A New Era Under BoP - How Balanced was the Hypercar Debut?

A new era dawned at the FIA WEC 6 Hours of Spa Francorchamps; not only did we see a new category get christened along with the next-gen regulations for car design, but also a shift to Balance of Performance (BoP) being used in Prototype racing alongside GTE.

It is a paradigm shift in the way to run a sportscars world championship – gone are the days of an EoT principle, being given for example an allowance of energy and trying to get the most out of it with your car. If you got more than the opponents, then you have earned an advantage on race day and deserved it, right?! Freedom to develop is costly, and when unconstrained it allows for a spending war that only ever increases cost as each tenth of a second per lap becomes more expensive to find the faster a car gets. Cautious OEMs are unwilling to join this spending war despite wanting to do sportscars, and those taking part grow dissatisfied with the costs, so grid sizes are at risk of collapse.

It is clear a change was needed, so what is the new style of regs about? 

Many of these expensive areas of design freedoms to chase performance have been removed or reined in, a trade-off being made for another freedom, that of OEM styling and powertrain choice without having a detrimental effect on racing results. This is something we have seen in GT racing having a myriad of road going machines including varied engine/gearbox layouts and bodywork aesthetics and even chassis materials all fighting together. This gives a better marketing return on investment, so more chance of OEMs joining. Homologation is frozen for five years, so there’s no chance of costly development wars and redesigning components. Again, better for an OEM thinking of joining.

The goal of Balance of Performance is to set out a performance window for the entrants to fit within. If they do not fit within it then changes will be applied to the cars, whether they be too fast or slow to make them fit. This may be changing the vehicle weight, engine power or modifying the aerodynamics. Now the goal is to design a car that only just beats the competition, reaching the edge of the performance window but not crossing it, to avoid hefty pace penalties.

The World Endurance Championship is still in a transition period using existing non-hybrid LMP1 (designed around a faster performance level) to prop up grid sizes before more Hypercars enter. Will the BoP manage to balance entries designed under different regulations, let alone ones designed for different lap times?! The Toyota GR010 is 1040kg and has 520kW and the Alpine LMP1 is 930kg and has ~450kW which is up over 100kg from last season to give an idea of the challenge it has.

BoP has been proven to work well in GT racing under single formula racing, can it work for several in the same class? This is the key issue for the future stability of sportscar racing.

6 Hours of Spa Analysis

It was clear after qualifying that the Toyota LMH had the best one-lap pace, but what about race pace consistency. The race trace shows how the best laps of the class shaped out.

What surprises me is the consistency (gradient) of each car, mirroring what was previously shown last season in GTE Pro best lap traces. The linear portions match each other well but also show the constant discrepancies between LMH and LMP1 packages. The previous season had much better consistency for the Toyotas than non hybrid entrants because of how they pass traffic with boost more available (now only allowed above 120kph).

The Alpine was more competitive for its best 10 laps, but the BoP algorithms use the best 60% (for this race around 97 laps). They should expect a bit of help at Portimao the next round based on this. It would help close the gap in qualifying, or even swap to Alpine pole positions, less of an importance in endurance however.

The averages for the top 60% laps are shown below. For those with experience with watching WEC/reading Sportscar Engineering, the gap is historically competitive; around 4 tenths of a second for the BoP measurement window (more on this historical comparison below!). 

The key is whether this is acceptable for race pace gaps - for both the entrants and for the organising body… Look out for some politically motivated articles before the next round!

How does this compare with previous top class sportscar racing?

What was the FIA WEC like before moving to BoP? 

The past season had a relatively complicated Success Handicap system that added a theoretical lap time handicap based on championship points standings on a race-by-race basis. Using similar 60% top lap windows on each race we can compare the field as we do for this past race. Season 8 included the Toyota’s predecessor, also a Hybrid and arguably the fastest sportscar of all time, against several LMP1s without hybrid systems. The Alpine is based around the Rebellion entry, so is a good comparison to see the impacts the BoP has made.

The 24h of Le Mans has its own balancing regulation so I have omitted it from the results, as well as the last round at Bahrain where only Toyota were present in the top class. The gaps between cars is hard to read, so we must expand it removing lap time fluctuations from different circuits along the calendar. 

I first chose to normalise by effectively setting the pink fastest lap line as the x-axis, so now the data is showing the gap between each car’s average and the fastest race lap.

This expands the traces and starts to make it easier to read the gaps between the cars and how competitive the most recent race was in comparison with each other. 

I think we can go further though to show the gaps better between each car. To compare to the best car, I normalised to the fastest in class. This also removes the spike for a race that has a big gap to the fastest lap (Spa 2019 had very bad weather let’s not forget!). 

The above chart shows the gaps between each car more obviously because the x-axis has the best-in-class constrained upon it. The most representative round was round 1, as there was no Success Handicap applied due to a clean slate in the championship standings. As you can see, the Rebellion (now Alpine) had a gap over 3 times as large to the front of the class at Silverstone!

All the averages above are displayed per lap, to reduce the impact of circuit-to-circuit variation because of different lengths, I then normalise to circuit length (dividing the time gaps by circuit length at each round). This gives the time gaps between each car per km, a better representation of how cars compare to each other as a whole; a gap at Spa does not translate exactly to a gap elsewhere!

It is still clear however you look at it as per kilometre or per lap, the Hypercar class is several times more competitive than the end of the LMP1 era, with more wildly different cars racing against each other. Considering the feedback loops of an AutoBoP process, this should only improve further with more racing.

Removing The Success Handicap Factor

As you can see the Success Handicap of Season 8 impacted the championship leaders pretty hard introducing wild swings in performance race to race making the Toyotas several seconds a lap slower after they had built a lead. Therefore, I wanted to use the above method on the Superseason where there was no Success Handicap applied, only base EoT. The EoT did get adjusted over time, but nowhere near the scale of Success Handicap, giving a better representation of the pace of the cars at each circuit.

This is even clearer in illustrating the baked in gap between the LMP1 Hybrids and the Non-Hybrid machines, and how the move to BoP has compressed the field well. Considering how difficult it is to balance cars with different powertrain technologies, they have done a good job of doing that with cars built to very different regulations on top!

It must be said however that yes, the Success Handicap did not do a good job race by race at balancing pace, it did very well at a season level. 

Averaging the top 60% lap times of the Toyotas and Rebellion across the races they shared, you can see how incredibly close the pace was, with the #1 less than a tenth off the pace of the lead Toyota… That is frankly unbelievable after watching the season play out with limited action on track! Now the hope is this gap can be seen race to race rather than season to season...

Pit Time

Another factor of this equation is how the cars perform in the pit lane. An electric launch from the pit box gave Toyota an advantage before vs LMP1, so what about Hypercar?

I believe the discrepancy is worse in Hypercar over a 6 Hour period, as the Toyotas can spend less time in the pits overall, with the potential of even saving a pit stop. 

Because the weight and power output of Hypercar is increased, the energy needed per ~45/55-minute stint needs to increase. The Toyota was designed around this fuel requirement, but not the Alpine which cannot fill the full amount of fuel it is given in the BoP! The volume possible inside the car is a known quantity for the ACO and cannot be a surprise. I wish to see this discrepancy accounted for, even if making the Alpine have an edge on pace to make up for the extra stop, and for the Toyotas to fight with pit strategy. What better way is there to market your efficient Hybrid technology by winning a close race on strategy by saving a refuelling pit stop?! Alpine have already been vocal about this issue since the race, and will be an area to keep an eye on for the season.

GTE Pro BoP - Can Hypercar be as Competitive?

We have seen back through the past several years of data, now what can we hope for the future? GTE uses an AutoBoP system for WEC rounds outside of Le Mans and is a good example of what the algorithms can do for balancing a class with performance adjustments. It has been successful at balancing in the past, and I hope this system can be applied to the top class. For example, the full season Porsche and Ferrari factory cars were on average just two tenths from each other and close in the pits:

As BoP is both based on prediction and reaction to racing/testing data, I hope this leads to the gaps converging smaller and smaller as more races are run and more data is gathered. If this is the case the racing will only get closer and more exciting through the season, I cannot wait!