I’ve said it before and I’ll say it again: I absolutely love time attack.
Forget the intense competition and driver focus – just look at the wild cars that get built in the pursuit of lap times. Sami Sivonen and the Audi R8 1:1 Professional Amateurs crew are a prime example of a team pushing the rulebook (and physics) to the limit, all in the name of speed.
The R8 1:1 is no stranger to these pages, having been featured six years ago in much tamer guise to the car you see now. “We’ve almost changed the whole car since 2017. The frame around the driver is the same, but pretty much everything else is modified or completely rebuilt,” says Sami.
The most significant upgrades are the in-house-designed and built front and rear subframes, allowing for custom suspension geometry including an active third damper. This in essence connects the suspension at both sides of the car and ‘pushes back’ against forces which act equally on the independent suspension.
Sami’s R8 is setup to handle vast amounts of downforce and dive forces with little compromise to ‘low speed’ handling characteristics, as the independent Öhlins coilover suspension does not need to be too stiff to counter the Dynamic Aero Solutions-developed aero package.
Oh, and when I say downforce…
… I mean lots of downforce.
Lots, and lots, and lots of downforce.
“We were gaining so much pace [since 2017] that the stock suspension components did not want to deal with the loads,” Sami explains. “We basically had two options: improve on what we had around the stock chassis or go all in and fully build the car around WTAC rules.”
Sami and his team have really pushed the rulebook with the Audi’s custom aero package; the rear wing being 2,400mm wide and the front around 2,800mm end to end (WTAC-spec). “It makes our R8 possibly the widest race car in the world,” says Sami.
“With European regulations the overhang is bit more limited, so the front wing is around 2,650mm wide, using modified foot plates.”
The result is 4.8 tons of downforce at 280km/h. At 300km/h there would be six tons, but that sort of load would be a big problem for the wheels and tires.
With all of the extra performance potential in the chassis, attention was then directed to the Audi’s V10 powerplant for more outright speed.
“The base engine is the same, but we’ve made the change to water-to-air inter-cooling and lower compression to aid efficiency,” says Sami.
In 2017 the team were using Garrett GTX3576 turbochargers, but now the engine bay is home to a pair of Precision PT6870s with plans to go bigger still. “The main goal for all the improvements has been thermal efficiency but we have gained a lot of driveability as well as torque and power.”
The team has seen a max torque figure of 1,280Nm at the hubs, whilst power has jumped from around 960kW in 2017 and is now 1,016kW at the hubs too. That’s a smidge over 1,362hp in old money. “Torque exceeds 1,000Nm at around 4,000rpm and continues all the way to redline, which is at 8,700rpm,” Sami added.
And yet with a power figure as ridiculous as that, the livery is still the main talking point of the R8 in its current guise.
WTAC Australia was the inception of the idea, when Sami’s Audi was involved in a game of cat and mouse with Rob Nguyen’s Mighty Mouse Honda CR-X.
It was apparent early on that the big old Audi was the faster car between the two that weekend, and the spectators jokingly named the R8 the cat, being the only car that could catch Mighty Mouse. Unfortunately, some unrepairable damage to one of the Audi’s wings knocked it out of contention and it came second to the CR-X.
Mr. Nguyen decided to pop down to Sami’s garage and crack a joke along the lines of ‘the fat cat ought to lose some weight…’
… igniting the idea that the Audi – which is actually rather light all things considered – would bear a mobster-inspired cartoon cat toying with a little mouse in between its claws.
Sami and ‘The Fat Cat’ crew have set official track records at the Porsche Ring, Pärnu in Estonia and Motopark, Virtasalmi Finland, as well as GT-car based records at Mantorp Park in Sweden, TT-Circuit Assen and Botniaring, Finland as well as an unofficial track record at the Alastaro Circuit, also in Finland.
They’re also planning on conquering one of my personal favourite circuits, the Nürburgring GP layout.
The Professional Amateurs are one of the most fun yet devastatingly competitive teams in time attack at the moment, and this image sums that up brilliantly. I can’t wait to see what else Sami, Henri, Riku, Mikko, Sanni and Märt can add to their record streak.
Photos by Alen Haseta
Credit : Source Post