Hot-rodding the Toyota MGR

[thingstodo]

Originally Posted by e*clipse

First, I'd like to thank Thingtodo for the excellent description of how to properly connect wires in high-power applications. I'm just not sure of where to get a hydraulic crimper and what the taping procedure is about.

The tips are not mine. Our electricians contributed them. I will thank them.
I had asked for their tips for my own education some time ago

On e*bay, search "hydraulic cable crimper" and you should get a range of items .. from Chinese made crimpers that have dies that you change out manually (like the one I have) around 6 tons of pressure .. up through the more automatic crimpers that are name brand and use a rotating wheel to choose dies, in the 8 - 12 tons of pressure .. and finally to the crimpers that look like a cordless drill, choose your crimp size automagically, and power the crimp with a trigger ($$$)

Taping. The higher voltage tape (5000V and higher) is a specialty tape that is supposed to prevent corona (not the beer!) from forming around sharp edges of the lugs and bolts. The corona causes some sort of problem if it is not mitigated with tape.

For 1000V and under, electrical tape is used to prevent the connectors on the motor leads from touching each other and from touching the junction box or anything else. I end up using a bit of tape the first time, then pull it off to check the connections about a week later. After that check, bury the connections in a ball of tape.

[thingstodo]

Originally Posted by e*clipse

Here are some possibilities:
Enerdel 15Ah pouch cells rated at 15C discharge.
NEB 20Ah hybrid super-capacitor rated at 25C discharge
CALB 40Ah cells rated at 12C (torture tested on EV TV)
A123 20Ah pouch cells rated at 30C discharge
Nissan Leaf 23Ah (I think) cells rated at 8C discharge (This is cell, not module data)

If anyone has any more options, I'd love to hear about them.

CALB has a higher rated cell that is physically smaller and lighter. CAM72 is what they are called, I think. Price premium - just under $2 per a-h. But they take up less room and weigh less than the CA series. EVTV testing has gone up to 15C .. or was it 20C? Unless you are going to short circuit the batteries and weld with them, I don't think there is much difference? I guess the dragsters would notice the difference.

The web site for CALB lists a 25 a-h version but I have not seen one for sale so far.

Another link from EVTV

EVTV Motor Verks Store: 1 CALB CAM72FI LiFePo4 Cell, Lithium Battery Cells, CAM72FI

There is also a CAM80 which has a different form factor.

[freebeard]

Originally Posted by e*clipse

We'll use the 6.86:1 ratio of the MGR, and consider no weight or aerodynamic issues.
26" tires will allow a top speed of 115 mph, based only on the motor rpm limitation. However, reality is aerodynamic drag, friction, etc are working against hp that decreases from mid rpm > max rpm. The car will be power limited long before 115mph.
Personally, I don't see any use for increasing the tire diameter unless you find a way to dramatically reduce the aerodynamic drag or dramatically increase the power from the motor.

I found my way here from the Aerodynamics subforum. And this time next week I hope to be on The Salt for the 36hp Challenge. So I bring a perspective of self-imposing limitations, for the challenge. The record for a stock bodied 36hp Beetle is about 90mph, a belly-tank Lakester—about 129mph. So 68hp (as a base) is comfortable for me.

I'll start with a simple EV conversion; ultimately, with a 2nd MGR, I'd like to run a reverse tricycle belly-tank in the 130mph Club—probably the only class that would accept such a curious beast.

Here it is, dragging a fourth wheel to try to fit in better.

[4x4EV]

awesome, I have been watching these motors for a BMW rear wheel drive conversion, would leave tons of space under the hood for controller/computer/bms/batteries, good value compared to alternatives i have been looking at

[e*clipse]

Wholey ****e! That is REALLY cool!

I didn't know such a class existed - what an awesome idea!

Alrighty then; I stand very corrected - with a vehicle like THAT to wrap around the power plant. My numbers were merely for standard vehicles with standard frontal areas and standard Cd's.

With an open mind like that, there's a world of possibility. I'd love to keep in touch and see how the challenge went.

- E*clipse

Originally Posted by freebeard

I found my way here from the Aerodynamics subforum. And this time next week I hope to be on The Salt for the 36hp Challenge. So I bring a perspective of self-imposing limitations, for the challenge. The record for a stock bodied 36hp Beetle is about 90mph, a belly-tank Lakester—about 129mph. So 68hp (as a base) is comfortable for me.

I'll start with a simple EV conversion; ultimately, with a 2nd MGR, I'd like to run a reverse tricycle belly-tank in the 130mph Club—probably the only class that would accept such a curious beast.

Here it is, dragging a fourth wheel to try to fit in better.

[e*clipse]

I'm not too familiar with BMW back ends, but in general, these motors are not much larger than a standard rear differential. For my 1G Eclipse, I will be able to fit two motors in the back end (I've already removed the rear differential.) The motors will have to face backwards, necessitating some oil system mods.

You may want to consider the vehicle balance, and how you can creatively get it closer to 50:50. Most front motor cars are seriously weight biased toward the front. It's likely if you put the entire battery pack in the front, it will only get worse.

For example, on my Eclipse, the rear differential and driveshaft weighed 100lbs, exactly what one MGR weighs! Now, if I go with two MGR's in the rear, I've moved some of the weight biase toward the rear, but the battery is a pretty huge chunk. On the other hand, It might be possible to split the pack so that along with the additional electric motor weight in the back you could achieve a very nicely balanced car.

Originally Posted by 4x4EV

awesome, I have been watching these motors for a BMW rear wheel drive conversion, would leave tons of space under the hood for controller/computer/bms/batteries, good value compared to alternatives i have been looking at

[freebeard]

With a mind that open you never know what going to fall out. Here's the same design in a motor home size:



This could be built with 3 MGR, with welded spider gears, the wheel bolted/sprocketed to one output shaft and a emergency/parking disk brake on the other.

I'd love to keep in touch and see how the challenge went.

Oh, we will be talking again.

/my MGR still hasn't been delivered, but the shop's on notice I'll need the big orange cables/connector.

[e*clipse]

Great! I live for these sorts of competitions.

Also, I can show you some stuff I did for the super-milage vehicle competition. At the time, I had access to a wind tunnel and all the CNC time I wanted...

What do you plan to do for the power connector?

- E*clipse

Originally Posted by freebeard

Oh, we will be talking again.

/my MGR still hasn't been delivered, but the shop's on notice I'll need the big orange cables/connector.

[e*clipse]

Here's a post from another thread, but I think it will be happy here.

It's a cutaway of the MGR, and a great way to help make sense of all the pics I've posted.

[IMG][/IMG]

[4x4EV]

Why both in the back end? Put one for fwd in the front and rwd one in the back with the gears. Even weight close to direct drive awd or partial 4wd /2wd and shut off one or the other to conserve power