When I attended a weekend driving school in MA, I was introduced to left foot braking for FWD cars. Really liked the generated oversteer, but I have a question for the more experienced auto-X/track drivers, what are the ideal situations for LFB? Like any technique, there are the right situations and the wrong ones, i.e. heel/toe and hand brake usage. Is it a simple concept enough to say that you use LFB whenever you need more oversteer? Would just like to expand on this.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HondaLaw &raquo;</TD></TR><TR><TD CLASS="quote">When I attended a weekend driving school in MA, I was introduced to left foot braking for FWD cars. Really liked the generated oversteer: </TD></TR></TABLE>


???? Are you sure you are explaining this correctly?

 

Yeh, I'm not referring to cart left foot braking. There was a thread posted about it a while back "Braking Stability" that somewhat touched on LFB.

 

Theoretically, a bit of left foot braking in a corner should unweight the rear end of the car, which would allow it to rotate more. I dont do it, but it should work.

 

Generally its an option to use in turns that dont require downshifting. I think its a bit faster, since you can trail brake in while remaining partially on the throttle, and get back on it sooner than if you did it with your right foot.

 

Also nice for keeping your turbo spooled, especially the big heavy-lag ones.

(If you had a turbo to spool).

 

LFB keeps my VTEC solenoid spooled

 

All good points, especially the turbo lag point More suggestions, more driving pointers

 

It will induce more oversteer, so I've been very timid at using it in high speed corners (like south bend @ VIR).

Practice on the street, then start with the slower corners on track and build up your confidence and technique. Its bitten me a few times, but the turns were slow enough that I kept it on the track.

 

You'll quickly notice that your left foot is used to the stiff clutch, when you slam your forehead on the steering wheel slowing for a stop sign.

 

Yeh, I practice on country roads and a some on/off ramps. How fast were you moving? It strikes me that LFB could easily bite someone's car. It all lies in feeling out how much to apply, its a technique where you think a little more will be fine and then suddenly you're off the track/road.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HondaLaw &raquo;</TD></TR><TR><TD CLASS="quote">Yeh, I practice on country roads and a some on/off ramps</TD></TR></TABLE>



<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote"> How fast were you moving? It strikes me that LFB could easily bite someone's car.</TD></TR></TABLE>

Probably around 60-65, VIR Turn 3.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote &raquo;</TD></TR><TR><TD CLASS="quote">It all lies in feeling out how much to apply, its a technique where you think a little more will be fine and then suddenly you're off the track/road. </TD></TR></TABLE>

Thats why I "practice" driving on the street, in traffic, just for muscle memory, not really driving fast.

 

I don't use it on the track. Too crappy to try it right now. I need to get "toe-and-heeling" at speed down first.

 

My friend and I go out early at 4.30 on Sunday mornings to this country road by where he lives. The lone tractor once every few days. As far as the on ramps go, just for memory and feel, no 90MPH into traffic. Trust me If I messed around like that I'd be out of a job.

That was a pretty decent amount of speed to .RJ Did the car grab?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by HondaLaw &raquo;</TD></TR><TR><TD CLASS="quote">That was a pretty decent amount of speed to .RJ Did the car grab?</TD></TR></TABLE>

Eh, just slid. Corrected and kept going (a bit slower than before ).

Its hard for me to trailbrake hard with the left foot, something i'm still working on.

 

The problem with using it on a turbo-laggy car is that while under boost, you don't repressurize the brake vacuum assist reservoir. LFB works great on a turbo car til the vacuum assist is emptied, and then your brakes need a lot more force to work. In the case of my car, when it runs out, the brake pedal can get kicked back rather viciously if you're deep in the pedal travel already.

 

i practice left foot braking every time i come to a stop, or ever time i slow down for a corner. it only takes about 2 days of consistent practive to get used to it. for a stop, just throw it in neutral and brake to a stop. for a corner, (obviously) leave it in gear and slow down to the speed you want. at street speeds, you can try carrying the braking into the corner just to get used to the feeling of slowing down during turn-in.

there are other reasons to lfb. most drivers are nowhere near the limit of adhesion for the transient part of a corner, ie: turn in through a little before the apex. the idea being that the smoothest possible way to drive the corner would be to have the braking force go to zero (at the apex) just as the driving force starts to increase (right after the apex). this (in theory, anyway) gets you closer to the edge of the g-g diagram, netting you a quicker corner entry.

as for the brake-induced over steer, that can be stopped with adjusting the brake bias more forward. you will probably lose some absolute braking force, but the fact that you will be closer to the limit of adhesion for a longer period of time is what makes the technique faster.

 

I LFB EVERY time I autocross. As soon as I started doing it, I immediately noticed that it was faster for me. Since then I have never used my right foot to brake (during autox) except to shift/downshift. LFB helps me rotate the car into a corner, settle the cars weight when I want to, and I just feel like I have more control of the car. Plus it takes less time to get on and off the gas if your right foot doesn't have to move all the way too the brake and back to the gas.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GSpeedR &raquo;</TD></TR><TR><TD CLASS="quote">You'll quickly notice that your left foot is used to the stiff clutch, when you slam your forehead on the steering wheel slowing for a stop sign. </TD></TR></TABLE>

dude..totally hear you on this one... (serious).

 

I don't autocross - it's way too hard - but I LFB road racing a lot, particularly in the wet. The biggest challenge is not using the brakes too much. I discovered that my brake lights come on with VERY little pedal pressure so it confuses the bee-jeebers out of people behind you, when you're hard on the throttle and just touching the brake pedal with your toe, in anticipation of needing to use it...

K

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GSpeedR &raquo;</TD></TR><TR><TD CLASS="quote">You'll quickly notice that your left foot is used to the stiff clutch, when you slam your forehead on the steering wheel slowing for a stop sign. </TD></TR></TABLE>

lol yeah first time i tried that i was with a friend and well let's just say he wasn't exactly complimenting me on my smooth driving!

autocross doesn't really give you time to LFB...

 

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

autocross doesn't really give you time to LFB... </TD></TR></TABLE>

huh?

 

i've always left foot braked when driving any car that is an automatic. i just started doing it on the track this year at any point where i don't have to downshift. i think the toughest part for me, because it isn't part of my subconscious yet, is making sure in my head what the upcoming corner needs (shift or not) and what each foot will be doing.

what i'd like to do is get some lap times and try to determine which method is currently faster.

 

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

lol yeah first time i tried that i was with a friend and well let's just say he wasn't exactly complimenting me on my smooth driving!

autocross doesn't really give you time to LFB... </TD></TR></TABLE>


Wazzat?

Heck, LFB is probably just as important (if not more) in autocross as it is in roadracing! The quick changes from throttle to brake to throttle in autocross makes LFB a big advantage.

 

[QUOTE=HondaLaw]
If I messed around like that I'd be out of a job.
QUOTE]

I expect so, since you indicated that you work for a Federal Law Enforcement Agency...