Hairpin turn in low hp kart

Here’s another “possibility” for a driving line around the corner. It’s only a possibility, but I think closer to actuality than we might think.

That sounds more “complete”, I agree. Glad I got idea first time, more or less accurate.

@alvinnunley Al, what is the benefit of that last line, what would you say, shorter distance traveled? Is that what gains the time? Seems it can work although it looks very very tight, not sure if tyres could hold up that long without serius speed reduction and lowered mid-corner speed, what do you think?

I’m trying to show the “actual” line through a corner. It may not be completely accurate, it’s hard to know without being there, but I think it’s closer than just having a big arc like the orange line shows. I’m relying on my 50 years of being in and around karting.
If the data does not support the theory, get a new theory. (Al Nunley)

This topic is much more detailed than my philosophy.

“Send it and don’t crash”

Carry on :+1:


As you said carry on, no one replies…I see what you did :smirk:


What are you trying to illustrate? The actual line seems to finish on the yellow. Looks like green would be a super late apex that totally blows past and would lose speed. Maybe not that late, hard to tell. But assuming green is a feasible turn in, I would imagine it would need to swing back right slightly and rejoin yellow.
My guess is that you’d be between the two and then ending up in yellow-dotted line.

I just wanted to illustrate the slip angle, green line as perfect (in perfect conditions, some insane tyres) and yellow one a real line if I would try to stick to the green one, in real conditions, underteering towards the yellow. The difference between the lines measured in angle is a slip angle. Just showed my understanding of slip angle, nothing much and of course checking with you guys if I understood it correctly :blush:

Ah. Ok that makes sense. But yah, rotation of the kart at turn will change orientation. Presumably as you accelerate out there’s a certain amount of forced understeer, again adjusting orientation slightly.

One thing to note… slip angle and sliding are two different things.

You can have a slip angle without any sliding whatsoever.

Yep. We are speaking to slip angles as opposed to sliding laterally.

None of this is particularly visible, mind you (rotation). I don’t consciously rotate the kart, generally, I just do based on what I’m trying to do. It’s sorta a butt/hands/foot experience.

There’s a very good article at Wikipedia on slip angle. As I read it, and I’m not great at these technical things, there’s always some slip versus the angle wheel is turned. One of the definitions they cite is (slip slide) I’ve always thought that was why rubber gets laid down in the turns. The faster, the harder, the turn, the more rubber that gets laid down. But I’m no expert on it for sure. And of course, Wikipedia is said to have made some mistakes at times.

Sticky. (New Castle summernats 2018 I think)

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Masters worst nightmare :smiley:

Indeed. I love getting X-rays.

Doc: you know you have broken ribs right?

Me: I’m a trapeze artist.

Alright, seems I got a basic understanding of it, but there is much more to think about. I will check some more articles including Wikipedia.

Oh and by the way, I love that picture Dom :joy:

11 posts were split to a new topic: [Video] Slip Angles

Going to track in 30mins. I will report back after session :checkered_flag:

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Sweet. May your lines be fluid and fast.

Not happy. Nothing much too add or take away. Best time 51.052 (L10), worst time 52.762 (L9).

Not usually trying to find excuses, but it is truth this was the first time driving during the night. I was also laying in bed entire last week, I was sick. First real thing besides 30min walk was this session so that probably did not help either.

On a positive note, I was very surprised about the track condition at night and found many fast drivers in the sessions before and after mine but no one raced with me, I was alone. It was so sticky and the kart loved it.

I felt pretty lost in the first three corners, I was driving the sequence differently almost all the time, different braking points, different lines. I couldn´t get used to one line, not sure why. If you could help me with the line here and some braking points, that would be great. Just an idea or two would clear my mind of stupid things like braking in the middle of corner and going too wide on the exit. Don´t know why I tried this to be honest.

Hairpin was great, your advices helped a lot and I got a pretty good line most of the time, thank you. :smiley:

Here is the main problem. Section of turns from T8 to finish line.

This section was terrible. Turn 8 was okay on the first glance but on the 9 I was carrying to much speed and I either broke before or just bumped right at the apex which costed me time either way. Where things got really messy is turn 10. I still had too much speed so brake was needed once again. The kart was pretty unstable and understeered even with the slight brake pressure applied. I really felt like losing time.

I was watching a faster guy, session before me and he was so smooth all the way around the track, incredibly constant.

Turns 11,12 and 13 were almost perfect and as track was in very good condition, there was no tyre screaming and I had a very good exit to the straight, very nice improvement. What I am not sure is, is that good line through last 3 corners produced by braking on T10? Or is it just me getting it right this time and not making the same mistakes? What do you think?

I know I am boring and I am really sorry about all the posts about things not related to the topic tittle but I am just trying to figure these karts out and stop struggling on such simple things. Again, I am not expecting you to solve the mystery of my bad driving, but just give me some thoughts :smile:

Still working on that GoPro, will probably buy some 4k camera soon :confused:

Are you accelerating between 8 and 9 or is it constant throttle? Sounds like you are saying that as you go through 8 it’s ok but then 9 starts to fall apart and thus 10 is a mess?

Sounds like you are pushing too hard into 9