DIY Electric Car Forums banner
281 - 300 of 360 Posts

·
Registered
1986 Honda CRX (EM57 2013 Leaf Motor)
Joined
·
223 Posts
Discussion Starter · #281 ·
After almost 2 months of break, I'm back in the garage.

I needed a break after 3-4 months of nonstop work and also time to do taxes.

I also was uneasy with the next step which was to cut the rear frame in order to fit the batteries. Also running 32 HV BMS wires didn't help and overall the complexity of trying to reinforce the frame, risking the existing brake and suspension system, all combined to make me unsure I could really successfully proceed.

After much thought, I decided to reverse course and place all the batteries in the rear and move the PDM back to the front. The weight FR ratio will be 51-49 and of course there will need to be work done with the suspension. What I found was stiffer rear springs and that perhaps I can lower the front torsion bars to reduce the silly lift in the front. Also given that I've moved the inverter, I can easily fit the PDM now without a hood modification.

I will need to still add support to the rear to bolt down the batteries but the overall project can act be completed rather than stuck in limbo. I don't think I am capable of redoing the frame to the level needed to achieve 60-40. Finally since I had originally placed all the batteries in the rear and gotten it running, this should be more than feasible.
 

·
Registered
1986 Honda CRX (EM57 2013 Leaf Motor)
Joined
·
223 Posts
Discussion Starter · #282 ·
Put back in the wood board in the rear. Added plates under the car to reinforce the bolt down of the wood and battery base.

Vehicle Car Motor vehicle Hood Car seat cover


Also ran some conduit

Motor vehicle Hood Automotive exterior Bumper Automotive tire


Need to pull the front battery and install the PDM

Motor vehicle Wheel Automotive tire Hood Tire
 

·
Registered
1996 Toyota Land Cruiser
Joined
·
497 Posts
Good call on moving ahead. It's not ideal but should still be awesome. The thing about the first gen CRX is that is has a rudimentary solid rear axle so with 51/49 when you enter a turn the rear will lose traction first. Makes for a fun to drive and responsive car, but also less stable and maybe less safe. Also it has drum rear brakes designed for minimal load of the front heavy car.

Since you are doing a lot of fabrication in the rear, it might be time to swap in some independent rear suspension from another Honda? I know the Prelude of the same era had a simple independent rear and the floorpan is not dissimilar from the CRX. 2nd gen CRXs also had independent rear suspension. Bonus points because you'd also get rear disc brakes.

It would be a lot of extra work, but at the same time it would solve the problems with the battery interfering with the axle and brake lines. It might even be lighter too.

It was something I wanted to do to my CRX but never got around to.

1g Prelude suspension show here complete with rear steering:

Tire Wheel Car Automotive tire Vehicle


2g CRX:

Wheel Automotive tire Tire Motor vehicle Automotive design
 

·
Registered
1986 Honda CRX (EM57 2013 Leaf Motor)
Joined
·
223 Posts
Discussion Starter · #285 ·
Good call on moving ahead. It's not ideal but should still be awesome. The thing about the first gen CRX is that is has a rudimentary solid rear axle so with 51/49 when you enter a turn the rear will lose traction first. Makes for a fun to drive and responsive car, but also less stable and maybe less safe. Also it has drum rear brakes designed for minimal load of the front heavy car.

Since you are doing a lot of fabrication in the rear, it might be time to swap in some independent rear suspension from another Honda? I know the Prelude of the same era had a simple independent rear and the floorpan is not dissimilar from the CRX. 2nd gen CRXs also had independent rear suspension. Bonus points because you'd also get rear disc brakes.

It would be a lot of extra work, but at the same time it would solve the problems with the battery interfering with the axle and brake lines. It might even be lighter too.

It was something I wanted to do to my CRX but never got around to.

1g Prelude suspension show here complete with rear steering:

View attachment 129419

2g CRX:

View attachment 129420

The challenge I have is that the 1G CRX rear suspension is significantly different from there really isn't much compatibility other than the 1G Integra.

Not my car but this picture shows how different these suspension systems are

Tire Wheel Car Vehicle Automotive tire


I might look into redoing the rear suspension at a later date after I get it running but for now I'm going to rein in the scope so I can actually get the car inspected and registered.
 

·
Registered
1996 Toyota Land Cruiser
Joined
·
497 Posts
The challenge I have is that the 1G CRX rear suspension is significantly different from there really isn't much compatibility other than the 1G Integra.

Not my car but this picture shows how different these suspension systems are

View attachment 129423

I might look into redoing the rear suspension at a later date after I get it running but for now I'm going to rein in the scope so I can actually get the car inspected and registered.
Yeah they are completely different, that was my point. I used to own a couple CRXs and hatches with the same suspension. I eyeballed a 1g Prelude and threw a tape measure on it a few times and with some fabrication I thought i could graft the independent suspension onto the CRX. Like I said it would be a lot of work but you have a lot of cutting needed in the rear anyway!
 

·
Registered
Joined
·
7,970 Posts
After much thought, I decided to reverse course and place all the batteries in the rear and move the PDM back to the front. The weight FR ratio will be 51-49 and of course there will need to be work done with the suspension. What I found was stiffer rear springs and that perhaps I can lower the front torsion bars to reduce the silly lift in the front.
Go ahead and crank the torsion bar anchors down. It's trivial to do and will lower the front, but all it's doing is changing the preload; the spring rate is unchanged so if the front axle load is significantly lower the front springing will be relatively stiff (compared to the original). It might work out well if the rear spring stiffness is increased enough.
 

·
Registered
1986 Honda CRX (EM57 2013 Leaf Motor)
Joined
·
223 Posts
Discussion Starter · #288 ·
Slow and steady.

The goal was to do two things after work over the course of 1-2 hours. Take out the 16 module stack in the front and remove the box. I ended up also test fitting the PDM and found I'll only be able to fit it forward without impacting the hood. Moving the inverter basically means no hood scoop or hood modifications required.

PDM back in front:

Vehicle Car Motor vehicle White Hood


Hood closed fully:

Vehicle Hood Motor vehicle Automotive lighting Automotive tire


And began marking welds and cuts I'll need to do. I'll need to cut the rear bar so that the cables going from PDM to inverter will clear.


Hood Vehicle Automotive lighting Car Motor vehicle




Going to need to reinforce it a bit. Will use some of the scrap mounts I made prior for the PDM...
 

·
Registered
1986 Honda CRX (EM57 2013 Leaf Motor)
Joined
·
223 Posts
Discussion Starter · #289 ·
Got more done today.

Cut, welded, and mounted the PDM. Ran out of welding gas again...

Motor vehicle Hood Car Vehicle Automotive design


I then connected the long conduit to the PDM again so I can extend the connection to the battery in the rear.
Motor vehicle Hood Automotive design Automotive battery Automotive tire



Ran the conduit from PDM to the back, and mounted it under the floor pan where the exhaust use to run
Motor vehicle Vehicle Car Automotive design Automotive exterior


Next I wrapped the conduit from inverter to motor
Electrical wiring Motor vehicle Gas Automotive exterior Computer hardware


I then ran the conduit from PDM to Inverter and began wrapping it but I ran out of orange tape..

Hood Motor vehicle Vehicle Bumper Automotive design


Going to need to restack these batteries next into a 24 module inline.
Motor vehicle Automotive design Gas Engineering Audio equipment


Also considering different layouts
Motor vehicle Electrical wiring Automotive battery Auto part Wire


Also thinking about how I can better seal the connections between PDM, Inverter, Motor. The tape doesn't hold or seal well so I'm wondering what I can use instead...
 

·
Registered
1986 Honda CRX (EM57 2013 Leaf Motor)
Joined
·
223 Posts
Discussion Starter · #291 ·
Do you have a 3d printer?
I don't have a 3d printer but I did get the 3d file from landcruiser EV and sent it to printathing to get it printed. I still feel like I need more insulation though. for areas like the PDM and inverter. I'm considering silicone caulking or whatever variant of it might work. Need to do research..
 

·
Registered
1986 Honda CRX (EM57 2013 Leaf Motor)
Joined
·
223 Posts
Discussion Starter · #293 ·

·
Registered
1986 Honda CRX (EM57 2013 Leaf Motor)
Joined
·
223 Posts
Discussion Starter · #294 ·
Making a note here that the diagram of the connector doesn't match what I have. Perhaps its because I have a Nissan 2013 Leaf 24kWh Battery pack:

Font Parallel Pattern Number Rectangle
 

·
Registered
1986 Honda CRX (EM57 2013 Leaf Motor)
Joined
·
223 Posts
Discussion Starter · #297 ·
Connector Pin Numbering.

These Connectors are the BMS wires that connect to the Batteries themselves.

LB7 and LB8 connect to an intermediate connector, which then goes to the BMS
LB13 and LB14 go directly to the BMS without a connector in between.
Product Finger Font Line Material property
 

·
Registered
1986 Honda CRX (EM57 2013 Leaf Motor)
Joined
·
223 Posts
Discussion Starter · #299 · (Edited)
Pins to connector matching

(edited because LB13 PIN 58 was originally going to LB8-33 which doesn't exist. Probably mixed it up with C33 but its fixed now below)
Font Slope Material property Parallel Pattern



More connector references.

LB13 and LB14 which is used for the 24 stack (ordered from Nissan parts)
Amber Orange Gesture Finger Font



LB7
Electrical wiring Wood Electronic device Wire Cable


LB8
Creative arts Gas Electrical wiring Electric blue Wire
 

Attachments

·
Registered
1986 Honda CRX (EM57 2013 Leaf Motor)
Joined
·
223 Posts
Discussion Starter · #300 ·
And so the depin and verification begins.

Started with LB8

first we remove the cover:

Textile Sleeve Grey Finger Nail


Then we pop up the lock. This type doesn't seem to come off but its necessary to raise it otherwise it locks the pins in place and we won't be able to release them.

Light Automotive tire Textile Orange Gas


Jeans Glove Human body Dress Sleeve


Here you can see there is a little piece of plastic that hold the pin in place. With a pick we raise it and it releases the pin.

Shoe Sleeve Street fashion Musical instrument Musician



So as I removed each pin, I rechecked that it matched with my connector map/diagram. LB8 is verified all correct.

And here LB8 connector is fully de-pinned

Electrical wiring Electricity Grass Cable Electrical supply


Now I'll start moving pins from LB13 to LB8.
 
281 - 300 of 360 Posts
Top