The NASA Honda Challenge Series was created to meet the needs of Honda/Acura owners looking for a series specifically tailored to accommodate a wide range of Honda and Acura vehicles and components.

The following rules are not guidelines for this class but an actual listing of the allowed and the required modifications. If these rules do not expressly state a modification is allowed, it is prohibited. No item, which is allowed, shall also perform a prohibited function. The driver is responsible for vehicle legality.

In H1 Hybrid, vehicles are classified by engine type and drive-wheel configuration only.

In H2 “Limited Preparation” vehicles, all Honda and Acura cars with the following engines: D15, D16, B16, B16B CTR, B17, B18A, B18B, B18C, B18C1, B18C5, B20B, H22, H23 (non VTEC), F20B, F22, F23, K20A2, K20A3, K20Z1, K20Z3, K24A1, K24A2, K24A4. Parts requirements, maximum compression ratios and vehicle weights apply.

In H2 “Restricted Preparation” vehicles, all Acura RSX, 2006-2012 Honda Civic, 2004-2008 Acura TSX, 2015 and up Acura TLX with 8DCT transmission, and 2013 and up Acura ILX with six-speed transmission and 2016 and up Honda Civic with L15B engines.

In “Factory Preparation” H2 vehicles, all 2000-2009 Honda S2000.

In “Factory Preparation” H4 vehicles, all 1986 to 2001 Acura Integra, 1990 to 2002 Honda Accord, 1988 to 2011 Honda Civic, all Honda CRX, 1996 and 1997 Honda Del Sol, 1988 to 1996 Honda Prelude and 2001 and up Honda Fit.

Horsepower — 140 to 215, depending on model

Compression ratio — 9.8:1 to 12.7:1, depending on model

Average cost to run a weekend

From $800 to $1,200 including fuel and entry fees.

Tires, size, brand and prices
Toyo Proxes RR, max width of 235 mm From $188 for a 205-50-15 to $239 for a 235-40-17 Maximum wheel width for H2 and H4 vehicles below 2,600 pounds is 7 inches. Maximum wheel width for H2 and H4 vehicles 2,601 pounds and more is 8 inches.

Brakes, brands and prices
Big brake kits allowed, driver preference on pads, Hawk, Cobalt, Carbotech, etc. $122 to $200 for fronts, which last about three events or more, depending on car weight $125 to $150 rears, which last a full season

Check the NASA Contingencies page for the latest programs.

• H2 Limited Preparation and H4, “Engines may be balanced and/or blueprinted. Lightening of moving parts beyond what is necessary to balance is prohibited. Engine bearings may be replaced with aftermarket replacements and engine clearances (piston to wall, valve lash, etc) are unrestricted and are considered blueprinting.”
• H4 “Cylinder head intake ports, exhaust ports, and intake manifold may be port matched but cannot be machined beyond one (1) inch into the head or intake.”
• H2 Limited Preparation, “Compression may be increased one half (.5) a point greater than OEM number.”
• Timing gears must remain OEM. Cars equipped from the factory with plastic timing gears may use replacement metal gears so long as cam timing remains stock. OEM crank timing gear may be adjusted with an offset key back to stock position. Offset keys may be used with cam gears on SOHC engines only.
• Polyurethane or hard rubber motor mounts and/or inserts may be used.
• Flywheel, clutch and pressure plate are unrestricted, provided each item individually would function properly with otherwise OEM parts.
• Suspension bushings of unrestricted origin are allowed.
• Camber adjustment devices (plates/shims/eccentric, etc.) are unrestricted but are limited to one per wheel. Front and rear upper control arms may be modified or replaced with items that allow camber and/or caster adjustment only.