Sorting out my lines

[Burba]

Been on a couple of karting sessions at different courses and noticed I lack consistency in entering/exiting varying corners on the circuit.
Sometimes I nail it exactly and other times I absolutely fluff it!

Anyone help me understand the thinking process I should be going over when I approach a corner - anything from a loose curve to a tight hairpin.

Many thanks!!!

[GravelBen]

I find the most useful thing for keeping lines neat and tidy is simply looking further ahead - whether you can do that on a kart track I don't know though.

[Burba]

any help is wanted at this stage!!

so let's assume i can see the corner before it arrives, how should i be positioning myself on the track to attack the corner?

i've tried to (terribly!) replicate curves through letters on the keyboard?!?!

( curve
S curve
L turn
U hairpin

[james_gt3rs]

I had my first track day for my 18th birthday in a Lotus Exige at Thruxton

I found that the instructors help you the most, they're full of great advice.

The hardest thing for me was going from apex to exit. You need to get right to the edge of the track, but it is so hard to bury the instinct to stay in the middle.

[mark_mcd]

Generally for karting you'd want to keep it smooth, aiming for the apex of each corner in as neat an arc as you can. If you tighten the line too much (especially on basic hire karts) you will find you will loose speed as the engine boggs down so don't be scared to use all the tarmac on exit when the instinct is often to tighten the line as it 'feels quicker'.

'Feels quicker' is another thing to bear in mind - just because you are screeching about does not mean you are going quick. You will find the fastest people are often the smoothest.

I'm certainly no expert but that's how I see it. Consider posting this in the 'Track Days' forum.

Edited by mark_mcd on Wednesday 22 April 16:02

[G_T]

Again I'm no expert, but I'd second the above.

The tightest line isn't necessary the best in an underpowered little cart. In my experience, depending on the kart, the engine can bog down and picking up that speed again is often slower than just taking a wider line.

[RobM77]

The important thing to remember is that a racing line has to contribute to the lap time.

The basic theory starting point, which I'm sure everyone on this thread is aware of, is that a flat out bend should have a symmetrical line with the apex in the centre of the corner. The only purpose of such a line is to increase the radius of turn and maximise speed.

Moving on from that, generally speaking, the slower the corner the more you advance the apex (make it later), to get a straighter exit and thus be able to use more throttle on exit (trading cornering g for accelerative g). The amount you advance the apex and how deep you go into the corner before turning is largely dependent on the grip to power ratio of the car you're in. A car with very low grip and a lot of power will benefit much more from advancing an apex than a car with more grip, where it would probably be quicker to just take a shorter distance round the corner.

It's a good idea to practise different lines as they can help with overtaking - not forgetting of course if you dive in early to a corner when overtaking the fact that the driver with the wider line can get a better exit is negated because you're in the way and he can't!

As for advice for actually driving the lines:

• Look far ahead at all times. This will increase your smoothness.

• Try and be accurate, neat and clip apexes nicely. If you do this, then the speed will come. If you concentrate on speed, you'll probably over-drive and end up going slower.

• Work out the best amount of slip for your car. A slick tyre for instance operates best at a smaller amount of slip than a road based tyre. This also applies to the surface you're on (wet/dry etc).

• Like most things in life, the preparation is the most important bit. With driving a racing line, it's the turn-in. The turn-in sets the balance of the car and set the scene for what you can do later in the corner. Racing FWD is good training for this!

• If you need to make adjustments in the corner then look at your technique. The ideal scenario is just one turn of the steering wheel, and once you start accelerating, you continue. If the technique's ok, then look at your setup.

• When looking at telemetry, faster drivers are almost always faster because they get on the throttle earlier. Something to bear in mind!

Edited by RobM77 on Friday 1st May 11:42

[Martin A]

Hi All

RobM77 said:

The important thing to remember is that a racing line has to contribute to the lap time.

The basic theory starting point, which I'm sure everyone on this thread is aware of, is that a flat out bend should have a symmetrical line with the apex in the centre of the corner. The only purpose of such a line is to increase the radius of turn and maximise speed.

I'm sure Rob meant no confusion when he posted this but that is the case if the bend is only just flat out. If it can easily be taken flat out then the line can be adjusted to suit the approach to the next bend (not that it might not be done anyway and speed compromised to suit)

RobM77 said:

• Work out the best amount of slip for your car. A slick tyre for instance operates best at a smaller amount of slip than a road based tyre. This also applies to the surface you're on (wet/dry etc).

Bear in mind that tyre slip like slip angle is a sort of misnomer and is actually tyre stretch until traction is broken. Knowing what the stretch is is an art that very few drivers are likely to have.

RobM77 said:

* When looking at telemetry, faster drivers are almost always faster because they get on the throttle earlier. Something to bear in mind!

Without having to lift again of course

Hope this helps

Best regards

Martin A

[RobM77]

Martin A said:

Hi All

RobM77 said:

The important thing to remember is that a racing line has to contribute to the lap time.

The basic theory starting point, which I'm sure everyone on this thread is aware of, is that a flat out bend should have a symmetrical line with the apex in the centre of the corner. The only purpose of such a line is to increase the radius of turn and maximise speed.

I'm sure Rob meant no confusion when he posted this but that is the case if the bend is only just flat out. If it can easily be taken flat out then the line can be adjusted to suit the approach to the next bend (not that it might not be done anyway and speed compromised to suit)

Indeed. In fact that starting statement isn't intended to mean anything on its own at all. I wrote that merely introduce the basic concept of taking a line through a bend to maximise radius and therefore speed so we could move onto advancing the apex etc. However, if a bend is flat out you'll still find that the act of turning the steering wheel and cornering will slow the car, so it's a good idea to take as much of a line as you can.

Martin A said:

RobM77 said:

• Work out the best amount of slip for your car. A slick tyre for instance operates best at a smaller amount of slip than a road based tyre. This also applies to the surface you're on (wet/dry etc).

Bear in mind that tyre slip like slip angle is a sort of misnomer and is actually tyre stretch until traction is broken. Knowing what the stretch is is an art that very few drivers are likely to have.

It's true that what happens between the tyre and tarmac is complex, but what the driver will feel with the seat of his pants is merely slip - albeit non-linear due to these complex effects. What I was referring to is using that delicate feel to measure out how much slip is optimal for any situation. Being able to do that for all four tyres is pretty much the core skill of motor racing.

Martin A said:

RobM77 said:

* When looking at telemetry, faster drivers are almost always faster because they get on the throttle earlier. Something to bear in mind!

Without having to lift again of course

Hope this helps

Best regards

Martin A

Obviously, yes I covered this in my final bullet point.

[ph123]

For corners, slow down as LITTLE as possible. (Momentum is critical)
And it's the corner EXIT that is all-important.
And if it's a number of corners together, it's still the EXIT ON TO THE STRAIGHT that's the most important. FASTER ON TO THE STRAIGHT, FASTER ALL THE WAY DOWN THE STRAIGHT.
As a rule of thumb, if you're not FLAT on the BRAKE, then you should be FLAT on he ACCELERATOR; that's when you know you're going FAST.
Lines per say, are slightly less important than they were: when you're 'racing' you'll have to block fairly consistantly, or throw yourself up the inside! So you'll have to sort off-line stuff then. Once you get the slightest gap on your persuer is the time to get back to the theoretical stuff (widest arch etc) Make sure you use ALL the circuit width, to keep your speed UP.
In karts, there's a lot in BODY LANGUAGE too when racing. HARRY, WORRY, HUSSLE, NIP AND BARGE till the guy in front makes a mistake, to get by. Make sure they get the message. (I ALWAYS tap the guy in front in the collecting area.) Sod the lines.
By way of counter-point.
Good luck. Fun isn't it?

[RobM77]

ph123 said:

As a rule of thumb, if you're not FLAT on the BRAKE, then you should be FLAT on he ACCELERATOR; that's when you know you're going FAST.

Obviously excluding the period from turn-in to acceleration point (where you're on a steady throttle), and when you do bring in the throttle you do so gradually as you unwind the steering. If you used the brake and accelerator as switches you'd spin on the first corner I get the spirit of what you're saying though - you do need to make the most of the car for every split second of the lap.

[tomhodgson77]

G_T said:

Again I'm no expert, but I'd second the above.

The tightest line isn't necessary the best in an underpowered little cart. In my experience, depending on the kart, the engine can bog down and picking up that speed again is often slower than just taking a wider line.

As above, im no expert and you may already know this but it's definately worth a mention. In 'an underpowered little cart'. As above, it is a long journey in order to get that speed back again. And if it is speed you're interested in (as well as correct lines) Brake as little as possible! in my experience on 'hire' karts, the tyres slow you down plenty on entry. (Feel free to correct me PH'ers)

[RobM77]

tomhodgson77 said:

G_T said:

Again I'm no expert, but I'd second the above.

The tightest line isn't necessary the best in an underpowered little cart. In my experience, depending on the kart, the engine can bog down and picking up that speed again is often slower than just taking a wider line.

As above, im no expert and you may already know this but it's definately worth a mention. In 'an underpowered little cart'. As above, it is a long journey in order to get that speed back again. And if it is speed you're interested in (as well as correct lines) Brake as little as possible! in my experience on 'hire' karts, the tyres slow you down plenty on entry. (Feel free to correct me PH'ers)

Yes, but of course if you're going to lose any speed in a bend it's best lost early on (pre-apex), because otherwise it severly compromises your exit speed. Most of one's time is spent on straights so this is where the speed needs to come. Slow in - fast out.

[RobM77]

fudgethelimit said:

Always hit the apex of the corner, don't try and push so hard that you miss the apex. For right handers start on the right hand edge of the road, cut in to hit the apex, then apply the throttle to end up on the right hand side of the road again upon the exit. Once you get the basic racing line consistant, start breaking later and getting on the throttle earlier. Beware of understeering off the track though. Keep everything super smooth too.

I think you've confused your left and rights there?

[Jes]

Not to mention brakes and breaks.............

[RobM77]

Jes said:

Not to mention brakes and breaks.............

To be honest the advice is nonsense really anyway, and doesn't really say much

[Graham E]

In a kart, it is always about exiting corners. This should always be your priority. Karts have mre grip than power (generally), so your cornering flow needs to scrub off the least amount of speed possible. On eg. a chicane or an s bend, comprimise the first 1 or 2 apexes, to maximise the exit speed of the 3rd apex. This will being your lap time down much more than a gung ho late brake to apex 1.

• all this goes out the window when you've got more power than grip, but back in my Karting days, that never happened

[RobM77]

Graham E said:

In a kart, it is always about exiting corners. This should always be your priority. Karts have mre grip than power (generally), so your cornering flow needs to scrub off the least amount of speed possible. On eg. a chicane or an s bend, comprimise the first 1 or 2 apexes, to maximise the exit speed of the 3rd apex. This will being your lap time down much more than a gung ho late brake to apex 1.

• all this goes out the window when you've got more power than grip, but back in my Karting days, that never happened

I know what you mean, but I think you've got the grip/power thing the wrong way round and a bit confused. In a car with a lot of power but little grip, the corner needs to be arranged more around the exit (i.e. advance the apex more to enable a straight line to get all that power down), whereas in a car with little power but loads of grip, the corner technique needn't be so orientated around the exit, and you'll gain more from maintaining cornering speed and travelling a shorter distance on a more classic racing line.

The other thing that affects this is the handling of the car. Going in deep and turning back on oneself (as with a high powered car with little grip) is also useful in a car like the one I race that understeers on corner exit. The turn in off the brakes can be used to turn the car effectively, and the straighter exit enables more power to be applied without understeer getting in the way.

A good example of this is on Sunday when I lost my front wing in a race, so I had to advance the apexes a bit more on all the corners because of the understeer I was getting.

[Graham E]

Sorry Rob, but I'm not confused. In a Kart, you have loads of grip to play with, and no power. Get is sideways, you scrub off speed and the engine can't overcome this. Hence, you bog down and go very slowly.

You keep referring to cars - the OP is asking about Karts. not sure if this messes with your theory?

[RobM77]

Graham E said:

Sorry Rob, but I'm not confused. In a Kart, you have loads of grip to play with, and no power. Get is sideways, you scrub off speed and the engine can't overcome this. Hence, you bog down and go very slowly.

You keep referring to cars - the OP is asking about Karts. not sure if this messes with your theory?

The same theory applies to cars and karts.

Have a read of your post again. You correctly state that with very little power and lots of grip (such as in most hire karts) you need to keep up your momentum and avoid dropping speed too much, but then you contradict that by stating that in a sequence of corners you need to slow down more early on to gain on acceleration on the way out, which is actually saying the opposite and is a technique for cars/karts with the opposite balance - high power and low grip.

Any cornering line is a trade off. The classic racing line with the maximum radius and a central apex allows the greatest speed through the corner and thus the shortest time, but if you advance the apex slightly and straight-line the exit more, then more acceleration is possible, so you'll be slower through the corner but quicker down the next straight. This technique is used in a car with high power but little grip, where it's better to lean on the strong point of the car, advance the apex and live with a longer time spent in the corner to gain a net benefit going quicker down the straights. In a car or kart with the opposite (high grip and low power), you won't gain much by advancing the apex and are better off scrubbing off as little speed as possible in the corner.