Friday, October 27, 2000

Really Give Me Brakes?

Really Give Me Brakes?

We love our cars, and we love to take them to the track. The Quattro Club has been especially good at sanctioning driving school events at race venues across the country. We sometimes hear afterwards of horror stories about brakes being destroyed during these events, tales of near-death (at least to those that had them) experiences. Further, the earlier Audi performance models such as the S4 and S6 had what many owners considered to be inadequate brakes, even for the street. In response to this there’s a significant cottage industry catering to Audi owners for brake upgrades. In fact, one of the more common subjects for articles in the Quattro Quarterly has been on that subject.

As technical director of BIRA (Brake Improvement Research Association – see Quattro Quarterly Fall 2000), I am consistently asked if BIRA (or other aftermarket) brakes are "adequate for track use". The concern seems to be that tracking a street car would kill the brakes, that it's a safety issue that any owner should consider before taking their car on the track. I'm going to toss a completely different spin on this and no doubt start some serious debate on the subject, but in my opinion any brakes that work properly are adequate for track use. Yes, even the stock brakes.

Keep in mind that these track events are not competitions, they're learning events. They are for us to go out and drive our street cars, vehicles TOTALLY inappropriate for track use, around a local race track and go fast(er). No one is going to notice if your car is a second per lap faster than it was last time, or if it's a second a lap faster than your buddy's car. Even if someone did notice, it's irrelevant. If going fast is really a need (or a strong desire) for you, get into organized racing because these Q-club driving events are not for you. Try SCCA (http://www.scca.org) or NASA (http://www.nasaproracing.com). Check your attitude at the Q-Club events door, please.

Since we’re not concerned about the fact that we're driving faster than before, we need to take care of our equipment to be able to enjoy the event. After all, isn't the whole point of these things to have fun? You've heard the old racing saw, "In order to finish first, you must first be Finnish" (oh, wait, that was Mikka). Actually, it’s "In order to finish first, you must first finish." To do this, you must take care of your car and drive within its limits, and that includes brakes. Taking care of the brakes may include slowing down (horror!) in order to make your brakes stay within their temperature limits and last the event's duration. Tell me, who's the guy out there having more fun: the one that drives like a bat outta hell, destroys his brakes in two sessions, and sits out the second day, or the guy that takes care of his car, goes a second a lap slower (not that any will even notice) and makes it the full two days?

I am significantly more impressed by a driver that understands his/her own personal limitations, is in sync (Zen?) with what the car is telling them, and drives appropriately, one that can make a car last for the duration, not have to work on it every session, and stays off the walls. A really good driver can take a totally stock car and go against any of us in the most modded-out Stage 27x car. Count the number of laps they drive over the two or three hours of track time out there, and you'll be surprised that this Good Driver will put in more laps, go farther, have more track time, and thus probably have more fun. Why? Because they are taking care of the equipment.

As I tell my students, "You can't win these events, but you can certainly lose them." The 'lose' part is totally controlled by one major piece of equipment, the MOST IMPORTANT piece of equipment in the car: the nut behind the wheel. That nut has total control over the car's operating parameters, including the brakes. Fancy brake setups, expensive brake fluid, stainless steel lines, big tires, big wheels, air dams and splitters are all meaningless fluff. Since the whole point is track TIME, doing it faster gives us nothing, wins us nothing except maybe a mention on Internet Forums, which will scroll off within a week to be forever ignored in the archives. How much money is that worth to you?

To summarize (and not get off too far on a rant) all this additive equipment is nothing when you consider we're in a non-competitive environment. We get nothing by going faster, and we are all capable of showing the discipline of driving within the car's limits. There's no trophy queen waiting for us on the podium, and there's no Speedvision announcer waiting to interview us. Besides, it's a heck of a lot more fun to make a slow car go fast than to try and make a fast car go fast. Go slow in a stock car and no one notices, it's expected. Go fast in a highly modified car raises no eyebrows, as it's expected. Go slow in a highly modified car and you look like an idiot.

Go fast in a stock car and folks are impressed.

OK, so now that we've gotten beyond this we’ve decided to mod the car anyway, let's say for cosmetic purposes (personal tastes.) What has this gotten us for the track? If we still maintain our discipline and drive within the limits of the car, all we've done is increase those limits to a higher plane.

In context, consider brakes. Before now, we drove within the limits of the stock brakes, and that required that we lift off the gas sooner (horrors!), brake sooner (horrors!), and make sure we cool the brake parts sufficiently before the next time we need it (yeah!). We were paying attention to the car, and noticed that the car didn't really stop well at that last turn, and that it's worsening slightly each time. The Good Driver is saying to himself, "OK, I'm overheating the brakes, and the worsening tells me I'm not rejecting enough heat before the next turn. I need to slow down to save the equipment." We finished the event and had a heck of a time doing it.

So what does adding the Stage 27x brakes buy us? More speed, more kinetic energy, more chances for balling up our little cars into a length of steel Armco. Does going faster make us a better driver? Not at all, I've met a lot of rich race drivers that couldn't drive worth a squat. They sure were fast, though, in those mega-millions cars (ever watch the Ferrari Challenge races? Hah!) Does going faster make us learn more? Nope, it's still all the same idea of driving the right way, at the right locations, all within the limits of the car. Does the Stage 27x brakes eliminate the need for being precise? Not at all; in fact, quite the contrary.

Does the Stage 27x brakes eliminate our concerns for brake system longevity and safety? ABSOLUTELY NOT.

All Stage 27x brakes will do for us is raise the bar a few notches more. You can still overheat the brakes, you can still fade the pads, and you can still wear out the components. All you've done now is raise the SPEEDS at which those failures happen, and increased the outflow from your pocketbook. Remember, raising the bar increases the distance you have to fall when you screw up.

OK, so let's talk about reality.

Our cars are luxury cars that can weigh almost two tons, sometimes more. Since many of us have modified the power in the car in that quixotic Mutually Assured Destruction quest for “enough power” (clue: you’ll never get there), we are capable of some serious speeds on even the shortest straights. Problem is, I don't know of any road course that does not have a turn at the end of a straightaway. So, you’re gonna have to use the brakes.

Unfortunately, all of our cars are equipped with loose nuts behind the wheel; the level of tightening varies. Even though I contend that any disciplined driver can drive these track lapping events with stock brakes, I concede that at the speeds we can drive the stock brakes, while "adequate" with discipline, are not "good". Because the stock brakes are designed for day-to-day driving and the occasional single hard stop from highway speeds, they are not up to the task of repeated stopping from high speeds as is required at these road courses.

So what do you do about it? First of all, you pay attention to what the car is telling you. The first indication of problems is brake pad fade. This is when you've over-heated the brake pads beyond their designed temperature specification, and they start to melt at the surface. This melting transfers the pad's surface to the rotors (and make it feels like they're warped). A melting pad does not have the friction coefficient as good as a non-melting pad; this is noticed as increased pedal pressure and if not kept in check a continued worsening of brake performance. Plain and simple, you've overheated your brakes and the only resolution is to SLOW DOWN and not use the brakes so hard. Many nuts think that they've boiled the brake fluid; this is not usually true. It is hard to boil brake fluid in a stock car with stock brakes. The pads will always fade first and since a fading pad is not generating as much power, it's not generating as much heat.

A loose nut will continue to drive hard, won't back up the stopping point, and will eventually completely slag the pads to the backing plates until Loud Noises begin to happen. Or, a loose nut will not compensate for the increased braking distances that come with fading the pads. In either case, if the nut doesn't do something quick (like, maybe go home) Mr. Armco awaits.

So, because our brake pads are made for normal everyday driving, I think it's a fine idea to have a set of pads purchased specifically for driving your car around a race track. This will allow you to do spirited driving consistently lap after lap, within limits. Anything over and above this, including BIRA designs, is for speed, not for safety. And I think you got my point on more speed at lapping events...

OK, so there we are. Greg thinks that all stock braking systems, with aftermarket pads and a properly tightened loose nut, are “adequate” for track use. If you want some bigger brakes over stock they are by definition certainly adequate for the track and will make you go faster, if that's important to you, subject to the laws of Physics and Thermodynamics. However, it's even possible for a heads-down loose nut to over drive aftermarket brakes to infamy, and I bet that even the “best” megabuck brake systems can be burned to a crisp in short order. However, for those same megabucks I can throw a pretty nice beer party after the first day's event. That will slow down my "competitors" a whole bunch more than aftermarket brakes will speed me up, and I’ll be more popular to boot!