I found the opposite effect with the opposite change,, on my old car. Went from 14x32 to 13x31 and got quicker. My opinion/belief is,, the smallest tire that will still get you hooked and going, will probably be your quickest times. Smaller tire, smaller/lighter wheel=less rotating weight,,,rotating weight(1#=4/5# static weight) the motor thinks it is in a lighter car=quicker ET..

If you like drag racing, support your local track.