DIY Electric Car Forums banner
1 - 20 of 31 Posts

·
Registered
Joined
·
279 Posts
Discussion Starter · #1 ·
OK, I have my 2013 Leaf motor (complete package) and I was planning to make a DeDion system to adapt to my standard truck type transaxle (getting rid of the diff and most everything inboard of the leaf springs). The problem is that overall length of the leaf motor and axles is 68" and I have 48" between springs.

Either I cut off 10" from each half shaft to make it fit (just barely, and with little axle left to spare) or I look at removing the Leaf diff and put the motor directly onto my existing diff. The gear reduction on the leaf motor is around 8:1 (can't remember exactly off hand) and my current diff is 5.5:1.

Currently, I can get only 105KM/h from the truck and the leaf I think can do 150ish. The question is, what will the effect of changing the ratio have on this motor? Has anyone used the motor by itself or with a different reduction? The low end is where the effect will be felt.
 

·
Registered
Joined
·
6,526 Posts
Currently, I can get only 105KM/h from the truck and the leaf I think can do 150ish. The question is, what will the effect of changing the ratio have on this motor? Has anyone used the motor by itself or with a different reduction? The low end is where the effect will be felt.
The Leaf can do about 150 km/h, but I don't know if that is limited by power, or by the top speed of the motor and the gearing - whichever is the limit, it's probably close to the other limit as well. If it is power, the LT will be substantially slower (even with the same gearing and tire diameter) due to much higher aero drag.

If the Leaf is limited by top speed of the motor, then changing the gearing from 7.937:1 to 5.5:1 will mean that the motor never uses the top half of its speed range (since the top motor speed would correspond to 216 km with the same tire size, and its unlikely that the motor will have the power to do more than half that). That means that in most conditions the motor will be turning too slowly to produce the power it should.

The motor will be turning relatively slowly, which means that for a given power level (if it can be reached) the motor will be using more current at a lower voltage. I assume that means more heating, but it has liquid cooling to handle that.

Although I understand the packaging problem, this is definitely going the wrong direction in gearing, at least for performance.
 

·
Registered
Joined
·
279 Posts
Discussion Starter · #6 · (Edited)
The Leaf can do about 150 km/h, but I don't know if that is limited by power, or by the top speed of the motor and the gearing - whichever is the limit, it's probably close to the other limit as well. If it is power, the LT will be substantially slower (even with the same gearing and tire diameter) due to much higher aero drag.

If the Leaf is limited by top speed of the motor, then changing the gearing from 7.937:1 to 5.5:1 will mean that the motor never uses the top half of its speed range (since the top motor speed would correspond to 216 km with the same tire size, and its unlikely that the motor will have the power to do more than half that). That means that in most conditions the motor will be turning too slowly to produce the power it should.

The motor will be turning relatively slowly, which means that for a given power level (if it can be reached) the motor will be using more current at a lower voltage. I assume that means more heating, but it has liquid cooling to handle that.

Although I understand the packaging problem, this is definitely going the wrong direction in gearing, at least for performance.
Yes, that is what I was concerned about. It is a question of performance at the much lower RPM and longevity that I am concerned about. It is a truck and I do want to use it to pull a trailer so I am concerned about temp and watts used. I would like to get to 120km/h but I don't need anything more than that
 

·
Registered
Joined
·
6,526 Posts

·
Registered
Joined
·
823 Posts

·
Administrator
Joined
·
6,310 Posts
Hi Canada

I would be looking at your first option - the DeDion - IMHO moving suspension bits like springs and spring mounts is a LOT easier than changing dynamic bits that have oil in them like reduction gears and motors

I would be looking to use the Leaf motor/reduction/diff as a unit

Have you looked at stuffing the whole Leaf front suspension in there?
 

·
Registered
Joined
·
823 Posts
If you were going with a de Dion or fully independent, instead of cutting-up the existing axle ends(of the VW), I would use something like these self-contained hubs: https://www.hendersonbearings.co.uk...-hub-with-from-2010-with-abs-encoder-pfi.html
These are the stock Leaf front hubs. There're probably too light-duty for your app. Heavier duty units are available from other vehicles. Check units from the IRS of large Nissan or Toyota SUVs. If your lucky, the splines will match and be the right length. If not, you'll have to do some mixing and matching of half-shaft ends or some cutting and welding of half-shafts.
 

·
Registered
Joined
·
6,526 Posts
I was referring to the existing axle, what he refers to as a transaxle? A transaxle being a transmission and axle combined- that apparently this is not.
I assume that he just meant "axle" - the truck's existing system is a conventional longitudinal front-engine rear-drive layout, with the transmission up front, separate from the live beam axle with differential in the rear. The only transaxle in discussion is the stock Leaf unit, which is a single-speed transverse transmission with integral differential.

The plan is - or was - to use the Leaf motor with its transaxle at the rear, driving the rear wheels in a de Dion setup.
 

·
Registered
Joined
·
6,526 Posts
I would be looking at your first option - the DeDion - IMHO moving suspension bits like springs and spring mounts is a LOT easier than changing dynamic bits that have oil in them like reduction gears and motors
The advantage of the de Dion is actually in not changing springs and spring mounts. I agree that it would likely be easier to fabricate suspension than to fabricate jointed shafts to work with the current semi-floating live axle.

Have you looked at stuffing the whole Leaf front suspension in there?
Although the truck is to be lightly loaded, it's still a truck - wider than the Leaf and likely heavier when loaded. The Leaf only has a 2167 pound gross axle weight rating (front). Also, the Leaf has a strut suspension which is likely too tall to fit under the cargo bed.

If you were going with a de Dion or fully independent, instead of cutting-up the existing axle ends(of the VW), I would use something like these self-contained hubs: https://www.hendersonbearings.co.uk...-hub-with-from-2010-with-abs-encoder-pfi.html
These are the stock Leaf front hubs. There probable too light-duty for your app. Heavier duty units are available from other vehicles. Check units from the IRS of large Nissan or Toyota SUVs. If your lucky, the splines will match and be the right length. If not, you'll have to do some mixing and matching of half-shaft ends or some cutting and welding of half-shafts.
We started into this in the original thread. While this thread is about using the LT's original live beam axle because the de Dion conversion isn't looking workable, full-floating hubs (instead of adapting the current hubs) could make the de Dion setup (or an independent suspension) viable.

The Ford Ranger EV is a precedent for using none of the original axle parts, but mounting to the stock spring mounts (and possibly with the stock leaf springs), in a de Dion system with transverse motor in the EV conversion of a vehicle which originally had a live beam axle.

Fitting independent rear suspension in vehicles that had a live beam axle is relatively common among major customization projects. Often a complete system from an existing vehicle is used; logically for the LT this would likely be from a larger SUV or large sedan. The keys are to
  • match track width
  • keep the suspension package low
  • find a system which is mounted with a subframe which can be modified to suit the truck's structure
  • match weight capacity
Usually the availability of a strong enough final drive is a factor, but in the case the Leaf motor and transaxle would be used instead... and fitting that in is another major factor (usually only a narrow final drive is involved).

Even with a complete independent suspension, adapting axles will still be required - nothing is likely to match the Leaf axle shafts.

One annoyance of this sort of conversion is that nothing suitable is likely to come with hubs that fit the VW wheels, which means either
  1. modifying the new rear hubs,
  2. modifying the original front hubs to match the new rears, or
  3. having different wheels front and rear (and thus two spares or a spare that only fits one end).
 

·
Administrator
Joined
·
6,310 Posts
Although the truck is to be lightly loaded, it's still a truck - wider than the Leaf and likely heavier when loaded. The Leaf only has a 2167 pound gross axle weight rating (front). Also, the Leaf has a strut suspension which is likely too tall to fit under the cargo bed.

Disagree
You already have to have enough vertical height for the motor (and invertor) the struts are about the same height

As far as the load carrying capacity is concerned you can upgrade the springs easily enough and the rest of it will be strong enough - if you decide any bits are a bit weak then beef them up!

Much easier and probably stronger than using the VW bits
 

·
Registered
Joined
·
279 Posts
Discussion Starter · #20 · (Edited)
Hi Canada

I would be looking at your first option - the DeDion - IMHO moving suspension bits like springs and spring mounts is a LOT easier than changing dynamic bits that have oil in them like reduction gears and motors

I would be looking to use the Leaf motor/reduction/diff as a unit

Have you looked at stuffing the whole Leaf front suspension in there?
Hi Duncan,
I had originally looked at stuffing the the Leaf system in the front but the way the LT is designed, the ICE sits directly between the front seats and just above a massive cross member, all of which is right between the wheel hubs. There would need to be massive suspension changes and structure changes to use it as is. I wish I could because I really don't like rear drive for trucks. I had a front drive VW T4 (eurovan transporter for those in North America) and it was one of the best designed vans I ever drove. Snow never stopped it at all. One bit of ice under the the rear wheel of this truck stops it dead. No LSD.

I have the complete motor and shafts plus the complete wiring harness and computer system etc but no other body components. I assume the ABS sensor and plugs from the Navaro the same as the leaf so, if the hub fits, it may be a good solution. I then just have to figure out the suspension. Given the way the motor mounts are made, the DeDion is the most logical attachment.
 
1 - 20 of 31 Posts
Top