996 Cup Axle - Failure Analysis
10-01-2015, 11:39 AM
#46
Rennlist Member
Much of the attention is being placed on the axle, but in the cases where the failure is at the nut or splines I wonder what the condition of the hub inner splines is. With excessive wear/play you will get concentrated stresses inside the hub. The hub bore will wear, and as they do you will have more play inboard which puts more stress outboard towards the outer spline and nut. Add in bearing runout and the axle is taking a beating. Big power aircooled cars have had the same issue.
Porsche does recommend reduced axle nut torque for the first 100km, but they don't give the values....
Porsche does recommend reduced axle nut torque for the first 100km, but they don't give the values....
10-01-2015, 12:00 PM
#47
Burning Brakes
As on any race car I guess. The car is transported on 10 year old tires. I never leave the ones that are still good to use on the car before or after an event. Always install them in the morning and remove them after the last session before putting the car back on the trailer.
10-09-2015, 07:42 PM
#48
When you put the car on the trailer when it still has the tires on you just drove you get:
- the tires being glued to the trailer because of the hot rubber. A lot of fun if you want to unload the car and it's stuck on its 4 wheels.
- tires cooling unevenly and because they are stuck on another surface they will suffer and might not be usable the next event (rubber stuck to the trailer, flatspots ...).
- you strap the car with hot wheels, wheels cool down, pressure in the tire goes down -> straps get loose.
- the tires being glued to the trailer because of the hot rubber. A lot of fun if you want to unload the car and it's stuck on its 4 wheels.
- tires cooling unevenly and because they are stuck on another surface they will suffer and might not be usable the next event (rubber stuck to the trailer, flatspots ...).
- you strap the car with hot wheels, wheels cool down, pressure in the tire goes down -> straps get loose.
