Hairpin turn in low hp kart

I’ve always felt, the hotter it gets, and depending on the tire, and of course there’s a limit, the more grip there is. Tires tend to lose grip as it gets colder. It’s impossible to say, with any certainty, not knowing what tire was on the kart. I always preferred my steering wheel to be 180° from where yours is. I felt that with my hands lower on the steering wheel I had more leverage. I doubt you have any choice, but the lower your hands, the more leverage you do get. Keep your elbows in tight against your body, more leverage.

Hmmm…I don’t know, never had experience with old/new tyres (at least never knew were they new or old) but in terms of overinflating, it sounds logical so it probably affects the grip levels. Also, the air more dense during the day so engine is struggling more then during the night.

@alvinnunley That completely opposes what I experienced so far. It could be that the new tyres work better during the day and that I got rubish ones yesterday. It could (most likely) also be that the race karts are affected by tyre wear differently as they are much lighter in comparing to rentals so they handle higher temperatures much better. I actually always thought that higher the t° = more grip, before I found out when the best laps are set.

They are set at about 8-11PM every day, so I think in my case, tyres work better at night. Maybe I can figure something that will change my opinion, might be.

In temperatures like that, the tires are probably just overheating. All you can do is slow down a bit more to keep from sliding. You’re always going to be limited by the tire’s ability to provide grip, so you always have to drive to the tire’s limit. If the tire’s limit is lower from overheating, there’s not much you can do to remedy it.

Driving looks alright, just a few spots where you missed the apex here and there, but nothing major.

First off, camera is great on helmet. No vibration reduction required. Thanks for filming, it’s fun to see you hustle!

My general observation is that I am seeing a quick driver with really good car control.

You place the kart really well and in the places you are not thinking about it, spot on.

Also your technique looks pretty good. I’m not seeing any crazy hand or foot stuff. Your braking seems ok, but it is hard for me to tell. I really am not qualified to coach on technique anyways, so unless I see something glaring, I’ll let others discuss that.

My guess is that you are right there, once you calm things down a touch. In the writing below, I point out turns that look good relative to others. Mainly it’s in what I am seeing rhythm wise. Your better complexes aren’t the ones you are trying the hardest, as expected.

I think you should take a few laps slow. At least take 1-3 and 8-finish slow. Feel out the turn. At a lower speed, work on coming into and out of 8 with a smooth transition to 9. The 9-11 is usually where things come to a head for you, based on 8. Slow it down.

I’m not sure what the solution is between 9-10. It may be that you need to constant throttle from 8-10. Or maybe accel through 8, lift, turn and accel thru 9, lift, turn and accel through 10. I am not sure, but your timing isn’t quite there yet. In your best ones, almost.

I would imagine that into 8 you can feel the left side get very loaded up. The question is can you have that load smoothly transfer over to the right side and commit to 9 without any screeching?

These two complexes (8-finish and to a lesser extent 1-3) are where you make or break your laps. The switchback is not an issue, it seems.

3:58-4:50 full lap good

4:14 How did this feel? It looks good from here. It looks like taking the apex here does open up the turn significantly. Can’t tell if bump slows.

4:28-50 looked much more in control. You had to remove speed a couple times but you were settled better and looks like the timing was more fluid. You also hit apexes. What was laptime for this lap comparatively?

5:39-6:32 full lap good: This looks tidier and you set up well for the upcoming switchback. As opposed to previous lap, you avoid the inside bump of the hard 180. This turn looks smooth and has good speed out. Exit of t3, you clipped apex this time. Normally, you run wide here.

5:23-5:43 Nice run from switchback… Goes right back to pushing too hard. You take 8 well and it looks like you get 9 but you run low between 9-10. However, though you are very wide for 10, your car control saves your bacon and you are able to just grab the apex on way over top. If I had to guess I’d say this was a slower lap than previous? Certainly more messy. There’s a slip on way out of 11.

6:46: this is a good effort. You are pushing it just past where it can go. Reel it back a hair. Couldn’t quite make it down to apex.

7:04-7:15: Same. Pushing very hard. But you get on each apex. This is maybe getting closer. But this is too much. It feels like the transitions are abrupt. This is the weight flow that @Matthijs_Hofman was talking about.

You hold onto this as best you can but it sort of gets ahead of you as you come thru 11 and skid a bit. (7:13). I am guessing the skid bled a lot of time here.

7:39-7:43 How was that? It looked like you carried momentum really well here and the engine sounded happy.

7:56-8:03 Entry from 8 is ok but you brake almost mid corner into 10 and have to readjust in 11.

8:20-8:29: I think I like your flow better when you take the 3rd apex rather than your other wide line. The run to the switchback looks strong here.

8:48-9:06 I like! You flow 8-finish. Maybe a touch less into 8. It looks/sounds like you are at 105% on the tires between 8-10 which might be losing you a little. Not sure. Edit: you give up a heartbeat at 10 entry. You almost had it.

9:05 too fast into 2, wide 3

9:10-9:16 Exact opposite line of previous lap.

9:20 Wide into 180, too fast?, bogging out.

9:39-9:58 You clip what needs to be clipped. It feels like it’s a bit rushed and the tires don’t seem entirely happy.

Good work, Pavle. Now just back off a touch in those two complexes. Slow down to speed up, I think.

Edit: You do a nice job of getting up to speed quickly. Your first flying lap was basically at pace.

I am going to say that in general @alvinnunley is correct. Warm tires do better than cold. But too warm gets greasy. It’s entirely possible that the evening ambient temp is better than the daytime 35c, as far as tire grip is concerned, though. Cooler air helps engine power too.

The sweet spot tends to be in evening when the air has cooled and the track is warm still.

Sorry TJ, you mean “driving looks alright”? Or doesn’t? I think I got meaning, just clarifying.

Yes, correct, sorry. Sometimes my brain tries to put two words in the same space!

Thanks for the detailed post about my session, I really appreciate it!

It is quite bumpy and I make sharper inputs than I think I should/could. Feels like the karts chokes a bit after bump but not sure if it makes difference.

It was a 51.106.

That was kinda between avoiding it and later braking (bad timing I think, but it didn´t seem like time was lost that way).

This is one of those mistakes, where I ask myself “Why would you do that?”. I just ruined a lap there, it was very good until that point, 8-9 was the one of the best lines I drove and too much speed sent me wide. I reckon I lost about .4 - .7s there. That lap was actually 51.142s (.036s slower than previous).

Yes, a lot. I cut the 9 too much, riding the apex, bumping down, going wide, ruins the 11 completely. This would have been a solid lap as well without being overly aggressive.

That whole lap was dead for me after hitting the tyre on the exit of t3. No idea why I did that lol.

Yeah, looks like nothing can be done, just drive when you are supposed to, not on 35°C :blush:

Thanks for the feedback guys! I never got any kind of review of my driving and I am happy that I am on a good path, as it looks like. I would just like to ask you, what do you think (as in top50 qualification period everyone gets ballast up to 80KG), how will extra 15KG affect the driving, if it will somehow? I have 63-5kg so I assume it will have some kind of effect?

You are welcome. Hopefully helpful!

One tenth of a second per 20 lbs approx? Anyone?

Can you list out the laptimes please? For all laps including in and out?

There is the list.

5 posts were split to a new topic: Typical Air Density Changes and Affect on Performance

The three fastest begin at what time in the vid do you think?

We’re really going down a rabbit hole on air density again, so I’m going to portion off the deeper discussion on that.

Generally rental karts will run better with colder air. However it largely depends on how they are jetted relative to the air density. Also, air density changes from highs to lows vary with climate.

In short, don’t assume… test\validate for a given kart\track.

Reviewing your video, you’re driving is pretty consistent. Your inputs are pretty large, but that’s because the kart has MASSIVE understeer. It’s pretty bad even for a rental kart.

Some of that understeer/push may be tires, but it also looks like rear is planted. You can also see caster dialled in there either. I think you’ll find that the push and heat is one of the reasons the fronts are getting a bit hot.

With no scope to adjust the kart, you are limited in what you can do to alleviate the kart’s opposition to turning…

  • If there’s an adjustable seat, you can try moving it forward.
  • If the seat isn’t adjustable adjustable, you can try putting something behind your back to move your body forward.
  • You can sit on the front\top of the seat although that can be hard to keep a good posture with.
  • I’m not sure “leaning outward” in the seat will help much with a kart that’s so heavy and planted, but you could try “thumping” the outside of the seat with your body as you turn in to help it rotate.
  • For turns where you might ordinary just slow a bit, try coming in flat out and see if you can get a better balance with wheel input adjustments.
    *Turning in slightly sooner may also help too, try that with power fully on, and or coasting.

Anyway, your driving at the high level is pretty decent, you’re aiming for good lines and using the width of the track to maintain momentum.

There it is:
L4 3:57 (51.106s)
L6 5:39 (50.807s)
L9 8:13 (51.012s)

Alright, thanks for the very useful information about these tricky condition.

I have adjustable seat, I can move it forward. The thing is, I read about the seating position and I found many sources that say moving the seat backwards help more in terms of overall performance. Could you please just briefly explain what it changes (I know it loads the front or the back, depending where you move the seat) as I heard a lot of different opinions and I am kinda confused now.

Also I am 187cm tall, so I tend to move the seat backwards not only because it is a bit uncomfortable but to keep my arms straight so I don´t make chunky inputs (with my biceps).

The idea with seat forwards is to plant as much weight over the front tires as possible.

As James pointed out, your kart understeers. Loading up front should help.

At 6’ 2" you are pretty tall but nothing crazy. Seat forwards. Pretend your arms are like a t-Rex and be really light on the wheel if possible. It’s like a golf club. No squeezing.

Took 3rd apex in first complex.

Went around bump (intentionally wide) in cutback.

Hit all apexes 8,9,10,11-end.

Do more of this.

Your next fastest is similar. L9 8:13 (51.012s). You take 3rd apex, but this time you come down closer to apex of switchback. But 8-11 looks similar and is solid.

If I were approaching this like I have been approaching my KK leaderboard push… I’d pick one style for the cutback. Either wide or on apex. Stick with that for now but figure out 8-11. Remove the cutback variable.

Once 8-11 is solid, determine which is best in cutback.

Alright, I will make sure to move the seat forward next time I drive, I really wanna see the difference, it is such a simple twitch that can help a lot, I am sure.

I understand what you mean by choosing a line, I tried to do so that session, it kinda worked but still a lot to work on. As much as I remember, last year, I was doing the tight line (hitting the 3rd apex) when I got those good laps, I remember that much. So I have good feeling about it, I will start to drive like that every time.

OK last thing from me… Yes, hit that third apex for now as well. Go with that. But also choose either running wide of bump at switchback or up on apex. Just remove those variables and get working on the 8-11 puzzle, IMHO. That appears to be crux of this lap.