A remap can be a cheap way of liberating more power but are they a good idea?
The process of remapping or ‘chipping’, is a method of increasing a car’s performance by modifying its onboard computer. Remapping has grown in popularity with a majority of modern cars being operated by their electronic control units (ECU).
Making changes to your car’s ECU usually requires a computer, with no actual physical changes to the car. As no additional parts are required, the cost of a remap is far less than upgrading an engine’s mechanical components. Here, we run you through the potential pros and cons of remapping, and how much you can expect it to cost.
What is an engine remap or chip?
When you press the accelerator in a modern car, it's usually a computer rather than a throttle cable telling the engine how to respond. How sharp the engine feels and how much power it generates is as much down to lines of computer code as its size, allowing manufacturers to design fewer engines but tailor the ones they do make to a pecking order within model line-ups, or target specific efficiency figures.
In response, tuning specialists now replace fewer engine parts and are more likely to suggest plugging a computer into your car's onboard diagnostic port (OBD). Using this connection, a specialist can overwrite the manufacturer's software with an aftermarket version in the time it takes to drink a cup of tea. Equally, the
standard engine map can be reinstalled in around the same amount of time.
An alternative route is to add an extra ECU, often referred to as a tuning box or chip. These devices are connected into the wiring loom under the bonnet, and rather than overwriting the car's engine software, they intercept and modify the ECU's signals as they are sent to the engine. Normally they come with a controller you can place on the dashboard to choose between a relaxed or sporty driving feel.
Why might you want a remap?
As we've hinted at above, most vehicles come with less power than they're actually capable of producing. This can be for a multitude of reasons, including the fact cars must be reliable in all manner of climates and conditions, whether they're driven in a snowy mountain village or an arid desert at sea level, all while hitting economy figures set out by the manufacturers.
In a temperate climate like Britain's, where such extremes are unlikely, remapping the engine accordingly can produce impressive results. This is especially the case with turbocharged models, where remaps often liberate between 20-40bhp and bolster the engine's mid-range pulling power.
While most drivers get their car remapped for the extra performance, there are other reasons to consider one too. If you can resist the urge to put your foot down, remapped cars can see fuel-efficiency benefits, and they're also quite popular amongst the caravanning fraternity. Adding extra power to an SUV can make towing a heavy caravan or trailer less of a chore, especially up hills or when accelerating onto a busy motorway.
What are the disadvantages of engine remaps?
The most common concern for anyone considering an engine remap is that it could cause reliability problems. To avoid this, we'd recommend only using a reputable company that’s been remapping cars for a long time, with lots of happy customers. Tuning firms like this are easy to find online and in the owners' forums for almost every model of car. Stafford Remaps technical director, Robert Rudd, told us: "Remapping does put extra strain on an engine, but not a dangerous amount. We check carefully that the temperatures and pressures our remaps put the engine through don’t exceed the acceptable parameters.”