ASK THE COACH
04-26-2016, 03:43 PM
#2431
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Thread Starter
Something that goes along with this discussion that I've been doing a lot with people lately is to write down what level of braking they are doing at each corner and then see if the data matches that. If yoy think you are doing a 7 pedal (out of 10), are you really braking at 70%? Lots of times on the soft spots, people overbrake because their perception doesn't match what they are doing.
04-26-2016, 04:40 PM
#2433
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Jim is pretty extraordinary...
He won the GTU class at Daytona in 1990 and six years later (1996), in the space of a few weeks, won OVERALL BOTH the Daytona 24 Hours AND the Sebring 12 Hours in a Riley and Scott Mk IIIB with Wayne Taylor and Scott Sharp.
VERY calm, considered guy and a gem to work with. Very special man.
He won the GTU class at Daytona in 1990 and six years later (1996), in the space of a few weeks, won OVERALL BOTH the Daytona 24 Hours AND the Sebring 12 Hours in a Riley and Scott Mk IIIB with Wayne Taylor and Scott Sharp.
VERY calm, considered guy and a gem to work with. Very special man.
__________________
-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
-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
04-26-2016, 04:48 PM
#2434
ASK THE COACH
Originally Posted by TXE36
I have found that my perception of nearly everything I do on the track is wrong, or perhaps better said as less than accurate. As a professional scientist, I'm generally good at objective observation, but at the track, that all goes out the window when I'm driving at speed.
Data is the only practical way to solve it. Coaching can help, but most of us can't afford a coach all the time. Data is required, at least for me, to calibrate my own butt as that is the only way I'm going to execute better.
With data and external video, I've learned:
1) I don't get on the gas as early as I think.
2) I don't get on the gas as hard as I think.
3) I don't brake as late as I think
4) I don't apex nearly as well as I think
5) It wouldn't surprise me at all if I'm not 100% on the brakes (wrt the above discussion).
I'm sure there is a lot of time, just in that list above and I'm sure there is more because I'm a novice wrt to data.
Perhaps those who are blessed as "naturals" in this sport simply have a better default butt calibration.
-Mike
Data is the only practical way to solve it. Coaching can help, but most of us can't afford a coach all the time. Data is required, at least for me, to calibrate my own butt as that is the only way I'm going to execute better.
With data and external video, I've learned:
1) I don't get on the gas as early as I think.
2) I don't get on the gas as hard as I think.
3) I don't brake as late as I think
4) I don't apex nearly as well as I think
5) It wouldn't surprise me at all if I'm not 100% on the brakes (wrt the above discussion).
I'm sure there is a lot of time, just in that list above and I'm sure there is more because I'm a novice wrt to data.
Perhaps those who are blessed as "naturals" in this sport simply have a better default butt calibration.
-Mike
I know we're blessed in Texas with a lot of good instructors and coaches, but have you ever had Tim Strehl look at video and data with you? He's been able to consistently help me lower lap times by looking at my data and video. I had my best finish in TT3 this past week due in great part to his analysis. He didn't try to improve every corner but a few here and there and I reset my personal PR.
04-26-2016, 05:52 PM
#2436
Rennlist Member
Jim is pretty extraordinary...
He won the GTU class at Daytona in 1990 and six years later (1996), in the space of a few weeks, won OVERALL BOTH the Daytona 24 Hours AND the Sebring 12 Hours in a Riley and Scott Mk IIIB with Wayne Taylor and Scott Sharp.
VERY calm, considered guy and a gem to work with. Very special man.
He won the GTU class at Daytona in 1990 and six years later (1996), in the space of a few weeks, won OVERALL BOTH the Daytona 24 Hours AND the Sebring 12 Hours in a Riley and Scott Mk IIIB with Wayne Taylor and Scott Sharp.
VERY calm, considered guy and a gem to work with. Very special man.
04-27-2016, 09:44 AM
#2437
Rennlist Member
Peter -
I found this to be so true... Two years ago, I had a very good pro driver wheel my car around WGI on stickers. Inside of four laps he was 2.5 seconds faster than me. What was the difference? Yes, faster in a couple of places, but but what was most clear as I studied data was braking.. We actually got on brake at about the same place. Got off about the same. Throttle about the same.
The key difference as I saw data graphs was the slope very similar to what you showed. He went from initial brake to super max threshold - much higher than I thought possible and much steeper up slope. Then he eased off, with a steep slope much faster than me.. Net/Net he carried more speed into a turn and through. And that added up.
Hard brake 1000%, then the rest of the time balancing the car into the turn.
And I thought I was pretty good on braking. Apparently not
I spent a lot of time working on my braking slope and it paid off.
Data tells all..
I found this to be so true... Two years ago, I had a very good pro driver wheel my car around WGI on stickers. Inside of four laps he was 2.5 seconds faster than me. What was the difference? Yes, faster in a couple of places, but but what was most clear as I studied data was braking.. We actually got on brake at about the same place. Got off about the same. Throttle about the same.
The key difference as I saw data graphs was the slope very similar to what you showed. He went from initial brake to super max threshold - much higher than I thought possible and much steeper up slope. Then he eased off, with a steep slope much faster than me.. Net/Net he carried more speed into a turn and through. And that added up.
Hard brake 1000%, then the rest of the time balancing the car into the turn.
And I thought I was pretty good on braking. Apparently not
I spent a lot of time working on my braking slope and it paid off.
Data tells all..
Remember, the braking "event" can encompass several phases.
1) Throttle to brake transition
2) Initial application of brake to max (or near max) pressure
3) Period of sustained high pressure
4) Initial release of brakes after rotating inertia of heavy parts is overcome (and aero load lessens pressure on the tire contact patch).
5) Final release of the brakes. "Shape" of the release and where it lies in relation to the corner entry and steering angle input.
This is good stuff that few pay attention to.
Here is a screen grab of a powerful GT car doing under 1:25 at MRLS with a pro driver. Max pressure .3 seconds from initial. Good release characteristics. Just a nice shape showing exactly how much pressure (and how fast) the driver's foot is pushing down, as well as the subsequent release.
Remember, smooth is not necessarily slow...
1) Throttle to brake transition
2) Initial application of brake to max (or near max) pressure
3) Period of sustained high pressure
4) Initial release of brakes after rotating inertia of heavy parts is overcome (and aero load lessens pressure on the tire contact patch).
5) Final release of the brakes. "Shape" of the release and where it lies in relation to the corner entry and steering angle input.
This is good stuff that few pay attention to.
Here is a screen grab of a powerful GT car doing under 1:25 at MRLS with a pro driver. Max pressure .3 seconds from initial. Good release characteristics. Just a nice shape showing exactly how much pressure (and how fast) the driver's foot is pushing down, as well as the subsequent release.
Remember, smooth is not necessarily slow...
04-27-2016, 10:44 AM
#2438
Rennlist Member
Thread Starter
It's a hugely important issue, which is why I raised the topic here.
04-27-2016, 02:16 PM
#2439
I think I may have gone "over-center" on being smooth with the brakes to the point where I'm not maximizing them. I think it is related to my observation that in the dry, I'm lucky to be in the to 50% wrt to my peers, but in the wet I'm easily in the top 5%. I'm guessing that in the wet, the brake performance I'm not using isn't there anyway.
Brake handling does appear to be the defining difference between merely competent and hella-fast. I may need to update my data system from just a brake light indication to actual brake pressure.
-Mike
Brake handling does appear to be the defining difference between merely competent and hella-fast. I may need to update my data system from just a brake light indication to actual brake pressure.
-Mike
04-27-2016, 02:30 PM
#2440
Rennlist Member
When Smooth isn't fast (braking)
04-27-2016, 03:06 PM
#2441
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The key difference as I saw data graphs was the slope very similar to what you showed. He went from initial brake to super max threshold - much higher than I thought possible and much steeper up slope. Then he eased off, with a steep slope much faster than me.. Net/Net he carried more speed into a turn and through. And that added up.
Hard brake 1000%, then the rest of the time balancing the car into the turn.
Hard brake 1000%, then the rest of the time balancing the car into the turn.
Hardest habit to break is expanding your horizons and do "sensory input" sessions, as Ross calls them, to FIND OUT what the car will do and HOW FAST it will slow down.
Average Am driver in a Pro-level GT car = 35-45 bar. Average Pro in a Pro-level GT car = 85-110 bar, depending on the master cylinder sizing and other factors, but the split is two to three times multiplied.
I think I may have gone "over-center" on being smooth with the brakes to the point where I'm not maximizing them.
Brake handling does appear to be the defining difference between merely competent and hella-fast. I may need to update my data system from just a brake light indication to actual brake pressure.
-Mike
Brake handling does appear to be the defining difference between merely competent and hella-fast. I may need to update my data system from just a brake light indication to actual brake pressure.
-Mike
Maybe not yet. IF the TM sensor unit is mounted properly, it has one of the BEST long g electromechanical accelerometers in the business, enough so that it correlates well with actual brake pressure (if the brakes are functioning properly). I have validated this in some of the fastest, most instrumented sports and formula cars in the world. The engineer says, "what are you putting that thing in for? We have what we need." Then, I can see the slew rate easily and the release in perfect fidelity...
Dan, Ross and I are talking about just this this evening over dinner.
04-27-2016, 04:01 PM
#2442
Rennlist Member
Thread Starter
Yep, Peter, your comparisons of bar pressures reminded me of how surprised many racers are when moving from a power assisted brake system such as in a 996 Cup into a non power dual master system such as a 997 or 991 Cup...and how much initial pressure is needed on the pedal to drive and brake properly before modulation begins very very soon after ...
04-27-2016, 05:46 PM
#2443
Burning Brakes
Yep, Peter, your comparisons of bar pressures reminded me of how surprised many racers are when moving from a power assisted brake system such as in a 996 Cup into a non power dual master system such as a 997 or 991 Cup...and how much initial pressure is needed on the pedal to drive and brake properly before modulation begins very very soon after ...
Really good info on braking in this thread. Thanks everyone for contributing!
-mike
04-27-2016, 07:13 PM
#2444
Rennlist Member
Thread Starter
Question for you: since I've not driven the RSR and you have, how do the brakes and braking differ ?
