Possibility of simple-ish hybrid conversion RWD vehicles...
 

I've been mulling over ideas for how the average DIY'er could convert a RWD vehicle to hybrid w/o too much trouble.

It shouldn't be too difficult to put something between the transmission and front of the driveline, be it a motor, pump, etc. that would recover braking energy.

* Oil pump and pressure tank
* DC generator/motor & batteries
* Flywheel (maybe using a hybrid car cvt transmission to engage/for gearing)
* Big frikin coil spring that winds up

Has anyone on here done an oil pressure/pump hybrid, like what UPS/Fedex were starting to do with some of their trucks a couple years ago?

I've always wanted a mechanical spring regen mechanism! Haha glad I'm not the only one who's thought of it!

Also, I've considered converting my CR-V to front wheel drive, rear wheel E-assist, but unsure of the effectiveness, and best means of execution to make it as fluid as possible.

I've pondered this too. I'd probably go with a smallish motor (~10hp, 25+ peak) sitting over the rear axle to the side of the diff with a chain drive going to the U-joint/diff input. It wouldn't have the torque to do take offs, but it'd have enough juice to keep you going without the engine once you're up to a certain speed, and it could regen on braking. You just need to gear it to match the max RPMs of the motor to the top speed you'll ever go and to the RPMs it'll go at the battery voltage you set up. Plus you could pre-charge it for a plug-in hybrid.

That might be useful... using an electric motor sized to provide just enough power for freeway or surface street travel that's able to do regen but leaves starts and acceleration to the engine.

It seems to me that the problem in many cases is having the ability to vary the mechanical advantage between the assist/regen and the drivetrain... Anything with a fixed gear ratio is going to provide much less braking power as the vehicle speed approaches zero, as well as less power to push at lower speeds...

Well, it's not as efficient, but you could use a CVT (Continuously Varible Transmission) belt-drive like they use on go-carts and snomobiles. that'll give you a 3 or 4 to 1 down to 1:1 ratio.

What about a compressed air system. An air motor/pump and a super high pressure air tank.
Bonus: You would never have to stop at a service station to air up your tires again.

I've thought of something similar, but in my mind, it would fit right behind the transmission at the FRONT of the driveline (less movement from suspension travel).

And rather than skip the acceleration and use if for "cruising", my thought was to do the opposite - use it to help the acceleration, a very inefficient, gas guzzling part of the drive. If this thing could "torque" the driveline from dead stops so the clutch didn't realy have to be slipped & then "freewheel" once the speed exceeds it's operating range.... Along with a "plug-in charging system" and solar "trickle" panels on the roof.....

Regenerative braking would be awesome, but I just don't have any idea what's needed to make that work. I'm not an electrical wizard by any stretch of anyone's imaginaton....:o

I've already considered a hydraulic regen, using rotors mounted at the wheel hubs in a similar arrangement to the Yamaha 2-Trac system which was used in some of their dirt bikes.

But your willing to get an electric drive to the rear axle of your CR-V seems to be perfectly viable. There was recently a similar project in India, involving an electric motor which was been specially-developed to be mounted in the original spot where a driveshaft would be. I just don't remember where I found it :(

I've often wondered about converting a FWD vehicle such that one or both rear wheels could be driven. The rear suspension cage on at least 2 of the vehicles I've encountered would have enough room in and around for at least 5 HP under near the middle. (some only look like about 1 or 2 but it would be a start)
Lots of sprung weight which would need to balance in the middle perfectly which is bad but it looks like room can be made.

The pressing issue would be how to "drive" an unpowered dummy tag axle brake rotar?

On one of the cars it looks like there would be room to drive the rotor from the bottom with some style of friction wheel, hmm, maybe everyone is making things to complex.

A hybrid cobalt or antique insight with prius like abilty would be interesting :)

As for a RWD, there are 2 spline double ended motors around, sandwhich one in and VOILA.

Cheers
Ryan

I wonder if there would be any drag from having it in there when not being used, though? - Assuming it was only used to "boost" the car from dead starts and/or maybe uphills....