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Giving it a Jolt

jc_chandler

Well-known member
Member
City
Denver
State
CO
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
BENEFACTOR
Gold Member
Lifetime Member
City
Portsmouth
State
NH
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
BENEFACTOR
Gold Member
Lifetime Member
City
Portsmouth
State
NH
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
 

timo439

Scrambler Junkie
BENEFACTOR
Gold Member
Lifetime Member
City
Portsmouth
State
NH
Not so sure, I get distracted by squirrels and shiny objects.
 

Kane

CJ-8 Member
City
Berlin
State
ct
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
City
Edmond
State
OK
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....."
 

Dave The Sparky

Rebuilding my CJ8 very,very slowly...
Member
City
Halifax
State
UK
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 Member
City
East Norriton
State
PA
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
City
Edmond
State
OK
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
City
Edmond
State
OK
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
City
Berlin
State
ct
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
BENEFACTOR
Gold Member
Lifetime Member
City
Portsmouth
State
NH
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.
 

Boomer

Iron Bender
City
Snohomish
State
WA
Small update. Got the steering wheel back in, mocked up the charge port in place of the fuel filler and started on the contractor box. Still waiting on parts.View attachment 90938

I would SO love to pull into a Tesla charging spot in mud covered, lifted CJ on 35s and stick the charging cable into what others would assume is a gas tank filler. I bet a lot of the reactions would be priceless.
 
Last edited:

designerRob

CJ-8 Member
Silver Member
City
Allen Park
State
MI
I love SO love to pull into a Tesla charging spot in mud covered, lifted CJ on 35s and stick the charging cable into what others would assume is a gas tank filler. I bet a lot of the reactions would be priceless.
Sounds like fun. Build thread somewhere?
 

timo439

Scrambler Junkie
BENEFACTOR
Gold Member
Lifetime Member
City
Portsmouth
State
NH
Been awhile since I last provided an update. I have gotten to the point of introducing the motor to the Jeep. It’s taken awhile as I fought flywheel bolt sizes, a warped flywheel and various other issues but I plan to mate the motor to trans tomorrow. I’ll start planning the motor and battery mounts as soon as this is done. Slow but steady progress, 4 kids, home schooling and house renovations (plus work to pay the bills all come first).

a few pics. Plywood is just to give the hoist a breather overnight.

D7F90CB9-3873-49C8-8484-5A0ACBD95A37.jpeg436ED6C4-A6ED-4452-A10B-D73DF0B84E22.jpeg39A9140D-CA8B-45E2-82BA-402542E5C19E.jpeg
 

FLCJ8

Legacy Registered User
City
Palm Bay
State
FL
Been awhile since I last provided an update. I have gotten to the point of introducing the motor to the Jeep. It’s taken awhile as I fought flywheel bolt sizes, a warped flywheel and various other issues but I plan to mate the motor to trans tomorrow. I’ll start planning the motor and battery mounts as soon as this is done. Slow but steady progress, 4 kids, home schooling and house renovations (plus work to pay the bills all come first).

a few pics. Plywood is just to give the hoist a breather overnight.

View attachment 91874View attachment 91875View attachment 91876
:popcorn::popcorn::popcorn::popcorn:
 
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