Anyone using the RSS underdrive pulley?
05-13-2014, 08:34 PM
#16
Rennlist Member
No real reason - Internet search had them high on the list, web site was easy to navigate and price was the same. After I placed the order they told me that RSS was backlogged on production so they would be out of stock for 2-3 weeks. Might not have been the case if I had gone direct but I'm not in any great rush so was willing to wait.
My friend runs RSS that is why I was curious. Interested to know your thoughts on the pulley after install..
05-13-2014, 10:42 PM
#17
RSS is nice as it comes with a lock wrench. I have the Mantis so I made my own. Either way stay away from the really lightweight ones with spokes that have holes in them instead of being a solid surface as those have known to break.
05-14-2014, 12:49 AM
#18
Rennlist Member
The RSS version looks to be slightly larger then the rest of the pulleys on the market. They claim you can use the stock belt. I went with a 4" from Precision chassis works which came with a shorter belt, I just need to fab a tool (unless someone will lend me theirs) 
05-16-2014, 04:30 PM
#21
Burning Brakes
Tnx FLY996
So basically the RSS pulley is about a little over an inch smaller then our original one which makes it spin at an faster RPM.
For some reason I always thought people go bigger on the U/D pulley.
So basically the RSS pulley is about a little over an inch smaller then our original one which makes it spin at an faster RPM.
For some reason I always thought people go bigger on the U/D pulley.
05-17-2014, 12:41 PM
#22
Racer
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Holding RPM constant, the farther the distance from the axis the higher the linear (tangential) velocity will be (re: belt speed). So an under-drive pulley which is smaller in diameter slows the belt speed down versus a stock pulley at any given pulley/engine RPM. That's as good as I can explain it so many years out of trigonometry classes. 
05-17-2014, 12:42 PM
#23
Racer
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Do you have to relieve some material from the engine case to fit this smaller pulley? I thought I read that somewhere... some owners may prefer not to modify in fear of destroying the long term appreciation expected from these future classic Porsches!
Last edited by Viper6; 05-17-2014 at 12:44 PM. Reason: spelling
05-17-2014, 08:23 PM
#24
Yes, there is a small boss that sticks out from the back of the engine case. Due to the smaller diameter of the pulley it will hit this protrusion so you have to cut off a small amount.
05-21-2014, 08:46 PM
#25
Finally installed the RSS pulley that's been sitting around since last year.
Also installed a new oem belt, original size.
install went well, only one rookie moment....hint, car out of gear before you spin the pulley for TDC....
Also installed a new oem belt, original size.
install went well, only one rookie moment....hint, car out of gear before you spin the pulley for TDC....
05-22-2014, 09:45 PM
#27
