In the past, the distributor was the one that was the responsible for timing the ignition spark. As the timing advances, the RPM increases as well. It was mechanical and crude but it was reasonably effective. For the most effective power though, you will need a variation of timing rather than a fixed advance curve ratio. This led to the creation of the electronic ignition system that gave a better control over spark timing and fuel delivery. A comprehensive map of variables is entered to the ignition program and then preset timing will be read from a table. Precise management over the engine ignition timing is made possible and you have total control over engine speed, air temperature, engine load, fuel delivery rates and even wastegate and turbo. Now, maximum power output is achievable across the rev range.
Electronic ignition gives manufacturers freedom to fine tune economy at common and popular road speeds, for example 30mph, 60 mph and 70mph that is shown to be what most cars spend most of their time in. A breakthrough now allows the timing to be advanced once the throttle is fully open to provide greater power or to back the timing if the car is cruising at a constant speed. Manufacturers understandably want their cars to be economical, safe and not have parts prematurely failing so they made sure build a wide tolerance margin. There is also the factor that different countries have varying grades of fuel and extreme weather conditions. The manufacturers must make sure to consider them to have the cars working well across the world. Each car that comes off the production line is unique, with some having 10bhp more or 10bhp less than the standard specifications, depending on how the parts and components were assembled. They adopt a standard map that fits all their philosophy rather than testing each car through an assessment and getting a bespoke map for each one. Manufacturers also use remap to create different power versions of one engine, facilitate better fuel consumption and produce a lower insurance rating. The scope for improvement increases once you add the fact that average PrettyMotors readers will be modding the cars with better performing components, and the case for remap becomes significantly strong. The other factor that manufacturers include is the possibility of the user neglecting regular servicing that leads to bad leads, blocked injectors, dirty plugs and clogged air filters, etc.
Anybody who has modified their engine and added performance parts may consider a remap. PrettyMotors recommends a remap on cars for a massive power gain if the car has an electronically fuel injection system and is a turbo model. Are there hidden drawbacks or price costs? The car owner needs to be prepared to have his or her car serviced more frequently. You will also need to use only high quality premium fuel, plus replacing components that fail because of the extra load that they are carrying. An engine that is tuned to generate more power is also susceptible to more strain and stress. Turbos can wear out more frequently, as well as the clutch. Careful and timely attention must be given to major parts such as pistons and bearings. If the car does not have a turbo then there is little to be gained by a remap- PrettyMotors recommends non-turbo cars to upgrade everything else initially (pistons, engine balance, exhaust, bigger valves, cams, increase compression, air intake, head work, etc..) before adding the remap to get the full benefit. On turbos, a remap will boost the lower rev range, thus the turbo will be running hotter and faster. You must remember to let the turbo cool down before turning off the engine otherwise an oil degrade will happen and that is an expensive repair to have. Installing a turbo timer will also prevent the engine from over-ticking. Most people purchase an off-the-shelf remap that can be purchased all over the country and cost typically at 200 to 500 pounds. These are better than the standard manufacturer maps because they provide massive power gains and have a one size fits all factor. Custom remaps are the best if you already upgraded major components such as the waste gate, turbo and done major engine work.
Times have changed and it is now possible to store a few maps that you can choose. You may select the economy option that is best for driving long distances that give a very minimal fuel consumption, or the power and sport mode that needs high octane fuel but provides you with explosive engine power at your fingertips. PrettyMotors advise that you purchase a switchable remap. It may be costlier but it gives an option to choose power mode or economy mode. Tuning boxes are not to be confused with remaps that contain a 3 pound resistor that fools the car into thinking the air is cooler. Not all cars are easy to remap, a case in point are the Toyota ECUs and the Rover MEMs. The ECU and the Maps are locked into the firmware and some ECUs cannot be reprogrammed. What should you do in this case? You are in luck because there are new remaps called aftermarkets or piggy back ECUs.
A Piggy back ECU connects in-between your engine sensor inputs and outputs and the existing ECU. All of them work slightly different and have all or some of the following configuration. Some piggy back ECUs adjust the readings like the engine speed, crank position and air temp to force the standard ECU into more aggressive timing. Some will perform their calculations and take complete control over engine management aspects like ignition timing and waste gate control. Some will modify the standard ECU output signals, guess the next one and modify the signal sent to enhance it. Tuning boxes are a new addition and they alter signals from and to the ECU to provide extra power or economy. Aftermarket ECUs are mainly direct replacements of the car’s ECU and handle all the functions that the standard one does. They are faster and more versatile, able to work a wide variety of tasks such as turbo timer and water and ethanol injection. Some extra caution is required as some aftermarket and piggy back ECUs do not have knock protection. If in this case, it is best to use high octane fuel and be conservative in setting the timing. All ECU upgrades still depend on maintaining the car in top running condition and paying attention to its overall health.