I have been reading through past posts on gear changes but have not found an answer.

I am racing a 2004 Grand Prix on a 1/3 mile dirt track. The rpm through a race seems low never exceeding 4800. The easy option is to try small diameter tires with a reduced contact patch. The other option being a gear and differential change.

The race is run in second gear there is no shifting. Can a gear/differential change run well without a tune in this application?

Cheers Jim