Michael...when braking

[f1.redbaron]

Some time ago, I started a thread in which I asked whether anyone knew the reason why a driver, while braking, would keep his foot on the throttle. The answer that made the most sense to me is to even out the ballance of the car - i.e. under braking, the entire weight of the car shifts forward, while when accelerating, that same weight will shift to the back. So I have a similar question...

I noticed that Michael, and DC to a lesser extent, tap their accelerators a couple of times while keeping their foot planted on a brake pedal. Why? Is the trying to ballance out the vehicle? If so, what is the benefit of that compared to constantly keeping your foot on the accelerator?

Thanks

[vyselegend]

Sorry it's not a very technical answear, but in some videogames the technique you describes make sense. In GT4 I use the throttle that way to fight understeer for exemple. If you have understeer in a tight corner, and you push throttle continuously while braking, you aren't helped at all because you obviously prevent brakes to operate and as you're too fast you understeer even more, but if you succeed to manage the balance whith brake and throttle, you can correct your line (cause obviously rear wheel spinning cause your car to oversteer) while you don't bother deceleration too much (at least lot less than if you keep throttle on).

In the crappy F1 2005, the interesting thing is that you can see the impact of traction control on this technique.(the game allow to set up traction control level in real time). The less traction control is applied, the more you feel the corrective effect (but the more it's dangerous too).

[vyselegend]

under braking, the entire weight of the car shifts forward, while when accelerating, that same weight will shift to the back.

There is something I remember about this. Last year at Istanbul, some test driver (don't remember who) explained that formula one is the only serie to make exeption sometimes with that principle. According to his sayings, teams were setting up the car so that the rear was diving while braking (as a normal car when accelerating). The reason was to put less wheight as possible on the front to keep steering efficient. (it was visible in the braking zone before turn 12, the tight left/right/left)

[f1.redbaron]

The reason was to put less wheight as possible on the front to keep steering efficient. (it was visible in the braking zone before turn 12, the tight left/right/left)

That's interesting because I remember Monza last year, when Michael lost it going into Parabolica, and how when marshalls had picked up the car, you could clearly see how the front end was loaded with ballast...I mean, the nose that thing was almost pointing to the ground.

[Sodder]

I had noticed the "thumping" of the accelerator myself but wrote it off to a flaw in the telematry. It seems to be that the "throttle bar" (for lack of a better word) during broadcasts jumps during down shifting and heavy breaking. The only thing that leads me to believe is that it has something to do with RPM ranges for each gear as he slows down the car but that dosn't make much sense.

I would also really like to know what is going on here.

[weisler]

i believe thats just the on board computer bliping the thorttle when downshifting. its the same as heel-toe down shifting in a car with a foot clutch, like they did in the old days! just matching up the engine RPM's with the trans/wheels.

[f1.redbaron]

i believe thats just the on board computer bliping the thorttle when downshifting. its the same as heel-toe down shifting in a car with a foot clutch, like they did in the old days! just matching up the engine RPM's with the trans/wheels.

OK, but then why does it only happen on Michael's car. Watch any other driver and you won't see it. Watch this video of Kimi's pass on Fisichalla (Suzuka 05):

http://video.google.com/videoplay?docid ... la&pl=true

(sorry, that is the best video example that I have)

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Also, I don't think that it is a faulty telemetry as you can clearly hear the engine revving (unless I'm hearing things)...

[West]

I would like to agree with you weisler, but when TV showed Alonso's telemetry I don't remember his throttle doing the same thing.

The thing is that the telemetry, if I remember correctly, showed the braking was at 100 percent with blips of thottle. This would make sense if you want to trail brake, as to let the car have a more neutral feel, or if u feel like you braked too early.

[DaveKillens]

Due to the geometry of rear wheel drive cars, they are stable under acceleration. When you apply the gas, they want to go in a straight line. There is a stabilizing effect when on the gas. In racing, when you apply the brakes very hard, the car pitches most of it's weight on the front wheels, making it very prone to instability. It's very easy at that moment to spin the car. Add to that the corner may be awkward, it may be decreasing radius, it tries to pitch the cart sideways. So it may sound funny, but you apply the gas to stabilize the car, to get the rear wheels back in line behind the fronts.
This is a trick many sim racers use too. I race many different high fidelity sims, many with different physics engines. But I can get the same result. I am braking hard into a corner, the back end wants to come around, and I'm right on the verge of instability. So I apply a little gas, and the car settles down, the back end wants to get behind the fronts again, instead of wanting to make the car go around.
So watch the telemetry close, and you will see that when a Formula One driver applies a bit of gas going into a corner, watch to see just how difficult the corner is, and exactly where in the corner this happens. On a very long straight braking zone, the driver won't be touching the gas. But as the corner transitions, and the car displays rotational momentum, the driver applies a little gas to bring the car back in line, to keep the car from rotating too much.

[manchild]

I think it could be for similar purpose as when in two-stroke karting races driver closes air intake with his right hand during braking in order to feed engine with more fuel mixture in order to keep it lubed and cooled a bit because more fuel will cool it down. Perhaps that is what MS and DC are doing too - feeding more fuel into engine in order to cool it down a bit and therefore prolong its life span (they use same engine too ).

[Hudsonhawk.]

but in some videogames the technique you describes make sense. In GT4 I use the throttle that way to fight understeer for exemple.

Now dats hilarious....I think I-die (Ide) the "kamakazie" plays GT4 too.....he was attempting this move when he launched Albers into a triple somersault. In GP4 if you cant win you knock them out of the way....or cut across the grass...

(Edited by Tomba)

[vyselegend]

I was speaking about corner braking idd.

Videogames are not very serious when talking about reallity, but it's not totally uninteresting. Did you know that some drivers learned the istanbul layout with the F1 2005 game? And Sebastien Loeb tested the Le Mans track with GT4 in the airplane just before driving the real car. So it may not be that ridiculous.

(Edit by Tomba)

[mcderd]

when watching the tv coverage it was apparent that the throttle blips were accuratley repeated during each heavy braking sequence. this would indicate that it is more than likely an ECU program that does it (might be driver, wouldn't be surprised) but would keep the revs of the engine close to optimum for acceleration on the exit from the corner.

would keep rpm in the correct range for the gear that's engaged. looks like a heal-toe manouver really. have seen similary telemetry feeds from drift racing and the heal-toe technique produces these telemetry characteristics...

[johny]

Videogames could be so accurate, have you played real simulators like LFS or GPL they really hooked me .

The blip of the throttle appears to me like some TC efect rather than the classic hell-toe also i've seen it on kimi telemetry last year (dunno this)

[Ciro Pabón]

Some weeks ago, I was reading about clutch configuration when Google threw me into our own forum (Technology/mechanics/transmission):

"Gearbox

F1 car gearboxes are different to road car gearboxes in that they are semi-automatic and have no synchromesh. They are sequential which means they operate much like a motorcycle gearbox, with the gears being changed by a rotating barrel with selector forks around it. The lack of a synchromesh means that the engine electronics must synchronise the speed of the engine with the speed of the gearbox internals before engaging a gear."

The bursts of throttle during braking happens with Schumi and Coulthard (I did not see his telemetry, just Schuey's).

Could it be that the Ferrari and Red Bull gearboxes downshift while breaking and the rest don't?Perhaps the gearboxes of other teams are able to shift, let's say, straight from sixth to second, so they do it on the exit, when you apply power, and the downshifting is "hidden" in the telemetry.

This can be disproved if you take a look to Massa's and Klien telemetry (not that they show it much) and DO NOT find the same effect. If they are "control taps" I shall take my hat off, because of its brevity. They are really, really short bursts.