This feature - Frequently Asked Questions.

Sprintcars are an amazing spectacle. To see the cars pitch into the turns on such small tracks is truely an awesome experience. When I was spectating years ago, I was always facinated with just how these cars worked - and to go with that facination, I had many questions. In this feature, I'll attempt to address the most common questions asked about Sprintcars from fans that have visited us in the pits. If you have any questions you'd like answered, please use the link at the bottom of the page and mail Cliff with your question.

The Questions

• How fast do Sprintcars go?
• Do Sprintcars have gears?
• What is the weight of a Sprintcar?
• What size and make are the engines?
• Are the wings on the cars adjustable from the cockpit?
• What tyre pressures do the cars run with?
• How much do the tyres cost and how long do they last?
• What gauges does the driver have in the cockpit?
• What is the start procedure for the car?
• What about turning the engine off?
• How are the wheels fixed to the cars?
• What lap times do the cars do around Western Springs?
• The wings on the cars look expensive, are they?
• Do all the cars run power steering?
• What does it cost to buy a car?
  
  
  
  
  

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Q. How fast do Sprintcars go?

A. At Western Springs, the fastest Sprintcars are approaching the turns at around 90-95 miles per hour (approximately 145 kph). On some tracks in America, speeds of 150 miles per hour are not uncommon.

Q. Do Sprintcars have gears?

The gear plunger and wing adjustment lever can be seen in this photo of the cockpit.

A. Not in the usual sense of gears. Sprintcars are fixed-geared. This means there is only one gear ratio on the car at any one time. There is also no clutch on the Sprintcar. The gear is simply engaged or dis-engaged via a "plunger". The plunger is a 'T' handle in the cockpit that the driver pulls up to lock the car into gear and pushes back down to lock the car out of gear (some cars use levers). Gears cannot be engaged while the car is moving (although the gear can be dis-engaged while moving, it cannot be put back in gear easily). The plunger is not hydraulic, it is a simple cable mechanism, similar to a handbrake cable, it simply moves a lever on the gear casing that engages the gear. Gear ratios can be changed very simply by pulling the cap off the rear end of the car and replacing both cogs (gears). It takes approximately 5 mins to do a gear change.

Q. What is the weight of a Sprintcar?

A. The New Zealand Sprintcar rules dictate that the cars be a minimum of 580 Kgs. In real terms this is approximately half the weight of the standard 4-door family car. The are two main reasons for the weight rule.

• Safety. Setting a minimum weight is a good way to ensure that the cars are sufficiently engineered to stand up to all the forces that are involved in racing (including crashes).
• Closeness of competition. This weight bascially ensures that everyone is on an even footing, thus providing closer racing.

Q. What size and make are the engines?

Stevie's car runs a 407 cubic inch Chevrolet engine.

A. Most of the Sprintcars in NZ are running 407-410 cubic inch Chevrolet engines (the capacity is equivalent to about 6.7 Litres). Most engines will produce around 600 horse power (approximately 3-4 times the average road car).

Q. Are the wings on the cars adjustable from the cockpit?

The hydraulic wing slider can be seen at the left side of the wing above the rollcage.

A. Yes, although normally only the top wing is set up to be adjustable from the cockpit. Adjustment is done using a small lever that moves the wing forward or back. Not only does this shift the aerodynamic centre of the wing forward or back, but also changes the 'angle of attack'. The wing is moved using a small hydraulic cylinder fixed to a slider, and is powered by the power steering pump and fluid.

Q. What tyre pressures do the cars run with?

A. The right rear tyre is normally run anywhere from 7.5 PSI to 14 PSI depending on track conditions. The left rear is run anywhere from 7 PSI to 3.5 PSI, again depending on track conditions. Front tyre pressures are not normally as critical as the rear, and they are often left alone throughout the night at around 12-15 PSI.

Q. How much do the tyres cost, and how long do they last?

This tyre was destroyed after just one run on a very dry track surface.

A. Tyres range from $250 right through to $700 depending on brand and compound. The tyres come in several different compund grades, some are supersoft, and others are a lot harder (for use with slick, dry tracks). Tyres used earlier on in the night of each meeting last almost as long as half a season, whereas tyres used for slick, dry tracks can be destroyed in one race. Front tyres are the best looked after and will often last the whole season if not punctured.

Q. What gauges does the driver have in the cockpit?

A. Standard instruments in the cockpit include oil pressure, engine temperature, oil warning light and a rev counter to 'remember' the highest revs that the engine reaches. There is no speedometer fitted to the cars. Other items in the cockpit include a fuel shut off valve, and and ignition switch.

Q. What is the start procedure for the car?

A. Once Stevie is pushed out onto the track by the motorcycle and the car is stopped, he engages the gears and turns the fuel valve and oil warning system on. As the car is pushed away, the engine turns over slowly building up the oil pressure in the engine. Once the oil pressure warning light goes out, Stevie switches the ignition on, and the engine fires.

Q. What about turning the engine off?

A. During warmup, Stevie will roll the car too a very slow speed and dis-engage the gears. The car is pushed back to the pits with the engine running to raise the temperature in the engine (warm up does not offer enough time to get the engines up to true running temperature). To shut the engine down, we simply shut the fuel supply off and then switch the ignition system off once the motor has stopped. After races, Stevie shuts the motor down before being pushed through the gates into the pit area.

Q. How are the wheels fixed to the cars?

A. On all cars, the rear wheels are fixed with one central wheel nut that is fastened to the axle. A special socket wrench is used to tighten and loosen the nuts by knocking them left or right on the thread. Front wheels are attached more like a standard road car wheel (five or six wheel nuts), but some cars do have front wheels mounted with a single nut. Since the rear wheels are removed all the time, a single nut system is the best option. A rear wheel can be changed in under a minute with ease.

Q. What lap times do the cars do around Western Springs.

A. Normally around the 12 second bracket. Not bad for a quarter of a mile!

Q. The wings on the cars look expensive, are they?

Wings are expensive. We mangled one on the first night of the 01/02 season.

A. Depending on what materials are used, and where they are bought from, wings can cost anywhere between 1000 and 3000 dollars. All of the wings are manufactured from aluminium, although some are made from higher grades such as aircraft aluminium. All of the wings are hand made and contain many internal parts such as braces and ribs to aid in the shaping of the wing. There are several different sizes available, but cars in NZ run wings that are 5 foot by 5 foot. A wing weighs less than 25kg.

Q. Do all the cars run power steering?

A. Yes. The cars are designed to turn left, and hence they are very heavily weight jacked to turn left. The pressure on the steering is enormous - and to attempt to run without power steering would be very hard on the driver. When the cars are sitting still it is easier to turn the actual wheels on the ground than it is to turn the steering wheel.

Q. What does it cost to buy a car?

You must admit, these cars are quite a sight. You'd expect them to be for the price!

A. A cheap second hand car can be picked up for around the 15-25,000 dollar mark. A new car with all new equipment can cost as much as $80,000 depending on all the gear you have fitted to it (in fact you can top $100,000 fairly easily if you wish). Most cars running at Western Springs speedway would be between the 40,000 to 60,000 dollar range. The single most expensive component is the engine, with some motors reported to cost up to $60,000 alone!

If you have any comments on this feature article, or questions you would like answered, please e-mail Cliff.