Author Topic: Alternator Upgrade (Read 29923 times)

Rick G · « **on:** January 30, 2012, 07:36:02 AM »

I have heard that if you change the winding configuration of a 32 amp Alternator from Star to Delta you get an increase in the rating up to about 43 Amp.
Looking for info about this but cant find anything.

Scott_ · « **Reply #1 on:** January 30, 2012, 07:49:56 AM »

Why go to all that trouble. Just get yourself the bigger alt and be done with it. They are available, just ask Drake.
Changing the configuration of the windings is no easy task if not impossible depending on the physical build of the winding assy.

WayneDW · « **Reply #2 on:** January 30, 2012, 10:00:34 AM »

FYI, Here is where the upgrade is sold:

http://www.kbikeparts.com/50a_alt/50a_alt.htm

$150.

Rick G · « **Reply #3 on:** January 30, 2012, 07:01:13 PM »

Quote from: Scott_ on January 30, 2012, 07:49:56 AM

Why go to all that trouble. Just get yourself the bigger alt and be done with it. They are available, just ask frankenduck.
Changing the configuration of the windings is no easy task if not impossible depending on the physical build of the winding assy.

Thanks but I am aware that our Psychotic Waterfoul friend has them but getting it to Australia is not a cheap exercise and the 50 Amp ones here are not readily available. I can get the stator rewound for about $120 but thought I would investigate the configuration thing before anything else was done.

wmax351 · « **Reply #4 on:** January 30, 2012, 09:24:12 PM »

Quote from: Rick G on January 30, 2012, 07:01:13 PM

Quote from: Scott_ on January 30, 2012, 07:49:56 AM
Why go to all that trouble. Just get yourself the bigger alt and be done with it. They are available, just ask frankenduck.
Changing the configuration of the windings is no easy task if not impossible depending on the physical build of the winding assy.
Thanks but I am aware that our Psychotic Waterfoul friend has them but getting it to Australia is not a cheap exercise and the 50 Amp ones here are not readily available. I can get the stator rewound for about $120 but thought I would investigate the configuration thing before anything else was done.

USPS medium Flat rate box is ~ 50 dollars

rbm · « **Reply #5 on:** January 30, 2012, 10:01:27 PM »

It is true that the power output of the alternator could theoretically be increased by rewinding the armature from wye to delta. The relationship between line and phase current in a delta configuration is I_L = 1.732 * I_P. In theory, a 33A Wye-connected three phase alternator rebuilt to delta configuration could produce 57A. But, I think there are other components on the alternator, such as rectifiers and regulator, would have to be changed as well to match the increased current not to mention larger gauge wire for the alternator windings. Furthermore, there are external connection differences between the 33A Bosch alternator for K100 and the K1100's 50A cousin. You'd have to provide a beefier binding post type output connector; the 33A unit only has a wimpy spade connector. The output cable on the 50A unit connects directly to the battery positive; on the 33A unit it routes through the starting relay. There are sufficient barriers to "clean install" that I'd consider a used 50A unit over a rebuilt 33A unit IMO.

Rick G · « **Reply #6 on:** January 31, 2012, 12:16:05 AM »

Thanks Rob that is what I was looking for. So in theory yes but in practice not too practical.

wmax351 · « **Reply #7 on:** January 31, 2012, 12:53:19 AM »

The 50 amp ones are easily rebuildable. I did mine a while back, before I installed my used one. I didn't replace the slip rings, as they were fine, but they are replaceable.

http://www.motobrick.com/index.php/topic,788.0.html

You could also look to shipping over the parts that differentiate the BMW alternator from a cheap VW/bosch one. Most likely the pulley side, and the bushing cup.

If Duck could chime in with some part #'s off of the 50 amp alternators, I could figure out what is needed.

TimTyler · « **Reply #8 on:** January 14, 2016, 03:44:50 PM »

When upgrading from a 32a to 50a alternator on a K75, is it necessary to switch out the driving dog or just the clutch housing (cup) and rubber mountings (monkey nuts)

EuroMotoElectrics recommends a new driving dog on their site, but when I spoke with them on the phone they could not confirm. The OEM fiches have the same Driving Dog part # 12311460304 but list it separately for "up to 7/1993" and "from 7/1993" as if they were different parts.

Martin · « **Reply #9 on:** January 14, 2016, 04:00:07 PM »

Rick G just curious where in OZ are you.
Regards Martin.

Inge K. · « **Reply #10 on:** January 14, 2016, 04:33:43 PM »

Quote from: Martin on January 14, 2016, 04:00:07 PM

Rick G just curious where in OZ are you.
Regards Martin.

Stanthorpe, Queensland......he isn't active here anymore, sign up at the K100Forum if you want to connect.

Tim, you need only the cup....as the 32 and 50A has different shafts.

Martin · « **Reply #11 on:** January 14, 2016, 04:41:59 PM »

Thanks Inge Stanthorpe Qld coldest place in Queensland, I believe it even snowed there. I definitely wouldn't be going for a visit in winter, I don't possess snow shoes :hehehe.
Regards Martin

TimTyler · « **Reply #12 on:** January 14, 2016, 05:59:53 PM »

Quote from: Inge K. on January 14, 2016, 04:33:43 PM

Tim, you need only the cup....as the 32 and 50A has different shafts.

Thanks, Inge!

TimTyler · « **Reply #13 on:** January 16, 2016, 03:02:13 PM »

Removed the 32a alternator. Awaiting delivery of the 50a EnduraLast from EuroMotoElectircs. It's "USPS Out for Delivery".

The brushes in my 32a were short and in need of replacing. I had replaced the entire voltage regulator w/ brushes and new monkey nuts 50k miles ago. The rotor spins smooth and free. Rubber bushings / monkey nuts are still in great shape. Drive dog is in good shape and can't be moved by hand.

Is it smart to add a heavier gauge wire from the alternator to the battery?

The Mighty Gryphon · « **Reply #14 on:** January 16, 2016, 04:06:23 PM »

Tim, I doubt you need a heavier wire from the alternator to the battery. The distance is so short that even at full output you wouldn't notice any additional voltage drop. I would just take a close look at the terminals on the wire. If they show any signs of corrosion between the conductors in the wire and the metal of the connector I would consider replacing the wire. If not, spend your time and money somewhere else.

F14CRAZY · « **Reply #15 on:** January 16, 2016, 06:10:23 PM »

I've been wondering how long those alternator drive rubbers last but with 50k on those it seems they last a while

rbm · « **Reply #16 on:** January 17, 2016, 11:31:48 AM »

When Duck was selling his 50A alternator upgrade kit, he included a heavier gauge wire as part of the package. You'd wire it directly from the alternator output to the battery +ve pole and abandon the 33A stock wire. On my K75 with 50A alternator, I've Duck's replacement wire plus an aftermarket 4GA ground wire. Maybe it's overkill but my electrics have been very reliable.

TimTyler · « **Reply #17 on:** January 17, 2016, 02:23:38 PM »

Thanks, Robert. I've got a heavier cable to install.

I had some problems trying to install the EnDuraLast alternator from EME. I finally removed the cup and nut and tried fitting the alternator onto the bike again and it just wouldn't snug up. After a while I finally figured out that the mounting surface of the EnDuraLast alternator is not properly cut. There's too much metal near one of the mounting screw holes. The product image on their site is correct, just not the one they sent me. Also note that the screw hole diameter is larger on the EnDuraLast, although I don't think that will cause a misalignment problem.

I'm tempted to grind off the metal myself but I'll try to practice patience.

rbm · « **Reply #18 on:** January 17, 2016, 02:52:18 PM »

Tim, be careful that the alternator fitment is correct. I blew a bearing in my intermediate housing when I installed my 50A because it captured the drive dog; it wasn't fun. Ensure the offset between the mounting flange and the top of the drive cup. That measurement should be 56.5mm.

TimTyler · « **Reply #19 on:** January 17, 2016, 03:11:09 PM »

Thanks, Robert. I saw your old post a few days ago while doing research, so that offset measurement was the first thing I checked yesterday when I couldn't get the alternator to fit. Both alternators with cups measure the same.

Props to EME for replying to my Sunday morning email today within an hour. John Rayski replied and told me I could return and exchange the alternator or simply grind the relief cutout myself which is what they do at EME. Looks like I'll be firing up the grinding wheel.

John also said "...the bolt hole issue are non-relevant and do and will work, as this will cause NOT a misalignment problem ."

TimTyler · « **Reply #20 on:** January 17, 2016, 08:03:42 PM »

I ground down the mounting surface so the alternator would fit. Taped over the alternator's vents to minimize metal dust getting inside while grinding.

Bike's all back together and runs smooth. Looking forward to a test ride tomorrow.

TimTyler · « **Reply #21 on:** January 22, 2016, 09:03:14 PM »

After upgrading to the 50a alternator the bike is idling lower than usual, even after the bike has been ridden for an hour. It's gone from 1100rpm to 800rpm. But then sometimes at a stop light (or whatever) it will idle at 1000rpm.

Is it harder for the engine to turn the 50a alternator than the 32a alternator?

Do the bike's electronics recognize the new alternator and treat it different than the old alternator?

Bill · « **Reply #22 on:** January 22, 2016, 09:28:29 PM »

All things being equal .... battery state, electrical load it should not require additional HP to drive it. The only condition where it would load the engine more is right after starting to bring the battery back up to nominal at a faster rate.

rbm · « **Reply #23 on:** January 22, 2016, 10:14:42 PM »

If you remember, one of my symptoms of binding was a lower idle. Maybe you can test for binding of the drive dog by mounting the alternator with washers to raise it away slightly. If the idle speed returns to normal, you need to adjust the depth of the cup.

TimTyler · « **Reply #24 on:** January 22, 2016, 10:23:25 PM »

I checked for binding by inserting the alternator without the rubber bushings and it fit the mount points easily. Then I unscrewed the cup nut most of the way and inserted the alternator again and it fit easily. The I added the monkey nuts, lubed them up, and the whole assembly slipped up snug easily by hand. There was never any resistance or need to snug up the alternator using the mounting screws.

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Author Topic: Alternator Upgrade (Read 29923 times)

Rick G

Rick G

Rick G