I am really struggling at Hill Country Kart Club, guys. I was pretty much last place at the most recent race. @APB9785 , feel free to chime in if you see this since you are my teammate and you have been faster than me ever since I stopped running underweight in practice.
I can do a 38.0 or maybe a high 37 on this layout at my BEST. Most of my race laps are more like 38.4 or 38.5, while the winner is doing mid-37s. Pole time was actually slower than pre-final and final at 37.7, but he got down to 37.2 in the pre-final.
Overall feel: kart feels sluggish in slow corners (understeer) and twitchy in fast corners (oversteer) and brakes feel spongy (not chirpy) ever since I added lead to the kart. Weight min is 375 lbs for Rotax Clubmax (Jr. Rotax engine on a senior chassis), as opposed to the 360 lbs I am used to in KA Sr. Also, this track is slippery concrete, not sticky asphalt, so my challenge is to adapt to the new weight and new surface. Watching the fast guys, it seems like they oversteer and slide through the corners on purpose, especially in turns 2 and 3. @APB9785 seems to do this in turns 7 and 8. I’d say his turn-in steering inputs seems more aggressive than mine, but maybe it just looks that way when I’m following him because he is taller and stronger than I am. I replaced brake pads and bled brakes, took a bit of grip out of the rear, and added front end by maxing out rear width and increasing front width from 10 mm spacers to 15 mm, which helped the kart rotate and killed a lot of the low-speed understeer. This made the kart too nervous and oversteery on high speed corner turn-in, so I went back to 10 mm spacers in front but kept the rear maxxed out.
Video analysis: I’ve included best laps from 3 different sessions here, as well as a reference lap from our driver coach. The part that is really messing with my head is that I was actually slower on brand new tires than I was on used tires that had >50 laps on them. Maybe it was just the conditions on the day, but that really shouldn’t happen. I feel like I’m not getting the most from the tires. Everyone here runs crazy high tire pressures and they say it’s because the surface is slippery. I’m talking 20-23 PSI cold.
Data analysis: Yellow is a 37.8 on used Levantos, Red is a 38.0 on used Evinco Blues, Blue is a 38.2 on new Evinco Blues, and I don’t have data from Tommy’s reference lap but he was doing mid 37s that day. Red and blue laps lost time coming out of the slow turn 2 and lost even more time through the fastest corner on the track, which is a very bumpy right-hand uphill sweeper that we call Helter Skelter (turn 4, 0:26 in the video). I couldn’t find a good track map online, so I made one. I really need to get data from Tommy. Sorry I don’t have good data to compare mine to:
https://youtu.be/n7az1HKITIc Here are more of Thomas’ laps for comparison.