Concertina Effect

http://openpitlane.co.uk/forum/showthread.php?t=11462

found this posted here, and thought it was pretty good.


THE "CONCERTINA EFFECT" IS REAL

This happens under braking and accelerating out of the corners.

Lets use an example. 2 drivers are approaching a corner and the braking point is at the
150 mtr board. The chasing driver is 100 mtrs behind the lead driver. Let say you are
the CHASING DRIVER.

o At the 200mtr board you are BOTH traveling at 200kph.
o At the 150 board the lead driver LIFTS OFF and starts to brake.
o You are still 250mtr from the corner so have no need to brake.
o At the 100mtr board the lead driver is traveling at 150kph.
o You are still 200mtrs from the corner, so not braking and traveling at 200kph. so you get close to the lead driver
o At the 50 mtr board the lead driver is traveling at 80kph, you are just at the 150 mtr board so just starting to brake
o You have been traveling at 200kph for 100mtr whilst the driver in front has been traveling at between 80 and 150kph
.... So YOU ARE NOW MUCH CLOSER TO HIM

o As you continue to brake you will get close still, giving you the impress that you are MUCH better on the brakes than he is.
..... You are probably not, it is the concertina effect.

o By the time YOU GET TO THE CORNER and say taking it at 60kph he has started to accelerate.
o Because you have gained IN DISTANCE on him you appear MUCH CLOSER at this stage.
o However he is now accelerating and traveling at 120kph and you are just exiting at 80kph
o As you both exit the corner, he further up, he is pulling away from you and looks like he has more power.

..... He doesn't, it's the REVERSE concertina effect.

o Only when you have reached the same speed as you were BEFORE HE BRAKED can you truly look at the distance between you both and say if you have gained or lost.

o It is better to pick a couple of key points on a lap to check your pace in relation to another car, either ahead or behind.
o This point should be on a longish straight towards the end, before any braking.

o Also, if you are the leading driver you will perhaps feel that you are weak on the brakes as the chasing driver appears to catch you under braking.

DON'T FALL INTO THE TRAP OF TRYING TO BRAKE LATER. because of this, it's an illusion.

Good post!

Usually when it comes to race craft, i'll often brake earlier, but apply less pressure to keep the momentum up!

And remember, distance is not a true reflection of gap, time is!