Underdrive pulley question

[Irish Pride]

I have an underdrive crank damper and i've also been able to track down the SHOShop underdrive power steering and alternator pulleys. The crank pulley is a smaller diameter and the SHOShop pulleys are larger diameter. I understand the principle of how they work, but what i need to know is can they be used together? If i use the undersize crank pulley with the 2 oversized pulleys will that cause the power steering and alt. to turn too slow?

 

[RonPorter]

That's the way the kit was originally sold. I ran mine for a few years and about 80K miles with no issues.

 

[Irish Pride]

Ok, i didnt know that. I thought the underdrive set consisted of just the water pump, power steering, and alt. So all i need to do now is track down a water pump pulley. Easier said than done though.

 

[jayro]

What set it your crank pulley from? Is it one of the sho source ones? The only issue I have ever heard about is the alt not charging completely at ilde due to the reduced rotation. Also lights may dim at idle as well. I am running just the sho source crank pulley and havent had any issues. The biggest thing that udp do is save your accessories.

 

[jon93]

Also don't expect your power steering to be strong at low rpm's with it being underdriven twice.

 

[Irish Pride]

Also don't expect your power steering to be strong at low rpm's with it being underdriven twice.

See, thats what i was worried about. I always thought that a set of UDPs consisted of Alt, PS, and WP only, and that the Crank pulley came about on its own as sort of a substitute to the UDP set. I was thinking that if i used the Crank along with the UDPs that it would cause over-underdriving.

 

[SHObill]

I would not use both sets together! Esp the alt! The old SS set-up were 2 larger acc. pulleys =alt & PS- & the crank pulley was just lightened-but same size-& it had an issue of separating. Even the lightened WP pulley is the same size as stock-just alum-as you don't want to under drive that either.

 

[Irish Pride]

I would not use both sets together! Esp the alt! The old SS set-up were 2 larger acc. pulleys =alt & PS- & the crank pulley was just lightened-but same size-& it had an issue of separating. Even the lightened WP pulley is the same size as stock-just alum-as you don't want to under drive that either.

Ok, so i should go with just the Crank pulley by itself, or just the PS and Alt pulleys by themselves. Makes sense, thats exactly what i was thinking. I should get better results by going with the crank so i guess thats the route i'll take.

 

[AREA 91]

Is the crank pulley 1 piece, or two?
The 2 piece (Hypertech) pulley likes to seperate.

 

[ShadetreeSHOguy]

Denny has the PS, alt, and WP underdrive pulleys. I do NOT like them at all. The car runs too hot for my liking.

 

[Irish Pride]

Is the crank pulley 1 piece, or two?
The 2 piece (Hypertech) pulley liket to seperate.

 

[SuperHO]

due to a pair of amps in my trunk, I:m only runnin UDPs on the water pump and power steering pump. The only time mine starts heating up is at an idle, though I hae experienced some low speed loss of power steering boost, though not enough for me to care.

 

[AREA 91]

I have UDP's on both of my SHO's. My daily driver has had them for 10 years with zero problems. I don't see the extreme temp's that you do down south.

 

[rbruso]

I have a SHOShop 3 piece (alt, PS, WP) set I bought back in '98-ish that I've run on two SHOs in Arizona without overheating problems. The only problem I've ever had was almost forgetting to pull the underdrive pulley off of my alternator when I replaced it.

There were minor changes several times with the SHOShop pulleys, but all three of mine are different diameters than their stock brethren.

 

[auto.guru]

wouldnt an underdrive pulley on the WP turn it faster - thus creating more cooling?

 

[rbruso]

Each pulley in the set is larger than stock for this type of setup, which drives the selected accessories slower. The A/C still runs at the stock ratio to the crank.

If I wanted to only underdrive the alternator I could swap in stock P/S and WP pullies. If I were having heating problems but everything else was fine I could just put the stock WP pulley back on.

I'd have to measure for a new belt, of course.

A smaller crank pulley underdrives all of the accessories. It's everything or nothing.