TOCA have announced a raft of technical changes, intended to further close the apparent gulf in performance between the normally aspirated cars and their NGTC-spec turbocharged counterparts in the British Touring Car Championship (BTCC).

The changes, which will get their first race test at Oulton Park on June 4-5, are more wide ranging than the reduction in boost pressure the turbocharged teams had to comply with at the previous round at Thruxton.

The most recent changes, again see the maximum boost pressure reduced – this time by 0.05 bar (the pre-Thruxton reduction was by 0.1 bar). However, the reduction is suspended. In effect this gives the organisers the ability to implement the change during a meeting, using today's announcement as the 24-hour notice mandated by the regulations.

The other changes, however, come into force immediately.

All S2000-spec cars will be able to run lighter at Oulton Park. The front-wheel-drive cars – the Chevrolet Cruze – will be 25kg lighter, while the rear-wheel-drive BMWs will be able to run 10kg lighter. The changes also remove the control on the first gear ratio on the BMWs that was introduced for the start of the 2010 season.