The grids of numbers that make up a “fuel map” are an indication of how long each injector will be open during one stroke of the engine depending on throttle position and RPM. These numbers can be altered to give the engine a precise amount of fuel at the correct time. The amount of time that the injector is open is referred to as the duty cycle. A longer duty cycle means that the injector will be open for a longer period of time. While the car is on the dyno, the exhaust gasses are measured with an oxygen sensor. This allows the tuner to determine whether the engine is rich or lean and exactly where in the RPM range and in which throttle position improvements can be made. The duty cycle of the injectors in conjunction with the fuel pressure determines exactly how much fuel is allowed to pass through the injectors during a firing cycle.
Tuning the injection system specifically for each engine can yield gains of as much as 10 horsepower or more! In most cases the peak gain is less, around 3-5 horsepower. Many times the gains achieved throughout the middle part of the RPM range are more important and will make an engine feel stronger than one with just a high peak number. These are the areas of RPM that are typically improved the most and tend to make the engine feel stronger to the driver. Throttle response is very important on starts and for rolling on and off of the throttle in the middle of turns. This is one aspect of the tuning in which we at Hyper Racing take much pride. Many races are won and lost on starts and restarts so you can not afford to have your engine falter during those times. If your engine feels sluggish coming off the turn during a race, it could be the engine is not tuned correctly at part throttle, when you get off the throttle in the middle of the turn then go full throttle coming off, the engine will blubber a bit if it is too rich or it will hesitate if too lean at part throttle. At Hyper Racing we tune every throttle position at all applicable RPM ranges for every engine we dyno so no stone is left unturned.
If you have an engine which has not been tuned, chances are you are using a standard fuel map for that model year engine and are missing out on some power. Our standard maps typically work well but improvements are always made after being tuned. If there is not a dyno close to you, we may be able to help you find one. Another option is to ship the engine and injection to us. We employ a custom built engine dynamometer which allows us to tune engines without having the whole car. This is normally a more popular option for customers outside of a reasonable driving distance to our shop.
A tuner should be familiar with the tuning software used with your respective combination of engine/electronics. If your tuner has any questions regarding procedures or software, feel free to have them give us a call. We have experience with most of the aftermarket tuning modules available and have dyno tuned over 1000 vehicles.
If you’ve had an engine “built” or have performed any internal modifications it is important to be aware of the engine builders’ specific break-in procedure. This information should be relayed to the tuner so that the builders’ recommendations can be followed. Some engine builders recommend that the engine is not started until right before the dyno test begins. Others suggest numerous heat cycles before dyno testing may commence. These instructions have proven to be the difference between a good engine and a great engine.
An important thing to remember is that each dyno is slightly different, each with its own calibration and design characteristics. An inertia style roller dyno will show lower power numbers because some power is absorbed into the tires. The custom built state of the art dynamometer facility utilized by Hyper Racing Fuel Injection Technology uses splined 4-bolt hubs that substitute the wheels and tires. The dyno then bolts directly to the rear axle using DYNOmite Eddy Current technology to control and measure the power output. We focus our efforts on consistency and repeatability, ensuring that you get the best that Hyper Racing has to offer.
