QUICK FACTS

The Nitrous Purge: Only cars running nitrous oxide can do this. The driver pushes a button that activates a solenoid called a purge valve, which clears the gaseous nitrous oxide in the line out into the atmosphere without entering the motor. This brings the liquid nitrous oxide towards the motor, ensuring a correct mixture of nitrous oxide and fuel when the system is activated.

Nitrous Oxide Bottle Temperature Vs. Pressure: A lower ambient temperature equates to a lower bottle pressure, thus leading to a potential rich fuel condition. Although not harmful to the engine in most cases, a loss of optimal power could result. Very high ambient temperatures can lead to leaner burning conditions and loss of optimal performance as well as possible damage to engine components.

Cool Air Equals Horsepower: Compressing air always increases its temperature. It is best to have the coolest air possible in the engine cylinders; hot air does not expand well when combustion takes place. It is always good to draw cool air from outside of the engine compartment, in most cases properly designed hood scoops will do a great job. Ram Air systems are designed to draw in cool outside air, they don’t really ram air into the engine. Many turbocharged and supercharged engines use an intercooler, which is a simple heat exchanger. Warm compressed air passes through the intercooler to be cool off; this will increase air density before entering the engine cylinders. Cool air is more dense than hot air because it holds less water vapor.

Header Thermal Coatings & Wraps: The reason behind race header thermal coatings and header wrapping tape is simple. The more heat that is retained inside the header's the faster the exhaust gas velocity will be, thus improving the scavenging effect and horsepower. Exhaust gases flow slower in cooler temperatures.

Valve Overlap: Lengthening valve timing in the engine brought on overlapping of the intake and exhaust valve events (Both intake and exhaust valves are slightly open at TDC). In the early days, this unintentional overlapping was at first considered detrimental. But later, it was discovered that a mild scavenging effect was obtained from this overlap event, the exhaust actually pulled some of the intake charge in. This means more horsepower my friends.

Handy Camshaft Tip: If your racer picks up performance when you advance your cam timing, most likely your cam is too big and needs to be smaller. If your performance improves when cam timing is retarded you may need a much bigger cam, cool info huh.

Two Bolt Main Caps: If your engine horsepower is 600 or less, two bolt mains work just great. This handy bit of info comes from a noted engine builder. Don't you love these tips, plus think of the money you'll save.

Pro Stock Fuel Systems: The average flow rate of racing gasoline is 7 1/2 gallons per minute.

Race Car Fuels: Top Fuel dragsters and funny cars burn nitromethane (CH₃NO₂), NASCAR engines burn 110-octane leaded gasoline and Indy cars burn pure methanol (CH₃OH).

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