With center of gravity data in hand, the AAR team had CMM tests (coordinate measurement machine) performed on the subframes and suspension components. From here they generated computer models of the front and rear suspension (in a program called Solid Works) and designed roll center and bump steer suspension improvements for both ends of their IS300’s. Part of this package included the design and fabrication of a stiffer rear subframe to reduce flexing and unwanted changes to suspension geometry, relocated suspension pick-up points, and fabricating stiffer alignment-adjustable rear control arms. Best of all, AAR plans to make their front and rear subframes and control arms available for purchase, so all you IS300 owners out there who want to lower your Lexus and improve handling and stability in the process, you’ll want to look into this option.
Thanks to these and other subtle changes made to the front and rear suspension, less roll stiffness was required to create maximum cornering grip, which allowed the Wojteczkos to switch to a smaller set of Hotchkis swaybars, a setup that has performed extremely well in testing. Further fine-tuning of the suspension is made possible by data collected from the shock sensors that are tied into a MoTeC ADL data acquisition system. Being able to examine how the Moton triple adjustable shocks are behaving over every bump and around any corner allows the Auto Analyser team to balance the compression and rebound stroke of each shock absorber for any race circuit they compete on. For ‘07 they’ll be adding real-time tire temperature sensors to the data their MoTeC collects.
Combine all the above suspension and chassis improvements with the existing front and rear double wishbone design from Lexus and what you end up with is a package that allows for excellent camber and toe control with minimal roll center migration. In other words, the AAR IS300s are now incredibly predictable handling cars that are capable of generating a ton of grip both under acceleration and in the corners, a reality I experienced first-hand while driving the #64 car for a few laps at Mosport International Raceway. To say I was totally blown away by the stability and grip of this machine around the very high-speed sweeping corners of Mosport would be a gross understatement.
The overhaul of the Auto Analyser IS300s doesn’t end there though. After experiencing some throttle and brake pedal geometry problems at their first SPEED World Challenge event last year at Mid Ohio, the AAR team had to adjust their Tilton pedal setup and build a custom throttle pedal for improved feel and a broader range of modulation as well as convert the brake box to a right angle bias adjuster so it wouldn’t interfere with heel and toe downshifting. These changes alone made the car far easier to drive in racing conditions. Replacing the Alcon single-plate ceramic clutch internals and adding a Tilton hydraulic throw-out bearing with dry brake also helped solve some of the power delivery problems that plagued the cars during initial testing.
The fuel systems on the AAR IS300’s are, like everything else these race engineers design, both intelligently and beautifully built. To eliminate fuel slosh and fuel pick-up problems, they designed a custom fuel cell and had Fuel Safe manufacture it to AAR specs. Inside this custom cell are twin surge tanks and twin pick-ups as well as a top of the line bladder. To fit the cell in the rear of the car, the rear seat panel was removed and a new custom panel fabricated around it. Add to that a quick fueling system with a 2.25-inch dry brake fuel filler and the Auto Analyser SPEED machines are ready for endurance events as well as the shorter World Challenge races. Further enhancing enduro-friendliness is a completely reworked diff cooling system, AAR having removed the unnecessary fan and relocating the cooler into clean air.
As for the drivetrain, the 290hp destroked 2.8-liter 2JZGE has a deliciously broad powerband, pulling like a train in every gear right up to the 8000rpm redline. During my brief test drive of the AAR #64 Lexus it was refreshing (for a Honda guy like me) to have so much torque available at lower engine speed. Blowing by less powerful machines up the back straight also demonstrated the fact that the 2JZ motor is a real powerhouse even in naturally aspirated form, and with a Getrag Supra TT transmission and Carbonetic carbon-LSD onboard there are no worries about the engine overpowering the gearbox or the rear inside tire. The 2JZGE engine’s specs for the IS300 are freely available on the SPEED World Challenge website, where the Vehicle Technical Specifications for all series-eligible cars are located. But what the specs won’t tell you is how well tuned the Auto Analyser engines are via the MoTeC M800 ECU or how much power their carbon fiber airbox, Burns Stainless 321 stainless exhaust manifold, and AAR 321 stainless .035 wall exhaust system make.
Based on the level of engineering and fabrication integrated into their completely revamped and revitalized Lexus IS300 SPEED World Challenge Touring cars, it’s clear that Auto Analyser Racing has what it takes to make the jump from amateur road racers to a competitive World Challenge team. Whether it’s the engineering and driving abilities of son Andrew, the fabrication and business skills of father Andy, or the tireless support of the rest of the AAR crew including sister Julie and mother Pat, it’s a real inspiration to see a family-owned and operated team compete so closely with long-established and factory-backed World Challenge teams. With plans to run a full season of World Challenge Touring action in ’07 and with a growing number of new sponsors like Motegi Racing (who are equipping the AAR cars with their forged Trak Lite wheels) coming onboard, the sky’s the limit for Auto Analyser Racing and we plan on cheering them on all the way to the top!
By David Pratte
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