Heel & toe technique

[Pauly75ts]

Hi! there, everyone,

 

Here's a video to show you how the best driver do it.

 

May he rest in peace.

 

http://www.jackals-forge.com/TMP/senna_nsx.avi

 

Rgds

 

Paul Yong

[King]

kum sia kum sia

[Koren]

with leather shoes one some more..

[Pauly75ts]

"with leather shoes"

 

Hi! there, Koren,

 

His leather shoes should cost more than your tyres.

 

Rgds

 

Paul Yong

[Vtim]

Paul,

 

I remember reading somewhere, forgotten the website, there are other technics beside Heel-Toe, you know any website

[Genie47]

I posted the video link on www.daewootech.com and it sparked a lively discussion over his "twitching" of the throttle.

 

The answer came from "Audacityracing", that Senna is "feathering" the throttle.

 

a car has the most speed ina corner when it at the instant where it loses traction. if the car breaks loose, speed is lost, but i order to maintain a high speed, you have to "feather" (or twitch if you will) on the trottle.

 

 

this prevents you from giving the wheels too much power while maintaining a high speed through the corner. you can break loose in small amount without sacrificing major speed, so the idea would be to cross that line (where traction is lost) as little as possible, but staying as close as possible

 

mmamdouh points out that Senna is practicing "manual traction control".

 

Quoting Audacityracing again,

 

you have to look at his driving style, he's got a very powerful rear wheel drive car...

 

when exiting the corner, a rear wheel car will produce massive oversteer if too much power goes to the wheels, at the same time, if there is not enough power, the same thing will happen where the back end breaks loose (due to weight shift as opposed to reduction in dynamic friction). oversteer caused by reduced friction (wheel spin) is the side of that spectrum that produces the fastes way through the corner.

 

 

it's an imaginary boundry (see circle of traction). the closer to the limit of breaking free, the faster the car goes

 

 

 

 

 

 

when it comes to front wheel drive cars, the same can be said for left foot braking...

 

 

in a fwd car, understeer occurrs when exiting the corner (and entering most of the time). to provide power to the wheels while maintaining an appropriate weight balance, you can "feather" the brake along with the gas to keep the weight forward (can produce oversteer, but that's easier to correct and control) and keep power to the ground

 

 

 

 

i can explain more and whip out some telemetry graphs if need be

 

Here comes the cheem part with telemetry graphs.

 

this is the circle of traction (sometimes called the circle of friction)

 

here you can see the direction that forces are applied during travel

 

 

ACEELERATION- both negative and positive

if the vehicle is going forward in a straight line, the force is applied to the rear... the front of the car becomes lighter and the rear heavier... this is also why you get thrown into yoru seat

 

the opposite is true for braking... under perfect braking (strightline) the force is applied forward (why your junk moves around your car when you hit the brakes hard)... the rear becomes lighter and the front becomes heavier

 

 

 

 

LATERAL ACCELERATION- turning

when the vehicle is in a full wheel lock turn, the forces are applied in the opposite direction than the car is moving (centripital, or centrifugal force). everyone has been thrown into the passenger seat when they turned hard

 

**note** perfect lateral acceleration (turning) is a condition where there is no change in vehicle speed.

 

 

 

 

 

to keep the vehicle under control, you must remain INSIDE the circle... i'll show an example...

 

you can see that if you braked 100% and turned 100% you would lose control... you are outside the circle.

 

 

 

 

 

 

 

this circle represents the imaginary line i was talking about... as the car accelerates, it loses it's ability to be controlled, as the car turns, it loses it's ability to be accelerated (slowed or sped up)

-------------------------------------------------------

 

 

you can make this graph 3D by applying the weights of the car. by placing the car's center of gravity on the center of the circle, you can determine handling characteristics. you can do some pretty easy trig and figure out how the weight will shift under each circumstance (assuming you know the corner weights and location of the center of gravity).

-------------------------------------------------------

 

 

one final note (for now)... the size of the circle is determined by the surface , the tires being used, weight, CG, and downforce (driving weight). in the picture below, you can see that wet and icy asphualt SIGNIFICANTLY reduce the size of usable traction.

 

 

 

 

 

HOPE THIS HELPS

 

Finall Audacityracing introduces "feathering"

 

now... to explain his feathering...

 

 

he was trying to maintain a perfect turn and throttle for the degree of turning he was performing...

 

 

he was trying to stay inside the green circle... by going outside the circle of traction you loose speed by having to correct. by "feathering" the throttle and steering he was able to keep this close area for the turn.

 

 

the car may have broken traction 1,000,000 times in that turn, but he always dialed it back in.

 

the car may have dropped below optimum speed, but he "feathered" to get the car back to optimum speed (considering the turn)

Edited October 18, 2005 by Genie47

[Genie47]

I think moderator must move this over to Racing Stories. This is very good video now with good info.

[En0203]

anyone also can say as long as u have heard it once, but to perform it is a different story

[En0203]

must move this over to Racing Stories

 

maybe should move it to tips and technical resources folder instead

[Genie47]

The key note in the posts is the mention of FWD cars. The throttle feathering is for the RWD car but the FWD car needs you to feather the brakes with LFB. He did mention that it is easier to control compared to throttle feathering.

[En0203]

the FWD car needs you to feather the brakes with LFB

 

this is the toughest part since we don't control the brake well with the left foot, it needs a lot of practise. i would say heel and toe is much easier to learn compared to feathering the brakes with left leg

Edited October 18, 2005 by En0203

[Genie47]

Must learn. No choice. Unless you can fork out money for an RWD car (most notably BMW). All cars now are FWD.

 

BTW, brakes are not as sensitive as throttle. You really have a lot of play.

 

Then again, if you are racing with your FWD grocery getter, you got to pay more attention to the maintenance of brakes and the brake fluid replacement.

 

That is why I am completely baffled by all these hoo-ha over CAI and all that. FWD car go tracking better improve brakes first.

Edited October 18, 2005 by Genie47

[En0203]

Must learn. No choice. Unless you can fork out money for an RWD car

 

in MY RX-7 is around RM$60k to RM$100k

 

i am forseeing the same for RX-8 (perfect 50:50 weight distribution) in the next 10 yrs

 

 

 

 

brakes are not as sensitive as throttle

 

not that easy, or maybe my left leg is stupid

 

 

 

anyway, i just realised my '74 lao pok car is a good car for training

 

1) u are forced to learn heel & toe and double clutching because u simply can't downshift at high speed without these two

 

2) u are forced to use ur left to brake while right to accelerate to dry the drum brakes in the rain after u go thru the water ponding area, otherwise u may not be able to brake later

[Atlantis_boi]

Yes agree esp our left foot is not as sensitive. I've tried LFB b4 & it's hard 2 control. Once in a blue moon I will try when there's no car behind me cos but til nw stil cant increase the sensitive & skill of my LFB I guess I nid more regular practice.

 

u are forced to use ur left to brake while right to accelerate to dry the drum brakes in the rain after u go thru the water ponding area, otherwise u may not be able to brake later Flinstones style braking haf 2 b applied if the brakes r nt workin.

Edited October 18, 2005 by Atlantis_boi

[En0203]

ya practise makes perfect

 

but we don't need such skill lar we are not racers anyway

[Goodspeed]

there is more video at http://www.jackals-forge.com/lotus/

Edited October 18, 2005 by Goodspeed

[En0203]

hyperlinked

 

http://www.jackals-forge.com/lotus/

[Pauly75ts]

"you know any website"

 

I've no idea.

 

Such dangerous driving frightens me.

 

Rgds

 

Paul Yong