External Alternator

[makenzie71]

What I really want is 300w, more would be better. My list goes as such:

35w HID low beam, on all the time
65w high beam
15w to tail
25w to brake
15w to turn (X2)

Thats my minimum requirements. But there's another 100w of accessories I would like to be able to run sometimes.

[GS1100ez]

so your 300watt is requiring 23amps of use at say 13.5volts

23amps of draw isnt all that much
especially seeing as you wont be drawing 23 amps at ALL times

but i dont know what the stock output is either

[alton_blair]

Don't forget 45w for the stereo

[rustybronco]

have you given some thought to driving an external alternator from the right side of the engine. not the stator side.
then you won't have to worry about sealing systems for the crankcase.
make a spacer to replace the signal gen cover thick enough so you can run an internal pulley and run the belt through a slot in the adaptor. drive it off the large nut with a bearing on the outer (extreme rh side) to support the shaft and pulley load mounted in this "adaptor".

then choose/make a pulley to fit on a small/compact alternator.

[Billy Ricks]

I'm thinking you're probably in the 270-280 watt range already. In '83 they went to 310 watt stators on the 750. An RM stator would probably put you over 300. RM claims they put out as much as 20% more power than OEM.

[alton_blair]

If you would use one of these

http://www.americanpowerinc.com/police.htm

I would have to think your battery could handle sitting in traffic for a long period of time because it would be fully charged. This is definatley not my strong suit, but high output even creeping forward in traffic should be faster charge times right?

[reddirtrider]

If you would use one of these

http://www.americanpowerinc.com/police.htm

I would have to think your battery could handle sitting in traffic for a long period of time because it would be fully charged. This is definatley not my strong suit, but high output even creeping forward in traffic should be faster charge times right?

Your battery can only charge so fast. It's tiny, so it doesn't need a large alternator. That bad boy is meant to deliver lots of current that is needed in an ambulance (quite a bit of medical equipment to power). The motor also drives the alternator, not the rear wheels.

If you're not moving then the alternator won't be spinning in order to develop current, so you'll be running off the battery.

It's probably as much work to tap off the countershaft as it is the crank. If you use the crank then the motor width is reduced and you get more bang for the buck. In addition you're not running off the battery when stopped.

A motorcycle alternator will work fine. At one time I was thinking of doing something like this and using one from a ZRX1200. If you have the necessary machine tools it might be worth trying, but after farming out several jobs to machinists for the 1100 mods I realized it was out of my budget.

[alton_blair]

Your battery can only charge so fast. It's tiny, so it doesn't need a large alternator. That bad boy is meant to deliver lots of current that is needed in an ambulance (quite a bit of medical equipment to power). The motor also drives trhe alternator, not the rear wheels.

If you're not moving then the alternator won't be spinning in order to develop current, so you'll be running off the battery.

Ok good point I will shut up now.

[makenzie71]

well before I get crazy stuff going I'm trying out a new stator/regulator/battery to see if that cures my issues. All the aftermarket pieces claim higher output so we'll see. I'd really like to rewind my own with heavier copper (14g) but I don't know how to calculate how many turns it'll require to get the propper voltage.

[reddirtrider]

Ok good point I will shut up now.

No need. These forums are about ideas. There's no such thing as a bad idea unless it's implimented and costs lives or money. It's good to hear differing viewpoints.

I'm an engineer so I look at the negatives of any idea before the positives. Please don't interpret that as criticism.

[alton_blair]

No need. These forums are about ideas. There's no such thing as a bad idea unless it's implimented and costs lives or money. It's good to hear differing viewpoints.

I'm an engineer so I look at the negatives of any idea before the positives. Please don't interpret that as criticism.

I don't, but I will step back and let the more knowledgable people have a crack at this and enjoy the read. These are the things that could make our bikes even more reliable and enjoyable.

[reddirtrider]

well before I get crazy stuff going I'm trying out a new stator/regulator/battery to see if that cures my issues. All the aftermarket pieces claim higher output so we'll see. I'd really like to rewind my own with heavier copper (14g) but I don't know how to calculate how many turns it'll require to get the propper voltage.

Well, the idea of driving an alternator from the crank isn't new (obviously). I do think that although it hasn't been offered as a product, there still would be a market for it for 2 reasons. One would be for those such as yourself that want more electrical power. The other would be for those who want a slimmer motor. The cost of development and production would be the limiting factor for most GSer's. Check out how much the external starter kits cost for a baseline.

[Billy Ricks]

For what it would cost you could probably drop an oil cooled GSXR engine in your frame and have an external alternator. If you seriously want to try an adapt one take a good look at how Suzuki did it on the early Gixxers.

[rustybronco]

I'd really like to rewind my own with heavier copper (14g) but I don't know how to calculate how many turns it'll require to get the propper voltage.

14ga wire will be to much to large I suspect. probably somewhere around 18?ga me thinks.
also see...

http://www.thegsresources.com/_forum/showthread.php?t=134690

http://www.thegsresources.com/_forum/showpost.php?p=968723&postcount=98

http://www.thegsresources.com/_forum/showpost.php?p=967880&postcount=85

Without changing the stator, there is an extra 34 watts avaliable to the load if required so that is about a 20% increase in avaliable output power.

the usage of led turn and brake light bulbs will add to the power available...

[Billy Ricks]

14ga wire will be to much to large I suspect. probably somewhere around 18?ga me thinks.
also see...

http://www.thegsresources.com/_forum/showthread.php?t=134690

http://www.thegsresources.com/_forum/showpost.php?p=968723&postcount=98

http://www.thegsresources.com/_forum...0&postcount=85

Everything I've seen says they used 17 gauge. It's an odd size but that's what I think the tutorial on rewinding says they used.