We did not. Didn’t have them in time for this weekend. Didn’t really need them I don’t think, the front end was working well. But for sure want to test that stuff still.
Here is the rubber build-up from this weekend. Lots of karts getting up on two wheels a bit, especially taller drivers. Certainly the grippiest I can remember Dousman ever being.
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I remember it was there or Michiana back in 2002 it was like that. I remember someone asked me what my goal was for the final. I told them it was to finish right side up
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Wanted to note that I am compiling all the tuning knowledge into a little guide in the first post of this blog, so if you are looking for a quick guide you can reference that. It’ll evolve as we go. Should be receiving my stiffer stub axles and a couple other little odds and ends this week to test.
Little bit of an audible on the race schedule… we’ll be skipping Stars this weekend in Cinci. Some things came up and we feel it would be more beneficial to test on familiar ground. I’m going to go out to Dousman and run a bit and possibly race the club race Sunday if I can.
The factory is developing some long bulky magnesium hubs for the front end to help stiffen it up. Some of the Prodigy guys tested the long aluminum front hubs and felt they still were too soft.
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It’ll be TJ vs the teenagers this Sunday! Probably not that much different than the regional/national stuff though. It’s heat racing, so elbows up!
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If I win, I get a 12-pack of my preferred beer. If one of the kids wins, I’ll buy 'em a Fortnite gift card.
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Been a minute since I updated. Haven’t been in the kart since USPKS, just too busy with helmets and family life. But I got my stiff spindle stub ends in this week and wanted to go test them out, along with a few other things.
Conditions were cloudy and 65 degrees F. Track was a little slick but still had some rubber from the recent big races.
C (stiff) stubs - definitely more positive front end feel. The kart had understeer in session one but the stiffer stubs helped that quite a bit for session two. I kept the same front width from the stock spindles to make it an even comparison. I think on the soft kart especially these are very helpful for the front end. The stiff stubs are the same dimensions (though slightly longer) as the stock stubs but supposedly a stiffer alloy. I went 0.5 faster on these stubs but a couple tenths of that was probably track evolution. The data does show that I could carry more entry speed though.
Stub end comparison. Longer is the “C” stub (stiff).
Front ride height - for you @Pippen_001, raised front ride height (rear is high as well), and that helped the front as well. It made the steering a bit heavier and the kart rotated a bit better. Since my rear and front ride height both are up, I think I need to raise the seat. The high front ride height made the kart feel like it wanted to self-center the wheel more. This change required me to be more diligent on steering input. Too abrupt of an input made the rear snap at max load, but very manageable. So for a smooth driver this change works well. A more aggressive steering input will make this a bit more unstable so drivers with fast hands might not like it as much. But if you can drive this way, it does transfer more weight and helps the front rotate the kart. Picked up another 0.3.
Negative camber - per @Paul_Montopoli’s request I tested lots of negative camber. I turned the top pill 90 degrees. The tire wear did not change much, surprisingly, we still were using most of the front tire and it didn’t really feel like it gave up much on turn-in. But it released off the corner better and felt faster through fast corners. Data shows better apex speed in fast corners with slightly lower entry speed in slow corners (but better acceleration on exit) and overall faster. Negative camber probably would help more on a faster more flowing track. Maybe you want less negative camber on a twister track. It reduces the scrub in the front end and is a noticeable change for corner exit. Found another 0.2 with this change.
Shows how much negative I was running and the associated tire wear.
I was using the B (medium) axle, standard rear hubs, 1385mm rear track, 3F wheels.
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Wow that’s trippy. Never would have expected thread on stub axles. What locks it on? A set screw?
Also this is essentially a KR? I’ve only seen those with the sniper style caster/camber adjusters. I would still like to try those out.
Yeah the stubs thread on tight and then there is a set screw to secure it in the groove on the spindle.
The chassis is very similar to a KR2. A couple of the guys have recently slapped all KR components on to see how component changes affect the base handling of the kart.
Interesting. I liked the Will Power one I tried briefly back at GoPro for a handful of laps. Certainly felt different would like to try one again.
How relevant is the set up data to someone running in the 206 class? I just started running a bestkart chassis(the 4 stroke version) at Pitt Race and my second race in it will be the 7th. Really havent done any set up changes to it besides changing gears. Just trying to get used to it.
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Same kart as far as I know, so all should apply with the caveat that lower HP 206 may require some different tuning. But happy to help if you have specific questions.
Appreciate it! Does 3 small spacers on stock hubs on the front sound about right for a baseline? That was really the only thing that didnt come pre set.
Yeah that’s a good starting spot. The baseline I’ve been establishing is:
- 1390mm rear track (might need narrower for 206)
- 15mm front spacers
- large front hubs (stock hubs probably will be fine for 206)
- half caster in (probably could be neutral for 206)
- front bar out
- tie-rods mounted on bottom or second from bottom hole on the steering shaft (will make the front start working properly)
- 1-2 dots of negative camber on the pills
- B axle
- AMV 3F wheels (9F for lots of grip)
This setup has been really balanced in low or high grip situations. The little tuning guide in the first post should be helpful for fine tuning it to your situation.
Ill have to check my settings against those. I do have the b axle and the bar out. The wheels I got with it are the mag/aluminum. Ill have to get a set of the 3s when I have the funds or find some used. Im a pretty novice driver still but loving the kart so far. A big improvement over my 2014 brava lol
Final Stars event is this weekend! The Prodigy guys have been testing a lot and we’ve been sharing a ton of data and setup notes over the past few weeks. I haven’t gotten out to test lately because I’ve been so busy with helmets.
Based on my recent testing, I decided to raise my seat up for this event. It was even with the bottom frame rails, but I have raised it about 15mm now, which is typically where I ran it on the OTK. I liked how the kart felt with both ride heights up, so to me that signaled a need to get the CoG higher as a baseline. Pretty normal with a shorter driver.
We’ve also been testing front bars, rear hubs, and axles, so there are a few things we want to try this weekend that might have interesting results.
The big point is that it looks like rain all weekend, so that’ll be interesting to see how that plays out.
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Good luck and keep us posted.
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What is your height?
Five-foot and seven inches. (20 C H A R A C T E R S)
Would you make this change of raising the seat even if the track was dry? What does this do for your handling?