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Caballus

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I don't think the rotors look bad, but they are warped. This rotor has 16k road miles and 5 track days on it. Granted, days at the track as a noob are not all that hard on brakes.

I am still amazed at well the brakes on this car work. I have many scary memories of asking too much of the brakes on my 65 Mustang and 89 LX 5.0.

oldrotor.jpg
Any idea of what caused them to warp? Not super common for these cars.
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Any idea of what caused them to warp? Not super common for these cars.
I think, if truly warped, that's another sign of overheating. Takes serious abuse given the capacity of the system on these cars, but it lines up with the excessive pad wear also. I'd wonder if it wasn't driver behavior but sticking caliper pistons or some other issue that created constant heat.
 

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Any idea of what caused them to warp? Not super common for these cars.
if you warped those bad boys, you had to been like Superman on those brakes lol Jk. That was the whole point of the floating pin design was to help with cooling
 

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Brakes are one component that can be more stressed by n00bs than by experienced drivers. N00bs (and lots of "pretty good but not amazing" drivers) tend to over-slow for corners, and that means longer brake applications and therefore more wear per application, and less cooling time between applications. Brake system needs are proportional to HP more than lap times.
That is a perspective about new drivers that I had not considered. Just to be clear, I consider myself a new driver since I can count the number of times I have been on a track on my fingers.

The entry to Sebring's Turn 17 is what I am thinking about. On my first track day, I was braking at the first of three sets of cones that serve as braking markers going into 17. Now I blow by all of those cones and make the initial turn into 17 before I begin braking. I feel confident saying that I am asking more of my brakes now, compared to my first day. But I do understand your point.
 

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Any idea of what caused them to warp? Not super common for these cars.

I cannot say for certain what caused them to warp. It would probably be wise to try them with some new pads before I trash them since the pads show so much damage, the pads could be the cause of the pulsating.
 

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Caballus

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I think, if truly warped, that's another sign of overheating. Takes serious abuse given the capacity of the system on these cars, but it lines up with the excessive pad wear also. I'd wonder if it wasn't driver behavior but sticking caliper pistons or some other issue that created constant heat.
if you warped those bad boys, you had to been like Superman on those brakes lol Jk. That was the whole point of the floating pin design was to help with cooling
Definitely out of the norm.
 

JAJ

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I don't think the rotors look bad, but they are warped. This rotor has 16k road miles and 5 track days on it. Granted, days at the track as a noob are not all that hard on brakes.

I am still amazed at well the brakes on this car work. I have many scary memories of asking too much of the brakes on my 65 Mustang and 89 LX 5.0.

oldrotor.jpg
If you're new to this (I've been at it for 18 years) you might benefit from some coaching on braking. It's common for new drivers to wait as long as possible to start braking and reach maximum braking deep into the braking zone. This approach feels great when you're driving because you get the sense that you're carrying as much speed as possible as long as possible before you finally have to start turning the car.

But it doesn't actually work that way and it's the opposite of what the pro's do. There's a technique called "trail braking" that will allow you to go (a lot) faster and it'll keep your brakes in better shape too. I don't know if there's a thread on this forum, but there was one a while back on TMO that covered it pretty well, and of course there are lots of good articles about it too.
 

Caballus

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If you're new to this (I've been at it for 18 years) you might benefit from some coaching on braking. It's common for new drivers to wait as long as possible to start braking and reach maximum braking deep into the braking zone. This approach feels great when you're driving because you get the sense that you're carrying as much speed as possible as long as possible before you finally have to start turning the car.

But it doesn't actually work that way and it's the opposite of what the pro's do. There's a technique called "trail braking" that will allow you to go (a lot) faster and it'll keep your brakes in better shape too. I don't know if there's a thread on this forum, but there was one a while back on TMO that covered it pretty well, and of course there are lots of good articles about it too.
Scott has probably got the best (free) stuff out there. Would have taken some of his courses if his cars were not all right hand drive (left hand shift). https://driver61.com/uni/trail-braking/
 

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If you're new to this (I've been at it for 18 years) you might benefit from some coaching on braking. It's common for new drivers to wait as long as possible to start braking and reach maximum braking deep into the braking zone. This approach feels great when you're driving because you get the sense that you're carrying as much speed as possible as long as possible before you finally have to start turning the car.

But it doesn't actually work that way and it's the opposite of what the pro's do. There's a technique called "trail braking" that will allow you to go (a lot) faster and it'll keep your brakes in better shape too. I don't know if there's a thread on this forum, but there was one a while back on TMO that covered it pretty well, and of course there are lots of good articles about it too.
I appreciate the advice. I often make the comment that a little bit of knowledge is more dangerous than zero knowledge. Just because you can start a fire does not mean you can control that fire. Seems I am in that danger zone between initial knowledge and competency.

I am at the point where I can drive faster than I was, but I am not driving smart. Before I solo qualified at Chin, my instructors unanimously stated I was braking too early. Perhaps I have compensated too much and am now braking too late.

I will do some more research on braking technique. Again, thanks for the advice.

Thanks @Caballus for the link. I'll take a look.
 

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I appreciate the advice. I often make the comment that a little bit of knowledge is more dangerous than zero knowledge. Just because you can start a fire does not mean you can control that fire. Seems I am in that danger zone between initial knowledge and competency.

I am at the point where I can drive faster than I was, but I am not driving smart. Before I solo qualified at Chin, my instructors unanimously stated I was braking too early. Perhaps I have compensated too much and am now braking too late.

I will do some more research on braking technique. Again, thanks for the advice.

Thanks @Caballus for the link. I'll take a look.
No worries! Look at it this way - you've done enough now to have confidence in yourself and the car and you're ready to start adding some new strategies for getting around a track quicker. Going fast is all about being relaxed behind the wheel, getting your vision right, and being smooth on the controls. Trail braking is just one more technique to help you smooth out your style.
 

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oldbmwfan

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I appreciate the advice. I often make the comment that a little bit of knowledge is more dangerous than zero knowledge. Just because you can start a fire does not mean you can control that fire. Seems I am in that danger zone between initial knowledge and competency.

I am at the point where I can drive faster than I was, but I am not driving smart. Before I solo qualified at Chin, my instructors unanimously stated I was braking too early. Perhaps I have compensated too much and am now braking too late.

I will do some more research on braking technique. Again, thanks for the advice.

Thanks @Caballus for the link. I'll take a look.
I love this post - this is the right attitude to have. Always learning. I've been driving on track since 2002, and there is always room to improve. And you're totally right - there are lots of mishaps among people who have gotten over the total novice hump and started to pick up speed, but haven't yet developed the control and techniques to recover when something goes wrong. That just means some awareness and caution is warranted as you continue to improve.

Re. braking technique, you might not be braking too late, but you might be braking too progressively. Here's how I think about it.
- At initial application, move the pedal two credit card thicknesses - this just sets the pads against the rotors.
- Then quickly, but not roughly, SQUEEZE to full application. It's very fast, but it is a SQUEEZE, not a "jab." You'll feel the suspension compress (nose dive) and it should STAY compressed (no "bounce back"). Those first two steps are really 1 movement, but think separately about the "set" and the "BRAKE." Objective is to get to max braking very quickly, but without bouncing the nose or roughly unloaded the rear.
- From that point, you will hold brakes until your turn-in speed, then gradually release as you turn-in.
- As you advance and in corners where trail braking is helpful, you might be lightly on the brakes, gradually releasing pressure all the way to the apex of the corners.

Here is a great example (Schumacher is a left-foot braker, so his right still has some throttle on).
compare.jpg


The other great aspect of this graph is how quickly, but smoothly, both drivers ramp up to full throttle. They had help, though; this was the traction control era so software was helping them prevent wheelspin! Without TC, you might need a more gradual application.
 
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honeybadger

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Excellent info above. I had planned to post something as well, but @oldbmwfan beat me to it. Great insight and resources.

One thing Iā€˜d note - a proper brake ā€œsqueezeā€ will feel like a jab to a new(ish) driver because it happens so fast. For example, my own brake application happens in a split second in braking zones like T1 or T12 at COTA. There are other corners that will feel much more gradual (such as T15 because youā€™re turning and braking at the same time. In corners like these, you need to adjust your braking pressure based on how the car is setup going into the corner. A split second brake application only works when the car is straight and settled. If itā€™s not, youā€™ll need to adjust how you apply the brakes to help get the car settled OR maximize braking given an unsettled car (think decreasing radius turns, off-camber corners, etc.).

As for trail-braking, hereā€™s a short clip of T12 at COTA in HB. Note, this was on lap 4 of the first session after my winter updates, so I was still playing around to find my ideal braking marker. On this lap, I braked too early, so I started releasing pressure really early so I didnā€™t scrub too much speed heading into the corner. Itā€™s a fairly decent example of adjusting on the fly to keep things as smooth as possible. Notice how the brake indicator is on all the way until the apex.



As an interesting tidbit, Iā€™ve played around with a ā€œjabā€ on the brake pedal that goes straight to 100% at 155 at COTA and a more progressive, but very quick squeeze as oldbmw noted above. The sqyeeze was faster and more predictable lap after lap. The jab often didnā€™t give me the initial bite that a squeeze gave and it could unsettled the car by asking too much from the tires.
 

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@oldbmwfan and @honeybadger I appreciate your perspective and knowledge, and the time you spent gathering the charts and creating a short clip too!

Your description of the squeeze, and the difference between a squeeze and a jab seem small, but I can understand how a jab would be more of a shock to the balance of the car. Perhaps simply thinking "squeeze" instead of "brake right....NOW" would yield the desired result.

Alas, I had planned to put all of this good advice to use this weekend at Sebring but life has other ideas. Perhaps next month I'll put it to the test.
 

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One thing Iā€˜d note - a proper brake ā€œsqueezeā€ will feel like a jab to a new(ish) driver because it happens so fast.
This is totally true - it might feel violent, but it's controlled.
(Side note - the HB's exhaust note is totally intoxicating)

As an interesting tidbit, Iā€™ve played around with a ā€œjabā€ on the brake pedal that goes straight to 100% at 155 at COTA and a more progressive, but very quick squeeze as oldbmw noted above. The sqyeeze was faster and more predictable lap after lap. The jab often didnā€™t give me the initial bite that a squeeze gave and it could unsettled the car by asking too much from the tires.
So, fun fact about why that is true - and it's the same reason a gradual-but-quick turn-in is faster than a sudden "yank" on the wheel. When you gradually load a tire, even doing it very fast but gradually rather than very fast and suddenly, the actual tire max grip increases. Think of "stretching" the tread to its max grip point like a rubber band. If you do it all at once, you overwhelm the tire and it slides, and kinetic (sliding) friction limit is much lower than static (rolling) friction limit. But even that static limit can shift a bit because the rubber is pliable. The "jab" doesn't give the initial bite because you overload the tire instantaneously, the tire slips a tiny bit, and your max decel force is now lower.

This is the "magic" of the pro-level driver. A good amateur can seem to be driving "at the tire limits" somewhat consistently, using the tires to the point of breakaway. But the pro still does three things better:
1) By being smoother and approaching the limit gradually, the limit of tire adhesion is fractionally higher, so the pro is already going faster when they hit that edge of grip. This shows up in data as a higher apex speed even if both drivers are experiencing slip.
2) The pro stays at or near that limit at all times, from brake to turn in to apex to track out. The amateur, even a quick one, usually has points in a corner (most commonly just after turn-in on high speed corners) where they are over-slowed and not stressing the tire
3) The pro does it every lap, consistently.

Every time I've had a pro drive my car, I'm 1-1.5 seconds slower, and looking at data shows I'm losing a bit in the entry part of most corners, especially the really fast "cojones" corners. It's not being massively off or making huge mistakes anywhere; it's about being a hair slower everywhere and it all adds up - and it's pretty much all tire management (and confidence and balance at the limit so corrections keep you there).

This thread has me jonesing to get on track again, and it's sleeting outside in the Midwest. Ugh.
 

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@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.
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