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Re: Hybrid Conversion SJ

Posted: Thu Mar 15, 2012 10:04 pm
by dan_2k_uk
justaddmud wrote:Can i just ask, why you want to keep the gearbox?

Surely a motor that can produce 100% torque from 0 rpm would make gears pointless, hitch the motor straight up to the t-box, no need for a clutch as there is only one gear, and as for reverse, just reverse power to the motor

with the right gearing it could go quite fast, reduce weight, grivetrain loss and could mount the motor where the gearbox was

its an honest question, so please don't shoot me down in flames
Even with 130ft/lbs of torque imagine pulling away in 5th all the time.

Couple that with the motors reccomended max of 2500rm even if it could pull away like that the top speed would still not be.that great.

Re: Hybrid Conversion SJ

Posted: Thu Mar 15, 2012 10:56 pm
by twiss
justaddmud -
I have found an adapter kit for an SJ gearbox that allows me to keep the standard clutch.
This way it makes it nice and easy!
I don't want it to be much different to driving a regular SJ, apart from for super cheap.

The 100% torque output is pretty much from 0 to 3000 rpm, but then it drops off after that.
This is why I want to keep the standard gearbox, so it will pretty much drive like a regular SJ...

I want to get it so 70mph is 3000 rpm or less.
I'm not gonna mess about with the gearing, I'm just gonna stick bigger tyres on it until I get the gearing I want :)

Anton -
I think you've gone wayyyyy over the top there. I'm not going to be putting a motor on each corner!
I want it to be an electric powered SJ, with the same transmission and axles.
Also, I'm not going to need 200ft/lbs of torque from 2 motors.

Each motor costs almost £1,500 so I will only be getting one, an AC motor requires about 9 car batteries and a DC motor requires about 12 car batteries.

The whole set up I'm looking at about £3000.
But if I can get to work for a fiver a week thats paid for itself in 2 years

Re: Hybrid Conversion SJ

Posted: Thu Mar 15, 2012 10:58 pm
by twiss
Oh also, with the AC motor instead of the DC, you can use it up to 6k rpm, but the power still drops slowly after 3k. :)

Re: Hybrid Conversion SJ

Posted: Thu Mar 15, 2012 11:29 pm
by Anton
justaddmud wrote:Surely a motor that can produce 100% torque from 0 rpm would make gears pointless, hitch the motor straight up to the t-box, no need for a clutch as there is only one gear, and as for reverse, just reverse power to the motor
Your idea is very similar to mine! Didn't see your post, I promise I wasn't stealing your idea!
dan_2k_uk wrote:Even with 130ft/lbs of torque imagine pulling away in 5th all the time.

Couple that with the motors reccomended max of 2500rm even if it could pull away like that the top speed would still not be.that great.
It wouldn't be like that, since you can't stall an electric motor, and it has 130lb-ft from 0 to redline. So it'd be more like doing a rolling start at 30mph in 3rd with a turbodiesel that's just coming into it's peak power band. Only you get that acceleration from 0 to wherever the gearing redlines you.

It'll PULL. It won't break any 0-60 records, but it won't be anywhere near as dire as you think. Bear in mind the transmission on a sammy results in about a 35% loss of power, and by ditching the gearbox and t-case, you'd only be loosing power in the diff gearing (probably about 15%) so you'd be getting an extra 20% of power at the wheels for free, plus the associated range increase, lower fuel costs etc. i.e. it should pull like a 155ft-lb ICE engine.
twiss wrote:Anton -
I think you've gone wayyyyy over the top there. I'm not going to be putting a motor on each corner!
I want it to be an electric powered SJ, with the same transmission and axles.
Also, I'm not going to need 200ft/lbs of torque from 2 motors.

Each motor costs almost £1,500 so I will only be getting one, an AC motor requires about 9 car batteries and a DC motor requires about 12 car batteries.

The whole set up I'm looking at about £3000.
But if I can get to work for a fiver a week thats paid for itself in 2 years
Well, I guess it's my fault for writing war and peace - but you missed my point. I wasn't suggesting that you put a motor in each corner - I said I thought about suggesting it until I did the maths and realised it was a *TERRIBLE* idea!

The *real* suggestion was to put ONE motor where the t-case is now, connected directly to the front and rear props. With 31's and 3.73 samurai diffs, you'd have 63mph at 2500rpm, with the torque to get you there quick enough. And if you drop a motor in that's capable of more rpms, you can adjust the top speed/acceleration by dropping different diffs in - V6 vitara diffs, for example, at 4.something:1 or 1.6 vit diffs at 5.something:1.

That way you get rid of the torque losses associated with the gearbox and t-case. I'm not an EV designer or engineer, though - so I'd say you'd better talk to someone who's built one if you do consider my idea, as they're much more likely to know if it's a good idea, or if I'm missing some vital piece of the puzzle.

I would like to oppose your idea of using car batteries though. Bad idea. They're not designed for deep cycling - what you need is fork lift truck batteries. Go talk to a company that maintains forklifts, and get their old used up batteries. They throw them away once they get down to 40% capacity - which is still good enough to use as a "proof of concept" before you throw real money at brand-new deep-cycle batteries, especially if you use the arc-welder trick to bring them back to near 100% for a short while.

Re: Hybrid Conversion SJ

Posted: Thu Mar 15, 2012 11:38 pm
by donkeychomp
I've got 4 'AA' batteries and a recharger.

Any help?

Sorry, couldn't resist it.

Re: Hybrid Conversion SJ

Posted: Thu Mar 15, 2012 11:52 pm
by twiss
Again though I don't specifically want an electric vehicle...

I want a vehicle that feels the same to drive as a regular SJ, but for a fraction of the running costs.
If its electric then so be it

I would consider putting a motor in the middle for an off road plaything/buggy, but I want this to be useable on the road and to feel not much different to my current SJ.

If you didn't have the drag from the gearbox and transfer case you would have practically no engine braking. The electric motor doesn't give the engine brake effect, so I will take what I can get from the gearbox resistance!

I want gears and engine braking just like a regular car

As for batteries I would be using optima yellow top deep cycle batteries.
If I'm doing it I'm gonna do it properly.

I will add, why would I mess with the ratios when the motor has almost the same "power band" as SJ engine

Also having 62 mph at 2500 rpm would be pretty hard to get your speed right!

1613rpm is 40mph and 2016rpm is 50mph

Getting it right for speed cameras would be a pain

Re: Hybrid Conversion SJ

Posted: Fri Mar 16, 2012 12:18 am
by Anton
twiss wrote:I want a vehicle that feels the same to drive as a regular SJ, but for a fraction of the running costs.
If its electric then so be it

I would consider putting a motor in the middle for an off road plaything/buggy, but I want this to be useable on the road and to feel not much different to my current SJ.
Ah, ok. Fair enough!
twiss wrote:As for batteries I would be using optima yellow top deep cycle batteries.
If I'm doing it I'm gonna do it properly.
Good man! If it's worth doing, as they say...
twiss wrote:I don't specifically want an electric vehicle...
Then, and don't take me as being negative about your original idea (which I like, I do! Just throwing ideas at you, not criticising), but have you considered hydrogen hydride tanks?

That is to say, rather than charge batteries and drive electric, use that same electricity to make hydrogen fuel from tap water, and feed the hydrogen into hydrogen hydride fuel tanks. Same *crazy* low £ per mile figures*, but running a normal engine - but with LPG-ish attachments. Only thing coming out of your exhaust would be steam, and the cost might not be too different to an EV setup, but without the weight issues (batteries are HEAVY and take up loadsaroom, where hydride tanks take up the same room, if not less than a petrol tank, and weigh similar amounts to a full petrol tank).

And before you worry about the safty aspect, hydrogen hydride tanks release their hydrogen slowly (which is why you might need more than 1 - although 4 is enough for a Chevy V8, so....) - if you cut one in half with a chainsaw and then tried to set it on fire, it'd smoulder like a huge ciggerette.

This has the advantage that if you run low on fuel, you can switch back to dino-juice.

I've wanted to do that with my SJ for years. I just can't afford it!!!!

*especially if you have a wind turbine to make your power - FREE motoring, anyone???

Re: Hybrid Conversion SJ

Posted: Fri Mar 16, 2012 12:22 am
by ianedwards
ive liked the idea of a electric 4x4 since i seen a electric freelander on ebay,

i recon youve got a sound idea going on here, it would be quite an interesting project if your serious about it.

an sj seems the perfect base for it,

Ian

Re: Hybrid Conversion SJ

Posted: Fri Mar 16, 2012 1:50 am
by Tramp
Nice idea, I'm looking forward to seeing this done. I can't help but wonder if you would be better off buying one of these & just fitting a gen-set on the back!

Image

http://www.bradshawelectricvehicles.co.uk

Re: Hybrid Conversion SJ

Posted: Fri Mar 16, 2012 1:53 am
by twiss
Cheers!

as for the hydrogen, seems a bit ott... I'm good with a spanner or a soldering iron, I'm not really into gas and LPG.
It will be easier as well to get free tax if I am using a purely electric system instead of using an engine
+ if i'm using an AC motor, I will have 6 batteries in the back (where the fuel tank would be), and 3 in the front. The motor only weighs 70lb, which is 30 less than my 16v engine...
I dont think 3 batteries will weigh 30lb. Although I have to get another battery to power the car electrics as well... But I dont think its a massive weight increase over and full tank of petrol and a 1.6 engine