The car had done four or five seasons of autocross before the first shaft failure. It was the left side shaft that had failed. The parts are Westfield factory parts, as are the replacement parts. Nothing different, no changes over the life span of the car. the car was professionally built by Alamo Sportscars in Texas. I will post pictures later of the failed parts from the first failure. Do not know if the second failure is the same since I have not dismantled yet.
The failed shaft broke in two places. The splined hub at the wheel end shattered into several pieces and the shaft itself sheared inside the differential leaving a piece of shaft and several pieces of metal in the oil seal area. I had to remove the diff and make sure that it was OK, which it was.
The universal joints did not fail and the shafts are parallel to the ground. The tires at time of both failures were Falken Azenis but I have used Hoosier autocross tires and soft compound race slicks during earlier seasons. Wheel/tire sizes are rear 225/50/R16 on 7.50in rim and front 205/50/R15 on 7.00in rim. Westfield spec is 13" or 14" wheels so the car rides about 1 1/2" higher than factory specs.
On the question of torque the Hayabusa engine develops about 115lbs/ft which seems OK for a 1300 engine and an 1132lb car. The biggest problem driving it is the limited clutch travel, lack of flywheel effect, short stroke and small reciprocating mass - it stalls very easily! It has a great spread of power all the way from 5500 to 10500rpm and with this rev range it hits 60 in first and 80 in second. most autocross courses are run entirely in first gear.
Autocross starts are pretty rough, the tendency to stall so easilly means that starts require getting the wheels spinning then modulate the throttle/back off to get grip before the start time lights.
