I feel the need to elaborate, in truth I always do but generally resist the urge as i'm not sure how much good it does. If it does any good I don't really want to be helping my clients competitors but as this is not really a place that they would go, I'll give it a shot.
First some basic
A car only has so much grip, shared between all 4 tyres, it's based on the tyre, track surface and the amount of weight pressing down on the tyre.
For a car with 50/50 weight balance front to rear/side-to-side this would be 25% of the grip at each corner/tyre.
Grip is use for braking, accelerating and cornering, often 2 of those simulataneously.
You alter this ratio whenever you do anything with the pedals or steering wheel but you never gain or lose grip (except over bumps, rises, compressions etc.) but lets not consider them here.
As wheel as providing grip tyres also provide resistance (i.e. braking), even in a straight line, the more grip you've got the more braking effect you will have (cars with semi-slicks are generally slower in a straight line than cars with road tyres).
Whenever you add lock you increase this braking effect. If you push a stalled car in a straight line it is fairly easy but gets progressively harder the more lock you add. At half lock this braking effect is considerable, agree?
The more braking effect you have the slower the cars rate of acceleration, agree?
Therefore the more lock you have at any time the slower the car is capable of accelerating.
More gains are got from exiting faster than entering faster or making time under braking, agree?
Given the premise (not entirely true) that the best way to exit faster is not to lose so much speed in the first place then CARRYING more speed in and through a corner is very beneficial, agree?
You can carry more speed through a 30deg bend than a 45deg bend, agree?
This is partly because you will have more lateral grip from the tyres but also because you will have less braking effect from the front tyres (less lock)
If you could go through a 45deg corner BUT only use 30degs of steering you would be faster, agree?
If you agreed with everything so far you will also note that, not only will you get into, through the corner at higher speed with less lock that the rate of acceleration you can achieve ON THE EXIT is higher with less lock, agree?
Some Physics
A tyre gives it's best OVERALL grip when sliding slightly (fact). If a tyre IS sliding then the direction the car is travelling will be slightly different from where the tyre is pointing, agree? this is called the "slip-angle"
A (radial) road tyre gives it's BEST CORNERING GRIP when sliding at between 8-12 degrees of slip (fact), a trackday tyre is nearer 5-8 degrees and a slick 3-5.
Lets just consider treaded tyres, if a treaded tyre is sliding it generates tyre squeal (in the dry), agree?
OK, lets use an example to examine how a knowledge of this would help in real life. Lets use Turn 1 (Riches) at Snetterton which I think most on here will have driven. It's pretty much a 45deg right-hander, agree?
I'm going to consider only RWD as it's the easiest to underdstand and to make point, most of what follow is also applicable to FWD (but NOT ALL)
I mentioned earlier that whatever you do with the pedals and steering wheel moves the weight around the car (aka grip).
If we are driving down the pitlane at a constant speed the weight balance will still be the same as static (50/50).
If we are accelerating towards Riches then we have moved more weight to the rear of the car (you can feel the rear dip when you accelerate from a standing start, same physics apply).
When you come OFF the gas you get an opposit "re-action" and weight is transferred more to the front of the car and, as we hit the brakes we transfer even more weight forward. This is considerable, anyone who has braked hard for the esses (or the old Russell) with a little lock on will have felt the rear get light and floaty. This is because at maximum braking you [can be] close to 90% weight front and only 10% rear.
If you get to the turn point and turn to aim for the apex you will likely need 45deg of lock (as an example). Physics dictate there is a maximum speed that this is possible without getting beyond the optimum slip-angle for turn in (i.e. you get v.bad understeer).
Whilst we are here it's worth mentioning that common-sense dictates that adding 45deg of lock with only 10% rear grip (vs 90% front) is also not a good idea, hence you need to be off or coming off the brakes as you turn.
I mentioned that steering also moves weight (grip) around. As you add your 45deg of lock you will shift weight to the outside of the car (i.e. the left side tyres in this case). Again this can be quite considerable (you may well have seen pics of trackday/race cars with one wheel in the air or an "unloaded" tyre hardly touching the surface.
With weight goes grip, so as the weight moves so does the grip, meaning that, once the car has settled into the corner and the weight has shifted YOU HAVE MORE GRIP than you had when you first turned in, agree?
Thing is, we have turned in and are heading for the apex but have more grip, so we often end up back on the power before the "apex", one thing we learnt already that is when we get on the power we reduce front end grip, so this has the effect of us "effectively" understeering past the apex and out to the exit. This won't be huge "noticable" understeer but more "scrub" as we drive against the angle of the front tyres with the rear (we still have our 45degs of steering.
We probably think this is fast as we are always told things like, "the sooner you are on the power the better" and to "unwind on the exit". We are told the later so as to negate this understeer, what this often ends up doing is making us take the corner EVEN SHARPER so as to give us "room" to unwind on the exit.
Physics will therefore dictate the maximum turn-in speed, maximum apex speed and maximum exit speed, all of which can be improved by DOING THING DIFFERENTLY.
Another question first. We are in a car park or the paddock in our RWD car, we trundle along at say about 5mph, add a 'bit' of lock and plant our right foot, what happens?
If you said the car would spin or start a donut you'd be absolutely right, but you didn't use anywhere near the amount of lock required to drive round in such a tight circle? you "steered" the car with the power. And this is what is meant when you hear commentators talk of how the drivers off old "drove the cars on the throttle", now read on ...
So, we are now heading for Riches as before, same approach speed. When we get to the turn point we are only going to add 30deg of lock rather than 45deg. What does this mean? we already agreed that we can enter a shallower corner at a higher speed, so we don't need to slow down as much so we can brake later (gain #1).
Thing is Riches is a 45 deg corner and we are only going to add 30 deg of lock so we won't get round it?
Yes we will as we havent finished with the steering yet. We know when we turn in it moves weight to the outside of the car and gives us MORE CORNERING GRIP THAN WE HAD ON TURN-IN, so as the car starts to steer towards mid-track (with just 30deg steering) we can add a bit more (as we have more grip). It could be that this extra application of lock now points us towards the apex BUT we are travelling faster, so (gain #2).
Thing is we know that there is more than one way to steer a car, with the power. We obviously don't want to spin but most cars < 200bhp wouldn't spin if you added power mid-corner, they WOULD tend to push into a touch of OVERSTEER but that CAN BE USEFUL.
Consider this again, we enter with 30 degree of lock, add a little more to say 40deg which will take us to within a cars width of the apex. We then ADD POWER which will add a touch of oversteer which tightens the arc we are on and, if done well actually points the car towards the apex, if done really well actually points it a little tighter such that we actually have to reduce our 40deg lock back to 30deg.
At this point we have braked later, entered the corner faster, got on the power (in this case before the apex BUT AT ANOTHER POINT - TBA) and are on full power as we pass the apex going FASTER and with LESS LOCK (gains #3 & #4) which means we exit quicker, often a LOT quicker.
Not sure how well that all sunk in but there is more, quite a lot more actually but I'll mention one more thing.
To do this well it relies on the drivers ability to bring the car to it's maximum cornering speed and to it's MAXIMUM CORNERING GRIP at the most beneficial point. He needs to really feel the weight and recognise when it is at it's maximum, specifically on the outside rear.
If this maximum speed "point" was 85mph and the driver was at 70mph he simply would not get this effect as he would not get the "turn effect" from the rear (unless a very powerful car), if he was at 80mph he would "feel" it but it would not be as significant and beneficial if it was at 85mph (not least as he has lost 5mph vs other driver).
(to be continued, too long for one post!)
Learning car control
(continued)
So, a couple of bits of terminology. You probably won't find these mentioned in any books as they are my names for them. The "effect" of using the power to turn the car I refer to as a "power turn". The point at which you have the car at maximum cornering grip I call "GMax". The important thing about this "point" is that it isn't in a specific place and is UNDER THE DRIVERS CONTROL. You decided where this point should be and "create" it where it is most beneficial. It's different for every corner. For instance, it would be very early for Riches, probably no more than 30% of the way towards the apex, but or the Montreal hairpin it would be pretty much at the (very late) apex. It needs to be at the point at which adding power would be the most beneficial (i.e. will help turn the car and not scrub speed).
Another bit of terminology refers to the steering technique mentioned previously, which is called "progressive steering"
In our Riches example the maximum weight shift is achieved once the car reacts to the extra bit of lock you add after the initial lock. This is where if you add power it will help turn the car and you should never need to come off the power again. Going back to the earlier example where only one application of lock is added then this point would be just as the car starts to react to the initial lock BUT, it would not be maximum across the length of the car (front/rear) as by the time both ends load up the car would be going slower, hence less weight transfer than the progressive steering technique provided.
So, if you've read and understood that why would you need an instructor/coach?
When you drive most of the motor reactions are via the subconscious, you effectively direct it via the conscious but if it asked to do something which is outside of it's "comfort zone" it will fight you (you being your conscious mind). For the most part it won't let you do it, or if it does your in such a 'state' that it won't work, or work well and this will reinforce the sub-consciousnesses belief that it is wrong etc. etc.
You wont be able top bring yourself to enter at the speed required, you won't be able to resist turning more than you should to get to the apex, you won't allow yourself to add lock on the way into a corner when you already think you have turned in at the limit AND YOU DEFINITELY won't be able to get yourself to add power when you have got the previous stuff half right and are on the limit with the back end feeling light and about to let go!
An instructor is there to force you to do those things, not on lap 2 or lap 12 but eventually, being careful not to build up resistance in the sub-conscious. It needs more though to be really effective. Your sub-conscious will still rebel if it doesn't understand why you are doing this scarey thing, it needs to understand and accept it fully, partly this is down to explanation like the above and party down to having confidence that the instructor knows what he's talking about and wouldn't ask me to do something that would take us both off the circuit.
Then theres more, you have to learn to recognise the state the car is in, where the weight is, how much is transferred, is it 'full over' yet (it's not instant). To add power when the back is already light/lose you must really accept that when you add power it moves weight to the rear, thus adding grip to the rear.
You need to 'know' by FEEL when the steering has done "it's" work and you can then afford to trade grip from the front to the rear.
FEEL is a key word, you need to know HOW IT SHOULD FEEL which again doesn't come on lap 2, 12 and it's something that you are always striving for more of.
So, there we are, that's about 50% of the explanation, for that one corner, which is fairly close to a few other corners on circuits but no more than about 5% of all corners. The same principles apply but with the best will in the world you are not going to work it all out yourself. Not touched hairpin technique, trail-braking etc. etc. etc. not even touched on braking at all.
It just gives you some idea why 2 drivers, both who can "drive" well and feel they are at the limit, they drive the exact same line (identical data-logging traces for line) in the same car, same conditions yet one guy is significantly quicker than the other.... and of course you have everything in between.
Maxx
So, a couple of bits of terminology. You probably won't find these mentioned in any books as they are my names for them. The "effect" of using the power to turn the car I refer to as a "power turn". The point at which you have the car at maximum cornering grip I call "GMax". The important thing about this "point" is that it isn't in a specific place and is UNDER THE DRIVERS CONTROL. You decided where this point should be and "create" it where it is most beneficial. It's different for every corner. For instance, it would be very early for Riches, probably no more than 30% of the way towards the apex, but or the Montreal hairpin it would be pretty much at the (very late) apex. It needs to be at the point at which adding power would be the most beneficial (i.e. will help turn the car and not scrub speed).
Another bit of terminology refers to the steering technique mentioned previously, which is called "progressive steering"
In our Riches example the maximum weight shift is achieved once the car reacts to the extra bit of lock you add after the initial lock. This is where if you add power it will help turn the car and you should never need to come off the power again. Going back to the earlier example where only one application of lock is added then this point would be just as the car starts to react to the initial lock BUT, it would not be maximum across the length of the car (front/rear) as by the time both ends load up the car would be going slower, hence less weight transfer than the progressive steering technique provided.
So, if you've read and understood that why would you need an instructor/coach?
When you drive most of the motor reactions are via the subconscious, you effectively direct it via the conscious but if it asked to do something which is outside of it's "comfort zone" it will fight you (you being your conscious mind). For the most part it won't let you do it, or if it does your in such a 'state' that it won't work, or work well and this will reinforce the sub-consciousnesses belief that it is wrong etc. etc.
You wont be able top bring yourself to enter at the speed required, you won't be able to resist turning more than you should to get to the apex, you won't allow yourself to add lock on the way into a corner when you already think you have turned in at the limit AND YOU DEFINITELY won't be able to get yourself to add power when you have got the previous stuff half right and are on the limit with the back end feeling light and about to let go!
An instructor is there to force you to do those things, not on lap 2 or lap 12 but eventually, being careful not to build up resistance in the sub-conscious. It needs more though to be really effective. Your sub-conscious will still rebel if it doesn't understand why you are doing this scarey thing, it needs to understand and accept it fully, partly this is down to explanation like the above and party down to having confidence that the instructor knows what he's talking about and wouldn't ask me to do something that would take us both off the circuit.
Then theres more, you have to learn to recognise the state the car is in, where the weight is, how much is transferred, is it 'full over' yet (it's not instant). To add power when the back is already light/lose you must really accept that when you add power it moves weight to the rear, thus adding grip to the rear.
You need to 'know' by FEEL when the steering has done "it's" work and you can then afford to trade grip from the front to the rear.
FEEL is a key word, you need to know HOW IT SHOULD FEEL which again doesn't come on lap 2, 12 and it's something that you are always striving for more of.
So, there we are, that's about 50% of the explanation, for that one corner, which is fairly close to a few other corners on circuits but no more than about 5% of all corners. The same principles apply but with the best will in the world you are not going to work it all out yourself. Not touched hairpin technique, trail-braking etc. etc. etc. not even touched on braking at all.
It just gives you some idea why 2 drivers, both who can "drive" well and feel they are at the limit, they drive the exact same line (identical data-logging traces for line) in the same car, same conditions yet one guy is significantly quicker than the other.... and of course you have everything in between.
Maxx
Some videos of exercise based stuff.
Santa Pod Drift What Ya Brung Nov 28th 2012 External Footage
http://www.youtube.com/watch?v=WE8P8xEV5Es
Barkston Freestyle Drift (no longer available)
http://www.youtube.com/watch?v=mu1uZgpDvkg
Barkston Slalom
http://www.youtube.com/watch?v=r-s_pKQE49Q
Bruntingthorpe Training
http://www.youtube.com/watch?v=4qz1_JOV-pI
http://www.youtube.com/watch?v=5mgHFatSvmM
Maxx
Santa Pod Drift What Ya Brung Nov 28th 2012 External Footage
http://www.youtube.com/watch?v=WE8P8xEV5Es
Barkston Freestyle Drift (no longer available)
http://www.youtube.com/watch?v=mu1uZgpDvkg
Barkston Slalom
http://www.youtube.com/watch?v=r-s_pKQE49Q
Bruntingthorpe Training
http://www.youtube.com/watch?v=4qz1_JOV-pI
http://www.youtube.com/watch?v=5mgHFatSvmM
Maxx
Thanks for sharing some of your insight Maxx. I really enjoyed the read even though the theories are not new. I for one would be very interested in two sessions with you on a shared day, with practice time in between, I think I would improve dramatically. I would then be wishing I had you to myself for the day ;-)
Keep my name on the list guys, date an venue defendant.
Keep my name on the list guys, date an venue defendant.
'05 Subaru WRX 300
R.I.P
'89 ST185 GT4
ONLY 370bhp & 405ft/lb @ fly
12.7s 1/4 @ 109mph in the wet
R.I.P.
R.I.P
'89 ST185 GT4
ONLY 370bhp & 405ft/lb @ fly
12.7s 1/4 @ 109mph in the wet
R.I.P.
Welcome back from your holiday Maxx 
Judging by this post, it looks like a fortnight in Tenerife has charged your batteries up mate! 
Great posts and a wonderful level of easy to read information, that for me helped me take on several points (and I'd like to think my basic level of knowledge/skill is OK)
The day that Dunk and I hired your services worked well. As an open pitlane day your timings indicated above worked well from what I remember. I certainly recall that I saved a fair amount of time per lap, was more confident in terms of grip limits for that car on those tyres, and had an absolute scream
Judging by this post, it looks like a fortnight in Tenerife has charged your batteries up mate! Great posts and a wonderful level of easy to read information, that for me helped me take on several points (and I'd like to think my basic level of knowledge/skill is OK)
The day that Dunk and I hired your services worked well. As an open pitlane day your timings indicated above worked well from what I remember. I certainly recall that I saved a fair amount of time per lap, was more confident in terms of grip limits for that car on those tyres, and had an absolute scream
http://www.auto-genie.co.uk
07733 527430
stuart@auto-genie.co.uk
Valeting, detailing and undersealing
07733 527430
stuart@auto-genie.co.uk
Valeting, detailing and undersealing
Tony,TonyB wrote:Thanks for sharing some of your insight Maxx. I really enjoyed the read even though the theories are not new. I for one would be very interested in two sessions with you on a shared day, with practice time in between, I think I would improve dramatically. I would then be wishing I had you to myself for the day ;-)
Keep my name on the list guys, date an venue defendant.
OK, I'll keep a note and get back to you when I have something more concrete to offer. Track wise is would def be Snetterton I think as that is the best venue which probably would suit you also given your location.
Maxx
