After the dampest of squibs on Friday night, I spent Saturday Prepping the B7 and B74.2, to rescue what could have been a rather depressing weekend’s racing.
Practice with the B7 was OK, the backend was right with the heavier lower shock settings. Front End washed out on throttle, but the front is an easy fix on the B7, so no worries there. B74.2 on the other hand , was it’s usual handful, but was still making the horrible whining noises that it made all last year, despite the complete drivetrain rework. Poo.
On to Quali 1. A notch in on the lower shock mount, a mil of extra ride height and shifting the battery weight fully forward sorted out the on power understeer issues on the B7, didn’t even need the under servo weight. Boom, started 7th, finished 1st, 17 laps, job done, and that was the story of Quali. There is more to come from me and this car. Next indoor I’ll get set up with Core RC springs, Azani Tyres and totally send it.
What I really needed from today was track time with the B74.2 before the regionals start. I needed to get my eye in with the furious pace of 4wd, and get to the bottom of the horrible noise from the drivetrain that was a constant lead weight of a distraction.
I tried tweaks to the pinion/spur and all sorts, nothing was making it better. Then as I was putting the car down for Q2, Martin Hadley, told me the throttle PWM frequency was too low. And as I strolled to the rostrum, Matt Hodges gave me the exact same tip. Why is good advice is like busses? You wait months for someone to tip you to the wiser while your car sounds like an Austin Allegro with Covid-19, then two folk tell you exactly what’s wrong within 2 minutes!
Anyway, a couple of button pushes on the programming card, Throttle PWM frequency upped from 1k to 12k and the noise just disappeared, Cashback!
And, seeing my trouble with controlling the power in turns, Martin followed up and advised I go all the way with tuning the frequency all the way up, and he was right again. The car was tamed!
Really, it was mission accomplished by the end of Quali. And so the finals were just the icing the enjoyable day cake. The charts tell the story pretty well. I took advantage of some other’s mistakes to get from 10th to 5th in the 2wd B final. I managed to stay ahead of Kev Greenway for a few laps, but he had 1/2 a second a lap on me, and knowing I was already ahead of my start, when the mistake came, he took a nice clean line to pass and I decided to just bank the extra positions I had with a pace I could live with. Driving a final with 96% consistency.8
The 4wd final, I was just plain outclassed and tired. But now I had a working car, and a platform to build on. I went home happy.
Thanks Cardiff, you rock!