# 1970 Opel GT EV



## powerhouse (Apr 1, 2011)

This isnt the only Opel GT converted
A married couple also converted one, and they documented their entire process on youtube.
Its a great source for education 
Check them out http://www.youtube.com/user/mcrickman


----------



## Guest (Sep 1, 2011)

Nice car to convert. Go with the clutch. You will want the transmission and the ability to disengage the motor and shift fast and easy. It was designed to shift with a clutch no matter if you have an ICE or Electric motor. It will better utilize your power band with lower voltages and higher amperage setups. Hope you go with lithium from the start. Don't bother with lead unless you absolutely have not choice. Don't expect much from lead acid batteries. It will give you short distances but it will give you the knowledge of being able to build an electric car conversion. But in the end you will want to go with good cells. I have lithium and would never go back to lead. I would only use lead to test or for my solar back up. I'd even rather have LiFePO4 Cells for my solar back up. 

Pete


----------



## tomofreno (Mar 3, 2009)

Nice looking car to convert, and very aerodynamic! You might hit your goal of 44 freeway miles at 70 mph with a 156V*100Ah = 15.6kWh pack. With 80% DoD that is about about 285Wh/mile. I calculate about 288 for my bit under 2300 lb Suzuki Swift. I don't drive at that speed, so have never checked accuracy. Its nice to not cut it too close, so you can't even stop to pick up something/someone on the way. Do you know the drag coeff and cross sectional area? Have room for 49 cells? The 100's are definitely easier to fit due to lower height. CALB sells 130Ah also. Might check their size.


----------



## Lisa Macafee (Aug 24, 2011)

Thanks for the ideas guys! 

I've already been pestering poor Mcrickman about his conversion, he's got a great set-up!

As for the 160ah height, there's no backseat in the Opel, it has a "luggage shelf" which could be appropriated to hold pretty much anything but lead. The 130ah Calbs are a good idea. 

Is there a clear way to predict range and speed with lithium batteries? I know there's the EV Calculator for lead-acid,which was amazingly helpful until I decided that lead-acid was not a feasible option for the Opel (it has only a 550 lb.payload!).

Some calculation I did with Bob Brant's book, no idea if they're right... I think the drag coefficient is closer to 3.0, but I erred on the cautious side:

F = Cwa F=2000 lbs = 2 x 386lb force for 8 mph/sec acceleration = 772.6 lbs. acceleration needed 
coefficient drag = 0.32 -A= 18: rear, wheel wells, undercarriage, front, grooves, enginebay, skin 
climb = 40%incline = 742.8lbs. , rolling res. = 0.018 = 18lb/1000 = 36 lbs. , 77 lb drag 75 mph 
aero drag @75mph= 77.69 x 0.047 = 3.65 , aero drag = 77.69 + 3.65 = 81.34 lb drag sum drag= [email protected] 

1hp moves 50lb/1 ft/ 1 sec 1 hp = FV/375 hp= 117.34lb x 75mph/ 375 = 23.5 hp needed 
Max power [email protected]= 773lb accel. + 742.8lb climb + 36lb roll + 3.65lb wind + 77.69lb drag = 1,633lbs. Resistance or 740.7 kg 
300wh/mile x 50 mile range x 1.25 (bathealth) = 130Ah x 1.8 (fast discharge)= 234 Ah = batteries need amp hour rating of 234 to get 50 mile range 

Thanks again!! -- Pic of removed parts so far!


----------



## Guest (Sep 1, 2011)

> You might hit your goal of 44 freeway miles at 70 mph with a 156V*100Ah = 15.6kWh pack.


No but you may get your 44 miles at 55 mph. At 70 your really sucking amps just to cut the wind. That is a small pack and will tax the small AH cells at 156 volts at 70 mph with that car. My MG was taxed quite heavy even at 55 and 120 volts and 100AH cells. NO way to get 35 miles at 70 mph with the MG. After driving the Leaf for a few months now I'd truly say you won't do your distance at 70 mph and that small of a pack or AH cells. At 55 maybe if your easy on the throttle.


----------



## Guest (Sep 1, 2011)

Don't push the limits of the cells. You want your 44 miles at worst case you can think. So in cold weather you will want to build according to that. If you can do 44 miles at 70 in the cold I would assume your going to have at least 24KWs of 200ah cells. I am sure you could stuff enough in. Remember your car is pretty heavy too. Check out Jack Rickards Glass Replicas and check out his distances with a light weight vehicle. It's real stuff. I think your choice of vehicle is great. I am sure you can do an excellent job but build it according to your worst case needs. Then you won't be discouraged when the going gets tough and cold. 

Pete


----------



## dtbaker (Jan 5, 2008)

I am going to second what Gotti has already posted.... 120v x 100ah will get my little Suzuki Swift about 40 miles at 80%DOD under 'average' stop and go 35mph around town WITHOUT heat or headlights on.

There is a significant difference in consumption between 35mph and 70mph... and if you want to allow for heat and headlights I would ballpark your minimum need to be more along the lines of 144v x 180ah or 156v x 130ah with a 9"DC... and probably a Soliton Jr for the easy option to liquid cool those extended highway miles.


----------



## Bowser330 (Jun 15, 2008)

OPEL GT, awesome looking classic lines and super lightweight. Perfect for EV conversion.


----------



## Lisa Macafee (Aug 24, 2011)

Again, thanks for your thoughts!

SO, I'm gathering that 156 V lithium ion pack at 100ah is a no-go for freeway range of 44+miles. Would 156V at 130ah be enough you think, or would I need to go to 156V @ 160ah or 200ah? The price difference is thousands each increase is why I'm trying to cut it close... if only money were no object.

As to controllers, the WarP requires a separate $285 liquid cooling system, does the zilla 1k? And the solitron jr? I'm trying to find the most cost-effective options. I don't want to skimp on a crucial component, but I also don't want to buy something just because it costs more. Are there any real comparative benefits between the three controllers?

Thanks again! It's great to know there are other real people who have successfully completed a conversion. Much obliged for your opinions.


----------



## Lisa Macafee (Aug 24, 2011)

Finally got the engine out! My brother, Jim Macafee, and a former student of mine, Freddy Ramirez, are helping. Gearheads love cars! It has actually been a blast taking the car apart, I hope I can scrounge money for EV parts soon.

It has been suggested to me that AC systems are getting cheaper and easier to install, and can get better range on less batteries, hence actually being cheaper. Any thoughts on this?


----------



## dtbaker (Jan 5, 2008)

great picture... looks like a good time is being had. 

my personal opinion is that the cost of the AC system over DC is probably not worth the 10-15% extra range you may get from regen with normal suburban driving, unless you are total stop and go, or short steep hills like san francisco.


----------



## JRP3 (Mar 7, 2008)

Cool build, my dad had a GT when I was a kid, loved it. You might want to look into a flush headlight mod to get rid of the bug eyes when night driving, should help your cd a lot when the headlights are on. Have you asked mcrickman what his wh/mi number is at 70mph? That will give you a good idea how large your pack needs to be.


----------



## Bowser330 (Jun 15, 2008)

Lisa Macafee said:


> Finally got the engine out! My brother, Jim Macafee, and a former student of mine, Freddy Ramirez, are helping. Gearheads love cars! It has actually been a blast taking the car apart, I hope I can scrounge money for EV parts soon.
> 
> It has been suggested to me that AC systems are getting cheaper and easier to install, and can get better range on less batteries, hence actually being cheaper. Any thoughts on this?


Congrats!

AC is getting cheaper and more available however, as dtbaker mentioned, the power:cost ratio is in total favor to the DC. The cost difference could allow you to purchase higher AH batteries thus nullifying the benefit of AC.

Example:
Currentevtech.com sells an AC/BLDC system (motor+inverter) with 80kw peak power for 5,850$

Manzanitamicro.com sells Zilla1K (1,975$) 156V & 1000A capable, so considering a 20% voltage sag @ 1000A, 156-31V = 125V * 1000A = 125kw,
Warp9 motor (1700$), Total = 3675$

2,175$ towards more lithium!

130A CALB cells can deliver bursts of 1000A (for less than 10 seconds) 
49 in series = 156V nominal & 475lbs & ~7000$USD
156V*130AH = 20.3kwh / 275wh/mile =74 mile range @ 100% DoD, 59 mile range @ 80% DoD


----------



## socko (Sep 21, 2008)

Howdy - 

You asked about cheaper AC motors. I love my HPGC AC-50 motor + Curtis 1238 controller, gauge and wiring harness ~$4600. 36 x 200ah cells is a great combo. Peels out confidently and gives my 2550-lb Miata a 80 mile range at 90% DOD. The Opel must be lighter yet? Best of luck!

Cheers,
Brandon

BH Electrics, LLC
"components, consultation, conversion"
www.ampREVOLT.com


----------



## JRP3 (Mar 7, 2008)

Yes that is something to consider with the HPEVS AC systems, you get instrumentation including RPMs, Voltage, Amps, and motor and controller temperature, plus a wiring harness, all items you need to add to a DC system.


----------



## tomofreno (Mar 3, 2009)

I put together some graphs of torque versus vehicle speed for the AC50 motor Socko mentioned (with a 550A controller, they also sell a 650A controller), an AC31 (also sold by HPEVS), an 8" series DC motor, and 9" series DC motor a while back and posted them here:
http://www.diyelectriccar.com/forums/showpost.php?p=253358&postcount=311

The 9" ADC motor is similar to a Warp9 as far as torque, but the Warp9 has larger brushes and some other changes to make it more robust. The link for the graphs is at the bottom but please read the explanation of the graphs first so you understand what is being compared. They are of course approximations but seem to match data fairly well. The calculations use the parameters for my Swift: www.evalbum.com. It will give you an idea how those motors compare for the same pack voltage and car, and similar maximum current controllers. The difference in "available" and "required" torque is the torque available for accelerating the car. Bigger the difference, the more acceleration.

I agree you can buy more power per $ with a DC system, and if you want to squeal tires and accelerate from zero to 60 mph in less than 10 sec you can do that with the system Bowser described, but an AC system to do that will cost you FAR more than the DC or the HPEVS AC50 package - which will not do that (the Swift does 0 to 60 in 16 seconds, 0 to 40 in 8.5, and no squealing). I do not recommend pulling 10C from prismatic cells for even 10 seconds if you want them to last a long time. I think the jury is still out on how much such large discharge currents decrease cell lifetime. I'd keep it to less than 5C for short bursts, so 650A for 130Ah cells.

As far as I can see prices for AC systems aren't changing (nor DC). Since you mentioned you plan to work on it for a couple years, HPEVS is coming out with a new water cooled motor with new water cooled Curtis controller which is supposed to have about 150 ft-lb torque and 100 HP peak. No info on price yet. That would make the Opel jump.

I also agree with dt that you will get around 10% +/-5% energy gain with regen - on the higher side with more hills, lower side doing mainly highway cruising. At least that is what I get with the AC50. I mainly wanted AC for electric braking (slowing the car with the motor regen, rather than mechanical brakes). I really like that since I drive some in the mountains. I like driving with one pedal, ease up to slow a bit, ease up more to slow faster, press to accelerate. But depends what you want. I like efficient use of materials and energy, so went with a small efficient car. Others like to accelerate as fast as they can afford. The Opel is sharp! Should make a cool ev if you can find room for enough batteries to meet your needs.


----------



## bruceme (Dec 10, 2008)

Lisa Macafee said:


> Hello all, I'm new here.


I love it! Looks like a Lancia Stratos! 










On the clutch, definitely keep the clutch. I'v driven both. You will have times when you want the torque to accelerate right now, not in 3 seconds while you wait for the syncro. Motors are different those silly narrow torque gasoline engines... Electric engines give a riotous grunt down load and then kinda peter out and stop giving away energy at high revs, so upshifting actually give you more torque, not less, like a gas. It's weird, you have to try it. 

And it's real fun watching mechanics rev it up to get started in first, then you tell him to stop and shift into 3rd and show him how you can just put your right foot down.

I'm definitely in EV envy. This is going to be an awesome project. Good luck.


----------



## JRP3 (Mar 7, 2008)

Depends. I went clutchless with my AC 31 and I just leave it in 2nd gear most of the time for all driving from 0-65mph. With some practice and good timing I can shift faster than with a clutch when I need to, though downshifting is more difficult on the fly.


----------



## Bowser330 (Jun 15, 2008)

tomofreno said:


> HPEVS is coming out with a new water cooled motor with new water cooled Curtis controller which is supposed to have about 150 ft-lb torque and 100 HP peak. No info on price yet.


MORE INFORMATION ON THIS^^^^!

Sorry I don't mean to hijack the thread.


----------



## Lisa Macafee (Aug 24, 2011)

Thanks for the advice! I just want a commuter car, I don't need to go over 70mph except to pass people on the freeways, and don't need racing acceleration. I guess I should add that I'm working on a budget. I need the minimum power to do my commute. It'll make the difference between 1-2 years when I can afford the parts!

Where could I buy an HPEVS motor/inverter/wiring harness/extras combo? I can find BLDC motors, but not HPEVS like the ones Brandon and JRP3 mentioned?

Also, electricautosports.com rates the AC-50 combo for 72-108v, vehicles up to 3,800lbs. Could 108v, AC-50 get a 2,000lb car 70mph for 44 miles? That sounds too good to be true.

...Don't know why, but I really want regenerative braking. It seemed like the most awesome concept when I first started researching EVs!


----------



## dtbaker (Jan 5, 2008)

Lisa Macafee said:


> Where could I buy an HPEVS motor/inverter/wiring harness/extras combo? I can find BLDC motors, but not HPEVS like the ones Brandon and JRP3 mentioned?



I'm sure there are other places, but two good Vendors are:
http://store.kta-ev.com/acmotor-controllersystems.aspx
http://evolveelectrics.com/High Performance AC Motor.html


----------



## JRP3 (Mar 7, 2008)

Also:
http://www.electricmotorsport.com/store/ems_ev_parts_motors_ac.php
http://grassrootsev.com/motorsac.htm


----------



## JRP3 (Mar 7, 2008)

Lisa Macafee said:


> Also, electricautosports.com rates the AC-50 combo for 72-108v, vehicles up to 3,800lbs. Could 108v, AC-50 get a 2,000lb car 70mph for 44 miles? That sounds too good to be true.


The HPEVS systems can be run at 115V, 36 cells, and I'd think with enough battery a car your size should be able to do it. Aerodynamics are important at speed so plan on a belly pan to smooth out the bottom.


----------



## tomofreno (Mar 3, 2009)

> MORE INFORMATION ON THIS


 That, and this:
http://www.diyelectriccar.com/forums/showpost.php?p=256014&postcount=327
are all I know. Probably won't get much more out of them until they are further along with firmer dates and maybe cost.


----------



## tomofreno (Mar 3, 2009)

> Also, electricautosports.com rates the AC-50 combo for 72-108v, vehicles up to 3,800lbs. Could 108v, AC-50 get a 2,000lb car 70mph for 44 miles? That sounds too good to be true.


 Yes, it could do that. I've not had my car above 75-80 mph but it still had acceleration there, and its weight is a bit under 2300 lb. I'm using 36 cells like JRP3. Mine are CALB 180Ah. I would estimate my range at 70 mph on level ground as around 45 miles, maybe a few more. 

There are other things to consider if you plan to drive at 70 mph for 44 miles though, like how to keep the motor and controller cool, and not pull too high discharge current from your cells, so they last a while. If you have temperatures in the 90's F or above you will likely need to water cool the controller - it comes with no cooling at all. Most of us add a heat sink, some with a fan also, but I think that won't be enough for that sustained power output. My controller gets into the mid 60's C in 95 F ambient driving at 50-55 mph for 30 minutes. It cuts back power at 85 C I think. Motor is in the high 50's to low 60's C. it can go to 120 C.

You might also need to add a blower to cool the motor in addition to its internal fan, but it likely would be ok without it. You will have to do these things with AC or DC motor/controllers - unless it doesn't get over 75 F where you live, then you might get a way with air cooling. Most of us don't drive at that high of speed for that long (~ 40 minutes). You might check around and try and find some who do to get a better idea of what is required for cooling. Myself, I'd wait for the water cooled motor/controller if possible. It would handle your demands much better.

I also wouldn't pull much over 1C current from your cells for that long (~40 minutes). I would guess you will pull around 200 to 220A at 70 mph. So 180 or 200Ah cells would work. Smaller fraction of C the discharge current is the better for cell life. Do lots of searching and ask lots of specific questions.


----------



## Bowser330 (Jun 15, 2008)

Don't forget the member "cruisin", he is selling the HPEVS kit also, and has a good price too...I think 4400$ with the 650A controller...

The new upgraded version might be worth waiting for though...I assume it will be priced competitively with the 107hp 183ftlb BLDC setup that currentevtech.com has for sale for $5,850....


----------



## Bowser330 (Jun 15, 2008)

tomofreno said:


> That, and this:
> http://www.diyelectriccar.com/forums/showpost.php?p=256014&postcount=327
> are all I know. Probably won't get much more out of them until they are further along with firmer dates and maybe cost.


Thank you.


----------



## socko (Sep 21, 2008)

Lisa Macafee said:


> Where could I buy an HPEVS motor/inverter/wiring harness/extras combo? I can find BLDC motors, but not HPEVS like the ones Brandon and JRP3 mentioned?



Hi Lisa - I am actually an Electric Vehicles of America shop now and can give you a competitive price on this motor/controller combo. It may well be upgraded by then, too! If your car is around 2000-lbs it sounds like this would be well-suited for your scenario. 

cheers,
Brandon
www.ampREVOLT.com


----------



## socko (Sep 21, 2008)

'92 Mazda Miata with 23.5 kwh of lithium and HPGC AC-50 + Curtis 1238 650-amp controller - - 80 mile range at 85% DOD, 100+ mph top speed

http://www.youtube.com/watch?v=Ua4xqZBsdxI


----------



## Bowser330 (Jun 15, 2008)

socko said:


> '92 Mazda Miata with 23.5 kwh of lithium and HPGC AC-50 + Curtis 1238 650-amp controller - - 80 mile range at 85% DOD, 100+ mph top speed
> 
> http://www.youtube.com/watch?v=Ua4xqZBsdxI


At what speed was the 80 mile range recorded at? 40mph and below, mixed, mostly highway speeds (65mph)?

85% of 23.5kwh = 20kwh 20,000wh/80mile = average 250wh/mile


----------



## socko (Sep 21, 2008)

Sorry - good question. The majority of the trip (75%) was careful highway driving averaging 60 mph with convertible top up, some rain, during the day. 25% was city driving. This was a round trip, so numbers should be pretty useful.

The car currently has about 2000 lithium miles on it and is averaging about 2.2 amphours/mi.

Cheers,
BRandon


----------



## Bowser330 (Jun 15, 2008)

socko said:


> Sorry - good question. The majority of the trip (75%) was careful highway driving averaging 60 mph with convertible top up, some rain, during the day. 25% was city driving. This was a round trip, so numbers should be pretty useful.
> 
> The car currently has about 2000 lithium miles on it and is averaging about 2.2 amphours/mi.
> 
> ...


Wow thats really great to hear! Thanks!

Any idea on the fully converted weight?


----------



## socko (Sep 21, 2008)

starting = 2350 lbs
finished = 2550 lbs


----------



## Bowser330 (Jun 15, 2008)

Thank you again for the reply. This data should be very useful to the OP as the weight and drivetrain of your setup are in-line with planned options.


----------

