Well mixed results last night the reduced gap seemed to make little difference, first pass was a 12.114@112.1 MPH with a 17.67 60 ft. Put in 1 gal of 100 oct in 4 gal 93 and got a 12.06@114.4 MPH spinning of the line with a 1.89 60ft... So that twice now with more octane in the car i get my topend back. it has to be some issuse with the tune or a change in the premium gas. Its strange though the day i got my custom Eurocharged tune i had shell 93 in her but now she pulls timing after 4,400 rpms till redline. I wonder if there was some change in the 93 octane since then? AFR is goof fyi so it must be in the timing.

has anyone else seen weaker top end power on 93 gas?