PERFORMANCE
Tests were conducted after a chassis dyno setup. Actual quarter mile times were recorded with both the factory hood installed, then with the Motorcity Hood installed; all other factors remain the same. The testing was performed both with and without nitrous oxide. Several runs were made to ensure consistency.
Results (best quarter mile):
Stock Hood (no nitrous): 13.47 ET
Motorcity Hood (no nitrous): 13.41 ET
Stock Hood (nitrous): 12.08 ET
Motorcity Hood (nitrous): 11.97 ET
Conclusion:
On a twelve second car, quarter mile time was reduced by 1/10 second. The faster the car, the better the hood works.
Hood Make-Up:
The hoods are vacuum bagged. This is a form of compression molding which utilized atmospheric pressure to compress the resin into the fibers of the carbon weave. This allows for full saturation of the carbon fiber by the resin and also provides a relatively smooth, underside finish. In the same process the underside resin, which is not compressed into the carbon fiber is removed, allowing just the resin that is necessary to remain. This achieves a very desirable high fiber-to-resin ratio, not achievable under conventional hand laminating methods, which can almost double the relative lamination strength.
Why vacuum bag molding?
Vacuum bag molding is considerably more expensive than hand laid fiberglass, but the physical properties that are achieved are much higher; the high performance cars are more demanding. We are bringing a modern molding technology to the Corvette market that was formerly unavailable. We are offering a part that is worthy of the car. Molding methods of this type are used in both Indy Car Racing and the Aerospace industry.
What makes our hoods functional?
Our hoods are vacuum bag molded carbon fiber. We construct them with vinyl-ester resin that will withstand 450 degrees before it will distort (commonly referred to as HDT or heat distortion temperature).
Vacuum bag molding uses atmospheric pressure as a press (similar to shrink wrapping). All excess resin is removed leaving only the resin necessary to penetrate the carbon fiber thus providing the perfect fiber to resin ratio. This in return lessens the weight and increased the strength. Bad things such as brittleness and shrinkage, which are caused by resin rich areas (uncontrollable in methods such as hand lamination which is done at atmospheric pressure), are virtually eliminated providing our customers with and ultra modern part truly worthy of the C5. It also proves a nice underside surface of carbon fiber.
The hood was designed on a racetrack where aerodynamics is everything. The vent is placed precisely behind the radiator and in front of the engine to eliminate the air that you would normally drive over (the air that would remain under your front spoiler). Normally this air would continue underneath your car after it pressurized the engine compartment. The air around your engine remains trapped and superheats as the air your driving over continues under your car and begins to tumble and create drag. Since air takes the path of least resistance, it now travels out the hood vent, creating a venturi effect, which relieves the pressure in the engine compartment and produces airflow around the engine and components. Most people don’t realize that the hood vents seen in most racecars are to relieve the air turbulence from under the car, not just to vent heat. |
