Alonso, you said.
Oh, my. Like if it were a question of style! Style is for Emmy Awards. Style is for Blackberry covers. This is RACING. So...
Lessons on mid/late apex for beginners, by Ciro.
NOTE: THERE ARE NO EARLY APEX CURVES UNLESS YOU WANT TO END LAST... or unless you want to read A LOT of what I wrote here.
The mid/late apex depends on:
- the radius of the curve.
- the power of your car
- the grip of your car
- the distance between curves
- the sideslope and type of transition between curves
To keep it short (yeah, I know, I speak too much: no mocking, please) and sweet,
I won't delve too much into the last one, nobody listens when I explain transitions... no civil/road engineers racing here, believe me!
1. Radius
On a
large radius curve you are fairly fast while taking the curve. Because
you're fast at mid curve, there is no point in taking the late apex.
On a
small radius turn you gain little from mid corner speed. Take Seat curve (raise your hand if you know where it is): a puny 30 m radius, and a ridiculous 100 kph or so speed. Yeah, yeah, I exaggerate, but if I don't, nobody gets enraged by my ignorance (the fools!), so they won't "correct" my post and they won't learn a thing.
Back to the point: the time you spend around a tiny corner is small. It's small enough to make this an area you should despise when looking for shorter lap times. So,
you better brake early and longer, enter slower and wider into the corner, turn with all your might and quickly straighten the car for a long exit, so you can push the pedal to the metal as quickly as you can. The faster you push the right pedal, the faster you'll get out of this area. You want exit speed and you want it now!
2. The Power (with capital P) of your car
Sure, F1 has power. Not all racing cars have it. In command of a
low powered car (man, I love junior karts, they truly distinguish men from children. Ha, ha, how funny I am!) you want to point to a mid apex so you can carry all your meager speed through the curve, because the puny thingie engine you have in your back won't respond on exit.
On a
high powered car you look for a late apex (which means you turn hard and at the last possible moment, right when you can see the bolt heads in the barriers
). So, you have a loooong exit ahead of you, while your glorious engine pushes you against the back of the car and gives you the fast exit you are looking for.
3. The grip of your car
A
high grip car, with slicks the size of my posts is not the same as Green Powered Dude Reload electric car with bicycle tyres, sure. So, it will give you the ability to treat tight corners as if they were corners with larger radius. Conclusion: take the mid apex.
In a
low grip car what's the use of trying to carry a high mid corner speed? You under steer as hell and end up without a racing line. You use raw power (hopefully) to "straighten" the car. Use a tight late apex corner. Yeah, I know this is confusing. You have to test that. Go.
4. The distance to the next corner
If
there is 20 meters to the next corner, what do you gain from exit speed? Zilch. You take mid apex, get a fast midcorner and brake in time for the next one.
Now,
if there is a long, long straight after the curve, by all means, take a late apex, get all the acceleration you can on exit and laugh happily. Believe me, there will be a HUGE difference when you can accelerate early between you and the mid apex guys at the next entrance.
I would be very grateful if any racer here can give me his opinions, these are mine. There might be other factors. Theoreticians, guys, please abstain. Those claiming that John Doe is a "natural late apexer", pleeeze... if that's the case, then John Doe is an ·/&=%$hole.
BTW, a late apex requires a
late brake, "into the curve", and then to move the steering wheel
HARDER. Half the guys that follow racing lessons think that a late apex means you move the steering wheel less than normal. I know I'm not clear here, perhaps someone can put this in words better than I do. A late apex is this:
Freno means brake, transición means transition, aceleración means acceleration, vértice means apex and Aquí duro con este timón means Here, hard on the steering wheel
You can stop reading now (if you actually arrived to this point) and skip to the next post.
However, I cannot resist to say this,
for road engineers in the forum:
High superelevations and proportional, logarithmic transitions or clothoids (the "German secondary road without straights") throw away all what I've said (there are early apexes after all!) but nobody will believe me until we walk the road and you can
actually "see them with your feet"
In this curves, if the spiral is at the entrance, you can actually brake (gently!) AND turn (gentlier!) at the same time. If it's at the exit (hopefully it will be at both extremes, entrance and exit), then you can accelerate and turn like if you were in straight, but you have to accelerate
proportional to radius of curvature, which is changing all the time (it's a spiral, like the trajectory that a coin makes when you make it roll).
There is a trick at the exit of this curves:
tap lightly the brakes while you accelerate, á lá Schumacher. This will "settle down" or "push down" your front axle and will elliminate some of your oversteering! For example, this one:
Repsol curve: the yellow part of the curve has a clothoid with superelevation proportional to the radius of curvature. You have to move the steering wheel at the same time that you squeeze the throttle. All the advices I gave previously are invalid (radius and angles are estimated by me)
Circular curves with transitions on the straights, old style, like at Catalunya or old Silverstone, forces you to counter steer on the entrance. More importantly, those old curves force you to watch carefully where is the
axis of rotation of the transition that the designer choose.
This rotation of the road (in the horizontal plane, try to imagine it) is critical when the distance between curves is very short and the designer was forced to "hack it" and insert the transition into the curve.
Usually, you "twist" the road in the straights, so when you reach the circular curve there is full superelevation. Not here. There is no straight between curves, so you have to twist it on the horizontal plane, while you change from a left curve to a right curve (or vice versa). We are full of those in the Third World.
In english, this means that I think nobody will understand what I'm talking about until they actually take them, OR I spend half an hour making
3D drawings in a CAD package, to show how the road twists, so, let's leave that for another post, if there is one.
Wurtz curve. There is no straight between the curves in the S. So, the change in superelevation happens inside the curves. You better go for early apex on the second curve, or so I think, as is barely discernible from the track of the cars left on the road surface (again, all the dimensions are estimated from a restitution I made, so do not trust them too much). Besides, when you start the red section, in the green part at the bottom, the road alread has full superelevation, so the road is "throwing" you towards the left while you are in a straight! The cars go from bottom to top of the image.
Finally, there are a few curves where
there is strong weight transfer, caused by changes in the longitudinal slope. You go from full weight in the front wheels to full over steering because the car gets horizontal (or viceversa). This forces you to early or late apex, depending.
Monaco's Loew Curve. Check the longitudinal slope. We have shallower roads crossing the Andes! You lose 27% of weight in the front wheels at the exit and the angle of attack of the wings changes during the curve (not sure about this one).
747Heavy, the first paper you show use one radius for the curve. Is it some kind of elaborated joke? I did not get it at all. The second one analyzes drifting (on a bike?) to win. No comments, because either I also did not get it or those guys come from Japan. The third explains the same thing, I think.
I agree, Heavy: they are not for the "causal" fan (ha, ha! Another good one!). Burn them, I'd say.
