My voltage drops when I'm at idle and in gear at a stop sign when I have my brakes on or my A/C. I've determined the problem to be my idle being too low. It sits about 480-500 under the previous conditions (of course it's a little higher with the A/C on).

Anyway, I want to get a different size pulley to make my alternator spin faster at idle. For example, if I'm idleing at 500, I want my alternator to spin as if I'm at 1000.

Where do I buy one? What would be the diameter? It would be a smaller one right?

Lastly, will this have any adverse effect on my engine in anyway?

Thanks!

 

i would belive that you would need a smaller pulley... or an overdrive pulley... march may make something like that

 

So is this exactly what I need?

http://216.242.145.16/products/product.phtml?p=35

I did a search on the web and that is the only one I could find that will work with my vehicle. Are there any other ones? I ask because 32% seems more than what I need, I was thinking like a 20%...

 

Thats what you would need, i don't know if it will fit though.

 

It says it fits all GM and Ford Serpentine Belt alternators. SDPC has it listed here:

http://www.sdpc2000.com/cart.asp?act...=741&pid=89349

So I should order it? Will I need another belt? I just replaced mine with a new one...

 

Don't forget, it also doubles the alternator speed when the engine is at 5000 RPM....

 

Isn't that *really* low for an idle... I would think you'd want to idle a bit faster...

My voltage meter is weird, fluxuates quit a bit, with load it drops below level. Yet I never have any cranking or voltage problems...

 

yeah, I would get the idle to be around 600-700 and see what the voltage is doing... and, like RB83L69 said, it'll double the speed throughout the RPM band... not sure how that would affect it, but I wouldn't risk it..

 

92,

That smaller poly V sheave will work, but too bad it's aluminum. It will wear faster than steel, regardless of the alloy.

I think you need to get to the root of the problem. If you're not using an underdriver on the crank, then you need to check the idle RPM. Target idle RPM on a TPI is 650 in DRIVE. When you set the minimum air position, you set it lower so that the IAC can control it rather than throttle bypass air. If the engine doesn't idle at the correct RPM with the IAC functioning, you have a problem somewhere.

Remember that the dash mounted tachometer isn't all the accurate, so you need to verify the RPM with a handheld tach. If RPM is correct, you may have an alternator issue.

BTW - nice pair of 'Birds!

 

Thanks! I'll verify my idle using a digital timing gun.

So I should be at 650 at full temp in gear? Ho do I adjust the idle? Don't I have to break a hole in my TB?

 

at full temp with mine in gear... it sits at 550 RPM... no more...

 

First of all, get your idle fixed. Do a search on the procedure on setting the minimum idle. Overdriving an alternator is not the way to increase output.