the A/R changes in relation to the blade and housing series as well as the trim. Your 0.87 A/R may be smaller than his 0.70 dependent on the housings and blades. I am almost certain they are different as his turbo can make about 100more bhp than yours....however you will make boost sooner...i wonder if he can catch up in time to make it across the 1/4 mile before you :lol: