Guide to Remaps

Remapping with a laptop

As you already know, respected Fast Car user, an engine’s ECU controls everything from immobilising the engine to optimising fuel economy. Fair play, like, but this is Fast Car magazine: we don’t do MPG, we do BHP and torques! And we want decent performance increases with not a lot of hassle, and just as importantly, not much cash. This, my friend, is where remaps rule the tuning scene.

Vauxhall Corsa VXR on the rolling road

Regal Autosport's rolling road.

You see, the reason engines can be tuned so easily is that they’re manufactured to perform well within their limits from the factory. They’re basically detuned to increase reliability and fuel economy. Some manufacturers even quite heavily detune their engines to create lower spec models and meet insurance or economy standards.

Added to such factors are ordinary motorists’ needs for fuel economy, extended service intervals, ultra- smooth gear changes and cold-start simplicity. This is all stuff that’s controlled by the ECU, so it’s easy to see how many of the in-built compromises can be ironed out or even sidestepped completely by a remap.

Just like your Xbox 360, your ride’s ECU is capable of accepting spicy new software and remapping an ECU to increase performance is done in exactly the same way – by uploading a revised programme onto the ECU through the OBD port.

Regal Auto ECU remapping

Chris from Regal Autosport gets to work.

These programmes are developed by tuners – they’re based on a standard manufacturer’s ECU calibration file but with alterations to a number of key points. Each setting can be finely adjusted throughout the engine’s rev range, mapped to work alongside every other parameter.

The aim is to increase power, torque, performance and driveability without putting too much negativity into the car’s usability or mechanical safety margins.

Corsa VXR on the road

More powah! Awesome.

What does a remap alter? Well, it’s pretty simple really, and based on tried and tested tuning techniques. For example, fuelling may be increased to give an optimum air/ fuel ratio at wide open throttle, while maintaining reasonable fuel consumption throughout the mid-range. Ignition timing can be tweaked to provide a more advanced timing curve, again increasing power and throttle response.

Regal Autosport print out

Awww, pretty colours.

Best of all, turbocharged (and, to a lesser extent, supercharged) cars also have boost pressure controlled by their ECUs; by increasing boost (along with fuelling, timing and mechanical components where necessary), power and torque can be massively improved.

So there you have it, remapping is your friend. Painless, quick and with massive results, and all from around the £200 mark. Two thumbs fresh.

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