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Success favors the bold, and what better way to succeed at time trials than by throwing caution to the wind, uncorking your wildest fantasies of speed, and going full throttle into tomorrow.
Okay, let’s dial it back a little, tough guy. As the discipline of time trials becomes more popular, the techniques required for success become more …
Remember Why You’re There
We’ll start by saying that competitive time trials aren’t necessarily about track time. Sure, the additional track time over something like autocross is certainly a nice perk, but let’s remember that the whole point here is turning a single fast lap, and spending too much time on track isn’t always conducive that that goal.
Your first goal here is to form a plan based on what you actually need to achieve given the parameters of the competition. Do you need to set a single fast lap over an entire weekend of competition? Or will laps from multiple sessions be combined?
These variables affect your approach since each session will likely have its own unique conditions. A generalization that we can make here: Most tracks will yield the fastest lap when clean and cool. When those conditions are actually present is going to vary from track to track, but in general, early sessions are faster than late sessions.
As a track heats from both atmospheric conditions and friction, the asphalt softens and trapped oils can be wicked to the surface, reducing traction. Yes, in heavily loaded corners a rubber line can form, which can increase traction in some circumstances, but this isn’t always the case in this age of 200tw rubber.
So while you might get some mild rubbering-in through some corners, extreme heat can make that petroleum-based rubber just as much of a liability as a benefit. The bottom line here is to not rely on the track getting better throughout the day–unless the day starts wet.
Know Your Performance
A theme you’re probably already picking up on here is that going fast for that one perfect lap requires executing that lap at a time when a lot of variables are in their ideal range. And a key to exploiting those variables is knowing how you’re performing in real time during each lap and thus making critical decisions about whether a particular lap is worth continuing.
For this reason, one of the most important tools in your time trial toolbox should be a predictive lap timer. We commonly use a VBox Performance Box Touch, but there are numerous options out there–even some great phone-based ones that cost less than a tank of fuel.
[Turn a smartphone into a data acquisition system | The apps you need]
Your needs here are not elaborate. Quite the opposite, in fact, as your predictive lap timer should be easily readable at a quick glance and mounted so that frequent quick glances don’t take your attention too far from the road. We mount ours just above the center vents.
Our Performance Box Touch simply shows a number that compares our current lap to a reference lap–and that number can be positive or negative. Green numbers indicate we’re ahead of our reference pace, and red means we’re falling behind.
This real-time data lets us make decisions: Continue to use up tires and brakes while further heat soaking the engine or bleed off some thermal energy to maximize a subsequent lap?
How we know what’s happening when on track in our BMW: a VBox Performance Box Touch for predictive lap times plus an old iPad Mini4 running the MHD Tuning software suite. Photography Credit: J.G. Pasterjak
Our decision process usually starts as soon as the lap timer resets while crossing the start/finish line. Are we on pace or better from our reference lap? If so, then we’ll keep applying the steam and continue our ongoing assessment after the next corner.
If we’re behind our reference lap, that’s where the decision tree starts branching out. If our time deficit is increasing, that’s a pretty good sign to pull the plug, cool things off and try again later. If you know your car and the track, you’re not likely going to pick up a couple of tenths later in the lap.
If our time deficit is steady, however, we now want to know by how much. Can we overcome that bad corner exit just before start/finish, for example? (Spoiler alert: likely not.)
Cool, you’ve used your predictive lap timer to analyze your performance in real time as the lap started. Now you get to do that again after every corner. If this sounds like a lot of quick math to do in your head while you’re driving a car at breakneck speed, that’s because it is.
Another option for a predictive lap timer: your phone courtesy of apps like Harry’s LapTimer, TrackAddict, RaceChrono and TrackNinja. Photography Credi: Paris Van Gorder
Remember, this is as much a game of resource management–tire grip, brake capacity and engine power are all finite and variable–as it is driving skill. And the most impactful application of that skill will be when those finite, variable resources are in their ideal ranges.
The real-time feedback from a predictive lap timer may not conclusively tell you whether a performance deficit is due to driver or car, but during a lap it doesn’t really matter: There are never any points to be gained by turning a slower lap time than you already have, only consumption of your finite resources.
Tired Out
Let’s talk about perhaps the most important of those finite resources: your tires. For the purposes of this discussion, we’ll concentrate on 200tw track-focused tires, as those are the overwhelming choice in our current time trial scene. A lot of the same philosophies will also apply to slicks or R-comp tires, although those do change the calculus a bit.
We asked our tire test editor, Andy Hollis, when 200tw tires deliver their best lap.
[Grassroots Motorsports ultimate track tire guide]
His answer: It depends.
“It’s really hard to generalize because there’s so many variables and different characteristics among the brands,” he replies. “For full-tread Yokohama A052s, it will frequently be lap one. For the Bridgestone RE-71RS, it might be lap two, and for the Nankang CR-S V2, it might be lap three. Unless it’s a really hot day. Or a really cold day.”
We hoped for a more concrete answer but also weren’t surprised. The takeaway message here is that you should know the general characteristics of your particular tire and take those into account when pacing your out or warmup laps.
Andy’s tire tests detail each tire’s buildup and falloff, so that’s a great place to start, but the real answers are going to come from your own experiences. You may be running on a track with more or less friction than our test track. Or you may face warmer weather. Or colder. Or your tires may have some miles on them.
Keep notes, track trends, and don’t be afraid to log things that may seem purely subjective in the moment but could reveal important trends when examined over a long enough time span.
Power Up
The other big component of a solid lap time is engine power. While modern cars do a great job of being very condition-agnostic while still producing their advertised power output, there are some variables worth monitoring.
Chief among these–particularly in turbocharged cars–is intake temperature. Excess intake temperature will frequently cause the engine management to dial back timing to prevent pre-ignition, thereby reducing power. Even a difference of a few horsepower can make a meaningful impact on lap times when extrapolated over the multiple miles of a full lap, so ensuring that your engine is performing at its optimum is key.
[What being on track can tell you that a dyno won’t]
Intake temps are also important to monitor because they’re one of the few factors a driver can influence in real time. Starting a lap when your IATs are too hot is a waste of time at best and a recipe for possible engine-damaging ping at worst. A lap spent in clean air at moderate throttle loads to reduce those intake temps could pay off both in power output and engine life.
We log several engine performance parameters in our BMW 435i project car through our MHD Tuning software suite, but we always have real-time IATs front and center on our iPad. The iOS-based MHD package allows us to build a custom dash to monitor various engine functions, and that IAT gauge is positioned right where our eyes naturally flick to during competition.
One more piece of the puzzle to consider before rolling out: how to keep your car happiest on track regarding tires, brakes and engine. Photography Credit: David S. Wallens
For drivers of cars with more highly modified engines, some other engine parameters could be worth checking on. For example, on our C5 Corvette project, we found that it made better power when oil temps were at least 220° Fahrenheit.
The engine also liked cool intake temperatures, so we always had to find this sweet spot: oil hot enough to reduce the parasitic drag through the pump yet intake temps cool enough for max power. It was a lot to keep track of, but that’s just part of the fun, right?
You Still Have to Drive
Regardless of all that head math and gauge watching, you still need to execute between the apexes. Of course, that’s a whole other story, but just remember that all the real-time mathematic trickery is no substitute for competent driving.
Hopefully when you execute that competent driving, these tools help you succeed and deliver the desired results.