Left foot braking kicks butt

[StanBo]

Heel Gas and Toe Brake is hard if you are tall. I do Heel Brake Toe Gas because I can't get my leg angled the right way under the steering column far enough.

I think I need to figure out how to mount my seat farther back and get a steering wheel spacer, then I will be able to do it.

I'm 6'2"

A little off topic but I am 6 foot tall and have to drive the car with a helmet all the time.

I noticed that I could get full leg extension with my seat all the way back but the wheel was too far away.

My first step was both for security and lengthening. I installed a tekniq removable hub. It has a converter for the momo wheel I use and moved the wheel about an inch closer to my chest.

I instantly fell in love with it.

I recently added a 50mm sparco extender on the column to move it further out. Now all I have to do is add my rollbar and seat and I will be set.

Try the tekniq or an extender. They are really helpful. The only thing that is strange is using the signals. You have to get used to reaching for the stick when you could just slap it before.

I will try and scrounge up some pictures of it for you guys.

[drifter_for_life06]

Sounds like a plan for us "tall" people

[Matthew]

Quote »Are you guys serious? Left-foot braking and heel-toe do not increase lateral grip. Left foot braking is used to provide a quicker smoother transistion between acceleration and braking, then into the turn(trailbraking). But as you get to full lateral load you should be off the brakes, and perhaps only on the gas enough to mainitain speed until you are ready to accelerate out of the turn. If you need to use the brake in the middle of a steady-state turn, then you are doing something wrong. Using the brakes in the middle of a turn will start taking away lateral grip in order to allow for braking. If you try do go beyond the limints of the tire, you'll likely lock up the tire and understeer like crazy.

Heel-toe is just to drop you into a lower gear while you are braking. It also does not provide anymore lateral grip. Heel-toe should not be used while turning. It should be used when you are approaching a turn. For one, a slightly botched heel-toe during full lateral load may cause you to lose grip. Even if you don't spin, and the loss of traction is momentary, you've just scrubbed a couple tenths of a second of your lap time.

By the time I'm fully committed into a turn, my left foot is on the dead pedal pushing down to keep my butt planted in the seat. My concentration is on the road ahead and keeping the car at the limits. My rightfoot is holding the gas to maintain speed and perhaps make throttlesteer adjustments if necessary.

[/quote]But y0! i Saw it in Initial-D!It sounds like you people are using your left foot for trail braking, which is normally reserved for understeering FWD cars.

[stash420sx]

left foot braking is a tecnique used mostly for turbo cars. because turbo cars sometimes suck for technical events, such as autocross. you need to keep the rpm's up when going through certain corners and when shifting down to first from second is not an option.

[prigo]

Heel Gas and Toe Brake is hard if you are tall. I do Heel Brake Toe Gas because I can't get my leg angled the right way under the steering column far enough.

I think I need to figure out how to mount my seat farther back and get a steering wheel spacer, then I will be able to do it.

I'm 6'2"

I can relate, I'm 6'4, with a size 15 shoe.

I can heel toe if i wear my old wrestling shoes tho, they're alot softer and easier to do it with.

edit: btw, im also a pretty hefty guy (270lbs) you just gotta practice it man, like anything else, if your leg gets used to it, you can do it (its alot easier without bulky *** shoes ) But when I have my shoes on, I kinda roll my foot to hit the accelerator (when braking hard) since i got big feet (and ricer pedals, lol). You'll figure something out.

BTW, that idea about legnthening the steering colum sounds really smart, I might try that too ^_^

[CA18_Dreams]

I'm 6'2 and it works wonders for me... just got to learn how... and you can do it...

[Cyberkreig]

Matthew - sorry, what is trail brakeing?

[Matthew]

Trail braking is different than classic pre-corner braking where you are totally off the brake upon entering the corner, because you ride the brake, ever so slightly, into the begining of the turn. The purpose of this is to assist the car into rotating, and hopefully achieve higher enterence speeds. I drove a stock neon at a SCCA Texas Club event once, and it would understeer so badily that it would take braking well into the turn to maintain speed. It's not all fun and easy though, because trailbraking can be a double edge sword. Ride it too hard, for too long, and you'll end up rotating too much, and either scrubbing your speed off, or spining the car (and yes, i did the spin the neon). But an ungraceful stab at the brakes could push the front tires past their traction limit.As for the whole left foot braking in a 240, it's still an odd concept for me (at least) since i've never got as much time in a RWD car as i would have liked. Left foot braking is normally used, so you can modulate both the brake (which will induce over steer) and the accelerator (which cause understeer). Obviously, this isnt the case with rear wheel drive cars.

[Cyberkreig]

Ok.. i have used trail brakeing.. but i didnt know its name.. or why.. its just how i have to take some corners in the Stanza.

Like i said.. i dont use LFB in the 240 much. honestly i am too afraid the back will come out and i wont be able to recover it.. I do however use it all the time in my Stanza..

Seems to me that trail braking allows the momentum of the car to create the rotation.. where as with LFB the rotation is a side effect of the weight shift. I've never thought about it that hard before.

[StanBo]

Still off topic but here are the pictures I said I would post:





Here is a link to some more pictures of my removable hub and spacer.

[Sircnay]

Is it just me or does the dash and interior get dusty REAAAL fast.

[StanBo]

I only drive the car to practice and drift events. Most of the time it is just getting tooled on. That is all rubber and dirt and grime.

Oh just say no to tropicana bottled apple juice. I left one in there for ??? time and it exploded.

[C-Kwik]

Your car only has 100% of its traction to use. left foot braking may generate some oversteer to reighn in a front end that stepping away from you by loading the front of the car to produce more Force normal on your tires to increase grip but at the same time it is unloading your rear tires. If they dont begin to yaw out when you do this (the rear end developes a larger arc than the front end). Then you werent using a 100% of your tires traction to begin with. If your close to the limit a slight breath off the throttle should produce some oversteer as well, unless your front end is just too far gone. Higher entry speeds are achieved by late braking. Faster exit speeds are achieved by early braking so that you can coax the turn in towards the apex sooner and find your acelleration point sooner and not exced your road width on the exit. accelerating sooner means more time on the gas means higher exit speeds. What your are suggesting is theoretically unorthodoxed but to each his own.

If you are already using 100% of the tires' traction for lateral grip, you will only promote more understeer when braking. Weight transfer to the front wheels won't occur until the car starts to slow down. But since you are or should be using all the available traction for turning, you will have none left for braking.

Trail braking involves hanging onto the brakes while entering a turn like Matthew says. Ideally, you want the total traction to stay at 100 percent, while going from 100% braking to 100% turning. Asking the tire to do more will just lead to a loss of grip in both directions.

Doing this does provide slightly more load on the front wheels which can help turn-in, but this is because the weight is already over the front wheels. This isn't done to try and fix a problem mid turn while you are already understeering. It will only compound the problem.

Trailbraking is also not FWD or RWD specific. Nor is it only to cure understeer problems. It allows a driver to go slightly deeper into a turn before braking and provides better turn in/rotation to give a better angle to attack the turn.

And higher exit speeds are not seen by hitting an apex sooner or earlier. A late apex will point you down the straightaway sooner and allow you to get on the gas sooner.

[C-Kwik]

left foot braking is a tecnique used mostly for turbo cars. because turbo cars sometimes suck for technical events, such as autocross. you need to keep the rpm's up when going through certain corners and when shifting down to first from second is not an option.

That is a poor way to fix a poor choice in turbo. Consider, to keep a load on the motor to keep a turbo spooled, you have to apply a forward load and a rearward load, reducing the available grip on the front and rear tires(RWD cars). FWD cars might be okay doing something like this, but I'd be wary of adding any excess heat to your brakes. With proper turbo sizing, and as long as you keep the RPM's where you should, there should be enough exhaust energy while using enough gas to maintain speed through a turn to have good response from the turbo when you exit the turn. And typicaly, you should be gradually getting on the gas when exiting a turn anyways, so the turbo should have no problem getting to full howl by the time you hit full throttle.

As far as autcrosses, rarely have I seen a 1st gear turn. And if you are autocrossing, especially competetively, your choice in turbo should be focused on giving you a broad torque curve. And if there is a 1st gear turn, it's usually only be at the top of first anyways.

[Phax]

Is it just me or does the dash and interior get dusty REAAAL fast.

It's not just you. Try spending a week or so on the LA freeway system, with the windows rolled down. Mmmmmmm, road dust....

[Phax]

...Higher entry speeds are achieved by late braking. Faster exit speeds are achieved by early braking so that you can coax the turn in towards the apex sooner and find your acelleration point sooner and not exced your road width on the exit. accelerating sooner means more time on the gas means higher exit speeds....

Thanks for sharing! That was a good explination of the dynamics in high speed cornering. The idea of braking with the left foot, to stay on the gas through the whole corner, might work in some conditions. I'm sure that going around freeway onramps, and other such scenarios, that it could provide a bit of extra car control.

Full out, balls to the wall driving conditions are a slightly different story. For the most part, it seems like you find yourself either accelerating at a frantic rate, or slowing down from having just accelerated at a frantic rate. There are some turns in there too though. =)

[MrFox]

Trailbraking is also not FWD or RWD specific.

Trailbraking and Left-foot braking (braking under throttle) are 2 different things. The latter, I'd like to think of it as driver adjustable brake bias. A FWD response to simultaneous brake/throttle input would be the opposite of a RWD response.

I agree with your analysis of trailbraking response though.

[C-Kwik]

The idea of braking with the left foot, to stay on the gas through the whole corner, might work in some conditions. I'm sure that going around freeway onramps, and other such scenarios, that it could provide a bit of extra car control.

How so? If you do this, you will be going slower through the turn. Consider you put 20% of the rear tire's available traction into accelerating the car. Then put 20% of the front tire's traction into slwoing the acceleration down. That means it leaves you with only 80% traction available for turning. I don't know about the rest of you, but I actually want to drive faster.

[C-Kwik]

Trailbraking and Left-foot braking (braking under throttle) are 2 different things. The latter, I'd like to think of it as driver adjustable brake bias. A FWD response to simultaneous brake/throttle input would be the opposite of a RWD response.

I agree with your analysis of trailbraking response though.

If braking under throttle is left foot braking then what is the purpose? As I explained already, you are working against traction by doing this.

[MrFox]

If braking under throttle is left foot braking then what is the purpose?

All four wheels are used for deceleration. Power is applied to counteract the brakes on the driven wheels in order to change the ratio of front/rear braking bias.

The front/rear slave cylinders have a fixed brake pressure ratio. Usually the fronts brakes are biased way too heavily, and thus lock up too early while the rears are not even close to their traction limits. LFB with FWD can force the rears to contribute more w/o locking the fronts.

As for LFB in RWD, I haven't figure out yet a good way to use it in driving front engined street cars. It can be used to stabilize a loose rear by inducing massive understeer, but there are easier ways to accomplish this in a front engined car. It is a really useful techinque in autocrossing a tail-happy, superlight weight mid-engined car though (especially one with a cart like pedal setup; no clutch pedal to get in the way)

[Cyberkreig]

If braking under throttle is left foot braking then what is the purpose? As I explained already, you are working against traction by doing this.

The purpose is weight transfer.

How can you write a post like that above about cornering dynamics, and NOT understand that to tap the brake while under throttle will alter a cars balance?

[MrFox]

Weight transfer is accomplished by acceleration or decceleration. Simply dragging the brakes w/o slowing down is not going to alter vehicle weight balance, it'll only load up the dragging tires, as C-Kwik had pointed out.

I maintain that LFB is used to increase the brake bias of the non-driving wheels.

Lets try to maintain a civil and intellgent discussion please.

[Cyberkreig]

WRONG.

Tapping the brakes at any time, even under heavy acceleration will SLIGHTLY slow the front tires, thus moving part of the cars weight forward.

If you dont belive me go try it, Take a long smooth corner, accelerate gently through it and tap the brake, you will feel the nose of the car come down slightly.

[MrFox]

WRONG.

Tapping the brakes at any time, even under heavy acceleration will SLIGHTLY slow the front tires, thus moving part of the cars weight forward.

If you dont belive me go try it, Take a long smooth corner, accelerate gently through it and tap the brake, you will feel the nose of the car come down slightly.

I believe your cause and effect are muddled.

Tapping the brakes while accelerating, as per your example, will cause the nose to come down. But it is not because the front tires are slowed, it is because you have decreased the overall acceleration, causing the amount of rearward weight transfer to decrease.

We know braking causes weight transfer. C-Kwik's post was questioning how LFB can increase rather than decrease overall avaliable traction.

[Cyberkreig]

you are correct.. the overall acceleration is lessened.. but, by slowing down the wheels.. i mean duh.. but i definatly should have been clearer.

--

Well if we KNOW that braking causes weight transfer(forward)

and we KNOW that % of a cars weight over a wheel is directly related to the amout of traction that wheel can provide (i.e. car doing a wheely has 100% of weight on back tires, their traction is increased by said weight)

and we know that understeer is a lack of front wheel traction...

^ all that being true, CAREFULY adding weight to the front tires can reduce understeer

[MrFox]

And we have gone back to square one.

If you are already using 100% of the tires' traction for lateral grip, you will only promote more understeer when braking. Weight transfer to the front wheels won't occur until the car starts to slow down. But since you are or should be using all the available traction for turning, you will have none left for braking.

Trail braking involves hanging onto the brakes while entering a turn like Matthew says. Ideally, you want the total traction to stay at 100 percent, while going from 100% braking to 100% turning. Asking the tire to do more will just lead to a loss of grip in both directions.

Doing this does provide slightly more load on the front wheels which can help turn-in, but this is because the weight is already over the front wheels. This isn't done to try and fix a problem mid turn while you are already understeering. It will only compound the problem.

Trailbraking is also not FWD or RWD specific. Nor is it only to cure understeer problems. It allows a driver to go slightly deeper into a turn before braking and provides better turn in/rotation to give a better angle to attack the turn.

So you, C-Kwik and I all agree that trail braking works.

Now what does any of this have to do with left foot braking/braking under throttle?

Weight transfer is not the objective of LFB, because no power is needed to transfer weight forward;You are deccelerating!

Lets start again. My arguements:

-Left foot braking = braking under throttle-LFB and trail braking are 2 seperate things-The objective of LFB is *not* weight transfer

-LFB in FWD induces rear brake bias-This enchaces overall braking traction due to normally forward brake bias, and induces oversteer by loading the rear wheels in braking.

-LFB in RWD induces front brake bias-This induces understeer by loading the fronts in braking

[Cyberkreig]

i have no idea what trail brakeing has to do with anything.. completely different technique.

I disagree. IMO the goal of LFB is certainly weight transfer..

[drifter_for_life06]

thats what ive always thought, LFB transfers the weight of the car forward somewhat, affecting understeer

[MrFox]

Decceleration results forward weight transfer;Braking results in decceleration;LFB is a form of braking;So yes, LFB will result in weight transfer;

But it cannot be the primary reason to do LFB. Because plain old braking (POB) will produce the same results in terms of weight transfer.

Weight transfer is purely a function of overall vehicle acceleration (in terms of dynamically variable factors). It is independent of the dynamics of individual wheels.

[Cyberkreig]

I agree totaly with your first paragraph, yet i have no idea how you can conclude that LFB is not sued for weight transfer.

Of course POB will transfer weight.. however, when in a high speed corner(suffering from understeer) simply braking is of no use. Any driver knows that you need to separate steering from braking, to POB while understeering could be fatal.

LFB is not a constant or sustained petal pressure, it is a tap, that can not be done with the right foot, because it is busy carefuly setting your corner speed. This tap slows the vehicle only very very slightly, as you have not let off of the throttle, but it does transfer weight forward, increasing available tractoin.

please understand i am not trying to argue with you, i simply dont understand what you are trying to say.