A bad weather forecast in the Auckland region has forced organised to tweak the schedule at the International Midget Series at Vodafone Speedway Western Springs.

The World 50-lapper, featuring drivers from New Zealand, Australia and the United States, has been moved to an earlier time on Wednesday with the King of the Springs event pushed back to Friday.

Tonight's racing gets underway at 4pm with gates open from 2pm.

American NASCAR star Kyle Larson hit top form by winning last Saturday night's feature race and will spearhead the charge of the American drivers.