ca993twin

My mechanic ordered an RS pulley, and it looks wrong. It is at least 2x the diameter of the regular pullies. Even if this fits, it would slow the fan and alternator to unacceptable levels. Anybody have a real RS pulley? What does it look like?

Thanks

Bill Verburg

Alternator hub

alternator sheave stays the same

Lower single sheeve pulley

there are also 2 & 3 sheave pulleys

Bill Verburg

here's what it looks like installed on my RS engine

No AC on this one

ca993twin

Thanks... so what I was looking at was the lower pulley! Good. I guess I need that alternator hub, which looks like part 993-106-054-80? Is that it? Do I use the standard size belt?

Thanks for the help.

Bill Verburg

std 9.5x776 belt


993-106-051-80 impeller hub for the alternator

993-102-050-40 pulley(single sheave) for the crankshaft

993-102-050-41 pulley(double sheave for AC) for the crankshaft

But w/ AC you might as well use the stock -01 triple sheave
single sheave



Triple sheave


double sheave

geolab

If installing RS impeller wheel hub 993 106 051 80
bare in mind that you need different studs and nuts than for the standard.

Studs x 3 part number 999.062.093.02 (BM 6 x 35)
Nuts x 3 part number 999.084.094.02 (M6)
total cost for the 6 is less than a fiver ($5)

geolab

I am sure you meant it would speed-up the fan/alternator if it is 2x bigger


If you haven't ordered the pulley yet 993.102.050.41 , I have a suggestion.
There is one brand new from a german ebay seller who lists a lot of porsche parts.
The listing has ended on the item, but probably he still has it.
He was asking 99 euros for it without shipping. new is around $450
Send him an email.

ebay Item number: 160041007659

ca993twin

All,

Thanks for the help... this is becoming clear to me now. Since I retain the A/C, I think I'll retain the stock lower, triple lower pulley. Plus it should make installation easier, especially since this is for a turbo. When done, mine should look like Bill's.

Geo,

Thanks for the idea for eBay... I'll take a peek in a moment. But to show you what a doofus I am, I thought I was looking at a replacement UPPER pulley, where 2x diam would drive it slower. What I was actually looking at was the RS single, lower pulley.

geolab

The ebay item is for lower RS pulley with A/C.
For upper pulleys, please find attached the porsche update on this which could make things clearer, plus another bulletin that is Turbo specific

Garth S

Steve,
The simple route is to toss the Alt pulley halves, leave the 3 sheave crank pulley in place, and bolt it all back together with the single 776mm belt as already mentioned. The sole negative to this is the much discussed lower alt speed - which is generally not an issue: I've just pulled the fan from my spare and am in the process of installing the RS pulley.
The first pdf Geo kindly provided is referencing the upgrade to the alternator pulley sheaves wrt sheave and alt. drive belt failures - with the 'RS' set up, you are deleting those items and 760mm belt anyway ... and will run solely on the fan belt.

ca993twin

Garth,

I think we are on the same page... but due to incessant doofusness on my part, let me restate:
I will keep the existing, triple lower pulley (but I won't use the middle sheave). I'll get the upper RS pulley kit and combine the fan/alt on a single pulley and belt. Since I have no concern about the alternator turning a tiny bit slower, this should take care of everything. I can still use the stock belt, and my belt tensionor can be removed or wired closed. I can get that RS upper pulley kit for $108, plus shipping and duty, from Gert. Thanks.