Converting a fossil burner

[Tom Roy]

 

Photo: Jørn Uldalen
Found it! Found a car for converting to silent electric power! Yesss! I'm on the move!

What kind of car it is? Some think it looks like a Fiat Spider, others say Alfa Romeo, Triumph, Lotus or MG. It's called Ginetta and this model is the British company's most successful road model, the G15. It's made in a number of almost 600 from 1968 to 1974. Mine is one of the later and more perfected ones made in 1973.

Road model? Yes, Ginetta Cars Limited was founded in 1958, make pure racing cars, of which some only exist on the drawing board, kit cars and cars intended for driving on regular roads. The road cars are just begging to be raced, too - and quite successful at it.

The latest model is the G50, available as a fossil burner or plug-in electric. Take a look at it at their home page.

The G15 fits all my requirements for the 2001 Th!nk electric drive train I'm going to use:
* recently restored
* 13 inch wheels
* less than 600 kg - tech data says 534 kg dry, a visit to a scale said a hair below 600 - fluids and mandatory warning triangle and safety west included
* engine and drive wheels at the same location - here: rear
* spare parts available
* space for and capable of carrying 150 kg of lithium battery
* low cd (drag coefficient/wind resistance)
* good looking
* Bonus: rust free fiberglass body and galvanized steel frame, speedometer is driven off the left front wheel

Photo: Jørn Uldalen
The engine compartment is located at the rear and houses the longitudinal mounted 998 cc/61CID aluminum block with cast iron wet cylinder liners and the aluminum 4 speed stick shift transmission. Weight data for the package is 105 kg/231 lbs. After the conversion this compartment will be virtually empty except for a couple of electronic boxes; the inverter and the DC/DC converter. The conversion will feature a mid motor configuration which moves the CG forward and improve the weight distribution.

The water pump is external and belt driven, the pulley is visible on the left hand side beneath the frame, the inlet water hose curving down and forwards towards the front mounted radiator. The center, shiny pulley is the crank shaft pulley. Above the frame and between the two previously mentioned pulleys is the alternator pulley. The weird looking lump to the right of the generator is the rear engine mount. The other, unfamiliar thingie on the far right above the frame is the engine oil cooler. The ICE is tilted 45 degrees to the right. In short: British engineering at it's best. The more I study my new toy the more I nod my head in approval.

Update June 14, 2009

Testing wheel to fender clearance with 95 kg/208 lbs of lead. I can still get my hand between the rear wheel and fender, so I guess that's a "go". I'm considering a 44 cell ThunderSky 90 Ah battery weighing 141 kg/310lbs.

July 15, 2009

Some of you know how tall (if can you say that about a car) the 2000 Th!nk City is. There's got to be less drag in the low 1973 Ginetta G15 (closest to the camera)! The G15 is also shorter and narrower than the Th!nk. Wonder what the driving position is like in such a low car? In one original sales brochure it's called "Grand Prix driving position". Sit on the floor with your legs straight out, then put your arms straight forward and lean back until your feet are just about to raise off the floor. The seat back is not adjustable. Did somebody ask about a stiff neck?

January 24, 2010
The practical work on my project has been slow until now. But a lot of thinking is going on - ideas and solutions are constantly being replaced by new ones, then I find a new problem with that and start all over again. For instance the DC/DC converter - I located one that is lighter than Th!nk's original one and bought it, thinking that I'll figure out how to address the fact that the new DC/DC converter can not handle the full planned 140 volt battery voltage. I borrowed an idea that surfaced on the Norwegian EV forum in response to an EV with defective DC/DC converter; use a switch mode 12 volt battery charger instead. They are readily available and works on DC as well as on the AC grid.

The past week I've removed the front and rear chrome bumpers. I'm not going to put them back on and thus saving 5.5 kg of unnecessary weight. This idea came as a result of a comment to a photo posted on the Ginetta forum, stating that the G15 looks better without the chrome bumpers. The body contours does not change like it would on any other car I know. Now my G15 looks more contemporary with painted "bumpers".

February 11, 2010

Feel like I got a big step further in removing the ICE and transaxle. The "donuts" that I've been struggling with for days finally came off.

Clamps were made to compress the "donuts" which actually are rubber couplings.
Update: I just found that Volvo use a similar type of rubber coupling, called Hardy-plate. It's probably not so bad as I thought when I first noticed it.

February 16, 2010:

The engine/transaxle unit gave in after some extensive struggling; carburettor, complete exhaust, oil cooler and all. This is actually the first time that I've removed a rear mounted engine, and I can understand those who like the concept.

I put the complete unit on the bathroom scale with the aid of an "elephant" (engine hoist) and the scale indicated 115 kg. That's light weight and then consider that the oils and exhaust are included!

March 1, 2010:

Photo: the electric motor/differential unit (37 HP @ 0 to 10.000 RPM) closer to the camera and the old engine/4 speed transaxle (51 HP in standard form @ 6100 RPM) in the back ground.

 

The electric motor/differential unit weighs 59.5 kg and the speed controller/inverter (not pictured) 17.5 kg. Don't need a lifting device to move this baby around.

 

Photo: first mock up. Small, don't you think?

 

The first mock up in my - and every performance minded engineer's - favorite configuration: mid motor.

Update March 25: Unfortunately I came one inch short of space; there is interference between the motor and shock absorber.

 

The inverter will probably be installed on rubber noise dampers underneath the parcel shelf by the rear window. This will hopefully dampen the very muffled whining sound that some people find annoying although I'm not sure the dampers will work on that relatively high frequency.

 

Baby blue drive shafts, springs, chock absorbers and trailing arms are the previous owner's choice. I might repaint these parts at a later stage, but for now the paint serves it's purpose; to prevent the parts from rusting.

 

Tonight I also removed some ICE related parts at the front that is no longer needed; namely 7.5 kg of radiator w/ Kenlowe electric cooling fan and 8 kg of stainless steel fuel tank.

 

March 15, 2010

 

Making new parts is best planned on paper first to discover possible problems. Left hand side only is sketched.

Attempt 1 is simple and straight forward, the sketch showing existing parts. A CV joint will be crafted to the drive shaft where there is an empty space. But the finished part will not be easy to install on the car.

 

Attempt 2 adds a coupling to the drive shaft making it more complex and expensive. But adding weight close to the road wheel is not so good for handling. And besides the coupling would occupy the same space as the chock absorber.

 

Attempt 3 seems to be the final, working solution. The original Ginetta drive shaft and rubber "donut" (see photo of February 11) will be kept and adapters for the Th!nk differential shaft is ordered from GKN Driveline Service.

 

April 16, 2010

 

 

Please ignore the date on the photo, I forgot to set the date on my new JWS DV873 digital camera/movie recorder. (Need to spend some time reading the manual.)

 

Test installing the drive shaft adapter. Unfortunately I was unable to get a better camera angle. You can barely see the adapter to the left of the donut. It fits perfectly as planned and installation is as easy as with the original engine.

 

June 10, 2010

 

A possible change of battery has gotten most of my attention the last few weeks. Some used Kokam 100Ah flat packs has surfaced. I've searched the web for info and found only a few vehicles that use Kokam.

http://www.proev.com/

 

has the most info.

 

New cell configuration has been worked out, battery boxes have been designed and the weight calculations are favorable. The big question is: What is a fair value for used cells?

 

July 20, 2010

 

Actual work on the conversion has been halted lately due to lack of information on what will be allowed by the authorities. I see no reason to make engine mounts if I don't know that it will be approved.

 

Tire choice has been on my mind for a while. On the Eco Modder forum http://ecomodder.com/ I found this interesting info:

" wind tunnel development work for Subaru XT show a drag increase of 5.1 % when tire size is increased from 155 to 185 series radials."

I need to reconsider my sequence of requirements. To achieve the desired top speed of 100 kph/56 MPH I need to increase the tire size to 165/80R13. If the wider tire means that much more drag (= shorter range) then may be I should keep the Th!nk 155/70R13 tires or even step down to Buddy's 145 mm width. Perhaps the bigger tires on the rear drive wheels and narrow ones for the front wheels?

August 11, 2010

Back to the drawing board. The Kokam cells are no longer available. Kokam would have given the best power and range. It's hard to settle for something less at this time.

 

May 13, 2011

 

In a recent meeting with American Car Club of Norway, Norwegian Motorcycle Union and Norwegian Association for Modified Vehicles the authorities have agreed that regulations for modified vehicles will be made. The regulations will be similar to the regulations in Sweden and the UK. Text in the link is in Norwegian.

http://www.amcar.no/page.asp?ParentID=313&MenuID=418&DocID=...

Great, that took only 11 months.

[Kenneth Webster]

That seems very strange with the relative weights of Thundersky modules. Get a move on and you can take part in that round the world in 80 days with/ against I`ll see if i can find out more. Electrolux.

[Tom Roy]

That is (was) the plan. Then I discovered that by using 44 pieces of 90 Ah Thunder Sky cells, the total allowed weight would be exceeded. Reducing the capacity to 60 Ah didn't take off as much weight as I expected. So I checked the data again and found that one 60 Ah cell weighs 2,5 kg. That's 76,8 Wh per kg. (I calculate 3,2 V nominal). One 90 Ah cell weighs 3,2 kg. That's 90 Wh per kg. One 100 Ah cell also weighs 3,2 kg. That's 100 Wh per kg. The smaller cells are relatively heavier than the larger ones. Can that possibly be correct? I've searched for confirmation of the data from Thunder Sky's web page, but have come up empty handed so far.

[Kenneth Webster]

You must increase the nominal voltage from 114V in the Think to something like 140V. The you will have some fun! I have driven a Think with a 140V lithium pack and it is noticably pokier. This lighter vehicle should be quite impressive. The Think 3 phase motor is rated for 120v but it seems to handle a bit extra.

[Tom Roy]

Yes, an El Rayo vs GinELla race would be interesting. With less weight and higher voltage for the Ginetta, the winner will be no surprise :-))

[Electric Aid]

Since you are making this with a Think City Classic drivetrain we could maybe do a mini episode - shootout between your El Rayo and This one once it is finished =)

[Tom Roy]

Thank you on behalf of the four Walklett brothers who engineered and designed the Ginetta, Domenick. I will have some photos taken during the conversion. Be patient, plans are to drive the fossil burner this summer and have some fun, maybe a track day or five, then convert the G15 next winter. Watch my first post for more photos added one by one.

[Domenick]

Very nice looking Ginetta indeed. Looks like the steering wheel is even on the left! A nice big gallery of photos would be appreciated.

[Tom Roy]

Thank you, Andrew,
I've already got a 2001 Th!nk drive train. Will go for ThunderSky LiFePO4 and BMS from http://www.co2-ausstieg.de/

[andrew richard rose]

Nice Choice Tom ,
Any idea who's drivechain you are going to use ? Azure Dynamics is good ,
also the company is very helpful , addressing questions and problems by return of email
even for us "little " people !