On 18 Oct 2016 at 13:36, EVDL Administrator via EV wrote:

> I want to connect the electric motor directly to the rear
> differential. 

Jettas don't have rear differentials, do they?  Has VW ever made a 4WD 
Jetta?  I'm not aware of one, but then I don't follow VW.

If not, are you planning to fit a rear axle from another car?  Do you know 
which one yet?  Just curious.

Unless you can find a very low (high numeric ratio) rear end, you'll need a 
large, high torque, low speed motor to drive the axle directly.  You'll 
almost certainly have to carve out extra room under the rear seat floor or 
under the trunk to fit the motor.  There goes your nice flat front wheel 
drive floor.  And that big of a motor is going to cost you.  (I don't think 
the AC-75 you mentioned before is going to cut it.)

To get acceptable acceleration, you'll also need a high current controller 
and a battery capable of supplying that current.  These are not cheap items 

You'll have to give up at least the trunk, and probably also the back seat, 
for the battery.  Batteries capable of delivering the kind of current a 
direct drive system needs in a 3500lb car tend to be big, expensive, or 

I think I see what you're trying to do by idling the ICE in EV mode -- that 
way you don't have to deal with driving the power steering, providing vacuum 
for the power brakes, keeping the house battery charged, or even running the 
aircon compressor if you're so inclined.  The problem is that you're still 
burning fuel in EV mode.  One of the big efficiency advantages of EVs is 
that they don't have to idle, and you'd be giving that up.

I also don't think you'll gain anything by adding a generator to the engine 
for traction battery charging (if that's what you mean).  That will just 
lose you more efficiency.  It was possible to make it a net gain with 1960s 
vintage carbureted engines, but modern electronic ICE control is much more 

I've heard of reasonably successful projects like what you're proposing, but 
they had the goal of boosting the car's acceleration with the motor.  They 
didn't try to run it as a pure EV, at least not to any significant extent. I 
vaguely recall someone posting here years ago about doing a 4WD Subaru Justy 
that way.

If you want a true hybrid that you can drive as an EV until the battery is 
flat, then run as an ICEV -- may I suggest that you look into used Chevrolet 
Volts?  I see three 2013s on Ebay right now, all under $20k.  You might be 
money ahead -- it's not at all difficult to get into that range when 
converting, and when you're done, your conversion will have a depressingly 
low resale value.

David Roden - Akron, Ohio, USA
EVDL Administrator

= = = = = = = = = = = = = = = = = = = = = = = = = = = = =
EVDL Information: http://www.evdl.org/help/
= = = = = = = = = = = = = = = = = = = = = = = = = = = = = 
Note: mail sent to "evpost" and "etpost" addresses will not 
reach me.  To send a private message, please obtain my 
email address from the webpage http://www.evdl.org/help/ .
= = = = = = = = = = = = = = = = = = = = = = = = = = = = =

UNSUBSCRIBE: http://www.evdl.org/help/index.html#usub
Read EVAngel's EV News at http://evdl.org/evln/
Please discuss EV drag racing at NEDRA (http://groups.yahoo.com/group/NEDRA)

Reply via email to