By Haas’s own admission they have a problem: Their car is quick over one lap, but then struggles on longer runs.
Kevin Magnussen was thrilled by his car’s performance in qualifying at Melbourne. But three races in he admitted he “doesn’t really understand” their “frustrating” race pace.
The team’s analysis shows that the problem is with their use of the 2019-specification Pirelli tyres. They are not alone in struggling with the new tyres and related regulations. However Haas’s problem appears to be peculiar to their car, and more to do with the tyre temperatures than its general handling.
“It’s a combination of everything,” said team principal Guenther Steiner in response to a question from RaceFans. “You cannot put it down to [just] vehicle dynamics. It’s aero, it’s everything, brake cooling… there are a lot of things going on we cannot identify because otherwise it would be easy.”
The problem wasn’t apparent during testing, despite the long runs in cold temperatures at the Circuit de Catalunya. This is certainly because the problem is track-related. The home of the Spanish Grand Prix is predominantly made up of medium-to-high speed corners, so that despite the long straight, the tyres were loaded through the turns keeping them up to temperature.
As the season kicked off, the wider mix of circuit types caught Haas out and leave them in a quandary as we approach Baku, a track with long straights and no high speed turns to speak of. Steiner is rightly concerned “I’m not finding excuses, I’m just readying myself for the disappointment,” he said. “I hope we find something before Baku, but it is a race track we cannot get energy into the tyre.”
NB. Race pace calculated as an average over green flag running in each race
F1 tyres in 2019
How Haas can fix the problem is harder to judge than the pinpointing the symptoms, as the root cause could be in one or more of several areas.
Pirelli revised its formula 1 tyre specifications over the winter, partly to solve problems caused by F1’s ever-rising cornering speeds. These tweaks came with potential downsides.
First, all five dry-weather tyre compounds have switched to the thin-gauge rubber used at three events last year. The thinner tread creates less overheating in faster corners, which was leading to blistering last year. This suits the top teams who have the highest cornering speeds, but is a double-edged sword for teams with less cornering load, as the thinner rubber deforms less creating less heat internally and thus runs at lower temperature.
Further complicating the problem, all five tyres in the 2019 family run the same internal construction by regulation. There is little Pirelli can do to tailor each tyre to suit the compound, so warm-up may be compromised. Last in the regulatory changes are the tyre blankets, for 2019 the rear blankets must be set 20C lower than last year. This means that the rear tyres are not at the ideal working temperature when the car leaves the pits.
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Managing tyre temperature
How a car puts heat into the tyre comes from different areas. Aerodynamics are the first and most obvious source of problems. More downforce creates vertical load through medium and fast turns allowing the car to go faster, the increased lateral load puts more energy into the tyres and this keeps them warm. The flip-side is that if there isn’t the downforce to keep the tyre firmly planted against the track, then the tyre slides also creating heat, but in a negative way that tends to overheat the tyre.
In slower turns it’s more the mechanical grip coming from the suspension geometry and set up. This allied to downforce keeps the tyres in check, again too little grip results in sliding that overheats the tyre.
Another factor is the transfer of heat from the brakes, the brake ducts can be swapped for different versions to alter the level of heat transfer from the carbon brakes into the tyre via the wheel. Being able to tune this to the ideal set up to keep the brake hot enough to work and conduct heat into the tyre is a key part of the car’s set up for the track and conditions.
The root cause of Haas’s problems
Combining this we can conclude that the car in qualifying, as it leaves the pits with pre-heated tyres, gets a warm up lap and with the added power boost from its engine’s ‘party mode’ can use the tyres effectively. The Haas car is clearly fast as the qualifying results show, often qualifying ‘best of the rest’ behind the top three teams.
In the race its tyre temperatures begin dropping as soon as the pit crew remove the blankets on the grid. Even with the warm-up lap the tyres are soon losing the pre-heating effect. The thin gauge tyre tread exacerbates the problem. Less movement in the tyre, combined with the slower pace of a race lap, means the tyre isn’t being loaded as effectively as it is in qualifying.
With long straights and a predominance of slow turns the tyres further suffer and lose temperature. Then as the tyre wears the self-heating effect of tread movement makes the whole situation worse. Once the heat is lost there is little you can do to recover the situation. The driver could push harder to put more heat into them, but this is a vicious circle: You can’t go fast from the lack of temperature and the lack of temperature means you can’t go fast. The only option is to switch to fresh tyres with more tread and fresh from the tyre blankets, but this is only possible with extra sets of fresh tyres.
Cars which run fast in qualifying tend to work the tyres well, but then suffer with tyre degradation from overworked tyres in the race, and vice versa for cars that do not qualify well. Haas have the former problem, the car works the tyres in qualifying and under-uses them in the race. So, there isn’t a simple balancing of the set-up to compromise qualifying over race performance.
All teams face the same balancing act, but Haas are struggling with it more than their rivals. They are working to understand the problem, but this takes time, even with the testing days available post-Bahrain. Clearly the tyres are getting warmed for qualifying, the car is then quick, so it has aero and mechanical grip. In the race the car is slower, but the tyres aren’t overheating from sliding, but lose temperature slowly, so again it’s not from a shear lack of grip in fast or slow turns. Ideally, Haas could add a lot more downforce and run with the same loadings as the top three teams, but achieving this is the team’s aim anyway so unlikely to be a quick or easy solution.
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Adding a little more grip from aero or suspension is never a bad thing, but this will not necessarily solve the problem. From race engineers outside of F1, I have been told the stiff set-up on the VF-19 might be a contributing factor. A stiff set-up will bring good qualifying performance, and the driver can stay on top of the trickier car handling for a single lap, but over a race distance this is more of a challenge.
A stiff set-up isn’t added simply for one lap performance, it might be due to other factors, most likely aerodynamic. If the car’s aero is sensitive to changes in ride height, then the car needs to be stiffer to prevent the car moving around as much in order to allow the aero to work.
Contrary to inaccurate yet stubbornly persistent accusation, the VF19’s aerodynamics is very much the work of the Haas team, unrelated to its partner Ferrari. So if the car is sensitive to ride height, this is a Haas problem and within their hands to resolve, even if this proves to be a major and longer-term development project and not something for a quick turnaround.
While Haas does run Ferrari’s suspension, that is not to say the team sets it up the same way, so softer springs/dampers can be run to get the set up the team want. If Haas trial a softer set-up, it is their right to do so.
If the answer isn’t simply to add more grip, one direction for the sort of low-energy tracks that the team suffers on could be with the brake blanking. Maybe there needs to be more heat transfer from brake to tyre in the race, even if this causes heat problems in qualifying. Herein lies a problem: Haas buy in the brakes and their ducting from Ferrari, meaning this isn’t a development area the team have been able to work on.
This is one of the problems which the Haas-Ferrari ‘listed part’ approach brings. If the Ferrari-supplied brake cooling options do not meet Haas’s needs, then they are going to face tyre temperature problems. Haas can either start brake duct development of their own or persuade Ferrari to add more options to the ducts they supply. This is possible with their resources, but still not a solution for a turnaround between races.
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When will Haas fix it?
How quick Haas can identify and resolve the root cause is going to be difficult for two inter-related reasons. Haas out-sources parts production to the full extent the regulations allow, and therefore is able to run a smaller staff – indeed, it has the lowest headcount of any F1 team.
Will this compromise its ability to develop a solution? Steiner stresses: “It’s not the amount, it’s always the quality of the people.
“If you have got the quality and the quantity for sure you’re better. I think we can overcome it, we overcame a lot of things, we just need to work hard on it. After Bahrain we stayed there testing, found what the issues was but after Bahrain we didn’t have any time to actually react to it because the test was finished on Wednesday so we need to see what we can come up now.”
The smaller size of Haas’s operation made it harder for them to deal with the brake problems they suffered with in their first seasons. The team did not develop the braking set-up, so they do not have the level of understanding of it that Ferrari does, they cannot simply ask Ferrari to deal with it and therefore need to raise their level of understanding and resources to deal with it themselves.
Haas have the same problem here. They may not be able to recover anything before this weekend’s Azerbaijan Grand Prix but several of the upcoming tracks after Baku should suit the team far better, giving them some space to resolve the root cause.
Steiner does not believe Barcelona will be an issue for the team. “We didn’t have the problem there in winter and it was pretty cold so why should it come back? I cannot foresee that one.”
This just leaves Baku as a potential short-term stumbling block. Asked how he expects the team will perform at a venue where long straights and short corners may expose their problem again, Steiner said: “I don’t know. I can tell you when we get there.
“We will work hard and try to do the best and get something prepared. But to tell you if we have got something or not I cannot commit. We will just see in Baku.”
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