Who knows the specific differences between C4, C4S, and GT3 suspension

996 Mk1and Mk2 Has anyone got a link? I didn't see anything. Are the shock mounts the same? Are the spring rates listed somewhere?

What are you wanting to know or do specifically? All those models vary significantly: the first C4 is a NB, C4S is MK2 wide body and the GT3 is MK2 NB or MK1 NB (not available for the NA market) - all different

996 C4 and C4S would have traditional Macpherson type struts/springs non-adjustable. M030 sport suspension was on option on the C4 and C4S, as was X73 and X74. I am not completely sure on the difference between X73 and X74, X74 may have only been for the RWD cars but both are more aggressive than M030. Shock mounts, bump stops, and other hardware aside from the springs and struts themselves are interchangable between the M030 sport package and the Standard, and maybe with X73/74. There were also USA vs ROW versions of M030 with the ROW having lower ride height than USA. 6-GT3 had Bilstein adjustable ride height coilovers with H&R springs. Stock spring rates on the 6-GT3 were around 225 front and 550 rear. None of the parts of the GT3 coilovers would interchange to C4/C4S suspension (top mounts, etc), however you could put GT3 coilovers (whole) onto C4/C4S however they were not tuned for AWD on the fronts or the additional overall weight of AWD. I am pretty sure the GT3 (unlike the C2) used the same front carriers used on AWD cars....not completely sure there. GT3 also has adjustable sway bars, 5 holes in the front, 4 in the rear (or the other way around, can't remember.)

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I believe that's mostly accurate. One correction, wheel carriers are unique to the GT3/GT2 (as they have better bump steer geometry and are a bit beefier). Also AWD to RWD front uprights (i.e. carriers) are also different -to accommodate the driveshaft going through the middle of the carrier on AWD cars!

I like to go on one of the OEM parts websites and look at the part numbers between different models and years. It�s informative and kinda fun. Asking for a list of the differences between 996 models without being any more specific than that is asking a lot, especially throwing .1 & .2 into the overall request. Researching part numbers can give you a better picture of the differences, as well as the evolution of the 911. I have looked, on more than one occasion, for a resource that lists every difference between the 996 models and couldn�t find such a list anywhere; that info is scattered all over the place. If all you�re looking for is whether or not a particular part is shared between models from the factory, that�s easy enough to ascertain on a parts website that lists parts by year and model. If you�re asking what parts work with each other, that�s a more specific question that would probably be better answered with more information and context.

Thank you gentleman. Many of you know much of this information that would be good to understand. The issue stems from considerations for modifications of a C4. In honesty I should introduce my car, (here's my car, etc), but thought that these questions could be useful for those who come after me in the future. One of the questions is whether there is interchangeability for the C4, C4 S, and turbo models in the front as they share all wheel drive. The rear would be less complicated. Spring rates may or may not be changed, and if so this could be beneficial for sport oriented applications. M030 kits may cross reference to some degree. It would be nice to know if 996 turbo (same as C4S?) wheel carriers could be used, the turbo brakes could then be installed. Also, apparently the C4 chassis is the basis of the GT3 so there is crossover potential there as well. The differences being RWD vs AWD, but are the suspension attachments shared? That would allow installation of corresponding components.

So, as many aftermarket suppliers note the same shocks/springs for C4, C4S and since Turbos "share" suspensions with C4S the question is what possibilities are there for reasonable upgrading?