May 5, 2018:
Today Chris had his Chevelle out for the first time this 2018 season with the new, longer wheelie bars and the new, lower, 4.86 rear gears. Our focus was to get the wheelie bars adjusted properly on the launch and dial-in the shift points for the lower gearing in the car. We went from 4.71 to 4.86 for the 2018 season looking for a performance improvement.
However, today did not go as expected as the Chevelle only ran in the 10.60’s and we suspect we have a torque converter going away. We’ll carefully check the engine – valve springs and cylinder leakdown – but all indications are the torque converter is failing or the new rear gears in the aluminum carrier are binding! – Roger
May 12th Update: NOTE: THE PROBLEM WAS THE NEW CENTER SECTION!! DO NOT USE THE LIGHTENED GEARS IN A HEAVY CAR! THE GEARS BOUND UNDER A LOAD AND FRACTURED SEVERAL TEETH ON THE PINION GEAR!! – Roger
Q1 launch, captured by Tony Hutchison
Q2 Launch on May 5th 2018 – Jim Doyle pic
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After looking at data from the last run in 2017, compared to the very first run of 2018 with the new gears & carrier, logic tells me there COULD be a problem in the new center that is causing some sort of parasitic load. This was the ONLY change made between the two runs and we know from historic data that the car is quicker with the lower gears in the car.
The car is acting like we geared it up, not down!
Update: After looking at the data of our playback tach, we believe the problem is in the new aluminum center in the rear of the car. We’ll check the engine carefully and then reinstall the old 4.71’s and carrier to see if the problem is resolved!
Today we leaked down the motor, checked all the valve springs, readjusted the valves and lowered the fuel pressure to 6 psi. Earlier in the week Chris raised the ladder bars one hole to hopefully keep the car from climbing so high in the front on the launch.
We pulled the new Moser 3rd member out of the car and found hairline cracks in the pinion after only three runs, and multiple patterns on the gears. Something is deflecting. Chris & Paul put the old 4.71 3rd member back in the car and are heading out to the track to see how it runs this evening!
The car ran fine with the old gears and Strange nodule-iron center back in the car. In fact, Chris won four rounds this evening!
The Moser aluminum center, as was setup, was a BIG waste of money!!