tveltman

I know there have been tons of posts about this (I've read all I could find), but I have a couple of questions about the CS130 alternator conversion. Has anyone tried this successfully on a later model car? If so, has anyone attempted the 140 amp conversion (increase from 105 amp)?

About the only thing I could find was that the replacement may not completely solve the low-amperage problem at idle because of the difficulty of sourcing a pulley small enough to get the rpms up on the alternator. I know that there is a kit to boost the amperage, and i've seen the output charts for a CS144 (similar 140A alternator), and I think the conversion combined with the upgrade would solve the problem entirely.

I tried contacting the upgrade supplier, but they were unresponsive. One post I read said that someone thought the upgraded case was too big to fit in the appropriate space. Does anyone know for a fact that this is true?

I have cleaned my contacts and I can't squeeze any more juice out of this alternator, and yet I'm still draining the battery when running the headlights and windshield wipers at the same time. Too bad there is a law that requires you use both at once, or I'd not worry so much, but as we all know, we drive cop magnets and I need a ticket like I need a hole in the head.

Thanks for the help guys (and girls)!

Landseer

Yes, Leslie's husband has put one on an S4.

As I recall, he or she said you need to retrofit the old-style bracket and associated steering pump bracket that interfaces with it.

I've put a pair of CS130's onto my two 84's. They run all the needed accessories, no problem.

CS144 experiment by Sharkskin reportedly did not go well (didn't fit), despite 110% effort

If you need more amperage, you might check 928 Motorsports, I think they offer an upgraded unit but it isn't cheap.

tveltman

Yeah, there is a difference between a CS-144 and a CS-130 that has been gutted and modified to put out 140 Amps. I was merely mentioning the CS-144 output graph as evidence for why I felt it would remedy the situation. I'm glad that it can at least be done, although it's unfortunate that I have to source an older bracket to make it work.

Thanks!

Mitch Johnson

I have one of these on my 83, expensive yes but it is pretty much a plug and play solution.

SharkSkin

Actually, what I tried was a CS130D:



I did get it to fit but the problem was it wouldn't charge at idle, and calcs proved out that even with a custom pulley of the smallest possible size it could not be made to spin fast enough at idle to work properly. I documented the saga here.

I think this would be an excellent conversion for a racecar though, since it is lighter weight than other options(unless you spend big $$$), and has more robust bearings and better cooling than the CS130.

One thing to be careful of -- alternators built for high output often give up capacity at low RPMs to achieve this. A good rebuilder will know how far they can go without sacrificing low-speed charging. The pulley ratio is about 2:1 so you will need an alternator that can meet your charging needs while spinning ~1400 RPM. If the rebuilder doesn't have a tach on their test bench(or another way to confirm operation at 1400 RPM) find another.

RicerSchnitzzle

There are rebuild kits available for the stock alternator to take it up to 160a or 190a output. Plug and play when done. Much cheaper than Carl's as well. I have a 190a rebuilt Bosche alternator. Kit was about $250 installed.

123quattro

I pulled the stock pulley off the 928 alternator and put it on the Delco unit. It just takes moving shims around from each to get it to work. I think I also left the lock washer off and put Loctite on it. I have no issues of output at idle.

SharkSkin

The CS130 seems to be the way to go for a budget replacement -- lots of people seem happy with it. Note that the rebuild kit mentioned above only helps if you have a Bosch alternator to begin with.

shaaark89

where did you get the kit/rebuild?

Leslie 928 S2

That is sort of true, he did. What made using the alternator a touch easier for Kevin was that the S4 engine in question was implanted into an 85 Euro body....so Kevin already had access to the old style bracket from the original engine.

You can see the whole story here if you are interested.
84 S2 Conversion to 88 S4 Thread
Just FYI, Kevin's experience, like Sharkskin's, was that the conversion is not flawless....at least, not for modified cars. Stock cars, which have less draw from added aftermarket stereo electronics and other equipment such as fans and pumps attendant to most supercharger systems, often seem to be successful with it.

Kevin tried the smaller alternator pulley and stuff too, but charging is still nerve-wracking while idling in traffic, although the car has never actually died on him.
We too would like to know that answer.

RicerSchnitzzle

I got the alternator rebuilt at B&M Starter/Alternator in Pensacola Florida. I'll see if I can find the receipt. It may have a model number. The guy there acted like my request was an every day thing. I would imagine any starter shop could get it. He only re-used the case itself. Everything else inside is new.

Leslie 928 S2

And how does it do charging at idle?

RicerSchnitzzle

Not so well. Generally the higer the output the lower the output at idle and the harder to self excite. I had a smaller V-belt pulley installed which helped a lot. With my bigger cams I also keep my idle a tad high. CIS doesn't like vacuum flucuations at low idle caused by a lopey cam. I'm at about 900rpms idle.

I got the alternator to drive my big stereo, at 900-1000rpms it did fine at night with the lights on and my ears bleeding.

Leslie 928 S2

Yeah, that's what I was afraid of.

The smaller pulley only helped us just so much, and then we ran into belt slippage issues. Can only tighten the belt so far and then what?

*sigh*
Gain on one hand, lose on the other. What a hassle.

tveltman

This is what I was referring to. If you look, the 140 Amp alternator is rated according to generator shaft RPM, which will be approximately twice your idle RPM. This puts the shaft RPM somewhere between 1500 and 1900 RPM, depending on where your idle rests. At 1500 RPM, the 140 Amp CS-144 puts out about 65 Amps, which is arguably more than the old Paris-rhone put out, ever. Furthermore, you will note that as the RPM increases only slightly, you get a huge gain in amperage, so you may be getting closer to 80 Amp at idle. However, you will also notice that the temperature is listed at 27 degrees C, so the actual output is probably about 85% of rated at operating temperature, so your 140 amp alternator will probably put out somewhere between 55 and 68 Amps at idle, which is a significant improvement over the OEM. The other thing I will point out is that evidently you can get a 170 Amp rebuilt CS-130 (available here: http://www.alternatorparts.com/cs130_&_cs130d_alt.htm)

I've got no affiliation, but it seems like that would be an even more viable solution, so for everyone planning on doing it, this could be the way to solve the problem once and for all [maybe also replacing all the wiring might help, too ; )]