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My Smart fortwo use a VW golf transmission without clutch and I can drive only in third gear from 0 to 100 km/h.
If the operating range of the motor is wide enough, driving in a single gear is practical... after all, that's how production EVs work. If the transmission is not shifted while driving (because one of the stock gear ratios - presumably first or second - is suitable), the clutch is not required... and without the clutch, the flywheel is also not needed.
 

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Motor:
FIMEA Engineering N50D1, 15KW @96V, 140 Nm of torque, 7500 rpm max.
I found a manufacturer's web page for the N50 motor series, but it's short on information. Do you have any performance curves, showing how available torque or power varies with speed, at your design voltage? The rated power values at all voltages and speeds correspond to torque well below the stated maximum torque, so it's not clear if the power is continuous and the torque is for a brief period, or the torque peak is at a much lower speed, or what is going on.

It does look like a heavy motor for the power, perhaps only because it doesn't (in the base form) have any forced cooling. It should be possible to use a smaller motor with forced cooling; if a suitable motor is more powerful than desired, it should be possible to limit the power to suit legal requirements by a controller setting.
 

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With that nearly flat engine-side housing plate (where there would normally be a cast extension of the housing or a bolt-on bellhousing), the transaxle certainly is unusual... but this design is so old that the conventional layout was not yet well established. This feature does raise the possibility of replacing that plate with a custom mounting plate for the motor (and a clutch if desired).

The transaxle's input shaft presumably protrudes a substantial distance beyond the housing, to reach into the clutch hub. That means that any motor mounting needs to include a spacer (a function normally provided by the bellhousing), unless the motor has a hollow shaft allowing the motor to mount over the shaft instead of beyond it. YASA makes motors which would fit well, but they don't have anything small... their P400 is much more powerful (and therefore expensive) than required.
 

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... in addition to the strict power requirements, the vechicle testing department of my local authority also requests the motor to come with full documentation on CE-certification, EMV compliance and so on. This rules out all the likes of e.g. HPEVS motors, which would be much lighter. The Fimea motor has been successfully used here, e.g. in the conversion of a Mini, and are therefore certified to be used as traction/conversion motors.
That's certainly an important factor. :)

As it is mounted in the back of the car, the cooling could be a bit of an issue, so maybe it's not even the worst option even seen from that angle.
Given the desire to stay close to original where practical, I assumed that you would place any required radiator (whether it is cooling the battery, inverter, or motor) in roughly the same location as the original radiator, which appears to be over the axle. The complete electric powertrain should need less cooling than the original engine.
 

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For the clutch bell housing I am currently working on the CAD for the transfer case between the motor and the gearbox. Will also share it here asap to get your thoughts on it.
Btw - this is the front side view of the actual gearbox with the protruding input shaft...
It really does look like a typical transmission, but with no bell housing installed. Fascinating...

If you don't modify the input shaft, its length plus the length of shaft protruding from the motor sets the minimum length of the bell housing / spacer required, and a flywheel will add to that.

If you don't need a clutch, and if you are willing to modify the transaxle input shaft, and if the input shaft doesn't need support at the end... you could cut off much of the protruding shaft length and build a coupler which goes onto the remaining splines, reducing the length of the housing and how far back the motor must sit.
 

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With that nearly flat engine-side housing plate (where there would normally be a cast extension of the housing or a bolt-on bellhousing), the transaxle certainly is unusual...
This feature does raise the possibility of replacing that plate with a custom mounting plate for the motor (and a clutch if desired).
Btw - this is the front side view of the actual gearbox with the protruding input shaft...
So it looks like the sensible plan would be to design the bell housing or other extension to seat on the machined face and bolt through the provided holes (where the engine bolts to), leaving the transaxle case intact... especially if you're operating a clutch, but even if eliminating the clutch and thus not needing the throwout bearing and fork.
 

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The great length of the non-splined part of the transaxle input shaft suggests that it does need support - presumably from a very long or very deep-set spigot bearing in the end of the crankshaft.
Yes, there's a good chance of that, but it's also possible that it only needs support if the is the clutch disk hanging on it.

An internal drawing of the transaxle would help.
 

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My plan is to build a transfer case to house the flywheel and the clutch assembly.
The transfer case would consist of two round aluminium adapter plates (not sure yet of the required thickness, I started with 15 mm for now), each plate with the specific bolts (for gearbox or motor respectively) on an inner ring and the holes for connection bolts on an outer ring. I would like to mount the gearbox-side adapter plate on top of the existing machined cover as seen on the previous picture.

In between the two adapter plates I would insert a cylindrical tube of 5mm Aluminium, held in place by a milled groove on the inside of the two adapter rings, and bolt everything together on the outer rings.i
That looks to me like it should work (as long as the bolts don't interfere with the transaxle housing); an alternative would be to use weld the adapter plates to the tube... skipping the clamping bolts entirely. For this welded fabrication to work, one set of bolts (presumably the ones on the transaxle side) would need to be accessible outside of the tube; if both sets of bolts (into the motor and into the transaxle) are inside the tube, then it must be a two-piece housing to be able to assemble everything.
 

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Are there standard boxes for Tesla modules available or do I need to design them from scratch too?
I think you're starting from scratch. Although Tesla (like every other EV manufacturer) sees the need for an extensive and substantial enclosure, many DIY builders think the plastic cases on the modules are fine, so they don't put in them in a proper enclosure... there's not even agreement on what level of enclosure is needed, so with every conversion having different packaging requirements, there's no market for a standardized enclosure.
 

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I have 1980 Renault le car (lecric leopard)

It has torsion bar suspension as i believe yours dose...
I don't think the Renault 4CV has any suspension parts in common with a Renault 5 / LeCar; you're probably thinking of the Renault 4, which is much like a 5 / LeCar but very different from a 4CV.
 

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I can see that you seem to have a great knowledge in EV conversion there, and you got me intrigued: Would you like to share the link to your projects with me so I can have a look at your own stuff too?
Electric cars are just the latest variation of my area of personal interest, which is vehicles in general; it's also an overlap with my technical background. Being curious, I have looked into the mechanical and electrical power solutions in many different EVs and plans for conversions... but I haven't converted even one myself.

I started in this forum because I need to replace the engine in our Triumph Spitfire, and was considering an EV conversion (rather than just an engine rebuild or swap, which I've done with other vehicles). I learned a lot about the options... enough to decide not to do it! Seriously, there are some good Spitfire conversions in this forum, but there are also lots of reasons not to do this, at least for my situation. I do have a plan for the Spitfire (with a Chevrolet Spark EV motor), but it is unlikely to be executed at this point, for various reasons.

People come into EV conversion with many different backgrounds, from being able to build electronics and program embedded computer systems but having no idea how anything in a car works, to being able to rebuild an entire car but having no idea about concepts such as current, voltage, power, and energy. Some are very knowledgeable in a single brand or type of hardware but seem unaware of alternatives. I think an important function of the forum is to help fill in the blank areas.

For me, these conversion planning discussions are a great opportunity to learn something new. For instance, I was familiar with the general layout of the early rear-engine Renaults, but I didn't know about the truly bizarre choice of rear suspension (the swing tubes or "trumpet castings" as very narrow-based arms) until I looked at it more closely for this thread.
 

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... As you guessed, there is a pilot bearing/bushing on the crankshaft side holding the whole lengtht (about 30mm) of the non-splined part of the input shaft.
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In my understanding I will need to include some sort of a similar bearing/bushing on a coupler between the motor output shaft and the flywheel in order to support the input shaft. Do you agree?
Yes, with a clutch on the input shaft that support should definitely be provided.

Thanks for the photo, which is a reminder of how small this car is... the crankshaft flange and main bearing housing look like something sized for a lawn tractor, rather than a car. :D The principles are all the same, though, including that the flywheel bolts onto the flange as with any typical car.

Usually the centre of the crank flange includes a boss so that the face of the pilot bearing is closer to the clutch than the bolting face. In this case, it is actually a bit recessed, which may explain why the end of the input shaft is unusually long... to reach the pilot bore. It doesn't look like there's a (needle) bearing in there, so I assume that it just has a bronze bushing.
 

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R4/5 suspension sidetrack

I have quite a collection of different Renault vehicles, from 1924 to today! So eventually I might be able to introduce a few of my other cars too - and having said that I can include the picture of another car of mine today in answer to the question of member @swo regarding the torsion bars. Brian is of course right that the 4CV and R4 have nothing (or, let's say, not much) to do with each other. They are a few years apart, in between them there's even another car: The Dauphine.
The naming can be misleading, which is what tripped up swo. The 4CV (like the better-known 2CV and a bunch of larger cars I had never heard of) is from Renault's era of naming by nominal horsepower; the Renault 4 is from a later era of numerically-named models which started in 1961 (oddly, apparently with the "3").

Mechanically, the 4CV is one of the rear-engine cars, and the 4 and 5 are the later front-engine style. The design differences go far beyond the engine placement, so there will be little if anything in common. The 4 and 5, on the other hand, are similar to each other.

Regarding the torsion bars I will need to check the workshop manual. I might even have the one of the R5 somewhere in my office.
I think the Renault 5 is fascinating, because of the unusual engine placement for a front-wheel-drive vehicle (behind the front axle and transaxle), the novel rear suspension configuration (one side is ahead of the other, to allow for long lateral torsion bars), and the car is the basis for the awesome mid-engine R5 Turbo. But I've never worked on one. I thought I might find the front torsion bar adjustment in a quick web search; I didn't find anything clear, but it looks like it might be necessary to push the bars out of their splined sockets and re-insert them after rotation by a spline tooth or two to change height. Too bad if that's the case - I was expecting something like my 1985 Honda CRX, with adjustable bolts on the levers at the bar anchors.
 

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swo, would you be willing to start a separate thread about the R5? There's some interesting discussion there, but it's really not related to Remi's 4CV. I'll keep some notes about the issues that you've raised.
 

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Yea be great to have le car/ r5/ lectric leopard
Thread going
Not sure how to do that
Thank you
If you are using the regular web browser view of the forum, go to the All EV Conversions and Builds section, click the Forum Tools dropdown, and then click on Post a New Thread.

There will be something similar in the mobile view.

An administrator or moderator could also move the relevant posts from this thread to a new one, but there's no need to ask for that and it's always a bit difficult to decide which posts should move.
 
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