Oval Race Report
This will be the story of John P's car as it was most improved today finishing second. Other results
here. John runs the typical Associated type of Pan car. Tires on the rear were Purple/Double Pink split with the purple outside. I was thinking early that this was probably ideal. My rear purples were too hard, My rear Magenta (about equal to a double pink) worked fine. The harder you can run the less scrub in the corners. I suspected something in between Purple and Magenta might be ideal.
Johns car was oversteering quite a bit plus it had the very common corner exit oversteer. The wing was already very high, but could be improved with the wider one. He will probably buy that by next race. We started to increase left down tweak. In heat three I convinced him to change to the .044 inch wire diameter blue spring as he was running out of adjustment on the .039 inch spring. Heat three proved very fast laps for him, the fastest were as good as mine.
Next we worked on gearing using rollout. My preferred rollout is 3.07 inch/revolution. We found the diameter of his tires which measured 2.140 inch. Multiplying by pi (3.14) = 6.7196 inch. This is the circumference.
We divided tire circumference by desired rollout (6.7196/3.07)= 2.188
Thats the spur pinion ratio he needs.
His spur was an 84. Divide that by 2.188 and you get 38 that was the pinion he needed.
Well the car ran very fast laps in the main! Tires! Tires! Tires! Gearing! plus good drivability. He got into the marbles on lap 14 and it took a few laps to get the dirt off. He came in second.
Reminds me of when we tinkered with Josh's car and then he took the lap record qualifying round.
If your are running 13.5 brushless, 4 cell check that gear ratio out.
John