1
$\begingroup$

Power braking (increasing power while brake applied) at start help to start car at higher speed, but on other hand we lose traction due to tire slippage.

Does this increase acceleration (as shown in movies)? If yes, then why don't F1 racers do it?

$\endgroup$

1 Answer 1

1
$\begingroup$

There are a number of potential reasons for braking under power.

Braking generally gives finer, more consistent and more immediate control of torque than throttle position and so it may be useful for making fine adjustments to the torque applied to the wheels while keeping engine revs in a desirable range and avoiding the instability potentially associated with lifting off the throttle while turning.

Braking also affects weight distribution so can be used, in conjunction with brake bias adjustment, to mitigate under-steer and improve turn-in, especially in rallying, by transferring load from the rear to the front wheels. In fact the Mclaren MP4/12 had a system which used an additional brake pedal applied to one wheel only (depending on turn direction) to assist steering.

Another specific application in F1 was during the era of exhaust blown diffuses. In this case the high velocity airflow generated by the exhaust was used to generate down-force for there was a clear advantage in keeping revs high during cornering, holding off a significant amount of power with the brake if necessary.

In terms of traction from a standing start there is a complex interplay between clutch, throttle and brake as well as engine and throttle mapping and gear ratios. Modern F1 cars also have dual hand clutch controls (although regulations have changed this year) so this obviously makes balancing brake and throttle somewhat easier than with a foot operated clutch.

In general a good racing start involves balancing two competing considerations firstly maximising available torque by keeping revs in an optimum range and secondly avoiding wheel-spin (although a small amount of tyre slip may be beneficial).

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.