Ohkay- well you said 12 tooth cb- the standards are usually 13 tooth. the more teeth the more top speed, less bottom end accel. Since you have a 12 tooth and its not the 13 tooth, and you say it has tons of torque and rips off your tires- I assume its the standard spur gear as well. 46-48 tooth or what-not. With those gears your car isnt physically capable of going 50 or 60 MPH. count the number of teeth and ill work it out on an equation for you.