Braking, Braking...Damned Braking!!
09-26-2012, 06:02 AM
#46
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http://www.optimumg.com/docs/Brake_tech_tip.pdf
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-Peter Krause
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-Peter Krause
www.peterkrause.net
www.gofasternow.com
"Combining the Art and Science of Driving Fast!"
Specializing in Professional, Private Driver Performance Evaluation and Optimization
Consultation Available Remotely and at VIRginia International Raceway
09-26-2012, 08:25 AM
#47
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I think the term Squeeze is not the same for all people. Lnital brake pressure rise rate depends on the car and condition. One cars top rate of rise might set another into a slide.
I too drive a old dumb car with an LEG brake controller and ajustable bias valve. I know that a proper motorsports system could do a better job in many corners than I can as it could control single wheels or axels and a non ABS system cannot.
< That is an example of poor brake bias BTW.
I too drive a old dumb car with an LEG brake controller and ajustable bias valve. I know that a proper motorsports system could do a better job in many corners than I can as it could control single wheels or axels and a non ABS system cannot.
< That is an example of poor brake bias BTW.
09-26-2012, 09:02 AM
#48
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Cheers, Patrick! The black trace is what I desire to see nearly every time and certainly if the car is straight.
http://www.optimumg.com/docs/Brake_tech_tip.pdf
http://www.optimumg.com/docs/Brake_tech_tip.pdf
I think the term Squeeze is not the same for all people. Lnital brake pressure rise rate depends on the car and condition. One cars top rate of rise might set another into a slide.
I too drive a old dumb car with an LEG brake controller and ajustable bias valve. I know that a proper motorsports system could do a better job in many corners than I can as it could control single wheels or axels and a non ABS system cannot.
< That is an example of poor brake bias BTW.
I too drive a old dumb car with an LEG brake controller and ajustable bias valve. I know that a proper motorsports system could do a better job in many corners than I can as it could control single wheels or axels and a non ABS system cannot.
< That is an example of poor brake bias BTW.
09-26-2012, 09:24 AM
#49
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I've tried to apply the formulas in that article to the same data I showed before (but forgive me for not knowing how to do some of the conditionals... like brake smoothness only on the release...)
The top chart shows the brake pressure for me and Max (a novice driving my car). The middle chart is my Aggression and Release Smoothness. The bottom chart is the Aggression and Release Smoothness for Max.
The top chart shows the brake pressure for me and Max (a novice driving my car). The middle chart is my Aggression and Release Smoothness. The bottom chart is the Aggression and Release Smoothness for Max.
09-26-2012, 11:49 AM
#51
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Practicing on a wet track is valuable experience in learning brake feel -- slower speeds and longer duration in transition from acceleration to deceleration forces smooth driver input. And a slick surface provides almost no margin for err in controlling chassis movement. The way I see it, car control techniques required on a wet track work well on a dry track. (my picture notwithstanding.)
09-26-2012, 02:52 PM
#52
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Patrick, here's a comparison for 4 different drivers - same track, same corner. This is a g-force trace.
The red and blue (me and Dave) are track cars with pretty stiff springs, and we get pretty tall slopes. The black and green are both street cars, one's a turbo and one's a GT3.
Andrei (black) has a propensity to "stab" the brakes, as opposed to "squeeze" the brakes. See how his trace is different?
I'd say that Dave (blue) has the nicest brake release - aka trail braking into the corner.
Mark (green) lets off on the brake pressure, and then gives another little stab towards the end of the braking zone, and that's why his curve has that little "shelf". And, on Mark's trace, do you see how the slope is pretty gentle at the very beginning? That's where he's lifted off the throttle and is coasting before applying the brakes.
The red and blue (me and Dave) are track cars with pretty stiff springs, and we get pretty tall slopes. The black and green are both street cars, one's a turbo and one's a GT3.
Andrei (black) has a propensity to "stab" the brakes, as opposed to "squeeze" the brakes. See how his trace is different?
I'd say that Dave (blue) has the nicest brake release - aka trail braking into the corner.
Mark (green) lets off on the brake pressure, and then gives another little stab towards the end of the braking zone, and that's why his curve has that little "shelf". And, on Mark's trace, do you see how the slope is pretty gentle at the very beginning? That's where he's lifted off the throttle and is coasting before applying the brakes.
What are you doing on your approach to the braking zone?
09-27-2012, 07:28 AM
#54
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Great! This is a terrific thread because of all the perspectives presented. In particular, thanks to Van for his timely strip charts!
