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Discussion Starter · #1 ·
So I currently have a 2007 Lamborghini Gallardo rolling chassis with the factory Graziano transaxle. I recently started toying with the idea of an EV conversion, but am starting to get overwhelmed by all of the information/possibilities. I have a fair bit of diy experience with ICEs but EV's are new to me. My main goals are:

-Keep costs as low as possible. I plan on doing most of the work, but may have someone help with welding/fabrication of motor mounts.

-0-60 time somewhere between stock (about 4 sec) and 3 seconds.

-Top speed around 80-100

-Battery life between 20-50 miles

-Not concerned with accessories at the moment. I plan to get to ac, brakes, steering, electronics eventually but really just want to keep things simple for now.

I was thinking of hooking up a tesla drive unit directly to the cv axles, or keeping the Graxiano transaxle and coupling a motor to the input shaft. If anyone could recommend a motor/battery/controller that would work with my goals/expectations, that would be a huge help.

Additional info about the car that may help:

Curb weight approximately 3500lbs (Estimating about 2800 with engine, fuel tanks, exhaust removed.

Tire size is 295/30/19
(Diameter is 25.97)

The gear ratios for the transaxle are:

Gears ratios: I 16/41 (2.563), II 20/37 (1.850), III 26/37 (1.423),
IV 29/33 (1.138), V 33/31 (0.939), VI 36/29(0.806)
RM 16/45 (2.813); PTO DROP 22/31 (1.409),
pinion DROP 25/31 (1.240)

Total ratios: I=9.777, II=7.058, III=5.430, IV=4.342, V=3.584,
VI=3.074; REV=10.731
 

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Your 0-60 will be in 1st gear, so that says, if your tires can hook up, you get 0-60 in ~3s with a 315ftlb (2.75s with 350 ftlb) motor if you can keep the weight down to no more than 600lb for the pack. Given your reasonable range expectations, doing the numbers in my head say you can get there.

Top speed is determined by HP.
 

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This could win for highest original retail price of a car converted in this forum :)

I was thinking of hooking up a tesla drive unit directly to the cv axles, or keeping the Graxiano transaxle and coupling a motor to the input shaft.
Either approach can work. I assume that what you want to achieve by keeping the original transaxle is the AWD, with a single motor (most Gallardo variants are AWD). Almost no production EVs use a multi-speed transmission; the notable exception is the Porsche Taycan which has a two-speed rear transaxle to provide greater reduction for higher performance at low speed and less reduction to allow a higher top speed without exceeding the motor's limit.

The Graziano (which is probably the L140 model) might be of significant value (several thousand dollars in the U.S.) if sold, since it is usable as a replacement part in both the Gallardo and the Audi R8, and can be used in various mid-engine kit cars (Factory Five GTM, various Superlite models, etc).

As is always the case, the stock ratios in the Graziano are not great for any modern high-voltage motor: even first gear is not low enough, and the top gear or two are pointless. There are different ratios available, but changing them could be very expensive.

The drop gear set (which transfers from the driven shaft to the pinion shaft, so this is what you're calling "pinion drop") is replaceable to shift all of the ratios, but unfortunately the replacement ratios are generally taller (for higher top speed, or to better suit GM V8's instead of the Audi/Lamborghini engine), and you would want much shorter. I note that you list 1.240:1 as the drop gear ratio, but HCF Auto Parts lists 1.32:1 as stock... there are gearing variations in this transmission, and the 1.32:1 drop is part of other gear sets, such as the later Gallardo LP and at least some Audi R8s. Also, you didn't mention the final drive ratio (ring and pinion), but that appears to be 3.077:1... perhaps 40/13.

If it is turns out to good for nothing else, sorting this out has been an interesting education in this Graziano transaxle. :)
 

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Your 0-60 will be in 1st gear, so that says, if your tires can hook up, you get 0-60 in ~3s with a 315ftlb (2.75s with 350 ftlb) motor if you can keep the weight down to no more than 600lb for the pack.
The pack... and the motor and inverter and everything else?
 

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Motor is only 100lb. Bolt it to the transaxle. Run the car in 1st gear most of the time, higher gear on highway and for top speed.

He's sub 100 mile range, so...yes on the weight of inverter & pack.

Sports car - keep the weight & balance near stock or might as well sell that Lambo roller to me and do a C10 pickup truck.
 

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Discussion Starter · #7 ·
This could win for highest original retail price of a car converted in this forum :)


Either approach can work. I assume that what you want to achieve by keeping the original transaxle is the AWD, with a single motor (most Gallardo variants are AWD). Almost no production EVs use a multi-speed transmission; the notable exception is the Porsche Taycan which has a two-speed rear transaxle to provide greater reduction for higher performance at low speed and less reduction to allow a higher top speed without exceeding the motor's limit.

The Graziano (which is probably the L140 model) might be of significant value (several thousand dollars in the U.S.) if sold, since it is usable as a replacement part in both the Gallardo and the Audi R8, and can be used in various mid-engine kit cars (Factory Five GTM, various Superlite models, etc).

As is always the case, the stock ratios in the Graziano are not great for any modern high-voltage motor: even first gear is not low enough, and the top gear or two are pointless. There are different ratios available, but changing them could be very expensive.

The drop gear set (which transfers from the driven shaft to the pinion shaft, so this is what you're calling "pinion drop") is replaceable to shift all of the ratios, but unfortunately the replacement ratios are generally taller (for higher top speed, or to better suit GM V8's instead of the Audi/Lamborghini engine), and you would want much shorter. I note that you list 1.240:1 as the drop gear ratio, but HCF Auto Parts lists 1.32:1 as stock... there are gearing variations in this transmission, and the 1.32:1 drop is part of other gear sets, such as the later Gallardo LP and at least some Audi R8s. Also, you didn't mention the final drive ratio (ring and pinion), but that appears to be 3.077:1... perhaps 40/13.

If it is turns out to good for nothing else, sorting this out has been an interesting education in this Graziano transaxle. :)
Yeah, i guess the main reason for wanting to keep the graziano is to keep it simple. Ive seen the lovejoy couplers that connect the electric motor to the input shaft. The cv shaft flanges that connect to the graziano don't seem to be a standard Audi part like everything else and the cost of new custom length axles were pretty steep (about 2k vs $100 coupler). I suppose that could be offset with the sale of the transaxle though. I see them going for around $8,000 on ebay. Part of me does want to hang on to it though as I want to leave the door open for putting an ICE back in. At the moment, the 5.0 v10 is hard to find and a new one costs about what I paid for the car.
 

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Discussion Starter · #10 ·
I may go with a tesla drive unit after all. I made a cardboard template of the dimensions and it fits quite nicely. Looks like I would just need to mount it and make the cv axles and/or flanges longer. Is the tesla unit worth it in terms of cost/benefit compared to other motors like netgain? Are there any other production ev motors that might meet most or all of my criteria?
 

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I don't know anything about them, but one shop that specializes in Graziano transaxles offers custom axles:
HCF Autosport - Graziano L140 products (see "Custom Axles")

In this case you would want the normal Gallardo outer joints with inner joints adapted to the EV transaxle, which is the reverse of what they usually do (normal Graziano inner joint with outer joints adapted to some vehicle), but in this case the same type of joints are used at both ends. It's basically a matter of either adapting the Tesla output stubs to this style of CV joints and making up the right length of shaft, or making a shaft which fits the Gallardo outer joint at one end and the Tesla inner joint at the other end.
 

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Leaf motor would do it for a lot less money, though torque would be limited to 210 ft-lb without a custom controller board for the inverter.

The tricky bit in either case is getting enough battery modules in the car to get the voltage high enough for an OEM motor, and to get the power out of the batteries. Motor torque is usually limited by how much juice the batteries can provide when you put your foot down.

I got my axles here:


They were about $1500. Some people cut, sleeve, and weld two sets of axles (one from the electric motor's gearbox and the other from the stock car's gearbox).
 

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Discussion Starter · #15 ·
I don't think the axles will be as big of a deal as I thought. So far im looking at buying

-Tesla conversion kit (comes w/ tesla S motor, drive unit controller, accelerator pedal, wiring)
-2 Chevy volt batteries
-Custom axles
-Charger

Any other high dollar items (over $1000) that im missing so far?
 

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DC/DC converter, BMS, charge controller.

If you mean 2 Chevy Volt battery packs, is there space? If you mean 2 Chevy Volt modules...You're gonna need a lot more battery.
 

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So I currently have a 2007 Lamborghini Gallardo rolling chassis with the factory Graziano transaxle. I recently started toying with the idea of an EV conversion, but am starting to get overwhelmed by all of the information/possibilities. I have a fair bit of diy experience with ICEs but EV's are new to me. My main goals are:

-Keep costs as low as possible. I plan on doing most of the work, but may have someone help with welding/fabrication of motor mounts.

-0-60 time somewhere between stock (about 4 sec) and 3 seconds.

-Top speed around 80-100

-Battery life between 20-50 miles

-Not concerned with accessories at the moment. I plan to get to ac, brakes, steering, electronics eventually but really just want to keep things simple for now.

I was thinking of hooking up a tesla drive unit directly to the cv axles, or keeping the Graxiano transaxle and coupling a motor to the input shaft. If anyone could recommend a motor/battery/controller that would work with my goals/expectations, that would be a huge help.

Additional info about the car that may help:

Curb weight approximately 3500lbs (Estimating about 2800 with engine, fuel tanks, exhaust removed.

Tire size is 295/30/19
(Diameter is 25.97)

The gear ratios for the transaxle are:

Gears ratios: I 16/41 (2.563), II 20/37 (1.850), III 26/37 (1.423),
IV 29/33 (1.138), V 33/31 (0.939), VI 36/29(0.806)
RM 16/45 (2.813); PTO DROP 22/31 (1.409),
pinion DROP 25/31 (1.240)

Total ratios: I=9.777, II=7.058, III=5.430, IV=4.342, V=3.584,
VI=3.074; REV=10.731
You may want to do the exotic car a favor and use solid state batteries. They are half the weight and last many years. They also fast charge and fast discharge. They also will not need much battery management, due to no heat developed, when charging or discharging. They will be out there, in a couple of years or use the latest Tesla Panasonic batteries.
 

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I think a Tesla Large Drive Unit is the way to go on this project. A base unit will put out 450 hp out of the box, which will give you the 0-60 number you are looking for and a higher top end speed.

In the space of that cardboard cutout there is a super powerful OEM motor, controller AND transaxle all wrapped up in a single unit, you can't get more simple than that.

A single Volt Battery pack will get you the range you want at a cost of about $3K and will weigh about 350 lbs.

> Any other high dollar items (over $1000) that im missing so far?
As Tremelune mentioned, the BMS can be expensive. I went the route of Orion (from StealthEV) and one of their integrated charger/DC-DC converters. So including a Performance Tesla Large Drive, BMS, Charger and all the other goodies StealthEV sells I was at $14K. add $3K for the batteries, and I think all the large expenses are covered. Its all high end stuff, but for goodness sake, that's a Lambo sitting in your garage. The car is awesome, so make the drivetrain awesome too. (please don't put a leaf drive in it.)

You could cut some corners and buy an eBay drive and add your own controller, but for me, doing my first conversion, it seemed smart to buy a 'kit' that provides some level of support.

Good luck and keep us posted, that's an awesome project!
 
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