~50V for every 1000RPM and is in imminent danger of immediately zorcching (ie - a plasma flashover across all of the brushes) at about ~3000rpm (ie - 150V). In other words, the maximum amount of input power a WarP-9 can handle is about 150kW. I'm sure some drag racers have pushed that a *little* bit higher, but for a daily driver I wouldn't let a WarP-9 see more than 192V or more than 130-140kW (110-120kW highly suggested for new EV drivers). NB - the Soliton controllers let you specify a maximum motor power limit, as well as maximum motor voltage and current, and RPM (must hook up a tach pickup, of course, for the latter function to work).

 

[Ziggythewiz]

Which numbers are correct? 150V max, or 192? 3k RPM or 3840?