oldbmwfan
Well-Known Member
- Joined
- Oct 19, 2016
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- 789
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- Chicagoland
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- 2017 GT350R
First, you're doing the right thing - being cautious and progressive with throttle application is far safer and ultimately faster than matting it and hoping it sticks, or trying to save it when it doesn't. Safer for obvious reasons - no snap spins - and faster because a sliding rear is slower than a gripping rear in most cases.@oldbmwfan Your post was helpful. I appreciate the extra perspective you provided.
Your chart you posted above shows how quickly the driver gets back on the gas. I noticed your comment about TC and how the driver still rolls into full throttle.
The question I have involves my remaining fear when lapping a track: throttle induced oversteer. I am still rolling the throttle on slower than I could be because I do not want to be "that Mustang guy" that gooses it too hard and ends up in the wall.
When you feel the rear beginning to break loose, do you correct with steering the same way that you would when it has already broken loose? By that I mean you can either begin your reaction before or after the rear is sliding. Is the reaction the same? Perhaps the initial reaction is the same, but returning to center is different?
I was watching a video of Randy Probst where he caught a slide by what appeared to be a deliberate (could have been described as violent even) turning of the wheel and then immediately returning the wheel to center. Does the act of returning to center precede the rear coming back into line and thus still sliding? Or do you return to center after the seat of your pants tells you the rear is in the process of coming back into line? Or do you wait to return to center until the rear is back in line?
I had the rear step out on me going through Bishop Bend and I successfully saved it, but I don't really know what I did. It happened so fast. I want to understand what is going on when trying to save losing the rear end.
The tires have a finite amount of grip to give. You can use 100% grip laterally (like at the apex of a corner), or 100% of the grip longitudinally (max power for the rear tires or max braking for the fronts), or you can use a mix (like 50% lateral and 50% braking, when trail braking into a corner). The key is you can't exceed total tire grip, so if you are applying throttle as you exit the corner, you HAVE to roll it in ... if you are cornering anywhere near the lateral limit, by definition you can't apply all the power or you'll spin the tires (and probably the car). On corner exit, you can increase throttle as you straighten the wheel, so you're always using up the full grip budget with an increasing portion shifting from cornering to acceleration as you approach the straight. On most corners, you can be at full throttle just a bit before the steering wheel is straight.
What you see Randy doing is exactly what you wrote - anticipate the slide, countersteer, and then immediately come back the other way to prevent a snap in the other direction (tank-slapper). Once you catch a power slide, the car will want to slide back the other way when it hooks up if you don't get the steering out.
My biggest on-track incident and the only one that resulted in a non-drivable car was one of those. At Watkins Glen, I had oversteer going into T5 (the Outer Loop after the Bus Stop, big, fast right-hand sweeper). The tail came around to my left as I entered the right-hander hot. I was a little slow to catch it and I overcorrected, causing the tail to snap back to the right, and that spun me all the way into the outside wall at 85 mph. Wasn't my best moment. My mistake was correcting with too much steering (turning wheel left into the slide - correct move, but I overdid it), and then holding that steering input too long and not anticipating the counterslide to the right. Once the momentum was going right at that speed, my hands were too slow to catch up.
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