1200HP, 42PSI, 2.2L 4G63, Tilton Interiors time attack legend, redux.
After multiple lap records and back to back wins, owner, Pro-Am class driver and passionate time attack supporter Kosta Pohorukov and the infamous Tilton Interiors EVO IX V1 met an untimely end on track. While tragic, the incident that left the old chassis a write off enabled Trent Murphy of TM Automotive and others involved to use the winning formula on a new chassis and add all that extra knowledge they had learnt along the way to do it better.
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The result was a keen focus on weight reduction, slight aero improvements care of Voltex Racing and after the chassis was completed by Riverside Racing, an incredible 3 month build time in order to make it to the World Time Attack Challenge before heading to Tsukuba in Japan, the home of time attack. With the car producing upwards of 3000kg of downforce, it is no surprise keeping the class spec tyres intact is an issue and an RF tyre delamination saw the team finishing the event early due to damage, but still walking away with 3rd place in the Pro Class with Garth Walden at the wheel, and 1st in Pro-Am via Kosta himself.
The EVO 9's 4G63 retains its cast block as at around 1200HP it doesn’t give them any issues producing 1200HP from a 2.2L capacity. The Emtron ECU and MoTeC PDM and dash display/logger control the engine and a myriad of sensors which ensure engine reliability as well as helping dial in aero and suspension setups to get the most out of the car. A Hollinger 6 speed sequential helps get the power to the ground and while Trent didn’t give any specific numbers, the torque split has been adjusted to ensure the car turns into corners easily, as well as maintaining traction when the noise pedal is used on the exit.
Also discussed is the new BorgWarner EFR 9280 turbo which hits a max boost of around 42PSI and 116,000RPM and its advantages over the old EFR 9180, the importance of packers, bump rubber and getting your spring rates right, using Nitrous and why the MIVEC system is retained. Also touched on is the difficulty of reducing weight when so much strength is needed to handle downforce with the tradeoff being the weight is placed as low as possible to improve handling.