Glen

This is not a hard job and can be done from the top by removing the throttle body/plenum assemble. Just takes some time, not difficult at all. Definitely do not need to pull the gearbox to do it. Only done 3 cars this way so far....

Holger B

If it's 5 (or whatever the number may be) free hp, why wouldn't they come this way from the factory (after all, it's factory parts that you're swapping)?

Is there some drawback that I'm missing? Or maybe something emissions related?

viperbob

It is just a new mod for the later cars.

navdoc

cup 12 has the same information as I. The seal should be change or long erm there is a chance of RMs leaks.

cosmos

Whats the part # again? The one posted in the pic is useless.

Hi BOB!!!

vegasgolf98

Evan get it so you can add 2 points and play with Bob and Philip in PP!!!!!!

JasonAndreas

Did you try Porsche Motorsports? A regular dealer won't have the part number in their computer.

Cupcar#12

PMNA is the source for the breather and the seal - if you are not updating the seal there is a chance of oil leakage from the FMS - and as normal the RMS.

It makes the change a little more involved as the engine has to be dropped to change the FMS - but for piece of mind it is worth it

Why - the breather raises pressure in the crankcase by a good deal (i can not remember off hand how much exactly) before the BOV vents pressure.

i'll take a picture of the seal when i get home - and i am installing a different breather vent valve which works the same way - 5hp is the expected gain with this mod alone

JasonAndreas

Do you have the special tools (extracting bolt & the holding wrench) for removing the pulley so you can get to the FMS? I am going to buy the extracting bolt ($16USD) but I'd really like to avoid the $157USD crankshaft pulley wrench. I could possibly fab one if I had some pictures or if you are interested in renting for a day.

Balkan

If you are removing the pulley change it for the RS part ?

viperbob

Hi Evan. As the folks stated, that is the correct part# through PMNA. It also shows up in the PET.

Cupcar#12

i don't (on the list, as soon as i get a lift) as it is i use a buddies shop to drop the motor on his lift (this is a 964 cup).

Also can i get the part # for the RS pulley as well (might be a direct swap for the 964 pulley as well) - depends on the rotational speed if any gains in cooling/charging are to be found.

cosmos

Please post the part #'s for the RS pullies too. Also do I need smaller belts as well?? What other parts are needed for the pully?

Balkan

https://rennlist.com/forums/996-gt2-gt3-forum/216278-clutch-and-flywheel-again-question.html

I may have a spare new RS pulley with bolt.

JasonAndreas

My 964RSA is a daily driver so I'm not swapping out to the single belt 993RS wheel hub that fits on the alternator or to the 993RS pulley because of the potential issues with the 964 crankshaft. With my luck I would get stuck on the side of the highway in the middle of no where with a dead battery and whatever carnage results from a undampened and unbalanced crankshaft. I have a leaking seal behind the pulley so I plan to replace it with the PMS FMS in preparation for a one-way crankcase valve.