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Jaybird180

180 degree turns AKA Hairpin turns

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Looking for thought-line suggestions for taking 180 degree turns as I seem to be inconsistent in doing it. I have them at a several tracks I attend.

I know that the basic rule is to find a line that allow for application of Throttle Control Rule 1 - Great. But it still doesn't explain why I feel like I'm trying so many different things and getting results that are lackluster and at extremes; I'd like to reduce the variations so I can properly evaluate.

I think my entry speeds are ball-park consistent, which retrospectively are lower than I want; I think I can change that next time I go out by improving on my Quick Flick overall.

At one track the hairpin is at the end of the longest straight and if done correctly, I can get to the turnpoint for T2. I don't attend this track as often.

At the other track it's mid-circuit and what precedes it is a sweeping left. What I feel is amiss, is the exit of the sweeper can become a compromise of getting the right attack angle for the hairpin which exits onto a chicane that can be straightened if using an inside tight line. When I get the hairpin "wrong" on this track, I'm ALWAYS too low in RPM and downshifting on corner entry there is tricky because my line removes the straight, I have been going from the sweeping left to a hard right in a single motion - staying on the left side of the tire too long (hmmm...that's  probably a clue?)

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2 hours ago, Jaybird180 said:

Looking for thought-line suggestions for taking 180 degree turns as I seem to be inconsistent in doing it. I have them at a several tracks I attend.

I know that the basic rule is to find a line that allow for application of Throttle Control Rule 1 - Great. But it still doesn't explain why I feel like I'm trying so many different things and getting results that are lackluster and at extremes; I'd like to reduce the variations so I can properly evaluate.

I think my entry speeds are ball-park consistent, which retrospectively are lower than I want; I think I can change that next time I go out by improving on my Quick Flick overall.

At one track the hairpin is at the end of the longest straight and if done correctly, I can get to the turnpoint for T2. I don't attend this track as often.

At the other track it's mid-circuit and what precedes it is a sweeping left. What I feel is amiss, is the exit of the sweeper can become a compromise of getting the right attack angle for the hairpin which exits onto a chicane that can be straightened if using an inside tight line. When I get the hairpin "wrong" on this track, I'm ALWAYS too low in RPM and downshifting on corner entry there is tricky because my line removes the straight, I have been going from the sweeping left to a hard right in a single motion - staying on the left side of the tire too long (hmmm...that's  probably a clue?)

How are you choosing when to BEGIN your throttle roll-on?

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I tried to crack the gas as soon as my lean angle is set. Then I tried to wait until I had assured a tight line exit. It gave me the desired trajectory but it felt weird to wait so long to get on the gas. Trailbraking until I was on line didn’t seem to help much either. See...all over the place.

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Come to think of it: The track where the hairpin is T1 I haven’t been able to figure a good TP or Apex. I feel lost with no plan except for where I want to setup for T2.

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46 minutes ago, Jaybird180 said:

I tried to crack the gas as soon as my lean angle is set. Then I tried to wait until I had assured a tight line exit. It gave me the desired trajectory but it felt weird to wait so long to get on the gas. Trailbraking until I was on line didn’t seem to help much either. See...all over the place.

It would be a rare 180 degree turn where you could roll on the gas as soon as you have your lean angle set (at the beginning of the turn) and be able to roll on continuously for the whole rest of the turn. If the turn was large, and U shaped (as an example) you would most often have to roll off (or at least go flat) on the gas in the middle of the turn, more or less treating it as TWO turns, the first part with one turn point and apex and the second part with its own turn point and apex. Depending on the shape of the turn, you may or may not need to make another steering input to change your lean angle at the second turn point (ie if the turn tightens up in the second part, you will likely have to make a steering input to change the lean angle for the second part of the turn).

Alternatively, you could consider that your "real" turn point is somewhere in the middle of the 180 degree turn, a turn point that will line you up for the apex and exit you want. Everything before that would really just be pre-positioning to get to that turn point and you might very well be slowing down (off the gas and trail braking) ALL the way to the turn point which could be located near the middle of the 180 degree turn, or even later if it tightens up a lot at the end.

You could try working backwards from the exit (if exit speed is the priority) to find the exit line you want, then find the apex and turn point (in the second half of the turn) that will line you up for that without any additional change in lean angle . That will be your "second turn point" (or real turn point if you are thinking of it as one turn) then work backwards from THERE to find an entry line from the first part of the turn that will get you top that second turn point. Does that make sense?

If the turn is at the end of a fast straight and whatever comes after the 180 degree turn is slower, you may want to prioritize carrying the straightaway speed as long as possible and in that case you might choose a line that allows maximum trail braking as long and late as possible before you reach the second turn point, potentially sacrificing some speed in the latter part of the turn with a less optimum exit but a wide fast entry.

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Don't want to impede on Hotfoot's wisdom but some thoughts:

Not saying it's correct for your situation but there are definitely turns where it feels like you should be back on the throttle simply because it's "been so long"

e.g. Turn 6 at Vegas (9 clockwise). It's maybe... 150 degrees? Just the top result I found, so not judging their technique beyond this purpose, but going counter clockwise - https://www.youtube.com/watch?v=swAYYP1rQZ0 -- look at around 55 seconds. There's a solid 3 seconds there the rider is having to be patient; and even then the line never gets down to the apex curbing. Look at the next lap -- probably a hair before 3:00 -- same thing (and getting down to the apex better). Next lap -- 4:53 or so.

If it's got more "middle space", a double apex approach with a throttle pause or roll off and maybe releaning can be vital (the Twist II DVD demonstrates double apex as one of two exceptions to Throttle Control Rule #1)

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My mind is blown because I never considered two turns.

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Thank you both. I see now my approach has been all wrong for this because of two main reasons:

1- I see now I had a misunderstanding about when to get on the gas per TC1

2- I had been conflating my qualifying line and my racing lines. There’s a passing opportunity at the exits of both hairpins and I had been trying to work out a consistent line that would be fast and defensive and I didn’t separate those goals and consider the compromise scenarios vs ideal lines for those turns.

I still need to work on my entry speed and Quick Flick but now I have a new way of looking at these hairpins and when I would like to use each type of line.

 

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20 hours ago, Lnewqban said:

Great find, that is a REALLY good perspective on a very late apex turn. It really illustrates how long you have to wait to get on the gas, and how too low and entry speed would BEG you to roll on too early.

It's also VERRRY interesting to observe the differences in the accuracy of the throttle timing (and consequently accuracy of the line) of the front runners versus some of the later riders.

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As a sort of aside on this issue: This year Keith has been talking about, during the no brakes session, how you should set your entry speed not for your turn in point but for later (I believe he's mostly advising for when you reach max lean but in my experience it's a mix of max lean and when you can start the throttle). It's great advice, but for some reason I find that when I am trail braking it is easier for me to set that later point as my target (especially since trail brake ends shortly before I reach max lean more often than not); may be useful to you as well -- but don't let it distract you from proper technique since you can easily try to do 'too much at once' while you build up certain skills.

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