Can any one offer any insight on left foot breaking. I searched and nothing came up, so I thought I would try to find some information out about it.

A little back ground information. I was watching the 4th Initial D DVD and it had an EG hatchback on it, and one of the older men started to talk about how it was used in pro racing to keep the back end from sliding out.

I was driving the other night and I was going around a turn a lot faster than I should have, and I spun out. It happend just like how they explaned it in I-D, I was hoping someone could go into more depth on what it is and how its used.

Thanks,

Jack

 

I would start by not using Initial D as an instructional video for driving....

Its used in turns that do not require a downshift and/or to settle the car in the turn. It takes alot of practice (i'm pretty crappy at it, but working slowly) and you have to be very aware of its effects on weight transfer as you're driving the car on track.

 

braking = what you do to slow a car down
breaking = what Im going to do to your arm if you dont stop using it improperly




ps- left foot braking is primarily used to keep a turbocharger spooled.

Some drivers also use it for corners where they dont downshift, but that is mainly a preference thing. And of course, only on the track.
Its not something you can jump into right away. Your left foot simply doesnt have the sensitivity or feel to brake nearly as well as the right foot. Takes a lot of practice.

 

I did it once playing football, but never while driving.

 

What I heard about trail braking:

Going through a corner, while smoothly accelerating, the brake is gently used to make the rear wheels lose a little traction and help the car "come around". You can "turn it off" by releasing the brake if you get too wild.

I've tried it, but I cant get it right. Maybe it has something to do with my car having ABS and Electronic Brake Distribution?

More than likely, I just dont know what Im doing.

 

I should have video up in the next couple days of me left foot braking on track. It was a corner where I didnt' have to downshift so I could stay on the gas and brake to settle the car and let it rotate.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by elgorey &raquo;</TD></TR><TR><TD CLASS="quote">
ps- left foot braking is primarily used to keep a turbocharger spooled.

</TD></TR></TABLE>


with your AWD car it would be to keep the turbo spooled(correct me if i'm wrong).

the use with fwd cars is typically to help the rear of the car rotate in a situation where the car likes to understeer. i did this with my stock suspension, which liked to push. it worked part of the time, but stock civics are pretty underpowered, so a lot of the time i think it just slowed me down. however, with a big rear swaybar i have no problems with this.

my suggestion is to do a little reading or go to a driver's school.

oh, and don't spin out on the street. that's bad.

 

The only time that I right foot brake is when I am down shifting, left foot braking or trail braking really settles the car down, I can go into a turn and be a little out of shape and by trail braking keeping my right foot on the gas I can carrier a lot more speed though the turn, I took awhile to get the feel of it but now it comes naturally.

 

the schumachers do it, so it must be good!!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Wide Open Throttle &raquo;</TD></TR><TR><TD CLASS="quote">
the use with fwd cars is typically to help the rear of the car rotate in a situation where the car likes to understeer. </TD></TR></TABLE>

While I'm certainly no authority on driving skill, that's what I've always heard, that it's used for rotating a FWD car. If that's the case, it definitely seems like it would NOT help the car stop spinning, but rather would encourage it to do so. Someone else correct me here if I'm wrong, especially because I've been thinking about this topic lately.

 

Right, the idea is to promote rotation, not prevent it.

Left foot BRAKEing works well for me entering decreasing radius corners when fighting understeer, and helps me to be smoother with quick changes in throttle and brake application.

I only do it when I feel like I need a little extra help with a corner though, probably not the most scientific approach to using it.

 

Let's correct a couple of things here, Trail braking and left foot braking (LFB) are two separate things.

Trail braking is when you continue to brake while entering a corner. In other words you are approaching a corner, you do your maximum amount of braking in a straight line, then as you begin to turn the wheel to enter the corner, you ease off the brake, but not all the way. The further you turn the wheel the less you brake. This has to do with the friction circle concept, maximizing the use of the available grip of your tires. Thereby, braking deaper into the corner, and accelerating further in the straight.

LFBing, is simply using your left foot to brake. It is useful as stated previoulsy for balancing the car, smoothing transitions, help in the rotation of the rear of a car that is not set up optimally for certain situations/corners.

 

I use LFB a lot, it is easy to overslow the car, so in some cases I have found myself going overboard on it, as well as it can be hard on the brakes. In corners where downshifting is not required, I only use the left foot, and if downshifts are required, it is easy enough to transition the left foot onto the brake pedal if you want to. It takes practice like anything else.

 

Some of these have been mentioned, and a lot of the guys here pretty much have it right..i can practice my instrucintg by doing this so here goes...

Left Foot Braking times.

First and formost you can use it to shave transfer time from gas to break, if your right foot isn't going the distance then you can buy those few feet of full throttle time.

This works very well with Formula cars/sequential gearboxes/dogboxes where you are not using the clutch anyway. When I am driving those cars my left foot is dedicated to the brake once I leave the grid.

In some cases you may have a turn that you don't brake for, but you need to settle the car a little for turn-in. Usually people do whats known as a "confidence lift" where they crack the throttle, to ease your mind and put the weight a little on the front wheels. You can stay flat in theses cases, and just drag the brake with the left foot to point the nose. I practice this in all forms and types of cars.

Left foot braking to keep the revs up.
I learned this in karts. (where you are forced to left foot brake) With low HP cars that dont rev fast the loss of RPM in a braking situation can be devistating to lap times. With the karts, and my G-Stock CRX i will left foot brake in harder braking situations so that the revs stay up and I get to slow down. In the karts yes the clutch is slipping. In the cars..i imagine something is slipping somewhere..i guess i will fix it when it breaks. Beware a kind of reverse torque steer in this situation.

I will use that method in slaloms, lane changes, etc on the autocross course. In road racing, I will use it in kinks and higher speed bends that I dont downshift for.

Left foot braking for mid corner control.
As you learn in drivers school / Autocross school / books (or should have) you can control mid corner car behavior by steering with the throttle. Lift off the car points in, give it gas the car wants to track out, simple weight transfer behavior. You can use the brakes to do the same thing. If you are rolling into the throttle and the car starts tracking out early, you can just use a little left foot brake to point the nose back in (again, so you don't lose revs)

Left foot braking to keep your brake pedal up:
On tracks with lots of heavy braking zones you will feel brake fade often after a few laps. While exiting a corner and under full throttle..bring your left foot over and pump the brake a few times lightly to bring the pedal back up. (ok so this isn't the exact left foot braking we were talking about but oh well)

I think that about covers it. Its a great thing to use and know if you can pull it off, And its one of those cool times when you can practice a racing technique on the street. (to "teach" your left foot modulation)

As far as the Initial D thing goes..god am I glad i haven't seen any of those. the quote about the back end not coming out due to left foot braking is wrong wrong wrong. That is exactly what it is for. I wonder how much teachers would scream if Big Bird started saying 2+2 is 5 and then kindergarten kids started trying that.
Ug. Of course...i guess if they keep making initial d videos..I will have job security.

Jon K
http://www.seat-time.com

 

LFB

 

Shane, you were doing very well yesterday using LFB. You learned that from watching Initial D right?

Jon K
http://www.seat-time.com

 

Very nice write up racerjon1.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by sscguy &raquo;</TD></TR><TR><TD CLASS="quote">

While I'm certainly no authority on driving skill, that's what I've always heard, that it's used for rotating a FWD car. If that's the case, it definitely seems like it would NOT help the car stop spinning, but rather would encourage it to do so. Someone else correct me here if I'm wrong, especially because I've been thinking about this topic lately.</TD></TR></TABLE>

you are right that it helps a fwd car rotate mid corner, but it can also help settle a car as well. I remember readng an article where the brake/throttle telemetry of rubens and michael were compared.

Michael is a left foot braker, while rubens is not. To make a long article short, michael was able to brake further into a corner, since even when he at the braking limits of his ferrari, he was still almost 40% throttle. It basiclly allowed him to combat weight transfer. Since he was at 40% throttle, he didnt get the same weight transfer if you were simply standing on the brakes.

Made quite a bit of a difference.


Mike


Mike

 

Thanks Crosser.

Mike...excellent article. I think it was in F1 magazine. It really showed where it helped, and also it was a good article for dissecting telemetry/data acquisition.

They were able to point exactly to where Michael was 0.2 seconds faster than Rubens on their fastest laps.

Jon K
http://www.seat-time.com

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by racerjon1 &raquo;</TD></TR><TR><TD CLASS="quote">

Mike...excellent article. I think it was in F1 magazine. It really showed where it helped, and also it was a good article for dissecting telemetry/data acquisition.

They were able to point exactly to where Michael was 0.2 seconds faster than Rubens on their fastest laps.

Jon K
http://www.seat-time.com</TD></TR></TABLE>

it really was. Its neat to actually see where the faster laps come from.


Mike

 

So could anyone speculate whether EBD would negate the effectiveness of trailbraking?

 

i've always been interested in LFB. having gotten heel-toe down i feel pretty confident going into turns. but understeer owns me.

when you LFB do you initially start with a light constant pressure or jab at it, until the car takes the line your looking for?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by cougar10ag &raquo;</TD></TR><TR><TD CLASS="quote">
when you LFB do you initially start with a light constant pressure or jab at it, until the car takes the line your looking for?</TD></TR></TABLE>

Depends entirely on how soon your car will be leaving the track surface...

 

I'd imagine "jabbing" anything (brake, gas, or clutch) while on track would unsettle the car. I'm sure it would cause the car to rotate, but probably very suddenly and violently, to the extent that you would just completely spin out. When I'm not as smooth getting off the brakes, on the throttle, or letting the clutch out after a downshift, I am definitely causing unwanted weight shifts, so I think jabbing would have essentially the same effect.

 

Well it depends what kind of corner you're in as well... a jab on a highspeed sweeper might be sucidal but on a decreasing radius turn, at say 50 mph, you may need to induce more oversteer than a slow gentle push will accomplish.