Sim Racing Megatopic

Bimodal_Rocket · December 2, 2020, 5:26pm

So, any mathletes?

I have a question…

So I have been tracking my fast laps over the past week or two, saving every sub 42 lap. I have a long list of times now.

As time progresses, the laps get faster, obviously, but they also become more consistent, time distribution wise. But, the nature of the times changes as we get faster. We start seeing more “fast” laps but we also see less slow laps. While I haven’t been tracking everything, I imagine the overall distribution range-wise tightens with faster lows, faster average, faster highs.

Is there a way to use the times I have recorded to calculate probability? In other words, is there a way to get rolling percentage likelihood of posting a time sub 42? It’s probably a statistical analysis thing and I tuned out math. I’m a poet not a quant.

da_sniffa32 · December 2, 2020, 5:58pm

I can only way I can think of you being able to calculate your likelihood of posting a sub 42 time is by using the times from the past. But don’t take lap times from too far in the past because it wouldn’t be an accurate calculation, since you had slower lap times then. Instead, try to use the lap times from the same day or week or so.

Essentially, find the percentage of sub 42 lap times from the total number of lap times. For example, lets say on one day you did 100 laps and you wanted to see at the end of the day what your probability of posting a sub 42 lap time was. If you recorded 12 sub 42 lap times, your probability of posting a sub 42 lap time for that day would be 12%.

You would calculate it like this:

percentage of sub 42 lap times = (100 x number of sub 42 lap times) / total laps

That’s a way to calculate your probability based on your times now. I don’t know how to calculate the probability of posting a sub 42 time based on your lap progress/improvement, although I would be interested to see how you would do that.

Hope this helps and hopefully this wasn’t too confusing

Bimodal_Rocket · December 2, 2020, 6:02pm

Thanks. That makes sense. What I did was record every sub 42 lap for the past couple weeks. So, what I have is only the goodest laps. I wonder what can be inferred from that data. I could answer the question for sub 42 laps, what is the percentage on a daily basis of sub 41.8 of the fast laps. But, that’s a smaller set of numbers and probably not deep enough.

da_sniffa32 · December 2, 2020, 6:06pm

I think you could also calculate the percentages of times from each sector as well as the full lap. Maybe that way you could see which part of the track you are struggling in. I don’t know the ideal times for each sector are though. Maybe also see which sectors or turns you are posting inconsistent times at. That would give you more information then just the full lap times

Matthijs_Hofman · December 3, 2020, 7:42am

Thanks for checking in. I’m having so many problems with my Rift that it’s really a turnoff.

Sometimes it’s working, sometimes it isn’t. I am thinking this is down to the cable
I don’t sit right in the chair in my kart. Sometimes too high, sometimes too low, sometimes tilted or to one side
I can’t get the setup right for other sims, like iRacing. I am sitting so low in the car that I cannot even see the track.
And finally in the unique event that everything is working fine, I get motion sickness, probably due to a vibrating sensor.

I know that all problems can be fixed, but it’s difficult to fix one thing when a second issue occurs. I am the point that I’m thinking of leaving VR all together (at least this specific headset) and just enjoy this game old fashion on a computer screen.

Bimodal_Rocket · December 3, 2020, 12:55pm

There’s a key you bind to reset headset camera. Messing around with this, you can tweak your placement. Also, KK has camera adjustments in preferences. The folks who use multi screens have to adjust camera after setting POV as well. This establishes the x,y axis points for the actual seat of the car, rather than headset view.

I haven’t had to change the camera but I have to recenter headset every time it goes on.

The unit going dark doesn’t make much sense. It does seem like maybe there’s something wrong with the unit. Do you have a pal with a vr headset that you could try to compare?

Getting camera and seating position fixed is possible. Can you video what this all looks like and maybe I can ask on forum?

Bimodal_Rocket · December 6, 2020, 9:43pm

Pretty Fast Lap

Since I didn’t get to video my GLB 2 lap at 41.757, here’s the 2nd lap in the .7’s I have landed. This has been a very fun past couple of days. All of a sudden, I got much, much better. In the session yesterday, 30% of my laps were landed sub-42 and the bulk of the slow ones were very quick.

It wasn’t like a lightbulb went off or anything, I just started landing the chicane that gives me so much grief. That and I absolutely shellacked S3, repeatedly landing .6X final sector. In this lap, I do a so-so job in S1 and S3, but stomp S2, which is where I usually lose time. Ideally we’d like to see .30-.35 S1, .6X S2 and .6X S3.

I’m not quite there, yet, but I am very close. Today, my sensitivity seems the same and I am really feeling the kart beneath me. Let’s hope it stays that way. According to my optimal, I should take GLB 1 by almost a second. I’d be curious to see what a driver like Tanguy could do here, how far off I am.

Its funny how each step forwards is preceded by a step back, period of consolidation. It’s nice to be climbing the peaks again, rather than revisiting the valleys, as I have done so many times on this particular leaderboard push.

Bimodal_Rocket · December 15, 2020, 5:26pm

Here we go again, maybe.

Still plugging away at PFI-C but a little bored. So, decided to do a few laps of regular PFI.

Boy, is that weird when you are used to S1 and S3 being right turns. Here’s a reasonable lap for GLB 9 US 2. At some point, I will remember the line for the final bit. I bet everything I wrote here is rather silly, in retrospect. I may revisit this and provide better observations. PFI closing complex - KartKraft

markcr · December 17, 2020, 2:29pm

Hi All. I’m brand new to karting and have been going down to my local track once a week to rent and drive a session or two in a Birel Art rental kart. Fun, fun, fun! I picked up Kartkraft and have been really enjoying the sim. I’m using x30 karts to learn on. However, in the chassis tuning area I’m not sure what adjustments to make in order to get the x30 to handle better. I’ve just been using the Geel track for the time being. Can anyone help me with a few kart setup/tuning tips or known setups that work well? Thanks!!

Bimodal_Rocket · December 17, 2020, 3:17pm

Sure. The tuning is kind of intimidating but it’s actually kinda simple. I’ll give you my setup for x30 and try to explain a bit.

Brake strength: basically how hard you have to push to get rears to lock. There’s also a setting for brakes at the tuning level. I am typically at 100% in tune or close to it as well.

R/L Hub offset: this is rear width of hubs. You can widen or narrow. If I am not mistaken, generally narrowing the rear will make it less loose. So if back is too slidey, narrow.

Gearing: you need to find correct gearing for each track. For example I run pfi at 9-33 but pfi-c at 9-66. Ask for a start point and then add or remove rear teeth. Here’s a link to a very useful gear ratio chart:

Seat longitudinal and vertical: how high up and forwards/back you are sitting. Having weight up high is quite different. You’d think that low is best but the seat position affects how the kart jacks in turns. Counterintuitively, dealing with kerb flipping in one of the builds involved raising the seat! Moving seat forwards pits more weight on nose. More front end grip and less back end grip.

Scrub radius: not too sure in this but it’s a front end adjustment. It affects front end bite.

Caster: sorta how quickly the front end initiates a turn. High caster feels very loopy and free.

Ride height: another center of gravity adjustment.

Bimodal_Rocket · December 17, 2020, 3:43pm

As a new karter the first thing to do is get gearing right. The baseline tune is typically good for top 10.

However, just try my tune.

I kind of like a lot of teeth:
Pfi classic 9-66
Pfi normal 9-61-9-64
GVKC 9-65, 9-66
Geel 9-65 or 66
Amp: don’t remember but 9-63 or 9-62
NTK: I’ll look it up.

Cory Hayes pinned explanation of tuning on discord:

Bimodal_Rocket · December 17, 2020, 6:13pm

Unspectacular Lap, but Progress nonetheless

S1: 18.969
S2: 20.686
S3: 15.798

I am very fast in S2 generally and am still dealing with inconsistency in final turn and bridge. Because I have done so many laps of PFI-C, I am pretty much murdering everyone in S2. I posted the fastest one on the boards last time. My S3, however, is mostly punching well below weight.

You, don’t see that every day

S1: 18.858
S2: 20.641
S3: 15.953

Exact same laptime a few minutes later. In this one I am killing it until I don’t, which is the last bit. Aaargh.

You have got to be kidding

S1: 19.109
S2: 20.681
S3: 15.661

This time, we are living in the Upside Down. S3 is the high note and S2 is darn fine as well. S1, however, is not good. Anything slower than a 19.8X isn’t gonna cut it, really. It was great to nail the exit, finally.

Adding up the sector times, Lap 1 is 55.543, Lap 2 is 55.542 and lap 3 is 55.541. So, the game is bugged a bit here, it would seem, although it could be a rounding thing for the 2nd one, at least.

Still, what are the odds? I may have just achieved Peak karting life here, folks. An utterly meaningless but kinda cool driving achievement! Beating yourself by a thousandth, twice in one day!

What a truly weird day.

S1: 19.016
S2: 20.510
S3: 15.774

Again, extremely fast S2. Middling fast S3. I lost the mojo on way down and out of final bit. Not a great launch, that could have been a .6 with a slightly better angle. Not a great S1, very slow. But, encouraging results from laps with some lousy sectors.

Very pleased with today’s haul thus far. I am thankful for all the laps folks have put up on PFI. There’s many tenths to go, yet. I wonder what it all comes together as.

markcr · December 18, 2020, 12:38am

That’s outstanding, Dom! Incredible lap times. Thank you very much for the setup tips. I’ll try them out tonight and see if I’m a bit more in control.

Bimodal_Rocket · December 18, 2020, 12:39am

You are welcome and thank you!

I wonder if I’m not geared properly. Believe it or not I started at 9-65. That worked OK. I then dropped to 9-64 but it felt odd. 9-63 feels lovely. But I wonder. The only part of the track where the limiter comes into play is bridge. Does the 2 mph really matter between 9-65 and 9-63? Maybe it does and going 9-61 like Tanguy is smarter. Or maybe go short again for yuks. Not directed at you, don’t worry. I’ll let you run some laps first before I ask you for gearing advice.

markcr · December 18, 2020, 1:30am

Dom, your youtube videos are really an outstanding resource for a new guy like myself. Just watching your race lines, when you turn in, your steering inputs, your exits, etc has taught me a lot already. Now I just have to try it myself!! Thanks again!

Bimodal_Rocket · December 18, 2020, 3:05am

You are welcome. A lot of this is in the feets. The gauges don’t show it, but I am very careful about how much and when I apply throttle. You’ll notice the engine is always screaming and the throttle gauge is almost always pinned. When its off, its off for just a flash as the brake pedal also flashes on, just for an instant.
Coming out of a turn, you’ll notice the throttle often builds, sometimes even pauses midway. The throttle is kind of steering the kart. I am pushing the kart through the turn, feeling for grip and trying to find the limit of power that allows for 100% efficiency.
Anyways, as you get started, understand that your hands and feet are connected. What you do with your feet has a cadence that coincides with your hands. Good luck and have fun.

Bimodal_Rocket · December 18, 2020, 3:11am

Well I answered my own question, sort of. I dropped to 9-61 and 30 laps later my optimal in now 55.118.

The longer? gearing of 9-61 totally changes the cadence of the track. The first sector now becomes blazingly fast and you then struggle to accelerate out of the cutbacks in S2.

Thus far, I have managed to land a good enough S2 (20.646) that demonstrates that I can beat the ghost.

My next experiment will be to add 3 teeth and go back to 9-64. See how that goes in terms of optimal.

Dirty lap with 9-61 to demonstrate massive time difference in S1

S1: 18.789
S2: 20.646
S3: 15.853

Even going wide and dirtying bridge exit, S1 is 2/10 faster.

@NikG a year and a half ago you were describing riding the white line around the bottom section. Can you take a looksie here and tell me f this looks like what you recall? You can see here I stay on the inside line and try to let momentum hook me around the bottom “nose”. The other guy seperates off.

NikG · December 18, 2020, 5:16pm

I mean, its a game not real life lol. There’s lots of bits of where you do something in the game which just wouldn’t work in real life.

But, your line is the line I’d take. Is the ghost running the bigger gear, that would seem the most likely explanation. He just has that little extra punch on what is the slowest part of the track (at least I think it was, been a while lol).

Bimodal_Rocket · December 18, 2020, 6:18pm

Thanks. I was trying to make sure I understood what you had described. The entry gets thrown in and if you have enough momentum, it carries you around without having to separate off.

“It’s a game and not real life” yeah. I’m aware that there’s plenty we do here that wouldn’t fly irl (if it did we’d see same laptimes). But, as you said, the line seems to be pretty accurate.

What’s really interesting is the method you describe as common IRL (ride the inside line around) isn’t really used in sim. Most folks seem to take a more “from below” approach. I dont know why as it appears that it is possible to use the “correct” method and be fast.

Bimodal_Rocket · December 21, 2020, 12:46pm

A few moments about gearing:

I went in the other direction and went from 9-61 back to 9-64. The idea was to see wether gearing matters as much to laptime as one would think.

Maybe not so much.

With 9-64, S1 becomes very slow and S2 becomes very fast. There’s a different feel but overall, times are very close. After 30 laps or so, my optimal was 55.1 vs 55.0 for 9-61. Not that dramatic a difference.

I started walking it back and will likely settle somewhere 9-61-9-63.