Measure twice, cut once…
VBOX helps the RGMotorsport team verify performance
In a recent RGMPowered newsletter, RGMotorsport’s head honcho – Rob Green – talked about the need to measure things. As the Afrikaans saying goes: On to meet is te weet – to measure is to know. Indeed, he described it as the crux of the business. There are two kinds of things RGM is compelled to measure: power output and acceleration figures.
RGMotorsport’s credibility is closely aligned to these two number sets and their veracity.
So in the earliest days of the company – more than 25 years ago – Rob set his heart on having a dynamometer installed. The easiest way to describe a dyno (as it is known in its abbreviated form) is a machine that measures rotational force and calculates power from that.
But certain kinds of dynos can also form part of a testbed allowing an engine to be developed in live time, and changes to be made to engine electronics while the engine is powering the rollers.
But it is a funny business because it isn’t all about peak numbers and rather the shape and duration of the curve is what matters. This is where the numbers game becomes a little more complicated because the graph ending in a higher peak number may not be the one that works best on the road, where getting to the engine rpm where the high power numbers are found can be impractical.
Engine life, gearing, noise levels and a bunch of other stuff also come into it and a final road test remains part of the broader tuning process at RGMotorsport.
Of course, the measuring objectives are influenced by the intended use of a vehicle and I remember tuning guru Steve Green talking about how he could tweak the electronics of race cars for specific corners…
But I digress. The conversation here is actually about what comes next: measuring the performance in the real world. Like before and after dyno numbers there can also be fudged to an extent.
Just some of the ways of doing this include tyre pressures, fuel level, taking advantage of wind direction, and rounding numbers down in certain instances and up in others. You can end up changing the outcome quite a lot when you do all those things.
At Gerotek, where I’ve been testing for nearly 30 years (my first visit to the then-military facility was in early 1989), there’s a full weather station, and specific protocols in terms of testing above certain wind speeds. More than once, I’ve driven to Gerotek only to find the windspeed too high, and driven straight back to the office again.
If you want to be sure of your results, you should apply all these and other requirements as well as follow statistical principals like discarding ‘outliers’.
My background is as a motoring journalist, which is how I became familiar with Gerotek, its standards and the importance of using proper performance-measuring equipment. One of the brands which I’m passionate about is VBOX, a GPS-based range of laptimers and dataloggers. The brand’s global reputation is impressive and there is hardly a car or tyre brand that doesn’t use VBOX in some or other way to validate data – it is currently expanding into the opencast mining industry.
So when I started consulting for Rob Green a number of years ago, I was pleased to discover that the company owned a PerformanceBox, one of the first dataloggers developed by VBOX. It gets used regularly for on-road validation – before and after.
A decade down the line (and with a number of upgrades and firmware/software improvements along the way) the PB – as we call it - remains a firm favourite in the motorsport and magazine testing environment.
I recently got involved project-managing a Guinness Land Speed record attempt made by motoring journalist Jesse Adams, the plan including using a pair of VBOX dataloggers to record every metre of the run (which required Adams to drive 1 000 laps of Gerotek’s skidpan on opposite lock). As luck would have it, one device stopped running during a pre-event test run. The plan was to use it to verify time, distance and number of laps completed by Adams, providing a high-tech back-up to the witness and timekeeper evidence on the day.
So when I asked RGMotorsport’s management if I could use their ‘box they gladly agreed, fully appreciating and understanding our need to be able to verify the run - which the RGM PerformanceBox did perfectly, backing up the video and GPS evidence from a more sophisticated VBOX device.
At the time of publishing, Adams is still awaiting confirmation as to whether he has set a new Guinness World Record – moving it from about 144 kilometres of drifting established some three years ago, to almost 170…
We’ve got our fingers crossed, and looking at all the data submitted, we think we’re alright!