Posted: June 13, 2016
In short yes it does. But, before we delve into the art of Threshold Braking, it might be worth you covering some related track articles.
Whilst discussing Corner Entry Speed (click here to read) we covered a systematic approach to cornering, exploring how subtle adjustments in our technique can have big gains in speed and safety on circuit.
In Dissecting Corner Grip Limit Signals (click here to read), we explored how to interpret the audible and physical “Grip Limit” signals a vehicle communicates to us, as it approaches its limit of adhesion through a corner.
We are moving on now to arguably the most important subject in our circuit driving tool box: Braking.
Let’s begin by drawing on our road driving experiences before heading on to circuit.
Why? Because that is the map we have in our muscle memory for how to apply the brakes. We will be making small adjustments to your road technique so it is good practice to start with what we already know and build from there.
Just pause for a moment and focus on how you retard your vehicle when driving on the public highway, on approach to a hazard (we will use a corner for this example). Your initial application of the brake is smooth and light, you apply more pressure as the corner approaches, easing smoothly out of the pedal, before finally releasing the pedal and squeezing gently onto the gas to negotiate the corner.
All very smooth and timely, we have in fact sectioned your braking into three parts. We can summarise by describing the technique as Feel, Firm & Feather - it is safe and systematic.
My motivation to compare circuit braking with road braking is borne from experience.
When driving on circuit we need to modify the three F’s approach.
Our objective is to brake efficiently to the limit of adhesion of the tyre, over the shortest distance - a technique known as Threshold Braking.
Requiring practice and a little remapping of your muscle memory, if you are new to circuit driving the tendency is to brake as you do out on the public highway and not adjust your technique - this will predictably lead to problems.
As your speed increases it is imperative that you threshold brake.
Ultimately you will be achieving good speed on the straights. Braking in a road style could see you out brake yourself, as you will not be braking to optimum G.
Your braking technique needs to match your new found speed.
ABS if fitted will allow you to brake to maximum effect and simultaneously steer to avoid a hazard. From a technical aspect, it is a very useful road safety aid, but it will extend your stopping distance.
Via a wheel speed sensor, in an emergency braking situation, the ABS system recognises the wheel is about to lock and skid. Prior to wheel lock, the brake line pressure to that wheel is released and reapplied as the wheel accelerates.
It happens many times in a fraction of a second and does the job you want in an emergency on the road – but the nature of its operation will add metres to your stopping distance if used on circuit. Not good if you’re chasing a lap time or trying to stay ahead of the pack.
If you do not have ABS fitted, locking a wheel under braking will require a little more effort from the driver. The wheel/wheels will simply remain locked until you release the brake pedal pressure.
A locked wheel offers very little grip - if you are struggling in the braking zone to reduce enough speed to negotiate the turn you may have to consider Cadence Braking.
Cadence Braking requires a fast and robotic pumping on and off the brake pedal to allow the tyre to rotate and regain its grip on the road.
How quickly you apply and release the brake pedal will depend on how much grip the tyre has with the road. If the surface offers low grip you will have to pump the pedal more slowly than a high grip surface, as you need to allow the locked wheel more time to spin up before you can reapply brake pedal pressure.
Find a safe place to practice and explore how your vehicle behaves at its optimum under braking, and consider the need to know your vehicle before venturing onto a circuit.
To find true speed throughout a circuit lap we should be feeling comfortable braking as late as possible and over the shortest piece of tarmac.
If braking from high speed, the inertia of the vehicle will reduce the potential to lock the wheels at the initial press of the brake pedal. We can, therefore, afford to work the brakes hard with big pedal effort.
As the speed reduces, we need to consider reducing the pressure on the pedal. The inertia is reducing as the speed reduces. Keeping your foot nailed on the brake pedal at the same high pressure as the speed reduces will provoke the ABS, if fitted, to intervene or a wheel to lock, if not .
It is all about feel.
The reduction of Pressure can be achieved by gently curling your toes away from the pedal or perhaps a gentle easing of pressure on the pedal.
Imagine your braking as a straight line on a graph just below the point the ABS will activate or a wheel locks. Your objective is linear high G stops at the threshold of grip, without any peaks and troughs in your graph line.
Press too hard as the speed reduces and you will see a spike in your graph as the ABS kicks in, or the wheel locks. To correct this you will then need to ease off of the brake pedal which ultimately reduces vehicle balance and extends your stopping distance. Likewise braking with too little pedal effort will also extend your stopping distance.
How you come off of the brake pedal is also to be considered.
Falling off of the brake pedal aggressively will transfer weight through the platform of the vehicle to the back wheels, inducing understeer as you turn in.
Be fast and precise, not rough.
Master the process and your car will feed you positive messages, feeling settled as you turn in towards the apex.
It is a small yet significant adjustment to our road technique. Our three Fs for circuit now read Firm, Firm & Feather.
Travelling at 140mph will see you covering ground at 62 metres per second, so we should be driving to reference points.
We have them for the key points in a corner, so let’s extend them to the braking zone.
In order to add consistency and safety to a lap, we need to be systematic, almost robotic with our approach to the circuit.
Find a reference point to brake to: a count down marker; marshalls post; the start of a rumble strip - something that will not move - and brake at the same point on approach to each corner.
If you feel you are braking too early go past the reference point by a metre at a time and then brake until you find the optimum reference point. This is the safest way to build a fast lap reducing the potential of running out of road in the braking zone.
I have a very structured approach to braking techniques when coaching, there are no prizes for falling off so ease yourself up to the optimum lap, and make it an objective to master threshold braking every session.
It is worth remembering the technique of Threshold Braking is a moving target. As your track day unfolds you will experience many changes.
The track will rubber in, your fuel load will change, your tyres, brakes and dampers will all reach their optimum operating temperature and beyond if you push too hard for too long.
Accidents and spillages all add to the challenge as will changing weather conditions - so keep focused and work each braking zone systematically.
Trail braking is often a discussion point on a training day and a technique we teach when you have the basics cemented in your mind and you can drive consistently at speed safely.
It involves braking to threshold a little nearer to the corner than if you were braking in a straight line (discussed in the last issue). So as you turn in you are easing out of the brake pedal and onto the gas. In effect, you are braking with a degree of steering input applied.
The percentage breakdown of steering input verses brake effort is decided primarily by vehicle configuration, vehicle weight and the corner being driven.
Trail breaking optimises grip and stability as you turn in by using the braking effect to induce weight transfer to the loaded side of the vehicle. BUT and it is a big BUT, I would not advise you to practice this technique without instruction. It is fraught with problems and requires guidance from a professional in the passenger seat.
Safe motoring until next time when we will be looking at the abbreviated world of driver aids, ESP, VDC, PSM ,DSC and anymore I can think of.
Article originally published in Total Magazine 2009
"The best decision I ever made! I have trained with CAT Driver Training twice now & looking forward to coming back in the future. I trust in their expertise & there is always something new to learn, a habit to be explored & an exhilarating experience that pushes me to my limit & builds confidence in myself & the car. The knowledge, experience, understanding, patience, compassion & professionalism of the team are just some of the qualities that make them unique & I highly recommend them."
"Performance Driver Track Day Course I participated in the course arranged by Porsche Club GB and very happy to give 5 stars all round. The team has put a huge amount of thought and effort into making the facilities and training Covid-secure, which is indicative of their professionalism. I found the whole day both fascinating and a lot of fun, in briefings, on the various driving segments, and chatting with the team and other participants. I was genuinely in awe of how much Colin moved my theoretical and practical driving on, and what he got me to get the car to do in the space of one day - always building confidence, encouraging me to explore my limits, while not pushing me beyond them. Can't wait to return!"
"I have had a reasonable degree of driving training over the years as am ex police officer and advanced police driver. I took the performance driver driver training to learn about track driving, and found it excellent. My instructor was Paul who was fantastic. The training built up during the day and I learnt so much about the capabilities of my own car and although I was nervous about using my own car realised afterwards it was the best thing for me to do. The instruction was extremely informative from an engineering perspective coupled with driving, friendly and tailored to your individual needs and abilities. At no time was I encouraged or pushed to do anything I wasn’t comfortable with. It was extremely professional throughout. I would thoroughly recommend this to anyone whatever your standard of driving."
"Truly exceptional In my experience, driving instruction has generally consisted of being repeatedly told that you are 'doing it wrong' accordingly to some unknown standard or principle that you had hoped to learn about by taking said instruction. Then there is Colin. It is not that common to find an individual who genuinely understands both people and engineering. It is incredibly rare to find one who can actively apply both to deliver a sustained behavioural change. Colin adapts his teaching style to the way you learn. For me, he lead with the WHY of the learning point, grounded in physics and engineering. We'd then put it in to practice, often doing several variants of an excercise to explore how the car reacts to differing inputs, providing valuable context for what good feels like and reinforcing the learning point. Each point built on the previous ones, layering up and coming together in to a whole, one far greater than the sum of it's parts. Subtle changes to huge effect. I was concerned on the day that the learnings would rapidly fade, but I have found that because Colin has taught me an understanding the lessons have persisted, even if I do still need some more practice (48 laps of the Silverstone GP circuit last Thursday definitely helped!). Add to this the fact that Colin is great company and an absolute pleasure to spend time with, and you have one of the most positive learning experiences I've ever known. Truly exceptional. I could not recommend more highly. Thank you!"
"Superb day with calm knowledgable and professional guidance from Paul. Thank you Paul. The course is so well structured consistently building ability and knowledge in complete safety. I fully recommend anyone wishing to increase their knowledge, confidence and experience to attend."
"Far better than any track day you can imagine! There is a massive difference between a typical driver experience or track day events and CAT driver training. The main difference is that you drive your own car to the full extent of it's capabilities, and your own, while being given expert one to one tuition by brilliant trainers Colin and Paul, who come from a Motorsport and auto engineering background. Their combined domain knowledge of engineering and competitive Motorsport allows them to explain the physics of why the car behaves as it does and how you can exploit the cars characteristics for maximum performance., in a safe fun environment. The frankly brilliant experience on the track is matched by the quality hospitality hosted by Jo, and classroom training, which prepares you for what you will experience on the next stage. These stages include such delights as the ring, where you will drive with no hands on the wheel at 100MPH, providing you with a clear understanding of the fact the car finds its own balance , and my personal favourite the alpine stage, with hairpins a plenty and 'character building' drops and rock faces. I have to admit to being slightly 'corner shy' before the training, however after some brilliant coaching from Collin urging me to 'stay on the gas, stay on the gas!' I am now far more confident and safe in the twisty stuff!"
"I don’t want to make this review too long and detailed, so I think the best way to summarise it is this: I think I possibly learnt more in one day that I’ve ever learnt before and the skills are relevant to all driving and can be practised daily. On the way home, I drove the ‘long way’ just to practise and feel the difference in the attitude of the car. I used to do this now and again because there are a few good straights and it’s nice to give the car a ‘blast’. This time, I drove that way home because I wanted to drive round the corners properly."
"Extremely professional driver training. Period. I wanted a course that would deliver a very high level of training, in an organised and professional manner. The course exceeded my expectations in every way, I wish I had started working with CAT Driver training years ago. There is no doubt that if you are looking for absolute top level training, there isn't anywhere else to look. Somehow they manage to follow a very tried and tested course structure, yet it is tailored all the way along to meet your requirements and current skill set. very impressive. I cannot rate this company highly enough. I have more dates booked already."
"Very structured training Paul was very clear and methodical in his coaching. The training technique was built up in various sections during the day and all came together like a jigsaw puzzle in the end for a great result."
"It's hard not to be enthusiastic about the lasting impact CAT Driver Training will have on your approach to driving. I spent a day with Paul exploring the potential of my new vehicle. The coaching is clear, methodical and structured to allow you to go on learning for a full day without overload. The training venue is superb and quiet enough (on the day I attended) to allow uninterrupted driving. Brilliant admin team too. Absolutely 5 Star!"
"Everything you read about these people is true and i cannot really add anything apart from clicking these five stars and to say they are truly incredibly knowledgeable, professional and nice. I did the Performance Driver Track day in my amazing six-month-old 911 GTS 4 and I now know so much more about my car and myself. I was in a group of six people all with different driving skill levels from the complete novice (me) to regular track day enthusiasts and the day was a journey of discovery for everyone. I am so pleased to have done it."
"First class performance car training day. Many thanks to Paul & your great team for a really enjoyable training day at Millbrook on Friday. I learnt a lot more about the capabilities of my F430 and found many new limits! The attention to detail in the delivery of the training was exceptional. I would recommend this to anyone with a performance car who wants to fully understand and enjoy their vehicle."
"An amazing day. If you drive you should go to CAT. If you have a performance car you MUST go to CAT. A day with CAT will transform your driving, you it be safer on the road in any situation and it will be the biggest performance upgrade your car will ever get. I learned so much in one day without any pressure, effort or stress. Colin's coaching is world class, he makes it simple / interesting to understand and easy to absorb / remember. The whole day and and everything leading up to it are well organised by the team. They REALLY care that you have a great day and TOTALLY deliver. You owe it to yourself to go."
"Absolutely Brilliant! The best advice I can give: believe every one of the glowing reviews on CAT! I approached CAT because I wanted to feel more comfortable with my newly-purchased BMW, the first rear-wheel drive car to be used for every-day driving after decades of FWD cars. I wanted to find out what the car's capabilities are, what it would feel like in extreme conditions, understand what it was telling me at the limits and, generally to get advice on my own technique. I wasn't a novice, having done plenty of track days and laps of the Nordschleife but I just knew that there's always plenty more to learn... A day's Performance Driver session met every one of my targets, and then more! Paul was a patient, logical and technical instructor who took time to explain what would happen in each manoeuvre and then fully debriefed that stage so that I not only knew what the car was doing but also understood what effect on the car my own actions were having. The proof of the pudding was in the final stage - setting consistent timed laps of the handling circuit. I'd worried a little about this all day as I'd have described my driving as enthusiastic but perhaps not consistent. The results were close to unbelievable to me! By remembering all that Paul had demonstrated and explained to me I surpassed my wildest dreams. Fantastic! As a result of this day, I now have more belief in my ability to read what my car's saying to me which brings confidence and relaxation. The car and I are now a team, rather than me just sitting there making it go down the road. I can highly recommend the whole CAT experience. Professional, friendly, patient, technical when required and not afraid to challenge when necessary. Oh, and the lunch is good too! I wish I could afford to go back every month..."
"Achieve your driving goals here! Can't ask for more than that! The entire experience was a positive and pleasant one. Everyone I met at CAT Driver Training contributed positively to the day, regardless of the role, so thank you to Jo, Lynne and of course, Colin! CAT have existing programmes for teaching anyone the fundamentals and advanced techniques of how to drive fast, but Colin can identify really quickly what you can and cannot do, and is quick to understand how to best use your time. I went in with my own unique set of requirements which slightly 'broke' the programme, but it was no problem at all and the most impressive thing was that I achieved my goals by the end of the day! I wanted to understand my car, be able to find and drive at the grip limit, and also understand how to be a faster and better driver. A lot to fit into a day, but Colin managed it in the most efficient way possible, and we achieved them all! Colin has great insights into vehicle dynamics, as well as the human machine behind the wheel. He understands why we sometimes don't function as optimally as we would like! His ability to listen to you, translate your input and isolate what is not working with your current technique helps focus the day on exactly what needs attention. This focus, along with Colin's 'feeling' of how the package of car and driver is behaving, makes him uniquely qualified to provide great direction and input to help you become the best driver possible. A lot of people talk about it, but very few can translate the inputs to a specific process for you to follow as a driver. The process is all about starting with foundations and building on them. It doesn't always seem to make sense, but trust the system - it all comes together in the end! The time is not cheap, but it will help you achieve your goals, so how do you put a price on that!? Thank you CAT Driver Training!!
"Best In Class Driver Training The training provided by Colin at CAT Driver training is superb. I am lucky enough to attended training days with Porsche, Lotus, Aston Martin and the day with a Colin at Millbrook has topped them all being informative, challenging, practical and above all delivered by a true Petrol Head. Thanks again and I will be back with the 911."
"Reminding how to drive fast A day with Colin on a 'One to One' basis is almost essential for anyone who lives on a small rock in the middle of the English Channel or lives in a city. We don't drive fast and don't get the opportunity to drive fast unless we are on a track. Colin spent the day reminding me how much fun it was to have 'fast feet' and to make the Tyres 'squeak' as they reach the sticky limit. I think I lost about 7kg in weight during the day as I was worked so hard but oh what a day. Thoroughly recommended to anyone who had a petrol head. Best bit was the 'Alpine Loop' at the end of the day. Full gas on the exit with all four squeaking. 👍😃"
"Excellent! Colin, Jo, Paul and the team are amazing, professional and have a unique ability to cover all areas of driving properly. My driving capability has been enhanced beyond measure. I highly recommend them and the CAT Advanced Driving Academy Programme. During the course it became clear to me that CAT Driving are one of the very few on the planet with such experience and capability. They have designed a brilliant dedicated package focused on working with you and delivered with an attentive caring personal touch."
"Paul was amazing: awesome teacher with a great brain. Made me realize my Mustang has actually way more grip and better and better handling than I thought. Top notch facilities in Millbrook. Totally worth it."