ECU Remaps

What is the ECU (Engine Control Unit)?

All modern cars and vans on the road today have an ECU (Engine Control Unit). The ECU is the brain of the vehicles and contains a processor that takes information from various sensors throughout the engine. It analyses information such as the engine temperature, accelerator pedal angle, oxygen content in the burnt exhaust gases as well as many more parameters. Using the information from these sensors the ECU will then add the right quantity of fuel, at just the right time to give a good mix of fuel economy, performance and emission control when pulling away, overtaking, pottering down the road or zooming down the motorway.

What is ECU remapping?

When a manufacturer develops a new car the designers have to consider all the conditions it can be subjected to, in all the regions where the model will be sold. This means instead of just optimising the ECU’s program or ‘map’ to deliver the best performance or the best fuel efficiency, manufacturers have to make compromises to the map to take into account these potential differing operating conditions. These may include sub-standard fuels, extremes in temperature and altitude, differing emission laws and even the possibility that the vehicle may not be serviced regularly or in accordance with the manufacturers recommended instructions.

ECU remapping takes information from the ECU’s processing chip of the vehicles standard compromised map and adjusting various parameters within the map such as fuel pressure, boost pressure (on turbocharged applications) ignition advance and throttle pedal control among others to release the true performance from the engine. It is a completely safe process as it is just giving the engine the performance it should have had in the first place before all the compromises were applied to the original programming. Every engine has a unique map and by re-mapping, we can fine-tune the characteristics of the engine; unleashing more power and reducing fuel consumption.

The benefits ECU remapping

ECU remapping will improve engine power, torque, sharpen the throttle response and widen the power-band. The result is a more linear power delivery, making the vehicle feel a lot livelier to drive and the engine more flexible. As a driving enthusiast, you can benefit from the hidden power and torque locked away within your engine management system.

The other main benefit of remapping is a reduction in fuel consumption. With the extra torque especially at the bottom of the rev range you will see a fuel saving, as the vehicle requires less throttle input to maintain motorway speeds, you can drive in a higher gear at a slower speed as well as helping significantly when fully laden, towing or on gradients and even in start-stop traffic.

ECU remapping benefits for turbocharged diesel engines

Many see the modern crop of Turbocharged diesels as the future of road car tuning. These engines offer fantastic potential for reliable low-cost tuning without removing any of the appeal of buying and running a turbo diesel-powered vehicle, such as economy, reliability and longevity.

After your ECU upgrade to your turbocharged diesel engine, you will enjoy:

• Increased horsepower
• Increased torque
• Better throttle response
• Smoother power delivery
• Improved fuel economy
• Safer overtaking

ECU remapping benefits for turbocharged petrol engines

Turbocharged petrol engines have always been regarded as the sports flagship engine for good reason. They boast far higher power and torque figures than a non-turbocharged power-plant with similar displacement and are usually fitted to the manufacturer's flagship models. They are also ideal candidates for remapping as the ECU also controls the wastegate (turbo boost pressure control).

After your ECU upgrade to your turbocharged petrol engine, you will enjoy:

• Increased horsepower
• Increased torque
• Better throttle response
• Smoother power delivery
• Safer overtaking

Improvements in fuel consumption on petrol engine vehicles are smaller and nothing like that achieved by diesel vehicles.

ECU remapping benefits for non-turbocarger petrol engines

The normally aspirated petrol engine, whilst not being the easiest of engines to tune, will still benefit from an 8-15% power increase with added torque by careful reprogramming of various engine parameters within the map. Parameters such as the fuel and ignition curves can be fine-tuned to give better power and torque output. On some engines, the camshaft timing can also be tuned within the map, giving additional improvements.

In many cases, 'after market' tuning items such as free-flowing exhausts, high-flow air filters and re-profiled camshafts can only be fully utilised by the engine once the necessary adjustments have been made within the ECU. Careful recalibration of the correct maps can unlock the potential of your new engine parts. Further power gains may also be available when a higher octane fuel is used, allowing for more ignition timing.

Saving fuel with an ECU remap

When we remap a vehicle, especially when fuel saving is the priority we focus on improving the low-end torque in particular and widening the power-band as far as we can. This increase in low-end torque means less throttle pedal input is required to maintain cruising speeds, when fully laden or when on a gradient. It will also mean that the vehicle will be more comfortable in higher gears at slower speeds as well requiring fewer gear changes overall.

If you combine these factors with adjusting your driving style to make the most of the extra low-end torque you will see an improvement in fuel consumption. This is most noticeable on turbo-diesel engines where the savings could be as much as 20%!

What is actually modified in the vehicle?

We do not change any hardware in your vehicle, we just modify the operating parameters in the ECU’s program or ‘map’. Often, the map stored on the ECU’s processor can be accessed via the on-board diagnostics port (OBD) in the vehicle, normally found under the dashboard. In some newer models the ECU will have to be removed from the vehicle and the casing opened, our technicians will then use specialist tools to read the original map straight from the processing chip.

The technician will then upload the original map to our map writing team who will adjust the parameters to maximise the performance, fuel economy or a clever blend of both. Depending on the vehicle and ECU type the remapping process can take under an hour and if at any time you wish to return your vehicles ECU to the original settings, this can be done easily and free of charge as we always keep a copy of the original software as a backup.

Is an ECU remap legal?

Yes it is perfectly legal to remap the engine ECU. Although you should inform your insurance company of any alterations made to the vehicle.