Ohlins has won 15 of the last 17 Le Mans 24 Hours, largely through its supply of Audi. That figure would have been 16, but for the #5 Toyota TS050 HYBRID slowing with minutes to go in this year’s race and losing the lead on the last lap – a failure that had nothing to do with the dampers.
Inevitably, the demands for endurance sportscar racing are very different to those of rallying and rallycross. Even within the discipline, the wide range of cars, stretching from high-powered, aerodynamically-elaborate hybrid LMP1S through customer LMP2S and GTE machinery, is very varied.
“It’s tricky to define because with the teams we are working with, they have so many different motion ratios so the peak loads change a lot depending on the design of the car and what they are trying to get it to achieve,” says Jarlmark. “I would say that if you have the damper with no motion ratio, you would maybe see peak loads of up to 10kn on the rear tyre and six or seven on the front tyre – but motion ratios change that a lot.”
It’s the work with the LMP1 factory teams that has the biggest impact in terms of driving technology.
“It’s a very good test bed,” says Jarlmark Nafver. “It’s an experimental field that pushes us as far as we can. We have the TTC damper line, which you can use the top dampers in for LMP2, and you can use the entire range for GT cars but we do a lot of work on the LMP1 dampers.
“Teams always have interesting ideas on what the damper is supposed to do, and we help them to get it to do what they want. We constantly redesign valves and the complete damper system for the top end customers, and we do CFD simulations of the systems so you can understand the force progression from, for example, a kerb strike.”
The typical bespoke system will have an adjustment range of 50 ‘clicks’ (referring to the progressive clicks you feel as you rotate the adjusters). But once on the Le Mans weekend, the set-up work will probably be done within a range of about five clicks. Any more clicks and the changes between them becomes imperceptible.
The dampers are designed to run for 30 hours – more than enough to cover the race and also practice activities.