Zijn dit op een 964C4 de meest voorkomende banden maten?
Voor:
215/45/17

Achter:
255/40/17

Of is het meestal voor 225/40/17?

Wat is het maximale verschil tussen voor en achter (ivm vierwielaandrijving)?

Bij mij voor liggen 225/45/17 banden...

Zomer:
Mille Miglia Cup I (imitatie)
VA: 225/45 17 op 7,5" brede velg ET 55
HA: 255/40 17 op 9" brede velg ET 47

Winter:
Porsche 993 Cup II wintervelgen
VA: 205/50 17 op 7" brede velg ET 55
HA: 225/45 17 op 8" brede velg ET 30

Weet iemand het max verschil tussen voor en achter ivm 4WD?

a). If the control unit recognises that a given difference in speed is exceeded by comparing the axle speeds an initial pressure of approximately 40 bar will be built up in the longitudinal lock hydraulic system and to the slave cylinder. The slave cylinder acts upon a clutch lever assembly. The clutch lever assembly acts upon the differential lock clutch plate stack. This stack consists of two sets of clutch plates. One set is connected to the input drive shaft in the power transfer unit (rear axle) and the other set is connected to the output drive shaft in the power transfer unit (front axle). As the clutch plate stack is forced together drive or torque transfer is possible from the fast rotating axle to the slow rotating axle. If the increase in the difference in axle speed continues, the pressure applied to the slave cylinder and eventually the clutch stack is increased in steps with constant control of wheel speeds until perfect traction is reached. When the difference in speed returns to the tolerance range (0.8 kph), the locking torque will be reduced in steps by discharging pressure in the slave cylinder for the longitudinal lock b). If there is a ferreria effect (over-steer causing tending towards causing a spin) while driving in a curve the control unit recognises this and immediately applies pressure to the lateral differential lock slave cylinder which then via the clutch lever mechanism, forces the differential lock clutch stack together which locks the rear wheels together. The under steer created by this action counters the over-steer. Application of the lateral differential lock is designed in such a manner, that the rear- end dominated characteristics of the C4 is maintained with maximum exploitation of the co-efficient of friction. Locking torque is reduced in steps once the over steer has been corrected.
System corrections and tolerances: The following correction factors are integrated into the control unit to compensate for differences in speed whilst driving in curves or because of different rolling radii.
Curve driving correction factor: A correction value for the switching limit is determined in conformance with the driven radius by evaluating the wheel speed information while driving in tight curves, so that there is no premature operation of the longitudinal (inter axle) differential lock while driving slowly in a tight curve at less than 30 kph (19 mph).
Rolling radius correction factor: The control unit calculates a “rolling radius” correction factor while driving straight ahead. This correction factor is 6% maximum.
Rolling radius tolerance: For the purpose of explanation instead of using rolling radius data, rotations per km (mile) will be used. It is easier to work out the figures. The original Carrera 4 was fitted with Bridgestone RE71 205/55ZR16 and 225/50ZR16 tyres fitted to 6JX16 front wheels and 8JX16 rear wheels. These wheel and tyre assemblies rotated at 531 times per km (851 times per mile). This information was pre-programmed into the PDAS/ABS control unit of the C4 and the ABS control units of the Carrera 2. In order to calculate wheel speed the control unit requires to know the distance traveled by the wheel in a specific period of time. 531 rotations in one minute gives a wheel speed of 60 kph. The rolling radius correction factor allows a change of a
maximum of 6% between the front set of wheels and the rear set of wheels when travelling in a straight line. Note: The pre-programmed data was changed slightly in model year 1991 for the introduction of 17 inch wheels. The change was minor and makes no difference to this explanation.
Why is this important? Wheels and tyres are changed as the years go by. New 964 owners want their 964s to look more modern and kool. The original setup is either never know or forgotten. If a wheel and tyre assembly is changed to one which is outside of the 6% differential limit one of two things can happen.
a). If just the front pair or rear pair of wheel and tyre assemblies are outside of the allowable limit the PDAS/ABS or ABS control units will detect this and inform the driver by the warn system that the system (s) has failed. The most common error is made when changing the front pair of wheels and tyres. Either a wide front tyre with a too high profile or winter tyres with too high profile.
b). If the entire set of wheels and tyres are replaced with assemblies which are all outside of the 6% differential limit the PDAS/ABS or ABS systems cannot detect the change. The control units will continue to calculate the data based on the pre- programmed information. However the results of these calculations will now be incorrect. Most 964 owners install larger diameter wheels and wider tyres. This increase in rolling radius or rotations per mile will have a significant impact on the operation of the systems and in extreme cases impact the safety of the 964. The larger wheel and tyre assemblies rotate less per km or mile than before. However the system which cannot detect the problem will continue to use the original rotation (rolling radius) data for its calculations. This means that the calculated wheel speed will be lower than the actual wheel speed. The effect of this will be to delay the onset of traction control assistance and conversely will apply ABS assistance too early. Warnings related to this tolerance can be found in the 911 Carrera 2/4 and Turbo owner manuals.

eerset google hit,

6% samen gevat

Als het is omdat je nieuwe banden wil leggen, hou je best de voorgeschreven maten aan
die porsche aanbeveelt. (Ook in verband met RDW keuring) .

De maten kan je terugvinden in tecnisch boekje.

... gaat dan om de diameter (hoogte) niet om de breedte