Often times people only consider transmission upgrades after they break something, or it has become a necessity due to the power output of the engine. In this case, however, the owner of this ’07 WRX understood there was a need for adding some strength for those occasional trips to the drag strip. Since this car serves as both a daily driver as well as a toy, it was important to our customer to keep the car civil for commuting and highway driving, while still improving acceleration and strength in lower the gears.

To meet our customer’s requirements, we recommended replacing the stock gear set with PPG gears and synchros, using straight cut gears for first and second, helical cut gears for third and fourth, fifth gear remains stock. Using the stronger straight cut gears for first and second means the trans should withstand repeated launches at the drag strip without consequence.

It’s no secret that straight cut gears generate more cabin noise than helical cut gears, so by using straight cuts in combination with helical cut you get the best of both worlds. The strength where you need it, for launching, and by the time you hit third, the transmission noise is still docile enough for everyday street use.

Along with the installation of the gear set, we also installed a new Southbend clutch. After the clutch break in period he’ll be back to get the car on the dyno  for a tune, we’ll post an update and let you know what kind of numbers the car makes.