How Rally1 has changed the face of WRC design

Toyota's Tom Fowler provides an insight into the challenge of creating a brand-new hybrid rally car

Ogier test 4

Would you want to be M-Sport’s Chris Williams, Hyundai’s Christian Loriaux or Toyota’s Tom Fowler right now? If you’re an aspiring rallying engineer then absolutely, but for the rest of us. No thank you.

Never will the work of these three technical directors be under more scrutiny than it is this month. All three have been toiling away designing a brand-new hybrid Rally1 car for the 2022 World Rally Championship season. Monte Carlo will be the first test to see who’s done the best job.

Arguably the WRC has never undergone a bigger change to its regulations ruleset. Hybrid is of course the headline element and brings with it its own bespoke set of challenges that are fresh to rallying’s biggest brains, but the return of a spaceframe chassis, an increased weight limit and continual homologation jokers are just some more of the challenges facing the team’s various technical departments.

Toyota’s technical director Fowler offered an insight into just how much work has gone into the team’s new GR Yaris Rally1 in a recent call with select media, including DirtFish.


“I think one of the things that’s not seen by everybody is of course to most people the race starts in Monte Carlo on stage one, but effectively for the teams the race started from the moment there was a single word of regulation written on a piece of paper,” Fowler said.

“And the race was to design cars, produce parts and start testing those be it on dynos, benches or in real life. And all of that work is done not only to produce the performance but also the reliability – every part needs to be assessed, is it reliable enough in these conditions?”

Reliability then, unsurprisingly, will be a “hot topic” according to Fowler.

“And if we talk about how long that is, a development period of approximately one year, it’s very difficult to ensure that in one year every single piece of several thousand pieces that make a car are 100% reliable throughout every condition you’ll ever see in rally,” he continued.

“So of course the first season always has a stronger element of reliability and that depreciates over the years of the homologation which is exactly what we’ve seen in the past five years.

“So I’m quite sure that reliability will again be a hot topic in the next season and of course we have to do the best we can to make sure that we’re the best of everybody in that sense.”

It’s perhaps not the sexiest of points to mull over, but there’s a strong likelihood that the team that has built the most reliable Rally1 car could be in the box seat for the first few rounds of the season. It’s useless having the quickest car if it doesn’t make it to the end of the events – just ask Hyundai Motorsport.

That doesn’t mean to say performance has been sacrificed by any team however. Why shoot for just the most reliable car when you can also produce the fastest too?


One of the key areas where teams could potentially gain the upper-hand over one another is the packaging of the components. While each manufacturer has been supplied with the same hybrid kit from Compact Dynamics and will work its design around the same spaceframe chassis, where – and how – it chooses to position the various elements is free choice.

As you’d expect, Fowler wasn’t willing to give too much away about Toyota’s concept as that would give its rivals a hint as to what it’s been up to, but he did share some practical examples of what can be altered and conceded that from what he’s seen the M-Sport Ford Puma Rally1 is “quite a different concept to ours”.

“A very obvious one is how to include at least a spare wheel and in fact two spare wheels,” Fowler explained.

“Traditionally a spare wheel is obviously a very heavy piece of equipment that needs to be carried inside the rear of the car, and so we always try and put a spare wheel as low as possible, as far forward as possible and then get a second either on top of it or also directly behind it, as low and as far forward as possible.

The packaging is difficult because of the amount of big things we need to put in this small car Tom Fowler

“And you will see, or you may have already seen in the testing, because of hybrid motors and batteries and fuel tank position and so on, these traditional, very low, very far forward spare wheel positions are not available anymore. So we’ve had to come up with some other options and move things around so that’s one example.

“The packaging is difficult because of the amount of big things we need to put in this small car, and some of those I don’t really want to talk about because we have some things we think we’ve done very well and we want to keep those as secret as long as possible, and some other things very obvious like the fact that you’ll see the spare wheels are much higher, much further back than ever before which we weren’t going to hide as anyway you’ll see,” Fowler added.

“Looking at the spare wheels gives a good indication as to how space limited we have been because no WRC engineer would ever put the spare wheel where we’ve had to put it if they really didn’t have to, so that shows how tight everything is.”

How difficult has it been designing everything around a spaceframe chassis as opposed to a roadgoing chassis?


“This has been probably a very interesting part of the development from an engineering and design perspective,” Fowler admitted.

“It’s something that we haven’t done before in WRC obviously being production based for many years and it’s a totally different production method.

“In terms of the design, not really too many challenges, in fact [it was] a little bit easier because you have less limitation from the surrounding structures from the original car. You can effectively put tubes and structures and all the things you need in the place you want to put them because there’s no car in the way, to put it simply.

“But from a production point-of-view, some challenges because you have a very large fabrication which has to be produced to very accurate dimensions and so we had to develop our chassis production area here in our factory to have all of the right equipment, give the jigs enough area to produce these cars.

One day not working on it is one day less reliability, less speed, so for sure we've been pushing very hard Tom Fowler

“This has been quite an interesting but challenging part of the development, to produce a very large fabrication to very small tolerances which is not an easy task.”

In reality, none of it has been easy. But nobody becomes a WRC engineer if they want to steal a living. At least the last few weeks have offered the technical departments some respite as the 2021 season concluded in late November, giving them just one job to focus them.

“Obviously the intensity has been increasing over the year,” said Fowler. “We started the year keeping a very keen eye on what we needed to do with the current car to basically do the bare minimum to stay ahead of Hyundai, because we wanted to put the maximum we could into the new car.

“This is something that’s very difficult to judge, so there was obviously some indication earlier in the season that Hyundai had quite a good level of performance in certain rallies and it wasn’t going to be easy, so we had to redistribute our resources several times during the season to go back and forward to keep on top of everything, but we think we managed that quite well in the end because obviously we succeeded in our ambition to be champion of both titles and at the moment we are in a relatively good position in terms of all the things we need to do for Monte Carlo.

“But on the other hand, for the last six months we have been working basically every day so yeah, like I said earlier the race for most people starts in Monte Carlo but the race for the teams starts when you can start working on the car.

“One day not working on it is one day less reliability, less speed, so for sure we’ve been pushing very hard on both projects. The Monday after Monza was the best day because we could put the 2017 car in a cupboard and say ‘OK now we’ve only got one car to concentrate on.’ That’s how it’s been.”

In just two and a half weeks when the winner crosses the finish ramp in Monaco, Fowler and his team will know if their work has been worth it.