Can anyone give me a good explanation of how the Ateesa system on the GT-R works ?. Have read its more rwd for most of the time, then starts shifting to 4wd, as slip is being felt etc. Many thanks, regards, SIMON.
I actually started looking at this aswell a couple of days ago and started viewing the torque split graph on the MFD, it shows you how the system works, and you are right in saying that it is mainly rwd. I saw that when you drive off from a standstill then it transfers power to all 4 wheels but as soon as you are moving then it transfers back to rwd.
It is different from the earlier Skyline GT-Rs in that they did not send any torque to the front until actual rear wheel slip had started to occur whereas the R35's system appears to pre-empt slippage and feed some torque to the front as soon as the throttle is hit.
The 4wd system is based around an electromagnetic multiplate clutch from GKN. It gets signals from:
Vehicle speed signal (ABS)
Stop lamp switch signal (brake signal)
Yaw rate sensor signal
Side G sensor signal
Decel G sensor signal
Accelerator pedal position signal
Engine speed signal
oil temperature signal
parking brake switch
steering angle sensor signal
• AWD control unit controls distribution of drive torque between rear-wheel drive (0:100) and 4-wheel drive (50:50) conditions according to road conditions.
• AWD control unit controls fix the drive torque distribution for front and rear wheels to stabilize the start-up on icy roads.
• Makes possible stable driving, with no wheel spin, on snowy roads or other slippery surfaces.
• Via each relevant sensor, AWD control unit judges road conditions and the vehicle cornering condition and distributes appropriate torques to the front wheel to prevent the tight-corner braking phenomenon, as well as to improve steering stability in a curve and vehicle stability during acceleration in a straight line and high speed driving.
• It transmits/receives each signal from the following AWD control unit via CAN communication line.
• When driving, if there is a large difference between front and rear wheel speed which continues for a long time, fluid temperature of drive system parts becomes too high and AWD warning lamp blinks quickly. (When AWD warning lamp blinks, vehicle changes to rear-wheel drive conditions.) Also, optional distribution of torque sometimes becomes rigid before lamp blinks quickly, but it is not a malfunction.
• If AWD warning lamp is blinking quickly, stop vehicle and allow it to idle for some time. Blinking will stop and AWD system will be restored.
• When driving, AWD warning lamp may blink slowly if there is a significant difference in diameter of the tires. At this time, vehicle performance is not fully available and cautious driving is required. (Continues until the engine is turned OFF.)
• If the warning lamp blinks slowly during driving but remains OFF after the engine is restarted, the system is normal. If it again blinks slowly after driving for some time, vehicle must be inspected.
• While the AWD warning lamp is blinking or illuminating, the vehicle enters rear-wheel drive condition or weak 4-wheel drive condition.
I think the graph above is for the 34. Nissan seem to be quiet on this one for the 35 but i'm sure it is a major reason for the ring times.