MOTOR Tyre Test 2016: Dry Braking

It’s probably best the Sydney Dragway grandstands were empty during our testing, avoiding mass head-scratching as a car tried to do the opposite of the traditional action and slow as quickly as possible.

Our second dry exercise was again held beyond the 400 metres of extra-adhesion surfacing to ensure the tyres were being tested on a hotmix that has more in common with typical Aussie roads.

Having tested directional grip in the slalom, now the 10 sets of tyres were being tested for their performance under brakes – which in the Audi RS3’s case were proper bits of hardware. Eight-piston calipers up front with drilled discs are more than enough to shoulder the repeated hauls needed for this test.

Dry-braking performance isn’t only handy for the last-of-the-late-brakers on the track, but also for drivers who don’t fancy a rendezvous with a kangaroo that’s gone walkabout on a stretch of their favourite country road.

That makes our 100km/h cruising-speed approach hugely relevant, with a coned gate marking the point where Luffy starts braking – and a line of equidistant cones providing a visual reference for the final resting points in addition to the Driftbox readings.

With ABS making emergency braking as easy as ABC – limiting tyre slide as Luffy stomps on the brake pedal – the only variables in this exercise stem from the tyres themselves: compound stickiness, tread pattern and material construction.

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Efficiency is helped by having two sets of RS3 rims on hand. While one was ‘hot’ testing the resting set would be stripped and dressed with new rubber for Luff’s return

Those variables, though, were enough to put a full seven metres between the first-placed Dunlop (34.75m) – proving it had both impressive straight-line and directional grip following its slalom win – and the last-placed Nitto (41.75m).

Seven metres is nearly two car lengths. If Skippy had sat 40 metres ahead of the point of braking, the driver of a Nitto-shod RS3 isn’t the only one who’d have road kill in their bloodied lap. The Nexen and HiFly had respective stopping distances of 40.81m and 40.21 – starting to set a pattern for the performance of the cheaper tyres.

In a performance context, the Dunlop-tyred RS3 offers an advantage under brakes of 1.5 car lengths compared with the Audi hot-hatch when fitted with Nittos. Even the skid marks of the second-placed, German-but-made-in-the-Czech-Republic Continentals ended nearly two metres further down the track than those of the British-but-made-in-Germany Dunlops.

Just 57cm separated Michelin, Pirelli and Goodyear, while Hankook’s 6th place (38.19m) suggested its development had placed greater emphasis on lateral (cornering) grip over longitudinal (braking) grip.

DRY BRAKING RESULTS

Never trying

We couldnt do it without...

GETTING 40 tyres gathered, fitted, inflated, balanced and tested takes some logistical trickery, so a massive thanks to JAX Tyres. The JAX team was responsible for organising and transporting our 10 sets of rubber and executing more pit-stops than your average Bathurst 12-Hour race – 13 – so Luffy could test them all (as well as the control tyre three times) in a relatively short timeframe of a normal working day.

There was notable assistance, too, from Eagle SMF, who supplied the tyre changer machine the JAX Tyres team used to fit and remove all the tyres, using two sets of rims: one set being prepped while the other was on-track. If you need a change of boots for your car, check your options at www.jaxtyres.com.au – with full pricing transparency – and book an appointment online.