Giving it a Jolt

jc_chandler

Member
CJ-8.com Member
City
Denver
State
CO
#61
Everything I've read has said that you want to match the factory weight distribution as close as possible, so my thought is that 3 in the back and 4 up front would be the way to go. I could be wrong but I highly doubt an extra 45 pounds in the rear would noticeably impact handling, especially given that the lighter 4cyl engine weighed 375 lbs according to google. I'd also think that if you have to go a bit over it'd be better to do that on the side where the power meets the road. You could get slightly stiffer shocks in the rear too. Just my :twocents:.
 

timo439

Scrambler Junkie
LIFETIME
CJ-8.com Member
City
Portsmouth
State
NH
#62
Thanks man, in general I agree that targeting stock distribution is best but there is also an element of optimizing because the conversion creates flexibility that is not available with the dead weight of an ICE. In the case of a Scrambler, I have noticed how much more solid handling feels when I have a full tank of gas. If I base weight distribution on this, I should have a consistent feel (definitely not looking to corner like a Porsche).
 

timo439

Scrambler Junkie
LIFETIME
CJ-8.com Member
City
Portsmouth
State
NH
#63
Dash back on. New harness, new radio, battery monitor in. Not happy with the look but I’m focusing on function before form to prove it all works. I’ll make it pretty later.
More progress soon. Waiting on parts, still...

BTW, getting the dash in and connected sucks.
5AE7830B-0811-420C-AD68-A7F558DBEE76.jpeg
 

Kane

CJ-8 Member
CJ-8.com Member
City
Berlin
State
ct
#69
So I have a question. since it seams you are keeping the transmission do you plan to shift it like a combustion engine? If so how are you handling the motor rpm drop when you let off the pedal to change gears? Combustion engines hang near the rpm when shift but I am guessing the electric motor would drop of very quickly and then we you hit the pedal again after the shift the whole truck would lurch and jerk around.
 

93_Fummins

CJ-8 Member
CJ-8.com Member
City
Edmond
State
OK
#70
So I have a question. since it seams you are keeping the transmission do you plan to shift it like a combustion engine? If so how are you handling the motor rpm drop when you let off the pedal to change gears? Combustion engines hang near the rpm when shift but I am guessing the electric motor would drop of very quickly and then we you hit the pedal again after the shift the whole truck would lurch and jerk around.
Just shift it like a non-synchro'd trans and rev match with your right foot.

"Pfft! Granny shifting, not double clutching like you should....."
 
City
Halifax
State
UK
#71
As its an electric motor then correctly controlled it should be constant torque and not need a gearbox at all, but i guess its going to need the transfer box for four wheel drive.

I am quite interested in this conversion, electric vehicles are the future but how far in the future is open to debate...
 

barrys

Scrambler Junkie
LIFETIME
CJ-8.com Member
City
East Norriton
State
PA
#72
Just shift it like a non-synchro'd trans and rev match with your right foot.

"Pfft! Granny shifting, not double clutching like you should....."
All right Dom.
I hate when I get in my CJ7 and forgot that I am not driving my a work truck where usually only use the clutch when starting from a stop. For those that don't know, big trucks/tractor trailer, etc with manual transmissions don't usually require using the clutch when shifting the tranny.
 

93_Fummins

CJ-8 Member
CJ-8.com Member
City
Edmond
State
OK
#73
So I have a question. since it seams you are keeping the transmission do you plan to shift it like a combustion engine? If so how are you handling the motor rpm drop when you let off the pedal to change gears? Combustion engines hang near the rpm when shift but I am guessing the electric motor would drop of very quickly and then we you hit the pedal again after the shift the whole truck would lurch and jerk around.
So, I thought about this one some more, and I believe it would depend on how the motor is coupled to the transmission. For a clutch to exist, a flywheel and pressure plate has to exist, and the flywheel will have inertia that keeps it going (assuming there is no motor braking circuitry function) thus it should still decelerate slowly enough to allow for engagement without too much rock/jump.

However, if it's direct coupled, I fear for the over-amperage breakage that could occur, but also refer back to my throttle synchronization comment.
 

93_Fummins

CJ-8 Member
CJ-8.com Member
City
Edmond
State
OK
#74
As its an electric motor then correctly controlled it should be constant torque and not need a gearbox at all, but i guess its going to need the transfer box for four wheel drive.

I am quite interested in this conversion, electric vehicles are the future but how far in the future is open to debate...
Gearboxes are actually greatly beneficial to electric motor setups because it allows for a smaller motor to be specified and less peak amps needed. In direct drive situations, there's a lot of amperage drawn to torque past the startup inertia and then amperage goes down as you get moving resulting in a theoretically grossly oversized motor once at speed. With a gearbox, you can spec a lower overall peak amperage/torque input since the gearbox is a torque multiplier that assists in overcoming the startup inertia. Or something to that effect...I'm mechanically minded, not electrically wired.
 

Kane

CJ-8 Member
CJ-8.com Member
City
Berlin
State
ct
#75
So, I thought about this one some more, and I believe it would depend on how the motor is coupled to the transmission. For a clutch to exist, a flywheel and pressure plate has to exist, and the flywheel will have inertia that keeps it going (assuming there is no motor braking circuitry function) thus it should still decelerate slowly enough to allow for engagement without too much rock/jump.

However, if it's direct coupled, I fear for the over-amperage breakage that could occur, but also refer back to my throttle synchronization comment.

Yes the flywheel and clutch should give you the rotational mass needed along with programming out the motor braking during driving conditions. I didn't think of that before.
 

timo439

Scrambler Junkie
LIFETIME
CJ-8.com Member
City
Portsmouth
State
NH
#76
Yes, Flywheel and Clutch remain but there are some capabilities built into the motor controller based on clutch pedal pressure which may also impact behavior. I don't know enough about the details yet but will research.
 
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