bart1

Broke an alternator belt and put my old spare on. Decided to go ahead and do the RS fan hub conversion. Ordered parts from Rothsport and will probably install this weekend.

Is there a better DIY out there than this one?

https://rennlist.com/forums/964-foru...tl-photos.html

I was hoping not to have to remove the alternator or anything. I might should paint the fan or something while I have it out, but mine is in good shape, so I may just clean it up good and get a coat of wax on.

Any thought or pointers on the job? Thanks!

-Bart

Garth S

A couple of comments to a well done DIY in the 'good' link.

Disconnect the battery ground, for as at a minimum, you will be tugging the fan/alt combo out into the light of day: if the bearing sticks, the whole assembly comes out.

Generally, the bearing sticks to either the fan - or alt. shaft: occasionally, to both . Rather than use pullers on a $500 magnesium alloy fan, I prefer to cradle the whole lump in my lap ..... and tap the protected end of the alt shaft with a soft face hammer with the alt hanging downwards ( also something below to cushion the alternator when if pops off).

There is no need to consider the new RS hub a press/interference fit to either the shaft or bore of the fan: polish the fan bore with a fine emery cloth until the RS hub slips in easily. You will pat yourself on the back much later - when the fan has to come out for an alternator brush set, etc.

Lightly lube all contacts with a tacky grease, and assemble.

Doing this will allow one to easily remove the fan in future without loosening the alternator - yes, there is room to wiggle the fan out!

Do not loctite the M5 10mm nuts on the studs - use M5 nylock nuts, and carry a 10mm wrench with your spare fan belt.

Make up a jumper to short out the harness to the inner belt wheely sensor deal .... and throw the latter away!! If the single belt breaks, the loss of the alternator is more than adequate warning - whole dash lights up.

I sliced the male plug off a Bosch fuel injector, and soldered a jumper across the pins on the cut side: epoxy seal the exposed jumper, and this little piece plugs directly into the female harness.

haygeebaby

I have done the RS hub conversion and I found it to be a complete waste of time and money.
No noticeable difference.
If you go ahead then it is a great time to paint the fan and fan housing. Paint the fan red and get some bling in the engine bay. Powder coat of my fan housing black improved looks.

Mike J

I did not like the lack of charging when idling with the RS pulley - if using Halogen lights you can see them dim out if accessories are on. If you use the car in lots of stop and go traffic I think the battery takes a realy kicking.

I loved the simplicity of the pulley, and had it on my Targa, but will not upgrade the Turbo with it. Well recommended if you do mostly highway or track, but not for city driving.

Cheers,

Mike

David in LA

Pics please...was the fan itself painted or powder-coated? If the latter, any issues with reduced clearance?

TIA

kjr914

Penetrating oil and patience. Fan-to-fan bearing and fan bearing-to-alternator shaft will be nearly welded in place.... I had it out of the car and would turn the puller bolts and go away for a while...come back and do it again...and walk away. Slow and steady.

A search will bring up a method of removing the fan+bearing using some longer bolts that might work as well as the puller. Didn't get to try that way, but it seems to get some good reviews.

mcipseric

+1
Also be very careful when connecting the wires back to the alternator, when I installed my RS Alt hub, I switched 2 of the 3 and burned out the alternator and had to replace. $$$
Now that I don't track my car anymore, I want to go back to the 3 belt system.

bart1

Also found Mike's link here.

http://www.pcarworkshop.com/index.ph...or_Replacement

And Robin's:

http://p-car.com/diy/alternator/alternator.html

I suspect this is going to be one of those frustrating jobs that I get in the middle of and say "why didn't I just replace the gorram belts!?"

I don't drive in much city traffic with it, so I hope the charging won't be an issue. On a side note to that, I recently installed a battery disconnect switch on my Odyssey 925 to hopefully preserve it. Is there anything I should worry about on the ECU having to relearn after a disconnect? I don't have any emissions tests to go through or anything.

haygeebaby

I didnt have any problems with power to the electrics. I also run the 925 without any problems in stop start traffic.
Fan was also powder coated in silver. Housing was coated in black. No problems with clearance.

before / after:

bart1

How do you like the RS heater fan bypass? Another mod I've been on the fence about...

haygeebaby

CF pipe gives some nice engine bling but no performance gains to be had. It saves 3 or 4kg perhaps. The pipe is sitting in my garage since I installed the SC. The engine bay looked great when I painted the intake manifolds. If I had the car NA I would keep the CF pipe in there for looks only.

bart1

I looked around and never did find that method of using bolts to remove the fan. If anybody could point it out, I would appreciate it!

Edit: Nevermind, I see geolabs note now.

ToSi

Thread 3 long M6 bolts through the holes in the fan hub, long enough to bottom against the alternator. Tighten equally around & they'll push the hub off.

From the other thread, bolts thread into holes in hub next to where the puller arms are here:


To install, heat up the new hub in boiling water - it'll slip right on.

here's another good thread describing belt tension, etc. -> https://rennlist.com/forums/993-foru...e-v-belts.html

bart1

Done. I used long bolts but hub came off with fan. I'll post pics later. Belt is tight, will check after some miles. Rothsport belt is a little different size.

Mike J

Be careful with the belt - remember the association with misfire codes and non-Porsche belts.