boost ? timing? I'll assume on 100 u can run 20 * timing and 20#s of boost, this should net around 112-115 depending on tire size and whether you are locking the TC or not. With the GN1s you may mph a little higher. With 19* timing and 23 psi on 110/93 mix i went 115.4, and on 112 and 23* and 23 psi i went 118.