There’s just one day left in Dunlop’s five day Sebring test which has featured three of the four 2017 new LMP2 chassis plus the Aston Martin GTE team (see separate story) as the men (and women) in yellow look to continue their 2016 success in both classes and, in particular, to ensure that their LMP2 tyre offer suits the whole range of new LMP2s.
As DSC reported in the recent interview with Dunlop Motorsport MD Xavier Fraipont, Dunlop committed early in 2016 to developing and launching a new range of LMP2 tyres for 2017.
Dunlop began 2017 LMP2 track testing in summer this year with a 2016 Ligier chassis fitted with a more powerful HPD engine and converted to simulate the increased downforce of the new cars (prior to the new chassis being available for testing).
Sebring was chosen for the latest test not just because of its climate advantages over much of Europe over the winter, but also because of its mix of abrasive tarmac and smooth concrete, replicating the characteristics of many different circuits.
Dunlop arrived at Sebring last week with over 1000 2017 prototype tyres for the test.
A Rebellion Racing branded Oreca 07, the Ligier JS P217 test car and the Racing Team Nederland Dallara P217 (there was no Riley Multimatic Mk30 available, the Dunlop test clashing with the (mandatory) Daytona IMSA test).
(There is though a test programme left over in the US if Riley find an available car in the New Year and want to undertake a similar evaluation).
The testing process began well before the cars hit the track. Step one was to do virtual tyre modelling, step two was to test the tyres on a seven post rig that allows Dunlop to compare aspects such as grip and sensitivity to load, pressure and camber. This data is then checked against the driver feedback to ensure that the correlation is correct.
It all comes on the back of a full construction programme, taking lessons from LMP1 Privateer and 2016 LMP2 but looking too very carefully at the very different power delivery characteristics from the AER engined privateer LMP1s and the normally aspirated Gibson engined 2017 LMP2s.
Sebastien Montet, Director, Tyre Technology at Dunlop Motorsport explained: “For developing the new LMP2 tyres we took learnings from three areas. Firstly, our productive and successful return to LMP1 helped us understand the impact of increased downforce and power. Secondly, our work with the modified 2016 car allowed us to simulate 2017 power and downforce, and finally the modelling and simulation process allowed us to make significant development steps even before the new cars were launched.’
In the Dunlop test, the new LMP2 cars were close to the 2012 WEC LMP1 pace (the last time WEC visited Sebring). The new LMP2 cars were consistently lapping around 1m 47s. In 2012 the LMP1 pole time was 1m 45.8s. (NB: The LMP2 pole time in the 2016 Sebring 12h, running to IMSA tyre regulations, was 1m 51.2)
This gain comes from the combination of the new regulations and tyre specifications.
Most importantly, Dunlop are confident that they have a range of tyres that are durable and work well on all types of LMP2 chassis.
“Whilst finding improvements in individual lap times is important, the total race time is what matters. Our tests have confirmed that we have made the expected steps forward in performance , but we are also highly confident that we’ve built on the durability and consistency that was the bedrock of our championship winning 2016 season”.
The process was methodical, Dunlop brought no fewer than 20 different test sets of tyres per car to Sebring, all three cars undertook a short run on each of those 20 sets between Monday and Wednesday with Dunlop then using data analysis to focus the longer runs on “at least” 5 sets, but likely by Friday utilising 6 or 7 per car.
All told that totals well over 1000 km of fast running and a huge quantity of data to analyse rapidly.
It confirmed that the reference tyres produced for early testing had been heading very much in the right direction but also offered the opportunity to address compromises, and some emerging minor weaknesses in the early product.
So far, DSC understands, the test has gone completely to plan with “multiple tyre specifications that give us a very strong direction for 2017.”
There seems little doubt that the tyre war in LMP2 is set to continue into the new era – and that could see some truly spectacular racing with the rapid new cars.
Dunlop’s pre-season testing continues at Aragon, Spain and Monza, Italy in March before the ELMS and WEC seasons start at Silverstone on April 15/16.