Why mount it on the quarterpanels instead of the trunklid? Even though the trunklid could most likely support the couple of hundred pounds of downforce the GT-250 would create at our expected speeds and AOA, we felt the quarterpanels would provide a much more stable mounting surface. In addition, we didn’t fully trust the trunk’s latch to keep the wing down in the event of a spin out at speed.
APR’s GT-250 is perfect for FWD sedans such as ours: efficient, light, compact and is adjustable to provide smaller amounts of downforce. On a FWD racecar, the primary purpose of the rear wing is stabilize the car at speed and balance out downforce provided by the front splitter. This allows us to be more aggressive with our front:rear wheel rate balance and set the car up to oversteer easily at low speed, while remaining stable at higher speeds. The carbon fiber construction is light, and the amount of adjustability provided with this wing makes it suitable for nearly any car.
While we weren’t able to directly quantify the aerodynamic benefit of the splitter on the front of our car, we were able to find out exactly how effective the rear wing is because APR provides CFD data for all of their wings:
For our car, we mounted the rear wing flat (0 degrees AOA) to keep the car balanced at speed and maximum aerodynamic efficiency. The 104.46lbs of downforce and 14.11lbs of drag at 120mph results in an impressive efficiency ratio of 7.40:1. 14.11lbs of drag means we’re not very likely to notice much in the way of speed loss at the end of most straights.