The HMA team took two different approaches in building their two car team. Car #72 was the primary vehicle, encompassing the most extensive modifications and diverging the furthest from the OEM Odyssey. Car #73 was created to better show what can be done with off-the-shelf parts by the average enthusiast. Its modifications were simpler, less risky and less expensive.
Both of the One Lap Odysseys began life as LX models, selected for their lighter weight and lack of unnecessary equipment. Both vehicles were stripped of excess weight by removing various interior pieces that would not be needed for road racing. However, because the teams had to transport three people in each van over thousands of miles between event venues, certain comfort items (such as air conditioning) were retained.
Beyond the basics outlined above, the weight reduction process was much more extreme on the #72 car. The versatile "lazy susan" storage compartment was removed from under the floor, as was its heavy cover, to be replaced by a lightweight carbon fiber panel. The rear air conditioning system was also removed and the front seats were replaced with light weight racing seats. Combined with other body modifications (see below), #72 went from 4300 lbs off the factory floor, to only 3750 lbs in race trim. Surprisingly, this massive weight loss did have one drawback - the weight distribution went from 55% over the front tires to 60%. That, however, was a price the HMA team was willing to pay to lose that much weight.
Drivetrain wise both vehicles were similarly trimmed. Both utilized production line J35 engines (meaning they were not blueprinted or specially modified - they are exactly like the engine you can buy in any Odyssey on a dealer lot) and production 5spd automatic transmissions with OEM auxilary coolers (from the towing package). That's right, stock automatic transmissions. Fujita air intakes were fitted to both engines and both sported modified exhaust headers. The #72 car went a few steps further, incorporating a Honda Pilot intake manifold spacer for more low/mid range torque. #72 also utilized a full side exit race exhaust as compared to the simpler modified stock exhaust on #73. The final piece of the puzzle for both cars was tuning. Here is where the HMA team had an advantage over anyone else wanting to race an Odyssey. Their insider knowledge of the Odyssey, and their connections within Honda meant that they were able to finely tune the J35 engine, as well as remap the transmission controller for firmer shifts with a more aggressive shift algorithm. Final results? Testing on HMA's chassis dyno returned an estimated 290 hp and 255 lbs-ft of torque for #72. Final numbers for the #73 were not available, but were estimated about about 10 hp less.
Chassis wise, the #73 kept it simple and effective. Off the shelf H&R springs (meaning anyone can buy them) and a front stabilizer bar from the PAX equipped Odyssey Touring rounded out the suspension changes. Stock rotors and calipers are utilized with Advics Prototype brake pads. The connection to the pavement is made through 245/40/19 Michelin PS2 tires on ASA AR1 wheels in 19"x8.5" size at all four corners. Aside from using the same sway bar, #72 is setup completely differently. It starts with a complete custom H&R suspension package, including adjustable front coil overs and adjustable rear control arms (to divorce the relationship between camber and toe adjustment on the stock control arms). Braking is taken care of by a custom Brembo package using Brembo pads on stock rotors in the rear and big 14" two piece Brembo rotors up front squeezed by 4-piston Brembo calipers. Goodridge lines at both ends ensure a firm pedal under race use. Wheels and tires are the same brand and style as the #73 car, but the wheels are 9.5" wide and the tires are 275/35/19.
Clearly the HMA team did their homework (as evidenced by their success), but how do the Odysseys drive? The HMA team let us take them out on the road and on HMA's local evaluation track to find out.