Estimating the pace of Arctic Rally Finland 2021

Arctic Rally Finland is a completely new event for the WRC. The stages are driven in different configuration than on the national event, which is primarily contested with Rally2 cars. Can we use some mathematics to estimate how fast the upcoming event will be?

Cover image by Taneli Niinimäki / AKK

Rally2 vs WRC

Valtteri Bottas, Kalle Rovanperä and Juho Hänninen have all contested the Arctic Rally with a current generation WRC car. However, for Bottas it was his first ever rally, while Rovanperä was learning the car and Hänninen testing new things. We cannot assume they were going flat out all the time. However, the competition within the Rally2 (=R5) cars has been tight.

To find out how much faster a WRC car is compared to an Rally2 car on snow, we can pull some data from the Rally Swedens of the past years. We can take some different types of stages in different conditions and see how the paces differ and what kind of a ratio it makes.

Stage	Fastest WRC	Fastest Rally2	Ratio
Knon 2017	137.80 km/h	128.10 km/h	1.075722092
Hof-Finnskog 1 2018	121.00 km/h	114.90 km/h	1.053089643
Vargåsen 1 2018	99.20 km/h	95.10 km/h	1.043112513
Likenäs 2 2018	113.00 km/h	108.30 km/h	1.043397969
Hof-Finnskog 2 2019	127.00 km/h	122.30 km/h	1.03843009
Torsby 2 2018	95.30 km/h	91.00 km/h	1.047252747

Knon was so outrageously fast in 2017 that the second run of the stage was quickly cancelled. Hof-Finnskog is also a fast stage with many flat-out sections but also many junctions to cut the pace from time to time. Likenäs has a slow section on a rallycross track, but also some fast-flowing sections and long straights. Vargåsen is mostly a technical twisty stage, whereas Torsby has two technical sections and a fast section between them. The conditions in 2017 were sparsely snowy but very icy. In 2018 there was more snow and in 2019 it was more warm and slushy.

We can clearly see that on the Knon stage the difference between WRC and Rally2 is biggest. The stage had some very long straights where the cars drove at their top speed. It’s these speed ranges where the difference in power and aerodynamics is remarkable. Meanwhile, Jari Huttunen even managed to win the Torsby stage on a Rally2 car in 2019!

Estimated Rally2 times for the Arctic Rally FInland stages

Many of the national Arctic Lapland Rally stages are very fast. However, the five stages selected for the WRC event are from the slower side, or modified to reduce their speed. This makes it difficult to find the fastest Rally2 stage wins for the stages.

SS1+2 Sarriojärvi will be run similarly to the 2021 national Arctic Rally, except in the opposite direction. For these estimations, we assume that stages are equally fast to both directions. The fastest Rally2 car was Oliver Solberg with 114.1 km/h of average speed.

Teemu Asunmaa was the fastest Rally2 on Kaihuavaara, which will serve as SS4+7 on the WRC event. The stage is also reversed, and the most Western small road is omitted. We can use the onboard to calculate the time for the partial which is run in the WRC event. This equals to the average speed of 122 km/h.

SS5+8 Siikakämä was run at 139.5 km/h by Kalle Rovanperä in 2020. However, a very fast section of the stage has been omitted for the WRC version. Again we can use an onboard video to estimate what is the partial average speed for the WRC version. The latest top driver onboard I was able to find was Teemu Asunmaa in 2017. That year his time on the small road section was 13:54 and 20:00 on the whole stage. This year the whole stage fastest time was Oliver Solberg, 19:15. Applying the ratio of 19:15 to 20:00 makes 13:22, which equals to average speed of 121 km/h.

SS9+10 Aittajärvi will be driven exactly as in the 2021 Arctic Lapland Rally. This makes it straightforward to estimate. Juha Salo’s average speed was 126.4 km/h. However, it’s notable that Juho Hänninen’s WRC run this year was only 128.2 km/h, while Kalle Rovanperä the previous year only matched Salo’s Rally2 pace of this year!

SS3+6 Mustalampi is new and there is no reference onboards to estimate anything. Estimating by the recce video this looks like a very twisty and technical stage with many junctions. Some of the roads are bumpy and narrow, while only three short bits can be considered fast. Thus I would estimate this stage to be close to the Torsby and Vargåsen stages, meaning 100 km/h average speed for WRC.

Stage	Rally2 Stage win estimate
Sarriojärvi 2021 (reversed)	114.10 km/h
Kaihuavaara 2021 (reversed and shortened)	122.00 km/h
Siikakämä 2021 (reversed and shortened)	121.00 km/h
Aittajärvi 2021	126.40 km/h

Applying the ratios

Now we have estimates of the ratio between Rally2 and WRC, as well as estimates of the pace of a Rally2 car on the Arctic Rally Finland stages. It’s time to apply the ratio to get estimated WRC pace.

Aittavaara is a very fast stage with many long straights so I would choose the Knon ratio of 1.07. Kaihuavaara and Siikakämä have also fast sections but Kaihuavaara has also slow sections, whereas Siikakämä is never extremely fast. Thus I would choose 1.06 for them. Sarriojärvi is more technical, but also has some fast sections, so 1.05 should be appropriate.

Stage	Rally2 Stage win estimate	Ratio	WRC Stage Win estimate
Sarriojärvi	114.10 km/h	1.05	119.81 km/h
Kaihuavaara	122.00 km/h	1.06	129.32 km/h
Siikakämä	123.40 km/h	1.06	130.80 km/h
Aittajärvi	126.40 km/h	1.07	135.25 km/h

Whole rally average speed

Now we can estimate the whole rally average speed. We must calculate times to match the average speeds and stage lengths and put them together.

Every stage is run twice. Based on Rally Sweden it’s up to the conditions whether second runs will be faster, similar or slower. It looks like the weather will be warm, and in Sweden it’s sometimes made the second runs slower. But for this estimation, we are leaving this effect out and we just multiply every stage time by two.

Stage	Time	Length	Avg Speed
Sarriojärvi	15:33	31.05 km	119.81 km/h
Mustalampi	14:38	24.43 km	100.17 km/h
Kaihuavaara	09:15	19.91 km	129.15 km/h
Siikakämä	12:42	27.68 km	130.77 km/h
Aittajärvi	09:58	22.47 km	135.27 km/h
WHOLE RALLY	2:04:12	251.08 km	121.29 km/h

The resulting average speed estimation for the whole rally is 121.29 km/h, which we can round down to 121 km/h because nothing here is very accurate. It’s probably less than many of you expected.

Of course the pace of Mustalampi is just pulled out of hat. However, as a long stage it makes up a big portion of the whole rally. If its pace will be 95 km/h, the whole rally drops down to 119.8 km/h and if it’s 105 km/h, the whole rally is up to 122.6 km/h.

The fastest ever WRC event has been Finland 2016 with Kris Meeke’s win on the Citroen DS3 WRC up to 126.62 km/h. Mustalampi would have to be driven exactly at over 122 km/h (keeping all other assumptions), in order to beat Meeke’s record. I’m quite confident it won’t happen this weekend.

In fact, the average speed of Arctic Rally Finland will likely be even slower than the Jyväskylä-based summer Rally Finland has had in the two last years with its more technical route, its average being around 122 km/h.

Although Rally Sweden in 2020 was exceptionally fast with no snow and reached up to 124 km/h, its pace in the previous years has been 109-115 km/h. Arctic Rally Finland will easily be faster than that.

Of course there’s many things that will affect the results. The conditions will likely be warmer than usually, making the grip level possibly lower. In terms of the whole rally speed, it’s highly unlikely that the same driver wins all stages, so the whole rally average should be lower than the sum of the stage wins. I’ve also based my estimations on the pace of the national event, while the comparison of Rally2 and WRC was made based on WRC2 level Rally2 drivers. Will drivers like Mikkelsen and Lappi go faster in their Rally2 cars than the national heroes Asunmaa and Salo?

This was a fun semi-scientific experiment, and will be interesting to see how close my estimations were.