Drift cars with their extreme steering angles are pretty difficult to design suspension for. A lot of things must be considered because geometry that works well on a regular car can have bad side effects at extreme steering angles. Some of the issues are excessive tire tilt that reduces tire contact patch (one of the reasons why drift cars have so much static negative camber) and can cause the front end to wash out skate, Excessive weight jacking to the wrong side of the car in drift which reduces rear traction, Excessive front lifting which can overload the power steering system, overcentering and wheel wobble, poor self-steer, excessive Ackerman build up, the list goes on and on.
For our team, our car handles pretty well but since Formula Drift competition is becoming so fierce, we decided to revisit our front end geometry to see if we could get any more advantages for the 2019 season. We have had a CAD model of our front suspension for several years and CAD has been responsible for helping with many of the car’s improvements but we wanted to quickly play around with actual hardware to help us visualize things better and to actually be able to change the shape of our front suspension upright on the fly. Yes, we had done this in CAD but nothing beats being able to look at, measure and play around with the actual parts on the car.
So our goals would be to keep the tires flatter on the ground at full lock, make a little more angle, quicken the steering ratio, reduce weight jacking and stress on the power steering pump. From CAD we had an idea of how we wanted to configure the upright but we wanted to play with actual pieces on the actual car.
Chris Eimer from Eimer Engineering created a simple dimensional representation of the upright from the CAD drawings of the existing part in three pieces that were slotted so they could be moved around a lot to change the shape and where the offset, trail, Ackerman and steering arm length could all be easily and independently adjustable. He then printed it on his 3D printer to make some test fit parts.
Chris assembled the upright then bolted the hub to it. Of course, the plastic isn’t strong enough to hold the weight of the car but it is strong enough to cycle the suspension.