Ok i just got this 90 Iroc Z and i was reading the old receipts. i thought the car had an aftermarket crank pulley and it turns the guy that owned it had put on a march three pulley set. the problem i that i think the only march pulley on there is the crank. im not sure about the water pump but the alternator is def not the march one cause my friend changed the alternator before he sold it to me and he didnt swap pulleys. my question is: can this mess up the car or would it be ok if the only underdrive pulley was the crank or the crank and water pump?i am asking because my alternator gauge surges when i put on the directionals and drains a little when i put on the stereo or any power.

What is does: The Underdrive pulley replaces the main crankshaft pulley on your car. It is lighter and spins the accessories slower.

So if you have a underdrive pulley you're not spinning your alternator as fast as it was spun stock. This releases some of the drag caused and frees up power. So mainly you're spinning the alt. slower than normal. The other add on pullies just slow down the accessories even more. Like the alternator pulley is pretty small stock so it doesn't take much belt travel to turn it over but a underdrive pulley kit would be bigger pulley so it would take say twice as much belt to turn it over as the stock pulley.

You might try upgrading the alt. wire to the battery. That's usually a good start on getting more power. Also additional ground strap from battery to motor wouldn't hurt. You can do searches on this on the Car Audio board since we regularly chat about these.

I installed a set of march pulleys on my car, but i have an 87 which is not a serp. belt setup so it only came with a crank pulley and a alt pulley. after i installed everything no matter how tight i got the alt the belt still sqealed. the reason was that the alternator pulley had 6 ribs instead of 5 like the factory. i suppose it was for a serp setup. anyway. i put the factory alt pulley on and left the crank. it has been that way for about 6 months and at night with the lights and wipers and stereo on while sitting at a stoplight the voltage goes down to 11.6 or so. it actually is not good for everything. it can cause corrosion on batter terminals and car electronics are not designed for less than 12 volts. i am going to put the factory crank pulley back on. i didnt see any gains at the track from the pulleys anyway.

The march power and amp pulley set actually comes with a smaller alt. pulley to speed it back up to normal while the crank pulley slows everything else down. the pulley for the alt that came with my set was so small a socket almost would not fit into it to tighten the nut.

ok so i looked at it today and it turns out it has the crank and water pump underdrive pulleys but not the alternator. so i guess my question is should i buy a whole new set of pulleys or can i get the alternator one seperately. i really dont want to buy a whole new set but this is def bad for the alternator.

You can buy the alternator pulley only from march. That would fix the incongruity you are observing.

Also, you could help it all out by getting a grounding kit and concentrating it on electrical efficiency (it will explain how in the install suggestions)

Bad for the alternator? Seems you have some things mixed up.

The origonal March 3 piece pulley set had a larger diamater alt pulley that stock, effectivley slowing it down. Now, beings that the stock pulley is smaller than the March pulley, your alternator is spinning faster with the stock pulley than it would with the March pulley, yet slower that a completley stock setup, which is just fine.

Even though your running the March crank and WP pulley, you alternator isnt even spinning as fast as it would in the stock setup, yet faster than the full-on March setup. Your just fine, dont worry about a thing. If you need to see a demonstration, check out a how a 10 speed bike works, and youll understand what Im saying.

OK does anyone know where I can get thicker gauge wiring for my alternator or do I have to bring it to someone. There is a really good electrical guy near me. He has done work on my old T/A before and he is really good. So should I just bring it to him. Also someone installed an alarm and it is no longer connected and there are wires everywhere. I think I should just have him go through the car for me and fix all these problems.

Rob is right, I run the March Performance set minus the alt pulley. The one that came with the set was larger than stock and was making my volts go into the red. So I swapped the stock one back on and the volts stay off the red. If you have the crank and WP pulleys you are OK with it as long as your volts stay off the red. You will notice a voltage drop at idle when you run the lights and HVAC function or rear defroster. Other than that it should be fine as far as charging goes. If you want looks then buy the separate March alt pulley.

Ozzy

For thicker gauge wiring you just make a new one. Run it from the back of the alternator to the POS battery terminal like OEM. Check out the Car Audio board and do a search for it.

www.thezeb.com is doing free shipping and no tax right now you could get the wiring and connectors there.