Final month’s Monte Carlo Rally was a step into the unknown for all rivals within the prime Rally1 class, even Toyota driver Sébastien Ogier who chalked up his tenth win on the occasion.
One main cause was that it marked the primary FIA World Rally Championship spherical because the spec hybrid system was dropped from the premier class.
One other was that Monte Carlo signified the debut of a brand new tyre provider in Hankook, the South Korean firm changing Pirelli which held the publish for 4 years.
Maybe best-known in motorsport for its ongoing provide of the FIA Formulation E World Championship, and of the DTM from 2011 till 2020, Hankook arrived within the WRC with comparatively little top-line rally expertise in contrast with its Italian predecessor.
Nonetheless, it wasn’t utterly inexperienced to the off-road self-discipline, both. Hankook has supplied tyres to Rally2 automobiles in nationwide collection and provides the ERC4 class of the FIA European Rally Championship.
Nonetheless, stepping as much as work with the manufacturing facility groups of Rally1 offered a considerable problem that required intensive preparation and many testing.
Hankook wanted to develop tyres for various situations that may all be sturdy and secure when confronted with the elevated dynamic and aerodynamic calls for of Rally1 equipment.
‘The present rally tyres had been initially developed to align with the efficiency of Rally2 automobiles,’ says Roy Cha, workforce chief of the WRC tyre improvement take a look at workforce at Hankook.
‘Nonetheless, as Rally1 automobiles function considerably extra highly effective powertrains in comparison with Rally2 automobiles, changes had been made to adapt the tyres accordingly. This led to the event of revised constructions and compounds throughout all patterns to fulfill the calls for of Rally1 automobiles.
‘Particularly, the Dynapro product utilized in gravel competitions required substantial modifications, as adjustments to the construction and compound alone had been inadequate to handle the facility of Rally1 automobiles.
‘To handle this, a brand new sample, R213W, was explicitly developed for Rally1 automobiles by redesigning the prevailing sample.’
Compound curiosity
Hankook’s WRC vary consists of the next merchandise: Ventus (tarmac), Dynapro (gravel), Winter i*cept SR20 (snow) and the studded Winter i*Pike SR10W (ice).
The Monte Carlo Rally noticed many rivals use the Ventus Z215, which was obtainable in several compounds, in addition to the Winter i*cept SR20 on roads with situations slippery sufficient to make the super-soft Ventus wrestle.
‘The tarmac sample is used for each Rally1 and Rally2 automobiles,’ explains Cha.
‘For dry situations, the Z215 sample is obtainable in three compounds – exhausting, comfortable and tremendous comfortable. For moist situations, the [Ventus] Z210 sample is used with a single compound sort.
‘For gravel patterns, we plan to make use of two distinct patterns to account for the differing efficiency traits of Rally1 and Rally2 automobiles, with every sample providing two compound choices: exhausting and comfortable.
‘In finalising the specs, sturdiness efficiency was the highest precedence, adopted carefully by attaining a balanced efficiency between grip and mileage.
‘With no prior expertise supplying giant portions of winter rally tyres for main competitions just like the WRC, establishing a studding course of for winter rally tyres and guaranteeing constant tyre high quality offered a big problem.
‘To handle this, we keep ongoing communication with studding corporations and conduct thorough tyre inspections at each stage of the method.’
At each WRC spherical, every of the three Rally1 groups – Hyundai, Toyota and M-Sport – will get a devoted on-site tyre engineer from Hankook who inspects tyre knowledge in the course of the rally.
These technicians will probably be overseen by a chief engineer, whereas every of the assist classes – WRC2, WRC3 and Junior WRC – can have their very own Hankook advisors too.
Cha estimates that Hankook’s on-the-ground assist employees will quantity round 30 folks on common. This contains fitters, climate crews, operators and advertising and marketing personnel.
Testing programme
Hankook ramped up its testing of the 2025 WRC tyres final February. The programme lasted round 10 months and visited eight international locations, protecting all of the situations the automobiles will face in anger.
In line with Cha, greater than 2000km was coated throughout these exams. He says the Rally1 producers had ‘practically equal mileage shares’ starting from 500 to 700km.
The producers appeared usually supportive of the tyre choices that Hankook narrowed down on throughout its take a look at programme, though engineers from two of them have urged sturdiness on gravel may very well be one space by which to hunt enhancements.
‘I believe each time you alter tyre producer it’s an enormous problem,’ says Tom Fowler, technical director at Toyota Gazoo Racing WRT.
‘In rally, we’ve got a whole lot of totally different tyres. To characterise all of the efficiency variations between them is sort of an enormous job. We consider we’ve finished very nice work on that, so we’re fairly proud of the place we’re at.
‘By way of the specifics of Hankook, the vary of efficiency between totally different surfaces has some variability. Some areas had been fairly okay very a lot from the start of their first tyre they confirmed us.
‘On tarmac for instance, and snow in Sweden, the tyre is completely throughout the vary of what we all know from different producers, so no points.
‘The gravel floor has been a bit tougher by way of sturdiness. It is without doubt one of the greatest challenges of rally total, making tyres final lengthy sufficient on gravel rallies, that’s one thing which continues to be being labored on and improved.
‘It’s extra a put on subject: it’s not a basic challenge of the tyre. It’s simply that the quantity of damage that’s seen with that sort of automotive on that sort of floor over that distance, is greater than would go well with the itinerary of the present WRC.
‘The important thing level is that in some areas, the whole lot is as wanted from the start, and a few others want a bit of labor. However that’s regular.’
Growth path
All through the event of the brand new WRC tyres, Hankook and the FIA held conferences ‘nearly each week’, in keeping with Cha. This was to watch the progress of the take a look at programme and guarantee all producers had been getting sufficient time with the totally different choices.
‘After Hankook Tire gained the ultimate tender in December 2023, creating WRC Rally1-specific tyres for all surfaces inside a brief timeframe posed a big problem, akin to a race in opposition to time,’ Cha provides.
‘Starting with the Winter i*Pike car analysis for ice rallies in February 2024 persevering with by way of November, we performed a complete of 17 car evaluations to confirm tyre efficiency and sturdiness, in the end finalising the specs.
‘Sometimes, we ready three to 4 analysis specs and performed assessments by performing analysis exams within the morning, adopted by long-run exams within the afternoon for the chosen specs.
‘After conducting evaluations on numerous surfaces, we totally analysed the collected knowledge and performed inner discussions to determine essentially the most appropriate specs.
‘Following this, we finalised the specs for every tyre by way of conferences with the FIA.
‘Such rigorous course of was carried out to optimise tyre efficiency and sturdiness.’
Final 12 months’s uncertainty over whether or not Rally1 automobiles would proceed to make use of hybrid programs occurred in the course of the thick of Hankook’s improvement programme.
Finally, final November, the FIA dropped the 100kW hybrid system after a change in its upkeep process led to extra batteries being taken away for service, resulting in fewer obtainable components and issues over elevated prices.
In response, the FIA lowered the minimal automotive weight by 80kg and launched a 1mm smaller turbo restrictor value round 15bhp to take care of an analogous power-to-weight ratio for security causes.
‘With the removing of the hybrid system, each the burden and energy output have decreased,’ says Cha.
‘In consequence, the dangers associated to tyre sturdiness, similar to put on and punctures, have been lowered.
‘Nonetheless, since WRC1 drivers characterize the highest class, the lowered car weight will permit them to deal with the phases extra aggressively.
‘Due to this fact, from an total tyre efficiency perspective, we assess that this has resulted in a slight enhance within the security margin.’
Regulatory shift
Hankook’s WRC provide contract is legitimate till the tip of 2027, which is about to be the primary 12 months for brand new laws geared toward rising the variety of automobiles preventing for total wins.
The FIA revealed its plans for WRC 2027 last November. It’ll first prioritise inner combustion engine automobiles, however has left the door open for builders to carry electrified and hydrogen options sooner or later.
Street automotive producers and smaller constructors, which the FIA calls ‘tuners’, may even have extra flexibility in design, which means new kinds similar to SUVs and bespoke prototypes may seem.
What affect will this have on Hankook, contemplating the brand new guidelines are slated to reach throughout its WRC contract?
‘As flexibility in car design expands, we’re aware of the potential for automobiles with even larger efficiency capabilities than these at present obtainable,’ recognises Cha.
‘Particularly, we’re paying shut consideration to the opportunity of hybrid programs making a comeback or the introduction of automobiles geared up with EV powertrains.
‘Nonetheless, to our data, solely the tough define of the automobiles has been outlined at this stage, and the particular specs for every producer’s car have but to be finalised.
‘Due to this fact, as soon as every maker’s car format, together with the drivetrains, is extra clearly outlined, we will focus on future tyre improvement plans.
‘Whereas it’s nonetheless too early to stipulate particular plans for the longer term at this level, we plan to proceed with tyre improvement to ship dynamic competitors.
‘It will contain optimising tyres as quickly because the design framework for automobiles constructed underneath the brand new laws turns into clear.’
For now, Hankook could be very a lot centered on working by way of its maiden WRC season. Monte Carlo offered an encouraging start line, however there are nonetheless many extra phases and surfaces to go.
For extra about how the Rally1 producers tailored to life with out hybrids will be discovered within the newest challenge of Racecar Engineering. Subscribe today!
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