Look, I know you find rally cool right now, but we're talking about techniques that are in use and have been used since long before you were born.
That's right, you clearly know better because you've "been there and seen these cars fly by in real life." I applaud you.
You not believing that rally drivers (or indeed circuit drivers) use left foot braking as a way of adjusting weight transfer in the middle of a corner doesn't mean it doesn't happen.
It's mainly used in FWD and AWD cars as these tend to have fewer options for adjusting the car's line on throttle alone
Some more rules of thumb. Thanks!
From 5:36, you might have heard of this chap.
I must not, as I have never seen him in real life. I must be a fan boy.
Doesn't explicitly mention using the brakes to adjust his line, but it's rather clear, given the way he constantly feathers the brakes on the entry to, through, and out of the corner, that this is exactly what I was describing:
So what you just did is post a video that supports my side of the argument and then topped it off with making a claim that wasn't supported by your evidence. Claims that, according to your side of the argument, are as important of techniques as any of the other basic driving techniques.
I guess McRae forgot to mention that part about left foot braking.
Or maybe this guy. Note again how he isn't just using brakes into the corner, but all the way through. So all his balance adjustments are not "done under braking into a corner":
He's braking through those corners because they're part of the entry into the following corner. The "target corner" so to speak. In other words, the braking zone extends/overlap in many of those corners. How do you not see this. How do you not see that he doesn't do the same on corners that are are entered and exited through straights. I mean, he braked through the entirety of allot of those corners because they were part of the braking zone for the following one. This is basic stuff man. You're using some bad examples.
In fact, here is a "good" one. I say "good" because this guy has been on podium plenty of times and even 1st quite a few times as well. This is the Romanian Rally Championship.
And he is ACTUALLY using left foot braking in the manner you guys are referring to. The difference between his footwork and the foot work of all the other world level drivers you have posted as "proof" is clear. And no, its not a matter of "you're comparing him to world level drivers." Which brings me up to the negative side. His footwork is completely unnatural. Allot of times he does it completely unnecessarily. Which is sort of allot to say about the guys who aren't any quicker than him. I think if he ever makes it into JWRC he will have a though time driving like that. And you don't get better by practicing bad habbits.
Compare that foot work to this...
And lol, as if "reducing your rate of acceleration" as you describe is not also essentially "controlling traction", just as I mentioned.
Well if you put it in that context than yes, you are controlling traction since the tires are receiving different net loads in each situation. One more and the other less. But this isn't relevant to my statement. Without being on the brakes you won't be spinning the tires (*waits for alternative circumstances reply*) and you'll accelerate faster. On the brakes, you'll have more traction but you'll accelerate slower. I know I didn't need to explain this for any other reason other than to confirm my implied "sense of the term" to keep you from nit picking for the sake of impeding my point.
I mean honestly man, you could have even looked at the Wikipedia page for this:
One common race situation that requires left-foot braking is when a racer is cornering under power. If the driver doesn't want to lift off the throttle, potentially causing trailing-throttle oversteer...
...the driver could have chosen NOT to lift off, and modulated it instead. This is just humorous.
left-foot braking can induce a mild oversteer situation, and help the car "tuck", or turn-in better. Mild left-foot braking can also help reduce understeer.
Again with the general "rules of thumb" and "tricks of the trade."
It can "induce a mild over steer situation" why? Because you're using your left foot instead of the right? In what circumstances? This is just some general vague "hints and tips" that newcomers read and say "Whoa! I'm gonna try that at the next autocross!" And I don't need you to answer those questions, they were just being used to make a point. I think you knew this on my last post but chose to explain the terminology anyways. Which is a cruddy one at that.
In regards to the "mild left foot braking" part, I've already covered that in my previous posts.
I know Wiki isn't exactly the fountain of knowledge but it's there in plain sight.
Man am I glad I didn't waste my time looking up that revealing, eye opening quote up there.
Yup, something you can do if you're ever stuck with one of the driven wheels off the ground on a torsen-equiped truck/SUV/whatever really. It keeps it from going full-open.
Instinctively, I'd call this "getting unstuck lol" as the purpose is to keep the power flow from switching completely to the unloaded wheel. Traction control for an unloaded tire. Fair enough. Still not a phenomena that exists in motorsports.
Same thing as the focus video.
What you actually mean is "I've not heard of people doing this before through my limited sphere of knowledge, ergo it must not happen".
You've got me all figured out
In this particular automotive application, trimming means using the brakes to a small degree to make small adjustments to the car's balance. You could, if you wished, use the word "feathering" to mean the same thing.
So from the two relevant videos above with similarly laid out cars (fwd with a torsen differential,) by "balance" you mean keeping the inside wheel from spinning too much (mainly in reference to the focus video) and having the rear slide out a bit due to the rear tires already being unloaded and near/at their limit of adhesion.I agree with this.
What is NOT occurring, is the car oversteering (slight or severe) because the, already sliding front tires, magically gained more grip and turned in more. It's more a change in angle than a change in trajectory, not to say that the car's trajectory doesn't slightly change during this whole event, but what creates the oversteer/reduced understeer in the situation with the Civic is the rears sliding out, not the fronts gaining more grip and turning in.
Only if you're an oaf and hoof the pedal as hard as possible.
Something I never implied.
See any of the videos above - the left foot may be less sensitised to braking than the right foot, but it's possible to modulate almost infinitely once you get the hang of it. If you've ever been karting and had no choice but to brake with your left foot you'll be aware of this.
Actually this is an interesting thing in my case. From my first day on karts I had no trouble at all with my left foot. Where as in my car it's the complete opposite. I'm sure it has something to do with which muscles I'm using.
Trail braking helps keep the nose down so you're maximising front tire grip through a corner...
The "nose being down" is simply a byproduct of braking. The whole point of trail braking is maintaining the tires at the limit as you use them for two different things (breaking and cornering) when entering the corner. And thus, allowing you to maximize the length of the straight you just covered. So it's associated with trail braking but it's not a relevant phenomena at all.
...left-foot braking during the corner maintains this even when you're back on the gas.
You keep going back to this and it's beyond me how it makes any sense to you. It's clear that you have a skewed understanding of how the tires work during a basic cornering event.
Ok, one simple 180 degree corner. Geometrical in shape and, for simplicity's sake, lets use a geometrical driving line. The second you have finished trail braking and have touched the apex half way through the corner, you instantly get on the throttle (there's that left foot braking advantage) and feed it in smoothly and accordingly. The only times you'd ever touch the brakes on exit in this situation, is if you'd like to keep the inside wheel from spinning in a fwd car with a torsen. And even then, it's not a common thing to do because it doesn't make a significant difference in the big scheme of things. This is because there are other ways of getting around these particular, isolated problems that don't involve touching the brakes past corner entry. Best Motoring (not Hot Version) is a perfect example of this. There are plenty of videos of races featuring world-level motorsports drivers in these particular sorts of cars where they don't use left foot braking the same way as either of the two videos above. If you can find a video of someone using left foot braking for the same reason as in the Civic or Focus videos in a racing environment, do post it.
If you have the throttle wide open and brush the brakes, there is less momentum lost from having the throttle less open or closed than there would otherwise be. I'm surprised you didn't figure this one out for yourself, since you yourself said that left-foot braking is also done as a time-save.
You're using momentum as if its dependent on your throttle position. As if slightly lifting off the throttle to maintain a certain speed or reduce you're rate of acceleration is any different then applying the brakes the required amount to achieve the exact same thing. Speed is speed.
Yes, some drivers (like Walter Rohrl) used this technique to keep the boost up in the old Group B cars but this was during the transition from trail braking to throttle. He would get on the throttle a bit sooner than normal to keep the boost from dropping for the exits. He did not, on the other hand, stay on the brakes longer than needed to keep boost from dropping. That's just counter intuitive.
Once again, you're making it sound like they're using both pedals at 100%.
I disagree. What I did was highlight the effects of "adding more work" to a tire that is already at its limit of adhesion.
This being the case I'm not surprised you don't understand the technique, but once again, it doesn't mean it doesn't happen.
You're good at this figuring me out thing.
Picture the scene: You're in a rally car with a massive, laggy turbo, in the days pre-antilag. Which of these techniques allows you to minimise this lag so you've got full power on the exit of the corner?
1) Lift off the gas to tuck in the nose and adjust your line
2) Keep your foot on the gas but dab the brakes to tuck in the nose and adjust your line
Again with these vague situations. Either way, nothing I haven't already covered.
Still, I'm sure you're going to come up with some reason why myself, Stotty, a British Rally Champion and two World Rally Champions are wrong, right?
Well of course, I disagree with you and your blatantly wrong "understanding" of the debate.
You're misunderstanding your own physics here.
What would dabbing the brakes a little do, at the limit?
It depends. If the front tires are at their limit (maybe the rears too) and the car oversteers, then it oversteered because the rear tires slid, not because the front tires gained more grip.
Not before the car begins to slide.
Like lifting off the gas, in other words - and lifting off the gas would take that 100% lateral grip figure down a few percentage points.
Maybe if you're not at the limit. Which I have a suspicion you've very experience with.
I can think of 100 different effects of what would happen to a fully settled car (fwd/rwd) that's at the limit, if you lifted off the throttle, that doesn't involve an increase in lateral grip before I can think of one that does.
What you seem to be assuming is that you're adding braking force to a 100% loaded car. Which isn't correct - you're removing acceleration force.
First of all, I'm going to assume you're referring to lateral acceleration as longitudinal should be 0 considering that our imaginary car is cornering at a steady speed and has taken a set, with its tires at the limit.
In which case, 100% of the tires capabilities are devoted to resisting that lateral acceleration that's trying to push the car wide. So how do you "remove acceleration force?" Well since you only have 100% of the tires to work with, you have to start making some sacrifices. If you want to add some (regardless of how small) braking, then you have to trade something in for it. In which case it would be steering since it is what is taking up 100% of the tires available traction to begin with.
If you want more turning then you have to sacrifice some speed. Remember the car is at a steady velocity so some throttle is being applied. So now some of that throttle can be slowly removed. I mention "slowly" because at this point it will be a delicate battle with keeping the rear from sliding while at the sale time decreasing your turning radius. All while staying at that razor edge of adhesion (kind of like trail braking huh.)
What DOESN'T happen is being at this steady state cornering at the limit and expecting to, not only reduce speed by braking but ALSO expecting to maintain the same radius, let alone decreasing it! The point isn't that it's a small amount of braking, the point is that you're expecting the tires to do more than one thing at a time when they're already at their limit!
So again, I'm not surprised it's confusing you.
EDIT: Keef, I didnt know those Civics had clutch LSDs. Regardless, the "inside wheel traction controller" comments I made still stand since the Civic video wasn't relevant to them.
