Fan pulley
05-22-2012, 05:12 PM
#1
Drifting
Thread Starter
Fan pulley
I'm getting ready to have some work done on my 993 and going over the things I wanted done, I was told that the one piece fan pulley upgrade will lower the RPM for the alternator and that’s not a good thing. Is that correct? I do not remember reading anything about that. My indy suggests staying with the current 2 piece and shims. I thought the one piece pulley was the more "current" replacement to an outdated design?
05-22-2012, 06:35 PM
#2
Race Car
Even the single belt RS pulley system uses shims for belt adjustment. It does underdrive the alternator however there are plenty of guys here that have gone down this route without any adverse effects.
05-22-2012, 06:46 PM
#3
Race Director
Either you or your mechanic are getting some thing wrong. The pulley "update" is merely new pulley halves with an integrated spacer. This does not affect the speed of the fan or alt.
The rs pulley drives the alt. And fan on the same belt at the same speed, which can cause slight undercharging.
The update however will not give you any charging problems
The rs pulley drives the alt. And fan on the same belt at the same speed, which can cause slight undercharging.
The update however will not give you any charging problems
05-22-2012, 08:05 PM
#4
Rennlist Member
Well said Quad.
Either you or your mechanic are getting some thing wrong. The pulley "update" is merely new pulley halves with an integrated spacer. This does not affect the speed of the fan or alt.
The rs pulley drives the alt. And fan on the same belt at the same speed, which can cause slight undercharging.
The update however will not give you any charging problems
The rs pulley drives the alt. And fan on the same belt at the same speed, which can cause slight undercharging.
The update however will not give you any charging problems
05-22-2012, 09:14 PM
#5
Seared
Rennlist Member
Rennlist Member
Either you or your mechanic are getting some thing wrong. The pulley "update" is merely new pulley halves with an integrated spacer. This does not affect the speed of the fan or alt.
The rs pulley drives the alt. and fan on the same belt at the same speed, which can cause slight undercharging.
The update however will not give you any charging problems
The rs pulley drives the alt. and fan on the same belt at the same speed, which can cause slight undercharging.
The update however will not give you any charging problems
Andreas
05-23-2012, 03:57 AM
#6
Rennlist Member
I once fell on a 993 with the pulley update done wrong. They installed one updated pulley half on the outside.
The updated pulley with the spacer in one piece, should be installed in 2 pieces. IE you need 2 updated pulley halves not just the outer part.
If you use only one half new, and leave the other old half, the belt sits very high on the lip of the pulley. Which
gives the impression that the alt is going to turn slower.
regards
The updated pulley with the spacer in one piece, should be installed in 2 pieces. IE you need 2 updated pulley halves not just the outer part.
If you use only one half new, and leave the other old half, the belt sits very high on the lip of the pulley. Which
gives the impression that the alt is going to turn slower.
regards
