Well the first time to the track the car went 11.7s@116 then i got a tune, and the car went 11.5-11.6s @117-118, now a month later with no changes the best i can get is a 11.7-11.8s @115.. i replaced plugs wires,opti, with no change checked compression, everything seems good. any ideas?

 

probably the weather. your running in higher da now.

 

Probably humidity, the DA could be higher, the temp?

Have you datalogged any of your runs? Just to keep an eye on things?