Resolved 1G Bigger Alternator Pulley

[kiggly]

Does anybody make a larger alternator pulley for a 1g or know of something I could adapt to fit?

My alternator stops working at 9400-9500rpm and voltage takes a 2v dive off a cliff. Fuel pressure follows, which is not exactly desirable.

Thanks,
Kevin

 

[GDNF2ET]

I bet if you went to a local auto electric shop, they would have dozens to choose from on old cores.. Pic is an example..

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[lowell]

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[mercaholik]

Good god man thing is almost the same size as the crank pulley . Is that custom made or where did you order it from? What's the diameter?

 

[lowell]

88mm, vs 63mm for stock. Made by AEM.

Some interesting reading:
http://www.ffcars.com/forums/17-fac...can-alternator-spun-too-fast.html#post2714511​

 

[turbotalon1g]

Is voltage lower at idle?

 

[jimsgsx]

Is that a honda rim? Haha man that is huge.

 

[SrKegler]

Wouldn't a larger pulley on the alternator slow the alternator down instead of speeding it up.

 

[tmoney20g]

Wouldn't a larger pulley on the alternator slow the alternator down instead of speeding it up.

Yes.

Kiggly asked for a larger one, and was answered. Kiggly is also revving to 9500 rpm, where the article makes some good points in reference to what is going on.

Assume the underlying problem is the same as the article, and his alt is being way over-driven, so he wants to slow it down.

Crank Pulley Diameter = 6-3/8" ~ 162mm
Alternator Pulley Diam = 65mm ~ 2.559" (let's say 2-9/16")

So at 9500 rpm (crank pulley) via http://www.blocklayer.com/Pulley-BeltEng.aspx

It's a 2.49 ratio, so the alt is spinning at 23,655 rpm.

Not sure how big that AEM pulley is, but let's say its 4" in diameter, then the ratio would reduce to 1.59.... with Crank @ 9500rpm, alt would be at 15,105rpm. That's a pretty signification decrease in revs.

 

[SrKegler]

My bad guys, didn't really think the problem through. Just turned 70 last week, I'll blame it on CRS (Can't Remember S..t)

 

[redrkt]

Here is the AEM alternator pulley kit part # 23-7300c. Here is some pics:

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Also if you leave the 2 pin connector to the alt disconnected it helps keep the voltage at 14v at high rpm.