Here are some points I considered:
Clutched system for Civic:
- feels more like the original manual transmission, allows people unfamiliar with EVs to drive it more easily; downshifting much easier
- Allows troubleshooting of the drivetrain by allowing an intermediate disconnect point during operation
- Adds a safety feature if the controller shorts and over-revs the motor
- inertia from heavy flywheel slows acceleration
- clutch slave cylinder interferes with placement of front golf cart batteries but not Deka 9A31s
Clutch-less system for Civic:
- much less mass to spin up during acceleration
- shifting is a bit slower as the driver uses the synchromesh to spin the motor down and up
- shifting can only happen while the accelerator is not pressed
- clutch slave cylinder doesn't interfere with 8V golf-cart batteries
- this system still uses the springed center of the clutch disk to remove stresses on the drivetrain from bumps
For those of you wishing to make your own Civic-EV, Electro Automotive will ask you for the bolt pattern on your flywheel since they've had problems with Civic adapters in the past. Here's a picture of the bolt pattern I scratched from a purchased Civic flywheel. The resolution is 300x300 dots-per-inch. If you print this out using MS-Paint with the proper 300x300 scaling, make sure it exactly matches the bolt pattern on your flywheel before ordering the adapter from ElectroAutomotive.
Remember the transmission I pulled out of the Civic at the wrecking yard? I cleaned it up so I could get some measurements on it for the clutch-less system. I can verify the ElectroAuto adapter on this, but I won't need to measure it anymore since I'm not considering the EV-America clutch-less system for now.
Also make sure your transmission is the S20 transmission for the proper adapter plate. Here is a picture of my transmission label:
Next up: thinking about batteries and the controller system...