the biggest problem I found with asphault is being consistant, launch limter, clutch tune will get you consistant . Just by holding the throttle you will never leave the same way twice and if your feathering the clutch you just brought in more variables, I use a tach off a go cart works well and is easily removable if street racing, I have never ran 1/8 but I can easily get through all 6 , imo a 6 speed is a must on pavement