F1 Fanatic

Let’s write here our questions about F1 2012.
My question is:
Does anybody know when I should use front, rear and neutral brake bias?

Thanks @raymondu999!

accelerator and brake at the same time? that doesn’t sound right :)

as mentioned, i put the brakes towards the rear for trail braking (where you’re braking during or after turn in). for slow tight corners and hairpins, front bias should help the car slow down quicker as the weight transfers to the front. i tend to switch the brakes to neutral during fast/medium corners.

it all depends on your driving style, of course, and i find simple trial and error is the only to find out really!

for canada, where i just finished a career race, i found in qualifying my fast times were with rear bias right the way through the lap until the hairpin where i set it forward. then back to neutral for the final chicane, then back to rear bias for the next lap. the brake settings were 49-51. in contrast, in Spain i set it to 48-52 and only used front and neutral bias.

How much the game emulates real-life vehicle dynamics, I cannot say. Frankly speaking there are some setup options where (going by what they describe each option to be) they actually have things the wrong way around, and a setup change in f1 2012 sometimes has the opposite effect of real life.

Strictly speaking, from an engineering standpoint, you want a neutral brake balance (which isn’t the same as a neutral, 50-50 brake bias)

You want the car to be on the limit of all four tyres, and as such, you want the brake bias to be equal to the ratio of front to rear grip. This is true for cornering grip too – understeer and oversteer means you will be, at any point in time, driving below the limit on one axle.

Of course some drivers feel more comfortable doing things a certain way, which can take precedence over engineering sense – a driver comfortable with his theoretically slower setup can be faster than a driver who is driving a car with the theoretical best, but he doesn’t feel at one with the car. It’s like trying to cross your arms the opposite way – you have to think about it rather than just being able to do it instinctively on command)

@graham228221 With any brake bias, locking up is never good, because a wheel that is still rotating slows you down quicker.

I know where you’re coming from on the trail braking and rear bias. However, with trail braking, weight is shifted forward and off the rear axle. The front axle immediately has more grip than the rear. To avoid locking the brakes, with a rearward bias, you have to brake as hard as the rear (at that reduced grip) can take, and you won’t be using the front at full force. With trail braking and a rearward brake bias the front tyres still want to turn while the rears are being overwhelmed by trying to brake more (thanks to the bias being more rearward) at reduced grip.

The rear bias might sound correct intuitively – because then you have more front grip for turning. But it’s actually (somewhat counterintuitively) slower.

@snakebite it makes sense on thesurface, but you’re ignoring that the front has more grip than the rear, under trail braking.

Also as a one-time tyre engineer I call BS on you saying the rotating tyre doesn’t slow the car further.

Scientifically speaking, whenever a car is accelerating (in whatever direction – remember acceleration is a vector quantity) the tyre is never fully “gripping” the road. There is always, at an almost microscopic level, a level of slip. When talking about forwards/backwards (along the tyre’s rotational axis) then we talk of slip ratio, and when talking about cornering and lateral acceleration, then we talk of slip angles.

You can disregard the numbers here as different tyres have different numbers, but what you need to pay attention to here is the general shape of the curve.

This is a graph which plots slip ratio, against the traction force – ie the further to the right, that means a greater difference between road speed and the tyre’s rotational speed. If a car has its tyres at 0 rotational – ie a locked tyre – then the slip ratio is at its greatest (car speed vs 0kph)

Because each tyre is basically slipping at every accelerative force that goes through it, there is actually no thing as “grip” in the everyday conversational sense. There is always some slide in the car. Each amount of slide, however, brings along a different level of grip. As with the graph (which is from FSAE) the tyres hit an optimum “sweet spot” at a certain slip ratio, before there is less grip on either side of it. A locked tyre, which will tend towards the far right end of the graph – will have severely reduced grip.

Back to the trail braking debate, all of this is a transient condition, and it’s over so quickly that the driver being comfortable with the setup under braking will probably gain more time than the theoretical loss of a slightly worse off brake bias.

@bag0 heel & toe is done with clutch full-in though… so you’re just accelerating the engine (not the car) while you’re doing it. It is possible to use it in the fashion you do – a tap on the brakes, to slow the car down quicker than a lift + brake (given the time taken for your foot to go off the gas) but ideally, it would be quicker to enter at the correct speed already and balance the speed on the throttle.

@snakebite I do apologise for being so harsh. It was never my intention to be so rude, and I’ve slapped myself in the face for it.

ABS to be honest will not be on the limit. ABS doesn’t maintain the wheels from locking. What happens in the ABS world is that it’s programmed with a set slip ratio, as done by comparing the axle speed versus the speed of the car. Whenever the slip ratio goes above the optimum range – the peak of the graph I posted earlier – the car eases off on the brakes, and until it gets back to a predefined range, and then once it exits that range again it eases off again.

As such, ABS means you’re always braking at slightly less than maximum braking force. A really good driver who can keep the braking on the limit, at the optimum slip ratio (which is VERY difficult – imagine trying to balance the brake pedal on that knife edge of optimum slip ratio on ice) would always slow down quicker than an ABS-shod car brake.

At least that’s how it works in the real world – though I don’t know how it happens in the game. Again with the brake bias… I’m not entirely sure how the game handles that. The in-car setup screen with 50% front and rear sort of implies that 50% of the energy is going front, 50% going rear, but again – I don’t know how exactly they’ve implemented that in the game.