Racing a kart

[Pierce89]

You need to lift a rear wheel because turning a corner requires the two wheels to go round different radius turns (because one is further out from the centre). That means that the outer one needs to move further, and hence turn faster, but the two are joined by an axle, and hence can't turn at different speeds. The only way to change this, is to lift one or other wheel. So then the question is, which wheel. To turn the corner you need an inward force, the kart will try to carry on in a straight line. Because of that, it'll lean somewhat out of the corner, and put more weight onto the outside wheel. Because of that, the outside wheel will have more friction with the ground, and provide more inward force to turn you. So, you clearly don't want to lift the outside wheel, because it's what's providing the grip allowing you to turn. Thus, the inside wheel is the one you want to lift.

And how do V8 Supercars get around this problem if you can´t turn the car without lifting a rear wheel?

v8 supercars have differentials, + you lift the inside rear wheel

V8 supercars do not have a differential. They have what's known as a "spool" (fully locked)

[Blanchimont]

This video is called

Norton Engineered for Speed Technical - Ep 6, Differential

[timbo]

CanAm 917 didn't have a differential. It becomes a no problem once you have enough torque to spin the inner wheel at all times.

[N12ck]

this is getting a bit off topic, the fact is, to get round a tight corner fast you must lift the inside rear wheel, so there is no point talking about other series,

back to how to be fast, when in the wet, it is a good idea to lean forwards to get the rear end to spin up as you come out of corners, and as you brake, lean backwards to put weight on the rear axle

[beelsebob]

this is getting a bit off topic, the fact is, to get round a tight corner fast you must lift the inside rear wheel, so there is no point talking about other series,

back to how to be fast, when in the wet, it is a good idea to lean forwards to get the rear end to spin up as you come out of corners, and as you brake, lean backwards to put weight on the rear axle

Really? How does leaning forwards and lighting up the rears help?

[Ogami musashi]

Because as i said earlier in karting the drivers makes up for a large (sometimes the largest) part of the total package weight.

What lifts the inner wheel is a load transfert coming from the front. In the wet since you have less grip you have less load transfert hence the rear inner wheel may not lift, that's why you can lean outwards to help it lift.

[beelsebob]

Because as i said earlier in karting the drivers makes up for a large (sometimes the largest) part of the total package weight.

What lifts the inner wheel is a load transfert coming from the front. In the wet since you have less grip you have less load transfert hence the rear inner wheel may not lift, that's why you can lean outwards to help it lift.

I was querying leaning *forwards* under acceleration, not outwards in a turn.

[Ogami musashi]

My bad. Same reason; You unload the rear thus less grip thus you can spin the rear; when you spin the rear it can bring the engine to a more powerfull RPM..again check my previous post.

[N12ck]

higher RPM, I have done tests with and without doing that, and it is faster round a lap to do that,, Junior TKM, chassis was an Intrepid

[strad]

If I may...It's not that it won't turn but what happens is that the inside rear skips sideways.
Have none of you ever run a car with a spool or welded spider gears?
I seriously doubt V8 Supercars run a spool that locks the axles for that reason.
Usually reserved for drag racing and Some oval track and dirt racing. imo
edit
just checked :

Differential-9 inch

in other words,,,they run a ultra dependable 9 inch Ford diff.

They have been running spool axles for years

A spool lock the two axles together..Look up the specs...they run 9inch Ford DIFFERENTIALS

[machin]

quick google search solves this:

From http://www.v8supercars.com.au/technical ... y-of-terms

Currently, V8 Supercars use a “spool” diff which simply means both rear wheels rotate at the same speed all the time - even
during turns.
By direct comparison, most road car rear wheels cleverly rotate at
different speeds therefore assisting the vehicle turning process.

back on topic..... is the required technqiue: lean out of the corner all the way around?

Does the leaning forward acceleration technique work with low powered rental karts?

[strad]

Then WHY do they call it a 9"differential?...there is no differential without the ability to turn inside and outside wheels at a speed differential. That's stupid..they should say they run a 9inch HOUSING
Sorry for the confusion.
But that makes the series super stupid...road courses with a locked rear end.

[timbo]

Then WHY do they call it a 9"differential?...there is no differential without the ability to turn inside and outside wheels at a speed differential. That's stupid..they should say they run a 9inch HOUSING
Sorry for the confusion.
But that makes the series super stupid...road courses with a locked rear end.

strad, you should remember 917/30. If you have enough power it's a non-problem!

PS watched v8s on youtube and they lifting wheels a lot!

[SavantGuarde]

Back on topic:
Yay a kart Racing thread

I've raced karts for better part of 23 years and competed in virtually every single type of kart there is! Won national championships and competed at European and World Level. To go into everything about what can and cant be done to drive faster is a MEGA topic that a whole lot of factors come into, some of which have been addressed.

Firsty: Power of the kart - The less power you have the smoother you need to be and the more critical Weight is. Weight is a MAJOR penalty even for a kart with double the power, 5 kilos can be two tenths of a second lost! The only time weight is an advantage is in the wet, where it helps cornering. The more mass you have to move around (in corners or on the straight, the more is required of the tyres or engine to do so) with more power you can get away with more and driving styles have less, if any penalty on the performance and it starts to come down to personal preference, but on rental karts: BE SMOOTH! Every squeal of the tires is lost speed

Grip: how grippy is the track? generally for rentals the tyres are very hard and grip is minimal with little or no meaningful rubber laid down on the track. With this the need to raise the inside wheel becomes less imperative. This behavior is governed by the setup of the kart and how Stiff it is. I doubt a rental kart will ever be able to raise an inside rear but indeed this is what you will see karts doing at high levels. WHen rubber gets Crazily laid on the track things change again. It becomes a completely different style of driving (This is typical in things like world champs where very sticky rubber is used). Its bonkers, I could never get used to it. So try to keep that back end in check, every slide is lost speed .

So be smooth! Try to maintain speed through the corners as much as you can and carry it onto the next straight! you may brake a little earlier but if your engine doesn't have to do as much work on the next straight you will come out on top! Also, rental karts are NOT created equal, some will be dogs and some will be good. Try to jump in one that won the previous race or you have used before (dont be fooled by ones piloted by some 60 kilo guy ) Really these karts scrub so much speed off just by turning the wheel its amazing !

[krisfx]

Back on topic:
Yay a kart Racing thread

I've raced karts for better part of 23 years and competed in virtually every single type of kart there is! Won national championships and competed at European and World Level. To go into everything about what can and cant be done to drive faster is a MEGA topic that a whole lot of factors come into, some of which have been addressed.

Firsty: Power of the kart - The less power you have the smoother you need to be and the more critical Weight is. Weight is a MAJOR penalty even for a kart with double the power, 5 kilos can be two tenths of a second lost! The only time weight is an advantage is in the wet, where it helps cornering. The more mass you have to move around (in corners or on the straight, the more is required of the tyres or engine to do so) with more power you can get away with more and driving styles have less, if any penalty on the performance and it starts to come down to personal preference, but on rental karts: BE SMOOTH! Every squeal of the tires is lost speed

Grip: how grippy is the track? generally for rentals the tyres are very hard and grip is minimal with little or no meaningful rubber laid down on the track. With this the need to raise the inside wheel becomes less imperative. This behavior is governed by the setup of the kart and how Stiff it is. I doubt a rental kart will ever be able to raise an inside rear but indeed this is what you will see karts doing at high levels. WHen rubber gets Crazily laid on the track things change again. It becomes a completely different style of driving (This is typical in things like world champs where very sticky rubber is used). Its bonkers, I could never get used to it. So try to keep that back end in check, every slide is lost speed .

So be smooth! Try to maintain speed through the corners as much as you can and carry it onto the next straight! you may brake a little earlier but if your engine doesn't have to do as much work on the next straight you will come out on top! Also, rental karts are NOT created equal, some will be dogs and some will be good. Try to jump in one that won the previous race or you have used before (dont be fooled by ones piloted by some 60 kilo guy ) Really these karts scrub so much speed off just by turning the wheel its amazing !

Yeah I've noticed that the smoother guys are quicker when we race rental, but in Rotax it doesn't seem to matter so much, Sound advice although there's some points where the only option in rental is to properly sling it in haha.

I find braking is the hardest part of karting really!