Offset alternator conversion for racing

[Guest]

Recently I came across some information about an interesting modification that involved relocating the GS1000 alternator to outboard of the engine sprocket and using the sprocket drive shaft to drive the alternator rotor. Its purpose was to improve the cornering clearance. Obviously there were some new castings involved to make this work. Has anyone ever seen one of these conversions and can shed any light on the details?

 

[Buffalo Bill]

Interesting idea, sounds like the placement on the oil cooled GSXR engines.
However in racing, most people went to battery only ignition, losing the weight and clearance problems of the stator.

 

[GregT]

Plenty of pictures around on the net. Only worth doing if you're going to do endurance racing longer than say, 4 hours.
As Bill has said, battery powered total loss is popular - or self generating ignition if you're wealthy....

 

[limeex2]

I ran for 2+ hrs at a track day with alternator unplugged/total loss. Electric started all day and no running problems. Only remove it if you have cornering clearance issues or are removing the generator/starter systems to save weight on a race bike.

 

[John Kat]

I took a picture of the alternator mounted on a genuine XR 69 here:
https://www.thegsresources.com/_forum/showthread.php?179221-Genuine-XR-69/page2
I hope you'll see it as it was posted on photobucket...

 

[John Kat]

Here's another picture of the same XR 69:

 

[Buffalo Bill]

I considered total loss for my 1990 GSX7/1127 track bike and found this post on the gixxer.com forum. Convinced me to forget about it:

“My SRAD was constant loss. One thing you have to consider is that repeatedly draining and quick charging a battery will kill it fast. I had two I switched between and they still didn't last long. Remember, there's also training and in some orgs qualifying before sprint races.

For starting, there are purpose-made external starters. You'll see them in MotoGP, kinda look like a lawnmower with a go-kart wheel on top that the rear wheel of the bike is spun by.

That being said, do you REALLY need it? It's a lot of hassle for minor gains. Most racers, even expert amateurs don't bother. Yes, top-level professionals run that way - but they also have a team of mechanics to keep the bike running. I only had it on the SRAD because it came that way, every race bike I've had since I kept the charging system and starter on because it was just too much of a pain in the ass and it didn't REALLY make me faster. ”

 

[GregT]

I considered total loss for my 1990 GSX7/1127 track bike and found this post on the gixxer.com forum. Convinced me to forget about it ?

Compare apples with apples....All the GSXR air/oil family have an alternator behind the cylinders. I've removed them on race bikes primarily for weight saving reasons.
The GS/GSX air cooled family have the alternators on the crank end. Removing those is primarily a cornering clearance thing. If all your circuits are right hand turns - or you have a sidecar outfit - fair enough, you don't have a problem. Everyone else does though.....

The SRAD family and beyond, need the alternator because of the much higher current draw of the modern electronics. Right from the first SRAD, there's been a small diameter, high output alternator available for race use. I've got two kitted GSXR1000 L2's sitting here at present, both of which use racekit alternators smaller than OE. But of course $$$$$.....

 

[Buffalo Bill]

I only got 2 apples, a 1982 GS and a 1990 Katana. I'll have to take yours and other peoples word about what can be done and the best way to do it, and Thanks!
The GS; only lights and ignition use electricity so it make a lot of sense to remove the stator. Lights aren't allowed on track bikes here in the US, but I did see brakes lights on race bikes in the Northern Ireland Ulster GP, on video.
My 1990 Katana is only a part time track bike for now, seems silly/pricey to build my 1992 GSXR engine so it can compete with 2K bikes. I should just buy a 2K bike!!!
Would be fun to shame the arrogant owners of newer bikes!!! Actually I am doing that already!!!

 

[GregT]

Your lights in Ireland point is interesting. I'd be surprised if they were brake lights. Under FIM rules you have to display a rear light if it's declared a wet race.
We've recently adopted this rule here in NZ. Small surge in sales of bicycle LED taillights.....

 

[Buffalo Bill]

Your lights in Ireland point is interesting. I'd be surprised if they were brake lights. Under FIM rules you have to display a rear light if it's declared a wet race.
We've recently adopted this rule here in NZ. Small surge in sales of bicycle LED taillights.....

Makes sense in the rain. Looks wet to me…

 

[willycrash]

used to be a common mod on some bikes that ran huge HID lighting systems for endurance racing. somewhere I have a pic of a XR650 24 hr ice racer with an external generator.