Driving Ambitions upped the par on this cage fabrication job and welded thick aluminum supports onto the chassis itself to help disperse the stress loads from it. The cage was extended through both the front bulkhead and rear firewall to tie into the suspension towers and the frame sections. Inside the car, the same treatment was given to tie it into the aluminum rocker rails, a dual-box section that is critical in the chassis cabin rigidity. Three pneumatic jacks were also installed inside the cabin since lowered NSXs are impossible to get under. In the back, the floor section of the trunk was cut out as well as a section of the rear firewall between the trunk and engine. This makes top-side service access to the rear bank of cylinders infinitely easer at the track. The final product was sent out for the white powdercoat that you see here, which surprisingly saved 5 pounds in primer weight.
The fact that it's an NSX makes suspension work fairly simple, since most of the suspension geometry doesn't need to be altered for race duty. Only Comptech non-compliance parts as well as custom pillow ball replacements for most pivot points from Titanium Dave were used to change this streetcar into a track monster. Erik Messely, of EMI, stepped in with Penske three-way adjustable race dampers mounted on 7-inch-long, 1,250 lb/in Hypercoil springs in front and 950 lb/in coils in the rear. Huntley says it's critical to use heavier springs in the front of the NSX (even though the weight distribution is toward the rear) because of the front-motion ratio.
For power, Olsen went with the proven formula of turbocharging the NSX's C30A engine for power. Out of the box the engine is great for boost since it already has the forged internals. To make the most of turbocharging, Olsen had the Driving Ambition crew strengthen the bottom end with new forged 10.0:1 pistons, compared to the stock CR of 10.2:1, and a new billet knife-edge crank stroked to 86.5mm, compared to the stock 78mm. The rest of the 3.5 liters comes from 92.5mm bore slugs placed in new steel sleeves inside a semi-open deck. The car now makes 576 wheel-hp at 12 pounds of boost on a Dynapack chassis dyno.
Like most NSX turbo systems, the Driving Ambition kit uses one turbo mounted underneath the trunk and cooled by liquid to air intercoolers. This race application uses custom tubular 3-1 manifolds with 1.75-inch primaries merged onto a turbo and plumbed to 40mm TiAL wastegates. A 3.5-inch stainless steel turbo exhaust with Burns stainless mufflers finishes off the hot side. The exhaust tip can be rotated to face different directions, depending on the track the car is running, like the infamous Laguna Seca and it's stringent noise-control regulations. Further work on the engine includes mildly ported and polished heads, an extrude-honed intake manifold, and Comptech cams.
Instead of the usual widebody, Olsen insisted on the classic lines of the original NSX. So each panel was stripped down to just the shell (including the doors) and repainted in a fresh coat of red. For better airflow, the stock aluminum hood was cut to match the underhood radiator ducting and patched with aluminum sheets for a seamless result. Even the mirrors, radio antenna, and door lock holes were aluminum patched. Driving Ambition also replaced the stock rear bumper and trunk lid with one-off, pre-preg, carbon replicas. Final aerodynamic aids, like the dual-element GT-One rear wing, Taitec rear undertray diffuser, and front splitter, were added to make this NSX stick.
We rediscovered this gem at our annual Super Lap Battle finals at Buttonwillow Raceway where Olsen and the Driving Ambition crew came out for a little shakedown fun. On old heat-cycled tires and with minimal dial in, the car went out and set a blistering 1:51 lap time. The SCCA guys will be in for a surprise when Olsen starts the new season in ITE and SP classes.