Initial Braking Technique

[Rosso]

OK, I'll bite. Why do I seem to have soooo much trouble bringing big initial braking force to bear? The digressive braking skill seems to evade me.

I'm 6'-2", 195 lbs and a still run 5 miles of hills 3 times a week when I can work it in, so it shouldn't be physical. I move the seat up to the second notch from the rear so I can bend my knee and use my whole leg. I still wind up with what seems to be progressive braking at Laguna T2 and T11, tending to partially lock up as I approach the apex. I found I went faster (mid to high 1:40's at Laguna, so you know too much speed is not the problem) by braking earlier then getting back on the throttle at turn-in and avoiding the lurid trail-brake crisis down to the apex, but I still was locking up the left front entering T2 25% of the time.

How can I make trail-braking a tool, not an adventure? How do the 90 lb Wunderkind do it?

[WatertownNewbie]

Originally Posted by Rosso

OK, I'll bite. Why do I seem to have soooo much trouble bringing big initial braking force to bear? ... but I still was locking up the left front entering T2 25% of the time.

If you are really cooking over the crest of the front straight at Laguna, then you likely cannot produce lockup initially, no matter how hard you press. My guess is that you do not apply enough brake initially, then you realize that you are not slowing quickly, and you apply full brake (by which time the car has already slowed a bit). The main problem is that the amount of pressure required to produce lockup varies directly with the speed of the car. The slower the car is going, the less pressure required for lockup. If you push too easily at first and then try to compensate by increasing the pressure, you are converging swiftly on lockup. What you need to do is push hard initially and then gradually release the pressure as the car slows.

Now ... how to go from a 10 pedal on the brake to an 8? Do not move your foot. Instead, relax your thigh muscle. As the car slows, relax some more. Then eventually you will move your foot as part of the brake release.

[dalyduo]

I'm willing to play the clown here and fully flaunt my ignorance so that others may point, giggle and then properly lead you fully up the path of enlightenment.

Haven't driven Laguna but your issue sounds similar to what I used to do (and sometimes still do) trailing into big bend at LRP.

At a high speed turn-in with trailing brake the inside front wheel gets light, from the car's weight being disproportionately balanced on the outside front wheel, and tends to lock up if the brake release isn't progressive enough. Gerardo has the best analogy that I've heard of how to do it correctly and that is to relax your foot and leg muscles the same way you would release a tight handshake. Your leg muscles are fully clenched as you give the brake pedal full threshold pressure and then rather than trying to physically lift your foot off the pedal, think of relaxing the muscles in your foot and leg as you would release the grip of a tight handshake. That will give you the progressive brake release you're looking for.

When you first hit the brakes hard and pitch the car on its nose there is much more weight on the front wheels and they can, in that first half-second, handle maximum brake pressure. As the car slows down and the weight begins to equalize, there is less weight on those front wheels and they can no longer handle as much brake pressure without locking up. That's why the front wheel or wheels lock up even though you may not be adding anymore pedal pressure. The balance of the car has changed and you have to stay ahead of it by continuing to release brake pressure.

My experience of the best way to go to maximum threshold braking from high speed is to make a fast firm progressive thrust into the brake pedal that first allows the weight of the car to shift forward onto the front wheels and then permits maximum pedal pressure and stopping force. You may say..."Thats what I always do..." and you may be right but it is possible in a moment of excitement to grenade or lock the brakes at high speed by stabbing the pedal so hard and fast that you reach maximum pedal pressure before the car has shifted its weight forward. When you beat the weight shift of the car the fronts lock up and your corner is cooked. We are talking about just a fraction of a second difference in timing the way you apply the brakes, but it can make all the difference in the end result.

A couple of years ago we used brake pads on the R/T's that required enormous initial pedal force to achieve max braking. You almost couldn't lock them up from high speed. I'll never forget the day they changed to the current pads that required much less pedal pressure because everyone got to max speed on the straight at LRP and stomped on the brake pedal as they always had and for the first time with these new pads they all beat the weight shift and locked both fronts in big plumes of flat spotting tire smoke.
For most of that first session it looked like there was a house fire in progress at the pedestrian bridge going into big bend.

Going back to single front wheel lock-up. There is also a method of anticipating and shifting the weight of the car with some steering to control single front wheel lock up, but for an explanation of that more advanced technique I'll refer you to JP, MHP, Gerardo or any of our other esteemed instructors.

Hope this makes sense and and is helpful.

[Rosso]

Originally Posted by WatertownNewbie

If you are really cooking over the crest of the front straight at Laguna, then you likely cannot produce lockup initially, no matter how hard you press.

Actually, that helps explain things. That's how it feels to me. Couldn't force the fronts to lock on the initial shot.

Originally Posted by WatertownNewbie

My guess is that you do not apply enough brake initially, then you realize that you are not slowing quickly, and you apply full brake (by which time the car has already slowed a bit). The main problem is that the amount of pressure required to produce lockup varies directly with the speed of the car. The slower the car is going, the less pressure required for lockup.

Ditto. The lock-up comes near the end. Ususally just the inside front wheel.

Originally Posted by WatertownNewbie

If you push too easily at first and then try to compensate by increasing the pressure, you are converging swiftly on lockup. What you need to do is push hard initially and then gradually release the pressure as the car slows.

Sounds like the gradual release is my deficiency. Maybe I'm not too soft initially. I feel like I am really hammering the pedal, (talking T2 & T11 at Laguna) maybe I'm just too late, which is really the same thing?

Originally Posted by WatertownNewbie

Now ... how to go from a 10 pedal on the brake to an 8? Do not move your foot. Instead, relax your thigh muscle. As the car slows, relax some more. Then eventually you will move your foot as part of the brake release.

Hmm, I'm thinking I need to back up my brake point so I have ROOM to relax. Thanks!

[Rosso]

Originally Posted by dalyduo

I'm willing to play the clown here and fully flaunt my ignorance so that others may point, giggle and then properly lead you fully up the path to enlightenment.

Nah, hacks like me make you look good!

Originally Posted by dalyduo

At a high speed turn-in with trailing brake the inside front wheel gets light, from the car's weight being disproportionately balanced on the outside front wheel, and tends to lock up if the brake release isn't progressive enough. Gerardo has the best analogy that I've heard of how to do it correctly and that is to relax your foot and leg muscles the same way you would release a tight handshake. Your leg muscles are fully clenched as you give the brake pedal full threshold pressure and then rather than trying to physically lift your foot off the pedal, think of relaxing the muscles in your foot and leg as you would release the grip of a tight handshake. That will give you the progressive brake release you're looking for.

Newbie's comments have me thinking I'm just trying too hard. Braking too late was making the two heavy- braking corners a twice-a-lap adventure. Next to last session, I backed things up a car-length or so (I thought Mikel Miller was going to BEAT me with his clipboard - he was using the word "...dangerous...") and was way more comfortable. Instead of trail-braking (such as it was) virtually to the apex, I was back on the throttle just after turn-in and had much better exit speed.

Originally Posted by dalyduo

When you first hit the brakes hard and pitch the car on its nose there is much more weight on the front wheels and they can, in that first half-second, handle maximum brake pressure. As the car slows down and the weight begins to equalize, there is less weight on those front wheels and they can no longer handle as much brake pressure without locking up. That's why the front wheel or wheels lock up even though you may not be adding anymore pedal pressure. The balance of the car has changed and you have to stay ahead of it by continuing to release brake pressure.

Yep, deficient there

Originally Posted by dalyduo

My experience of the best way to go to maximum threshold braking from high speed is to make a fast firm progressive thrust into the brake pedal that first allows the weight of the car to shift forward onto the front wheels and then permits maximum pedal pressure and stopping force. You may say..."Thats what I always do..." and you may be right but it is possible in a moment of excitement to grenade or lock the brakes at high speed by stabbing the pedal so hard and fast that you reach maximum pedal pressure before the car has shifted its weight forward.

Don't think I've ever been able to lock-up the fronts on the initial shot for T2.

Originally Posted by dalyduo

When you beat the weight shift of the car the fronts lock up and your corner is cooked. We are talking about just a fraction of a second difference in timing the way you apply the brakes, but it can make all the difference in the end result.

Don't think I could beat the weight shift. Long legs and cramped footwell. Probly takes me longer to get from the gas to the brake pedal.

Originally Posted by dalyduo

Going back to single front wheel lock-up. There is also a method of anticipating and shifting the weight of the car with some steering to control single front wheel lock up, but for an explanation of that more advanced technique I'll refer you to JP, MHP, Gerardo or any of our other esteemed instructors.

Hope this makes sense and and is helpful. [/quote]

Very helpful. Thank you for taking the time to offer your experience.

[LimeRockRacer]

DD's point on the current brake pads is spot on. These pads are much grippier and do not require as much pressure initially to slow the car.

With that in mind I find it is easier to get caught in the trap that you can go later into the turn before braking. Occassionally this causes me to have to over slow thereby causing a slower exit. Additionally if you are locking up consistently and having to adjust I would guess your eyes are probably low as well.

Keeping your eyes up and experimenting with different braking points and carrying more rolling speed through turns and getting on the power sooner is what you need to work on.

I try to roll my foot off the brake when I am easing off the brake which gets me in a rhythym and prevents a quick snap off that causes spinning.

Hope this helps!

[Rosso]

Originally Posted by LimeRockRacer

With that in mind I find it is easier to get caught in the trap that you can go later into the turn before braking. Occassionally this causes me to have to over slow thereby causing a slower exit. Additionally if you are locking up consistently and having to adjust I would guess your eyes are probably low as well.

This all sounds TOO familiar. I think this is exactly what I was doing.

Originally Posted by LimeRockRacer

Keeping your eyes up and experimenting with different braking points and carrying more rolling speed through turns and getting on the power sooner is what you need to work on.

I staggered to same conclusion after a day and a half of misery. I knew I couldn't hit the pedal any harder with any type of control, so I had to try something else. Moving the braking points further out seemed safe if not logical. Low and behold, I found I could get on the power sooner.

Note well, I had no clue that any of my own remedies were the right thing to do untill you guys took the time to read my whine and share the benefit of your experience. It helps a lot!

Originally Posted by LimeRockRacer

I try to roll my foot off the brake when I am easing off the brake which gets me in a rhythym and prevents a quick snap off that causes spinning.

Hope this helps!

[Rosso]

Since I posed the questions above I came across an excellent article about just this sort of thing penned by west coast instructor Grant Riley. Here's the link:

http://www.teamjuicyracing.com/forums/showpost.php?p=11503&postcount=1

[PT Cruiser]

Originally Posted by Rosso

Moving the braking points further out seemed safe if not logical. Low and behold, I found I could get on the power sooner.

Just to muck things up a bit, I'll point out that if you really maximize the potential of the car at corner entry, you will have to get on the power later than if you overslow the entry, yet your corner exit will not suffer as a result, and you'll be a tenth or two faster through the corner than a driver who overslows the car a bit on entry.

How can this be? Simple. If you absolutely optimize corner entry, when you get to the mid-phase of the corner, the tires are already at their absolute limit of traction. If you try to accelerate at that point, you'll either push wide or get power on oversteer, so you have to wait until you can unwind your hands before feeding in the power. If, on the other hand, you overslow the corner entry, then as you enter the midcorner phase, the tires are not being used to their full potential. As such, it is possible to add some power --up until the point where the tires get back to their cornering limits. Of course, at this point, you've only have gotten the car back up to the speed that the driver who optimized his/her entry speed was at all along, even though that driver has been stuck on maintenance throtle while you are accelerating. Once you get back to the mid-corner speed that the fast entry driver was at all along, you won't be able to accelerate any quicker than the driver who optimized his or her entry speed (the same laws of physics apply to you, even if you did get on the power earlier), and thus you'll have no advantage down the subsequent straight. And since you went a bit slower at corner entry than the other guy, you will be a tenth or two slower.

Of course, all bets are off if you exceed the capabilities of the tires while trying to maximize corner entry speed, and have to perform big heroics to keep the car on the track. In this case, you will almost assuredly have a lousy corner exit and kill your speed down the next straight.

If it sounds like the line between hero and zero is a fine one, you are right. One article I read in F1 magizine analyzing Michael Schumacher's driving style made the analogy that maximizing exit speed was like trying to balance on a tightrope, while maximizing entry speed was like taking a running leap onto that tightrope.

I would thus submit that Mr. Rosso, in his approach to turn 2 at Laguna Seca, was originally exceeding the capabilities of the tires on corner entry, but in backing off to the point where he could accelerate earlier actually took the process just a bit too far. The trick is to find that elusive balance.

No one said this sport is easy. . . .I've been trying to optimize corner entry speed for about 7 years now, and I still can't do it as well as the best drivers. And it shows in my lap times --about .1 to .2 tenths of a second per corner per lap, which works out to a 10-15 second deficit over a 1/2 hour race. In percentage terms, this is a tiny blip in performance, but it seems to be the difference between mere competence and outright genius in a race car.

[birkmama]

I know the feeling of locking up in T2 in LS very well.

Two things: what PT says is absolutely right when you want to find laptime: think how you can maximize the load on the tires through the corner being at their traction maximum all the time.

But first I would recommend a couple of tricks to get assurance about your braking. When in lapping try to pick a point by which you would like to finish braking and then iterate the brake point. This exercise - regardless of speed results - will just make braking less adventorous and generate more suaveness in that right thigh/calf/ankle.

The othe thing you can try is to come over T1 a bit more to the inside and dial in a bit of right lock so the left tire gets more loaded under braking. I, too, doubt that you can get initial lock up in the braking zones of T2 and T11. But I am sure, that Pat is right and that you are able to beat the load transfer by braking too abruptly initially - since the RT2000 is realtively soft sprung. In this case you will never maximize the load on the front.

But again, summing it Peter has the best way to look for lap time. Good luck

[Andrew]

Check out Geraldo posting titled ' secrets to driving the RT2000.
Its an earlier posting on this forum and worth reading.