This Astra J VXR came to us for a Stage1+ conversion. This was a lovely low mileage example which had covered under 4,000 miles and was finished in Buzz Blue paintwork.

The first part of the process was to check the vehicle on the rolling road and benchmark it. This car made 278 bhp and 319 lb/ft torque.

The second stage of the process was to remove the factory pre-cat and replace it with a high flow straight through front pipe, removing the restrictive catalyst.

Then it was back onto the rolling road for mapping, data logging, map optimisation and full calibration and set up. The results on 97RON fuel; 319.99 bhp and 366.84 lb/ft torque with a much greater spread of power and torque which can be seen on the graph.