multi21

Could the statement quoted refer to Grip as it relates to high HP vs low HP?

sbelles

+1 but the attitude that one doesn't need to worry about corner speed if one has lots of hp is a pervasive one that is often exhibited by Ferrari and Corvette drivers and occasionally by GT3 drivers.

GTgears

I totally agree. Having watched you progress from afar, you are clearly much farther up the learning curve that someone like myself, but I think you are doing it right. Something like an E30 or Miata only goes so far in teaching one racecraft. Until one has driven and gotten some seat time in a faster car, one can only think about it. E30s and Miatas are great for teaching the basics, but a faster more powerful car requires a different quiver of skills to master. I think that one of the greatest mistakes I see people making is jumping to too much power and too much car before one has mastered the core skills. The reason I think that you have been able to progress in the way that you have is that you understand that and raise the bar to each new challenge. You didn't give yourself too much too car too soon. Now we are watching you move up to a new level because you have done the work to get there. Anyone can buy a bunch of cheap horsepower. But if one hasn't done the time developing the racecraft to put that power to the ground it is more gun than one should be trying to shoot.

winders

Not from what I was reading in chapter 5.

Based on what I am reading here, what is written in chapter 5 of "Going Faster" regarding trail braking and throttle application is incorrect and should be disregarded.

Scott

J richard

^^^^this

And key to the discussion about braking, look at the G-Sum (which is a dangerous topic on RL...) and compare it with throttle and brake traces. Once the throttle is closed you are immediately hard on the brakes, there's no messing around with the initial application of the binders, tapering off to the apex. What does that initial application look like as a total percentage of brake pressure? it would be interesting to plot the apex vertically, it looks to be about two segments over from the yellow line.

There are so many erroneous techniques and concepts that get tossed around that it makes finding a real kernel a rarity. End of braking and throttle at the apex are two important ones.

J richard

^^^^and this!

FFaust

"Erroneous" or misquoted/misunderstood.

Problem is, you've got to have lots and lots of experience to make up your own mind, and to differentiate between what works and what doesn't.

Thank God, the journey's the fun part.

333pg333

Thanks Dave. This is pretty much what I've been alluding to in questions I've posed on this and other forums. Can't quite get a straight answer but this description seems to fit pretty much along the lines that the engineer I dealt with was suggesting. In his terminology he didn't really discuss application points or releases, more, described the notion of not being able to pick up the throttle until apex or post apex. This correlated to data taken from teams including Aussie V8s. I also like what Mike/Fleadh is saying and demonstrating with the datalogs. (Note to self: Try that method) Perhaps there are some different cars that might require a different method. Note that this car pictured just won our Time Attack event down here (yes I know it's not 'real' racing) and look at how much downforce the car puts out as 1) he appears to hit a wall down the main straight and 2) he barely lifts, let alone brakes into a long sweeping 90o corner. Apparently he went to going through there flat out. Sure beats braking! It was once a Mitsubishi Evo lol. Did a 1:25 flat on R spec rubber. Compare this to a 4.0L RSR which did 1:31 on slicks recently.

Carrera51

Great thread. Lots of good insight here. Thank you Ross for starting the discussion.

mhm993

I've had a conversation with some students that we shouldn't refer to that portion of the track as "the brake zone". Sure it's that, but those students focus on BRAKE NOW! and stare at the numbers. I want them to consider it the "get ready to turn" zone, and better develop the skill to look up and slow down just enough to make a good fast apex. I think it helps them to connect each component of a turn. And perhaps it takes a student's primary attention off the middle pedal so he can instead focus on where his eyes are looking.

Van

This is a good discussion. I've done what Mike suggested, and plotted my total Gs in this screen shot. This is T1 at Lime Rock a few days ago.

Top graph is throttle position; 2nd graph is brake pressure; middle graph is steering angle; below that is the combined G vector; and the bottom is the time gap between laps.

Two things this thread will encourage me to do: pay more attention to the end point of braking, and not the beginning, which you can see on my brake pressure graph; and try to get that dip in the combined Gs between 600 and 800 feet up!

Matt Romanowski

Van - Your's looks better than mine! I've been working on this idea of smoother transistion off the brakes for a while, but Ross's idea of picking an off brake point is a great way to think about it. I can't wait to apply it at my next event and at LRP in Big Bend in September!

cello

Great thread all!

That would be interesting. The Pros I have right seated with (in same or similar cars as mine) essentially threw me up out of the seat on initial brake application and chirped the tires (yes with abs) .. Yet the car was not 'surprised' or out of balance at all (ie no wag, or side to side motion).

In talking to them afterward all essentially stated that the brakes were 'squeezed' on, so as not to unbalance the car, but done very quickly, and that the squeeze was to threshold, ie lock up, with immediate slight release. From that point, the brakes were released steadily so as to move weight off of the front tires and 'level' the chassis to prepare for turn in.. The end release is timed to be at the desired turn in speed with all four tire patches engaged with 'weight' moving fore to aft approaching apex, at a location that would change depending on the corner, speed, grip, etc.. If done right there would be a pause before one could again 'get on' throttle as essentially the car/tires would be at the limits (friction circle wise) and any additional input would unbalance the suspension/tire patches, and cost grip...

With new students I try to plant a seed re the above by teaching 'cadence braking' of sorts (usually after I show them in a ride). On the right type of corner, I try to have them apply their brakes on a cadence of '1,2,3'; hold, then try to have them release their brakes on a cadence of '1,2,3,4,5'.. for example (depending on corner). Sort of a simplified version of what I've been taught.. Seems to work in that it gets the student to think of engaging and releasing the pedal over time, and in differing manners, and not to 'pop off of it' at the end of the braking point. It also teaches the base technique for trailbraking (altho I do not necessarily tell them that)..

dan212

VR - Can you elaborate on what you mean here in the context of bending the car into a turn?

ProCoach

VR will answer well, but I can't resist interjecting that mastering or even achieving a higher level of focus and concentration executing THIS discipine (bending) is what will fix Van's drop in CombG at the end of braking and latG in Big Bend.

THIS is why the CombG is SO valuable as a tool for measuring and evaluating this most critical phase.

My definition of "bending the car into a turn" is the successful blending of the release of the brake and the addition of steering input very close to the same rate (and near to the total tractive capability) as the tire can accept, throughout the entire transition.

Pros do this really, really well.

It encompasses reading your "butt gyro" to gauge the heading, therate of yaw development, managing the speed and the proper evaluation of the weight of the wheel to help determine where the tire is in acceptance of and at a high percentage of total grip used EVERY FOOT OF THE TRANSITION between big braking and big cornering.

Sorry, I just get excited talking about this...