pecivil wrote: If you are at max accell, you have no grip left for turning...
I understand what you are trying to say, Monte, but this part is not really true. Most cars do not have enough power to use all the available tire grip of the drive wheels on max. throttle (except perhaps in first gear). Unless you are driving a 917, which as Mark Donahue said could "leave two black stripes between the exit of every corner and the braking zone of the next one," you are always losing time at many points on the course due to power limitations--any area where we are at full throttle and the drive tires aren't burning rubber, there is excess grip not being used. In this respect, we are ALL in "momentum" cars. In braking and cornering, it is often possible to use all the available grip in most cars, but acceleration is another matter. The "outside edge" of the friction circle in the acceleration quadrant is much more difficult to achieve on a regular basis, unless you are running an F1 car or a 917, or a car with very low grip, skinny tires and plenty of power (which is an odd configuration that wouldn't be very fast anyway). Most modern tires can generate close to 1G of grip, which most cars can exceed in braking and cornering, but not come close to achieving under acceleration.
I think you are slightly misreading what Jad said, though, or perhaps he could have been more precise with his language in the example you picked out, because you thought by "turning at max" he was saying "using max grip" (all available traction) for cornering. What I read, and what I think Jad meant, was the "max turning input (or steering angle)" necessary for navigating the corner, not "using max grip" available in the cornering maneuver. Some of the available traction in his example is obviously still being used for acceleration, because he is also saying "at full throttle" while still turning.
What Jad is trying to point out, I think, is that in a higher HP car, where enough power is available to easily spin the drive tires in the higher gears when full throttle is applied, it makes sense to maximize this superior acceleration ability to lower lap times, even sacrificing some corner entry speed, to allow longer, harder periods of acceleration, since this is the car's strong suit. This involves using a "Type 1" line (what Jad is calling "diamonding" the corner) more often than a lower HP car. The lower HP car would tune for cornering balance and carrying speed through the corner so it won't have to make it up on the exit. In many cases, it would benefit more from choosing the least turning angle and shortest distance around the corner at a higher average speed (coming closest to the "geometric" apex of the corner) to achieve a lower lap time. A high HP car might pay more attention to minimizing squat and dive, and choose the later apex, "Type 1" line more often, so they can achieve longer, harder bursts of acceleration without spinning the rear tires, utilizing their superior power to achieve lower lap times. If you can't burn the tires no matter how hard you step on the gas, getting the car pointed straight sooner is not as much of a concern or advantage.
I think Kim is also right in saying that any time wasted on the course is lost, but when he says: "Momentum to me means that you are not scrubbing off any more speed than absolutely needed to be able to exit the turn at maximum acceleration/speed" you have to consider the difference between the "maximum acceleration" capabilities of different types of cars. They are not all the same, and some cars may benefit from "scrubbing off more speed" than others, if they have the power to make it up and more by getting on the gas harder and sooner. The danger for the high-powered car is in inducing power-on oversteer during corner exit and having to back off the throttle to maintain control, thus the late apex is sort of a "safety strategy" too. Sophisticated traction-control systems are becoming capable of solving this problem, so with enough money and the right equipment, the "momentum" line can still be the fastest for even a high-powered car, by trail-braking to the apex, keeping the tires right on the edge of the friction circle under braking-and-cornering (sophisticated ABS systems can help do this), and then flooring it off the apex, allowing the traction control system to manage the power and control wheelspin so that all the available grip is used perfectly under acceleration-and-cornering, maintaining the highest possible average speed in the corner while covering the shortest possible distance. So Kim is right, too, if you're Michael Schumacher in an F1 car. The rest of us are probably better off sticking with "slow in, fast out." It takes a very smooth and progressive throttle input in a high-powered car with no traction control to avoid just spinning the tires on corner exit and losing much of the forward thrust in a cloud of tire smoke while making counter-steering corrections, modulating the throttle to get the tires to hook up again, and hoping you don't go off course as you slide sideways.
TT
), the high-HP guy will always win...
I would like the red group please.
) I am faster cutting arcs that are larger and braking earlier and less vs going with the late apex and tighter arcs "by the book" because I slow down less with the bigger arc.