This is actually a great start to the weekend. Kart responding to changes, feeling skate-y on a green track. Let us know when the track starts to tighten up and you head back the other way! 
We have already mentioned how āwe will fix XYZ we inevitably change the axle backā 
But yeah always positive when you make a change and it performs how you expect.
We are a couple tenths off Hodgson and Lemke but a ways off Gabriel who is probably going to be the one to beat. I think we are on a good path though if we can hang with those other two.
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Heāll come back to you in race trim. Heās always fast early in the weekend, but the crowd catches up. Keep it up!!
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About 0.6 off overall in that session, putting me around 20th overall out of 60-ish. Kart is getting better but we are still overworking the front tires. Going to put positive camber and some caster in to try and get the kart to get into the corner with a little less wheel input.
Also had no draft that time so that could be 0.5 around this track.
Overworking the fronts? Like graining? Sliding?
^Me pretending that I might be able to help TJ.
Slight understeer turns into greasy fronts by lap 4. So itās a tiny balance issue that compounds over the run. If we can use more of the tire or lower pressures I think we can keep the tire alive more. Or if we can get the kart to rotate a little easier we wonāt have to work the fronts as hard.
Also throwing three teeth at it for shits and giggles.
The bigger gear only hurt us everywhere. We were just out of the powerband.
Back to the smaller gear for quali, as well as reducing caster to half and throwing on the 9F wheels. Kart felt really close but I completely botched my last lap after getting a good tow on the straight. I jumped the curb too hard in green corner and had a big lift, losing about 0.3-0.4 just from that. Ended up 7th in group and 33rd overall out of 60. I think we had pace for top 20 but an old washed up driver cost us some time there. But we will race forward!
I have some more ideas to improve the kart as well. Wondering if we jack the rear ride height up and soften the axle if that gives us a better platform for future tuning.
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Would the time lost with the kerbage put you in the top 20, or higher?
Yay! Nice quali turnaround.
I wouldāve been on the cusp but itās hard to say because I literally drove in the dirt. It was a 0.4 loss according to data just in that corner but it couldāve been more since the tire was dirty for the next two corners.
I think the kart has top 20 pace. I think our baseline setup is pretty close to good now, which was the point of developing this kart so thatās a positive.
Iām also still learning the track because I am old and it takes me a while to dial in a new layout Iāve never run before.
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https://www.facebook.com/share/r/Yy7bBbynkKpWUbJw/?mibextid=WC7FNe
Got cleaned out in the hairpin. The start was stupid, I had the brakes locked and was just getting shoved and shoved. Same guy hit me three corners in a row. Then he drove over a few guys in the hairpin and I got collected.
Kart is okay though, no damage. We raised rear ride height to try and see if that would help rotate the kart without using the front tire as much. I think it helped in some spots but maybe hurt in the faster stuff.
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Good start in heat 2, on the fringes of the top 10, but then the axle started shifting and I had to limp home 4 seconds off the pace. Canāt catch a break!
Positive chassis changes though. We raised the rear ride height thinking that we just werenāt getting the inside unloaded enough. But I was concerned it would overwork the tire and bind it up. So we also went to a softer axle to allow the kart to flex a bit more and not force the tire into the track too hard. Those things felt good. Kart was digging nicely, maybe a little bit free in fast stuff but the tire started to come in and the kart was starting to neutralize but then the axle started moving.
I start P22 in the B-Main tomorrow. I need a top 10 to make the main event. We are going to SEND it and try and get to the final. With a clean race I know we have pace to be much higher, we just havenāt had a clean race yet.
I was doing a rain dance because I think this kart would be good in the rain and I think I have enough experience on a lot of these guys to be strong in the rain. But the rain came right after our heat.
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This is one of the worse feelings ever! From my experience you can tell because it knocks the pads in and youāve got zero brakes sudden entering a corner. Wish there was a better system than 3 set screws.
Yeah, the grinding of the brake rotor bolts on the cassette or the brake point constantly changing are certainly unsettling giveawaysā¦
There is, but they are expensive and not common. Iāve never used them, but some swear by them.
My method of set screws is zero loctite ever, run down to snug against axle on all 3. Then 3/8 turn on all 3, double checking for the amount of dimple inside the axle I expect.
There are axle collars that can give a little insurance
Yep, axle collars.
We always run them in endurance racing.
One each side, inboard and hard against the bearing colllar.
Well, our weekend ended a bit early with some more bad luck. It was damp but drying, so we though dry tires would be the way to go about 2 laps into the B-Main. Unfortunately once we got up to the grid, it started drizzling slightly, but it was too late to change tires and we were committed to the slicks. The frustrating thing was the weather forecast showed no rain on the radar, a 10% overall chance on the day, and yet it started raining. Just one of those things. So I tooled around out there driving the piss out of the kart on slicks on a wet track just hoping to keep myself on the lead lap long enough to gain spots through attrition. Eventually got waved off and then spun under braking for good measure. Hilariously, I actually gained one position on the final tally even though I ran 15 seconds off the pace for the session. So we didnāt transfer to the Main. This Stars format is tough; if you have one bad session itās pretty much going to put you into the B-Main. Hard to recover.
https://www.facebook.com/share/r/j2styxwGbwSbRWsC/
Other than that, we did actually collect a lot of good data on the kart and almost every setup change we tried worked as expected and improved the feel and balance of the kart. Below are all my setup notes from the weekend:
Stars Championship Series - 2024
Circuit : New Castle Motorsports Park - Reverse Shark Fin
Weather : 60-75Ā°F, humid, sunny, occasional light rain and clouds
Class Weight : 360 lbs
Chassis : BestKart F03 (soft)
Engine : KA100 Senior
Tire : MG Red SH2
Session | FP1
Front Track Width : 20mm
Ackermann : Standard
Front Bar : None
Caster/Camber : -1/2 | 0
Front Ride Height : Low
Axle Type : A
Rear Ride Height : Medium
Rear Bumper : Loose
Rear Track Width : 1390mm
Rear Hub Length : Medium
3rd Axle Bearing : Loose
Cold Tire Pressure : 18 psi
Wheel Type : AMV 3F
Seat Type : Tillett T11t
Seat Stays : 0
Max Engine Temp : 1125Ā°F
Max Engine RPM : 15,900
Engine Gearing : 10/72
Best Lap Time : 1:14.27 (lap 6)
Session Laps : 7
Notes : Flat-sliding in high-speed corners, kart feels like it is on top of the track, not enough sidebite
Session | FP2
Front Track Width : 20mm
Ackermann : Standard
Front Bar : None
Caster/Camber : -1/2 | 0
Front Ride Height : Low
Axle Type : B
Rear Ride Height : Medium
Rear Bumper : Loose
Rear Track Width : 1390mm
Rear Hub Length : Medium
3rd Axle Bearing : Loose
Cold Tire Pressure : 18 psi
Wheel Type : AMV 3F
Seat Type : Tillett T11t
Seat Stays : 0
Max Engine Temp : 1128Ā°F
Max Engine RPM : 16,100
Engine Gearing : 10/72
Best Lap Time : 1:13.40 (lap 5)
Session Laps : 7
Notes : Rear grip was improved, rear tire was digging into the track better, balance in fast corners is strong, not enough weight jacking for tight corners, inside rear wheel not staying unloaded, tire pressure too high, front tires fading
Session | FP3
Front Track Width : 20mm
Ackermann : Standard
Front Bar : None
Caster/Camber : 0 | 0
Front Ride Height : Low
Axle Type : B
Rear Ride Height : Medium
Rear Bumper : Loose
Rear Track Width : 1390mm
Rear Hub Length : Medium
3rd Axle Bearing : Loose
Cold Tire Pressure : 13.5 psi
Wheel Type : AMV 3F
Seat Type : Tillett T11t
Seat Stays : 0
Max Engine Temp : 1121Ā°F
Max Engine RPM : 15,900
Engine Gearing : 10/72
Best Lap Time : 1:12.7 (lap 5)
Session Laps : 7
Notes : *New tires, balance was improved, front tires still fading too quickly, need better front response on turn-in, front feels light
Session | FP4
Front Track Width : 20mm
Ackermann : Standard
Front Bar : None
Caster/Camber : max | 0
Front Ride Height : Low
Axle Type : B
Rear Ride Height : Medium
Rear Bumper : Loose
Rear Track Width : 1390mm
Rear Hub Length : Medium
3rd Axle Bearing : Loose
Cold Tire Pressure : 12 psi
Wheel Type : AMV 3F
Seat Type : Tillett T11t
Seat Stays : 0
Max Engine Temp : 1121Ā°F
Max Engine RPM : 16,800
Engine Gearing : 10/75
Best Lap Time : 1:13.2 (lap 5)
Session Laps : 7
Notes : Too much caster, kart was binding the outside tire and forcing it into the track too hard, scrubbing in fast corners, better front tire wear with increased positive camber, gearing possibly too high, not keeping engine in the power band enough
Session | Qualifying
Front Track Width : 20mm
Ackermann : Standard
Front Bar : None
Caster/Camber : +1/2 | 0
Front Ride Height : Low
Axle Type : B
Rear Ride Height : Medium
Rear Bumper : Loose
Rear Track Width : 1390mm
Rear Hub Length : Medium
3rd Axle Bearing : Loose
Cold Tire Pressure : 12 psi
Wheel Type : AMV 3F
Seat Type : Tillett T11t
Seat Stays : 0
Max Engine Temp : 1250Ā°F (new sensor)
Max Engine RPM : 16,800
Engine Gearing : 10/72
Best Lap Time : 1:12.7 (lap 5)
Session Laps : 5
Notes : *New tires, balance was better, slight understeer, 0.3-0.4 mistake on best lap
Session | Heat 1
Front Track Width : 20mm
Ackermann : Standard
Front Bar : None
Caster/Camber : +1/2 | 0
Front Ride Height : Low
Axle Type : B
Rear Ride Height : High
Rear Bumper : Loose
Rear Track Width : 1380mm
Rear Hub Length : Medium
3rd Axle Bearing : Loose
Cold Tire Pressure : 12 psi
Wheel Type : AMV 9F
Seat Type : Tillett T11t
Seat Stays : 0
Max Engine Temp : 1280Ā°F (new sensor)
Max Engine RPM : 16,800
Engine Gearing : 10/72
Best Lap Time : 1:13.0 (lap 5)
Session Laps : 9
Notes : Rear tires felt like they were deforming too much in fast corners, shoulder of tire was folding over and causing snap oversteer at apex, but very good balance slow corners
Session | Heat 2
Front Track Width : 20mm
Ackermann : Standard
Front Bar : None
Caster/Camber : +1/2 | 0
Front Ride Height : Low
Axle Type : A
Rear Ride Height : High
Rear Bumper : Loose
Rear Track Width : 1380mm
Rear Hub Length : Medium
3rd Axle Bearing : Loose
Cold Tire Pressure : 12 psi
Wheel Type : AMV 9F
Seat Type : Tillett T11t
Seat Stays : 0
Max Engine Temp : 1280Ā°F (new sensor)
Max Engine RPM : 16,800
Engine Gearing : 10/75
Best Lap Time : 1:13.5 (lap 5)
Session Laps : 9
Notes : Gearing felt better this time, still had good top speed but kart was working better in slower corners as well, turn-in was improved with axle change, less input to induce rotation, rear was slightly too free but improved as tires came in, axle shifted and slowed the kart down badly, overall balance and setup felt strong
Overall Notes
The kart felt very strong on rear stability and release on the exit of corners. The softer chassis feels like it requires some more stiffness in the front end, as we continually had slight understeer we couldnāt completely get rid of. We tried to counter this with increased caster. Too much caster caused the kart to flex too aggressively and made the outside tire bind from being overloaded. When reduced to 1/2 caster, the kart was able to get better turn-in and not overload the outside tire as aggressively. Rear ride height was a smaller change than we anticipated, but it did provide extra weight transfer and made the kart dig into the track better, as expected. However, this also began to bind the outside rear tire as track grip levels increased. To counter that, the A (soft) axle provided a more free rear end, while still maintaining enough rear stability. Raising rear ride height while also softening the axle helped the kart start to work better on turn-in without sacrificing exit speed. In general, the kart responded predictably to all chassis adjustments. Recommend testing stiffer front hubs or stub axles to improve front feel on turn-in and eliminate front tire graining and overheating.
After discussing with BestKart, we will have some different steering shafts, front stub axles, and hubs to test to improve front feel. On the stiffer chassis the front feel was good, but on this softer frame, it is lacking a little.
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Very interesting write up as always 
Have you considered the issue to be at the rear, while you were trying to compensate for it at the front ? (Obviously this is the quintessential setup question that will plague our beloved sport for the rest of times, but i ask anyways )
From my interpretation of what youāve written, especially considering the effect that the caster had on the feeling & performance, i deduce you had too much grip in the rear which was not alleviated by added caster (you can jack all you want, but if the outside tire has too much grip, you will push on entry and mid).
All other setup options (including raising the rear and changing axle) were what i would have done as well.
Would you consider trying running as little caster as possible all the while freeing up the rear as much as possible as well (even with short hubs, 1400mm at the rearā¦)?
From experience with low power application (X30s and Rotax), iāve always found that castering too much scrubs too much speed in mid corner and exit and ultimately kills performance unless the track has a LOT of rubber and the tires used are soft. As a baseline method, Iāve always tried to keep caster in single speed applications to the absolute minimum necessary due to this effect.
I deduce that this is further exacerbated with KA100 due to the lower power output.
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Yeah we started with negative caster and tried neutral caster but it just didnāt give enough jacking to get the kart rotated initially.
I think the rear was good because it was a tad free but started to neutralize really nicely in that second heat (before the axle shifted). I didnāt feel like it was bogging me down; it still rolled off the corner freely. The kart felt like it would flat-slide if I tried reducing the rear grip with soft hubs or wider rear. But certainly couldāve been worth something if I had more time to test it.
The front end just felt especially light. The steering was very light even with max steering rate and max caster. Noticeably lighter than the stiffer kart I had been testing before. So with that in mind I think the soft chassis is just a bit too soft in the front in comparison and was absorbing too much of the jacking.