[Elombard]

I have been seeing some info about this lately; I guess it’s a known issue. I just heard about it recently. I was getting excited to get an old 996 to play with since the IMS bearing retrofit is now pretty mainstream (at least in our world). And the new failure detection thing from Jake Raby can give piece of mind.....although it gives me heart burn that it’s necessary.

What I 'read' is that the crank shaft is not a high 'quality' casting or the machining is not precision. Porsche designed the dual mass flywheel to work as a dampener (and clutch shock absorber I guess) and absorb any vibrations. Apparently it’s more of an issue on the larger displacement motors with the longer throw and the 2.5 motors in the spec boxsters don’t have an issue when you remove the 'dampener' and put on a LWFW.

I wonder if 'billet' cranks will become an option in the aftermarket. I know they do this in the domestic aftermarket; is it uber expensive?

What about a crank dampener pulley on the other end of the motor as is common in many performance aftermarket applications?

I also read if you are doing a complete tear down on the motor and the rotating assembly is carefully balanced it may not be an issue. What is the cost of balancing on top of a rebuild?

Its disappointing because I love the way a LWFW transforms the way a car feels, even for driving on the street. The down sides of a LWFW are completely eclipsed by the improved throttle/engine response and heel and toeing for me. I also understand why many folks would not appreciate it. I would not want a LWFW on a commuter where regular heavy traffic is experienced.

Maybe this is more evidence that Porsche determined that very few purchasers of the 996 new would get much into the upper rev ranges or track the car and so $$ could be saved on the crank and/or balancing?

I was hoping that with some of the reliability upgrades available I could track the car with some piece of mind. The idea that the crank is not 'high quality' makes me think I should stick with the old cars or at least something with a less expensive motor.

Am I overreacting? What are others thoughts?


Sorry about the mis-print in the subject - not editable.