Core Skills – Dissecting the Corner & Grip Limit Signals

Improving your cornering ability on the racetrack can transform you from being an ordinary, middle of the pack racer into one of the front runners. Contrary to what we see regularly on track days, it’s not just about going in as hot and as wide as possible and hoping you make it out the other side in one piece. Preparations for the corner start a long way before it starts and the effects of a bad corner can still be felt many corners ahead. In this post we’ll be looking at how to master the core skills of cornering. In doing so, you’ll be able to enjoy consistently fast times on the track. Mastering these core skills is essential before moving on to the more advanced skill of trail braking which we’ll be covering in a future post.

First things first. We need to start by putting in a few steady laps to bring the engine oil, transmission fluids, tyres and brakes up to temperature.  Begin mapping the circuit at a steady pace to understand the lie of the track and where the corners are. Once you begin to feel comfortable with the complexity of the corners, you’ll probably feel a temptation to push on and find the vehicles limit of adhesion (grip limit) … but hold that speed for a moment!

Before entry

We need to confirm a key point: are you driving to a system, or relying on instinct to get you round the corner?  Without a systematic approach to cornering, you increase the potential for an “off” and make it difficult to find the vehicles true limit of adhesion. As we mentioned in the introduction, the corner starts a long way before we make an input with the steering wheel.  Braking in a straight line before you arrive at the corner is the safest technique and should be carried out over the shortest possible stretch of tarmac.  If I brake in a straight line without steering input applied, I am using all of the tyre’s available grip to brake. I am not sharing the braking with steering, so I will stop in the shortest possible distance.

At the corner

So, having retarded the vehicle to the correct entry speed for the corner, it’s time to settle the vehicle with the gas pedal. Doing this can have a big effect on the balance of the vehicle as you turn in.  By applying light pressure to the gas pedal, we compensate for the frictional loss between the tyre and the road as we apply the steering.  If I turn into a corner without applying the gas, the vehicle will slow and if that happens, it will experience increased body roll.  This has the potential to overload the tyres on the weighted side of the vehicle leading to a reduction in grip.  You need to think of your gas pedal as a levelling device and use it to keep your vehicle as flat as possible as you steer into the turn.

Your foot speed will play a big part in helping you achieve this. Try to dial into how long it takes you to slide from the brake to the gas pedal and how sensitively you’re able to do it.  Take too long and you allow a torque build up through the vehicle and into the tyres.  The additional weight transfer experienced by the tyres may induce a reduction of grip, or a spin as you turn in.  Mid and rear-engined vehicles are particularly sensitive to foot speed. The inertia created by the engine position creates a pendulum effect which could see you run into serious problems. Best case you’ll lose a lot of speed as you struggle to control the vehicle as you go round the corner. Worse case, you risk driving off the track or spinning out and taking someone else with you.

It’s not just the foot speed, but the sensitivity with which you get on the gas which will affect your cornering speed. A smooth application is essential and don’t be tempted to push too hard.  If I am on and off the gas throughout the corner, I’m shifting weight and just like unnecessary steering input, this reduces tyre grip.  Aim to apply enough gas to settle the car and then not have to adjust again until you are leaving the corner.

So to recap so far…  BRAKE IN A STRAIGHT LINE, BACK ON THE GAS, TURN IN.

To perfect the braking and turn in you must allow enough tarmac to get the job done.  Experience tells me if you are new to circuit driving you will probably brake a little late – the result being a frantic scrabble on the controls with a feeling the corner is approaching too fast to get everything done that you need to do.

Preparing to exit

Ok we have turned in and settled the car with the gas, described a nice steady state single radius turn and we are approaching the corners apex.  So when do you accelerate?  You could look for a fixed point on the circuit, but let’s try to be a little more flexible. Far more effective is to simply ask yourself: “When am I leaving the corner?”. It sounds simple doesn’t it?  You may already use this technique – but really focus on this and you’ll be able to find a few tenths, perhaps more in your lap.  Why?  Too early on the gas and you’ll have to back off or run out of road on the exit, too late and you’ll allow the vehicle to roll unnecessary weight to the heavy side promoting understeer.

Get it right and our levelling device, the gas pedal – will allow balanced lateral acceleration and forward motion to the tyres optimum potential: true grip limit.  It sounds counter intuitive but think the process through.  We can reduce understeer by squeezing the gas down and shifting a little platform weight to the rear wheels, thus reducing the weight on the loaded front wheel.  That is much easier to demonstrate in car than write about. Matching the unwinding of the steering wheel with the squeezing down of the gas will complete the turn.  So let’s complete my cornering mantra:

BRAKE IN A STRAIGHT LINE, BACK ON THE GAS, TURN IN, SQUEEZE AS I LEAVE WHILE UNWINDING THE WHEEL.

Be aware of the audible and physical messages communicated by the car and the tyres as we negotiate a corner at speed.  Road and track tyres chirp to us screeching as they approach grip limit.  Listen for a constant pitch – it will confirm your inputs are steady state.  A change in pitch of the chirp or screech can signify unnecessary adjustment of the controls.  Approaching grip limit, the weight or torque of the steering wheel will reduce as the tyres grip on the road reduces.

This can be accompanied with a feeling the vehicle is not following the path you have described with the steering.  Ultimately if you have gone in too hot, the tyre will roll onto the side wall.  With the tread block running against its intended direction of travel, you will experience a vibration through the steering wheel.  This can be a fine tingle through your finger tips to a full blown vibration and depends on the level of enthusiasm applied to the steering when turning in.  Remember our mantra and focus on the detail, the less you do the faster and safer you will be.

If you want to learn more about this topic or need advice on any aspect of your driving, why not give CAT Driver Training a call today on 01234 757 633 or email us at info@catdrivertraining.co.uk. Note: if you want to learn more advanced cornering skills, ask us about our 2-day trail braking course.