Jr. Dragsters Debut at Avenal - October 2005

by Tim Gaasch

This was the first trip to the race track for the kids. I had spent some time during the summer preparing the car for this weekend. We went to Pismo one time to run the car and to figure out how fast we could expect it torun. Both Jon and Sam were scheduled to run in the pee-wee class which limits the Elapsed Time (E.T.) to 10.0 seconds.We test drove the car with three passes between 11 and 12 seconds at Pismo. I figured the sand slowed the times between 1 and 2 seconds so we should be close.

Our first pass was 9.7 seconds on the Avenal track on Saturday morning. This was close to the 10.0 second run and I was optimistic that we could make our target ET. I changed thefinal drive sprocket from 78 tooth to 84 and the next run was 9.4 seconds. My next guess was to restrict the exhaust to choke the air flow. I did not have any restricting exhaust gaskets however I did have a smaller diameter exhaust pipe. We put this on and the final run for Jon came in at 9.0 seconds.

The former owner of this car ran 10 seconds on a 1/8 mile asphalt track. I have not worked on a Briggs & Stratton motor in the past and am unsure of the torque curves. I sat down on Saturday night and convinced myself that I had just changed the gearing and backpressure enough to move the peak torque curve enough to compensate for the larger paddle tires. I changed everything back to the original setup for Sunday morning and put Samantha in the car for her test runs. We had two false starts were the chain was thrown off before we could stage. Finally, on the third attempt Samantha made a pass at 8.4 seconds.

I was now lost. How could Jon make a run at 9.7 and Sam run the same setup at 8.4 seconds? Time was short because we got in under the last test and tune period and the kids classes ran first for competition. My last trick with the parts on hand was to reduce the compression with a second head gasket. We got this together and pushed Sam to the line. The car did not want to idle the same andas the light turned green the car died. We started again and made her pass at 12 .3 seconds.

We were now done for the weekend with five runs complete; however, we were no closer to a set-up than when we arrived. This simple little car was going to take some more thought and test runs before the next race. I expect we will investigate additional weight and more with gearing. The kids did have fun, but it can be difficult to maintain your enthusiasm when you have been disqualified on your first run. So far they are still excited about next time.