Theses days the power and performance of most cars is limited, not by any particular mechanical factor, but by the software running in the engine control unit (ECU).
Computer algorithms running behind the scenes while you’re driving a modern car affect all sorts of parameters, such as ignition timing, air/fuel ratio and turbocharging boost pressure. New car engineers typically set these parameters at the factory to meet product marketing targets such as power level, fuel economy and emissions, and that means new cars are rarely fully optimised for ultimate performance.
So if you want greater performance and pulling power from your car, or alternatively if you’re seeking mpg improvements, the first place to look is the little black box under the bonnet. Here at Auto Express we receive plenty of emails asking advice about ECU software changes. It’s a process typically referred to as ‘chipping’, or engine ‘remapping’.
Engine remapping companies specialise in altering or replacing the software in a car’s ECU, changing how it performs and potentially removing any restrictions on its potential. The old way of doing it involved swapping a circuit board or chip inside the ECU, but nowadays the new software is often installed via your car’s diagnostic port via a laptop or a handset provided by the remapping company.
The claimed performance gains are often eye-catching. For example, remapper Superchips lets you search the make, model and engine of your car on its website. We had a look and found a £365 upgrade for the MkVI VW Golf GTI that’s said to boost power from 207bhp to 251bhp, and torque from 280Nm to 324Nm.
Chipping turbodiesel engines can increase economy by seven to 10 per cent, because it adds torque lower down the rev range. This means the engine doesn’t have to work as hard as before.
Many companies do still offer plug-in kits that are pre-installed with the software upgrade. Like laptop installations, these also allow owners to remap their engines themselves. Both approaches mean you can restore the car’s factory settings should you wish, plus there’s no need to travel to the company’s premises.
Some people are concerned that remapping could cause problems with their car. But it shouldn’t affect reliability if you use a reputable company such as Superchips.
Its technical director Jamie Turvey 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.”
He added that most cars’ engines are built to offer more performance than they actually deliver. “You find manufacturers launch a car with a set power figure, but then over the life of the model they’ll introduce a few facelifts and performance versions,” he explained.
“They don’t develop new engines for each new version: mostly they limit the performance of the earlier models and then offer a little more power with each new edition. We just release the optimum performance.”
Obviously, you need to inform your insurer of a remap. But you may be pleasantly surprised by its reaction, according to Turvey.
“Historically, insurers would run a mile from chipped cars,” he said. “Some still will, but for the most part it’s very different these days. Some will just say ‘thanks for letting us know’; others will have a set fee.”
Have you ever had your car chipped? Were you pleased with the results? Tell us about it in the comments...