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Engine Breaking When Racing


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#1 dotmatrix

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Posted 13 July 2018 - 08:24 PM

Hello
This is probably a question about what you prefer when racing. When i go into a tight left-right-left cone chicane i find it Works best, besides breaking as hard as i can with the foot brake, to engine brake into the right hand turn by putting the car in second gear. This together with steering input makes the rear of the car skip to the right and also makes the car ready for acceleration. If i brake Harder with the foot the wheels lock Up, but i know and can hear that its very hard on the engine and gearbox.

Any Better ideas?
Thanks

Edited by dotmatrix, 13 July 2018 - 08:25 PM.


#2 nicklouse

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Posted 13 July 2018 - 08:31 PM

brakes what are they for? honestly it is hard to say as it depends on the car the handling and the surface. i rarely used brakes. but when i do i try and only do it in a straight line.

https://youtu.be/dqfQ0C65SJs



#3 Cooperman

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Posted 13 July 2018 - 08:44 PM

In racing, engine braking loses you time. The brakes do the braking - all of it.

Heel & toe during braking to keep the engine revs at the right figure to match the speed and aim to have the correct revs on when you finally accelerate out of the final corner of the chicane. The revs/gear to aim for are those that give maximum torque, not maximum bhp. If you change down to much to give additional engine braking, the revs will be to high on exit and time will be lost.

Brake deep into the chicane and this should induce some slight oversteer initially, then get back on the power through the next two corners applying a little more all the time until just before exiting the final corner floor the pedal to get maximum sped out of the corner using all the track.

The aim is to carry as much speed smoothly through the corners without going sideways. A stiffer rear anti-roll bar might help with 'turn-in' as will stiffer initial spring rate.

If you lock the wheels you are over-braking and it is then difficult to keep the car on the ideal line and maintain smoothness through the corners. It is speed out of the corner which is important as that governs the ultimate speed down the next straight an thus the best lap time.



#4 dotmatrix

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Posted 13 July 2018 - 09:03 PM

many approaches to that corner in your video there :) straight line breaking when breaking that hard is preferable yes.



#5 dotmatrix

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Posted 13 July 2018 - 09:12 PM

In racing, engine braking loses you time. The brakes do the braking - all of it.

 

its not like I am engine breaking by just letting of the accelerator. the sequence is something like this. aproach the chicane at full speed and a lot of revs in 4'th, clutch down, push brake pedal, into third, no accelerator, dump clutch, still breaking, past the first cone, start to turn in, when near the second cone into second gear, dump the clutch, when at the second cone, let go of brake and feed in the accelerator to full travel when at the third and final cone.

this is how I do it with this tight, slalom like chicanes. does this still loose time? the way I see it the engine braking acts as sort of an abs and gives me a bit more braking power without locking up the wheels allowing me to brake later into the chicane.

 

usually at faster more normal corners I concentrate more on late breaking and speed in the turn rather than concentrate on exit speed.


Edited by dotmatrix, 13 July 2018 - 09:17 PM.


#6 Rorf

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Posted 14 July 2018 - 05:32 AM

Too much engine braking will break the engine :lol:



#7 mister bridger

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Posted 14 July 2018 - 07:49 AM

Too much engine braking will break the engine :lol:

It needed to be said.



#8 grizzler73

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Posted 14 July 2018 - 09:50 AM

Balance, balance, balance. Read up on Jackie Stewart and Stirling Moss. Smooth and no sudden inputs that will unbalance the car. Now that's my theory, just have to apply it... ?

#9 Bat

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Posted 14 July 2018 - 11:38 AM

Hi,

As Sterling Moss is mentioned above, I remember watching something on the TV.

He was driving a 4x4 Sierra round a track. The camera man was sitting in the back, the car went through several corners with the tyres absolutely screaming and the camera bearly moved due to how smoothly the car was driven.

Cheers  :proud:



#10 Retroman

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Posted 14 July 2018 - 12:36 PM

 

In racing, engine braking loses you time. The brakes do the braking - all of it.

 

its not like I am engine breaking by just letting of the accelerator. the sequence is something like this. aproach the chicane at full speed and a lot of revs in  start to turn in, when near the second cone into second gear, dump the clutch, when at the second cone, let go of brake and feed in the accelerator to full travel when at the third and final cone.

this is how I do it with this tight, slalom like chicanes. does this still loose time? the way I see it the engine braking acts as sort of an abs and gives me a bit more braking power without locking up the wheels allowing me to brake later into the chicane.

 

usually at faster more normal corners I concentrate more on late breaking and speed in the turn rather than concentrate on exit speed.

 

Not easy to put into words or do and I guess we all do things slightly differently

Definitely try only to brake in a straight line

BBC Brake Before Clutch and make a concious effort not to use engine braking, matching the gear to the speed rather than using the engine to help drop the speed. Lifting off the gas as engine braking is fine, its when you dump the clutch and use the engine as a full brake that causes damage to engine and box, use the brake to loose the speed and then select the gear to match...

Your words are in italics mine underneath

4'th, clutch down, push brake pedal, into third, no accelerator, dump clutch, still breaking, past the first cone,

4'th slightly braking, into 3rd, clutch back up (not really dumping it) braking hard, trying not to lock up or brake and steer / turn at the same time Key to it is keeping it smooth

 

Another big one is slow in fast out, sounds a bit like you are going in too quick and braking / turning at the same time, which makes it more likely to lock and scrub less speed off. By loosing the speed a fraction earlier you can get back on the gas earlier which is more controlled and smoother

 

when near the second cone into second gear, dump the clutch, when at the second cone, let go of brake

more brake before 2nd cone and into 2nd gear making sure the clutch is up before turning and off brake before 2nd cone

Then on gas at 2nd cone / before 3rd cone, possible brake dab before 3rd cone then nail it

 

Again trying to keep it smooth, a good way to practice is a dog-bowl taped to the bonnet with a squash ball in plus some string so you can recover it and someone with a stopwatch

 

Driving at speed on the twist stuff is an art and your brain has to be able to go at that speed before you can, it comes with practice

 

Having some mechanical sympathy, keeping it smoother and less flustered helps

 

Its not easy to say or do but fair play to you for askin



#11 dotmatrix

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Posted 16 July 2018 - 11:16 AM

Thank you for All your advice. I Will think about it the next time i race.

#12 DeadSquare

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Posted 16 July 2018 - 01:55 PM

I'm not going to give away my secrets !



#13 Cooperman

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Posted 16 July 2018 - 02:21 PM

Driving techniques for different types of motorsport are interesting.

For racing on a smooth track when the track has been practiced on requires very smooth driving to keep the best speed into the corner and especially out of the corner. The speed is carried through the corner as smoothly as possible and any over-steer will lose time as the speed will decay a bit.

I on't know much about hill-climbs, but 'nick...' can advise on the optimum technique as he is the expert on here for that discipline.

Then we come to rallying, which is the most difficult. For tarmac rallying on pace notes, again over-steer is to be avoided whenever possible because it prevents the carrying of the speed through the corner. However, this relies on the pace notes being very accurate (mine always were/are  ;D ). For driving 'blind' on tarmac you need to look at the corner, assess it and brake into the corner provoking a bit of over-steer for safety then getting hard back on the power as soon as you can see it is safe to do so.

Driving on gravel always requires some over-steer. On pace-notes keep the over-steer to a minimum, but remember that you can't really get back on the power early unless you have a bit of over-steer or you will go into under-steer and thus lose a lot of time.

Blind driving on gravel requires over-steer into the corner on the basis that'sideways is safest' to quote Hannu Mikkola. So you flick the car the opposite way whilst braking, then as it swings back you feed in some over-steer and balance it with power and opposite lock. The same applies on ice, but slightly more so.

I won't go into the techniques of left-foot-braking in both front- & rear-wheel drive cars as that requires some advanced capabilities and is very difficult to learn. I used it in a SAAB 96V4 I had many years ago with good results, but I have always found it difficult in a Mini. Paddy always says that he could never get the hang of it the way Timo and Rauno did in a Mini.

But for racing, keep it totally smooth and have full throttle as early as possible out of every corner.

The other thing is to optimise the suspension set-up to suit each circuit.

I hope this is of interest even though is departs a bit from the original post.



#14 nicklouse

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Posted 18 July 2018 - 12:43 PM

please note that the term "racing" can mean many things. so stating the type of racing you do can help.

 

going round a corner with 6m wide track is very different to going round a corner with less than 2m of track.



#15 dotmatrix

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Posted 01 August 2018 - 09:05 PM

a lot of interesting answers here. thank you for that! :)

 

 

please note that the term "racing" can mean many things. so stating the type of racing you do can help.

 

going round a corner with 6m wide track is very different to going round a corner with less than 2m of track.

 

I do hill climbing, which in denmark means very short rally stages on very small roads through forests and over bumps etc. not many actual hills. but every other time they do a left-right-left chicane made out of cones to keep the speed down.






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