Underdrive Pulley's
 

Alright guys,

Im new at modding and I believe I want Underdrive pulleys(they make that whining sound I believe?) I was wondering which ones I should get, how much they cost, and how much and how long it would take to install them.

Be gentle, lol

-Abe

Underdrive pulleys are supposed to free up a few horsepower at the wheels by reducing the drag placed on your motor by the accessories.

Typically, they slow down there are a crank, alternator, and waterpump pulley. Hopefully, you have a high output alternator so you can avoid battery charging problems.

When I drove my 1990 5.0 daily, it wasn't a problem, but now that I let it sit and take it for only short drives about once a week, I can't let it sit too long, or it will be slow to start (or not want to turn over at all)....

I don't think my alternator is able to keep the battery charged on my short trips.

I don't think underdrive pulleys are supposed to make any noises. You might be thinking of a gear drive instead of a timing chain, but that's a whole other ballgame.

Good luck,

March makes good pulleys and has a pretty good selection. There are several other brands that I'm sure are fine also. They all pretty much do the same thing. You usually get to choose from steel or aluminum. I would stay away from off-brands or cheap ones though. A bad pulley will waste your accessories or could possibly break causing muxh damage.

As mentioned there are gernerally 3 pulleys in a set but you can use any combination of them - check your belt length though. The crank pulley is smaller and the w/p & alt are bigger. They will sometimes offer "race" sets or "street" sets depending on how bad you want your accessories to work. Slower accessory speed means you don't lose as much h.p.

Be careful of how your car reacts. Like the previous post your charging will most likely suffer without a 130 amp alt. With my March pulleys I don't charge at idle but it does when over about 900 rpm. At night with lights, stereo, heater fan/wipers etc it doesn't charge near as much.
Be VERY careful about cooling. I saw a big difference in the summer. Overheated a little at one of the August autocross events.

Install is fairly straight forward. You will need a allen head socket for the crank pulley because the smaller dia pulley doesn't offer as much clearance for the stock bolts. Might be able to use stock bolts with other brands.

You will free up some h.p. but you may have to beef up either of these systems depending on how your car is set up and how you use it.

Dan

Sweet thanks guys, thats what I was looking at was about $100 I will keep an eye on the charging once I install them......oh yeah, anything on the noise ? (do they make a slight whining noise) cause that is what I want hehe.

-Abe

No they shouldn't whine at all, if you want a whine buy a blower. :)

Also, I would not recommend getting the powder-coated ones, the paint will chip off after a few years...at least it has on my March pullies with black powder-coating - it is exposing a very nice looking bare aluminum pulley underneath :-)

******! I dont have enough for a blower LOL...there has got to be something that makes a whine and it not be a blower LOL.....
Yeah Red92LX5.0......I was already planning on getting the Blue Aluminum ones to match my paint.... hehe.....gonna start dressin up the engine a little.

-Abe

and just to let you know the dyno results on a bone stock mustang (mine):

peak HP (4300rpm) gain of 4 HP
peak torque (3400rpm) gain of 8 ft/lbs

hp gain at 5000rpm of 12 HP
tq gain at 5000rpm of 15ft/lbs

these are MAC pulleys that I have.. ($70 USD)
hope you get the same results, a great first mod !!

if your worried about charging some companies sell different types of pulles. the "power amp" set is used for cars with big stereos and is suppose to keep the battery charged. oh if you want that "blower whine" i'll sell you my power steering pump that is going, it's whine kinda respembles a blower. lol :D

I went with ASP pullies and had charging problems in the morning going to work with my headlights and radio on. My local speed shop changed the alt pully out to over drive it so it would charge fully. You could always go that route if you have that problem.
As far as the Whine goes, I believe your thinking of a gear drive. But the good news is I can get you a free 90 minute tape of my sister in law whining. Come to think of it, you might want to save up for a blower like everybody else:D

The whine you are speaking of is from cam gears. They are from a gear running the cam instead of a chain.

no charging
 

After I installed my ASP pulleys, my battery would not charge. It wouldn't even charge under acceleration with the rpm's up and no other accessories on. So I bought a 130 amp alternator. The installation was a piece of cake and now I don't have any charging prolems at all.

i think what you have been hearing is a worn out p/s pump lol don't worry that will come free in a couple years!