db_gt3

My info is coming from my mechanic who is smart and has 30+ years as a factory master mechanic, however I am also an automotive engineer and know a thing or two myself. As stated I would challenge anyone to come up with any actual documentation from Porsche stating that the use of the factory single mass flywheel on 996 GT3 will void warranty in the event of motor failure. My mechanic knows of no such documentation, and I do not beleive it exists. What is the problem?

That's what I am saying; you can't compare the wet sump boxter derived engine to a GT3 engine. I was'nt trying to imply anything, the M96 uses a bored out boxter block, and it is wet sump, as you yourself stated. The M96 motors are not built the same way as a GT3 motor, nor are they held to the same exacting tolerances, most notably the balancing which, for a standard M96 motor, is no more than a function of how much deviation exists in the weight of the motor's parts as they are cast and machined that determines how far out of balance the motor will be. They are not put under the microscope the way a GT3 motor is and as such you end up with an inherently unbalanced motor when compared to that of a GT3. This could be the reason for the catostrophic crank failure, or not, I don't pretend to know nor do I care. The M96 is not intended for constant track punishment, those that see that type of use will experience problems. The thing that I am trying to clear up is that this "tuner" is using flawed logic to explain a motor failure and others are applying the same logic to GT3 motors. And it does not make any sense on either front. This guy just put the wrong non-factory parts on his M96, caned it repeatedly at the track, and paid the price. Case closed.

Did not mean to offend your sensibilities.

va122

I just had the LWFW installed at the dealer, and the tech insisted on using the RS pulley to specifically prevent such an occurrance.

cfjan

What's the difference between stock pulley and the RS pulley?! Thanks!

va122

Weight I think.

GT3 Chuck

are you still under warranty...and if so, did the dealer tell you that putting in the RS flywheel would be covered...trying to determine if the Porsche service bulletin that stated that RS flywheel installations will void warranty was specific to 997 GT3 and does not include 996....

va122

Not a word about it one way or another. I'm not concerned until I see a buliten naming the 996.

db_gt3

Has anyone actually seen this service bulletin? If so can your post the document or a link?

GT3 Chuck

my dealer service tech is on that other forum...I'll pm him and see if I can get it but he is the source of the info...when he was talking about it (just last week)...it was specific to the 997 but I assumed that was because that is the current iteration...if you brought in a 996 today and asked for the rs flywheel it would be interesting to see what the dealer would say....

va122

They said yes to me, but i suppose it has to with your relationship

GT3 Chuck

for those, "I'll believe it when I see it guys"...

Technical Information
Service
36/08 ENU 1360 1
GT3 Engine: Flywheel and Pulley
Vehicle Type: 911 GT3 (997)
Model Year: As of 2007
Concerns: Flywheel and pulley
Information: Replacing dual-mass flywheel with single-mass flywheel.
We have discovered that the dual-mass flywheel, which is installed as standard in the GT3 engine (vehicle type 997810/-811), is being replaced in the dealer organization with the single-mass flywheel from the GT3 RS engine (vehicle type 997850/-851).

Information

Due to an increasing number of reported faults, we expressly wish to point out that the installation of the single-mass flywheel (from the GT3 RS) in the GT3 engine is not approved by Porsche.

Since the 911 GT3 (997) engine application is designed for the dual-mass flywheel, conversion to the single-mass flywheel results in the following problems and consequences:

• The single-mass flywheel causes fluctuations and vibration in the lower rpm range, thereby reducing the smooth-running performance of the engine.

• The crankshaft is subjected to one-sided loading, causing stress peaks that can result in damage to the crankshaft.

• The one-sided loading of the crankshaft can cause the pulley to come loose, resulting in damage to the belt drive and engine.

• Any damage relating to conversion or damage that can be attributed to conversion is not covered under warranty.

Please advise your customers of this information accordingly.

©Porsche Cars North America, Inc.

October 15, 2008

cfjan

Hmm.. same engine as the RS... ?!

GT3 Chuck

I don't know why you are getting out the popcorn...that is a copy of the service advisory sent out by Porsche...it's not from me....as far as I know there are only slight differences between the GT3 and GT3RS engines and the dual mass fw (GT3) versus single mass flywheel (RS ) is one of them

cfjan

Didn't mean anything by it, my apology if I mis-use the icon.. just thought that the GT3 and GT3RS have the same engine, that's all..

GT3 Chuck

no apology needed...no offense taken...

gt3'er

Is there any reason to think the 6GT3 engine would not be vulnerable to the same "consequences" as the 7GT3 engine?