I used the DMS machine shop to make some front control arms for my 2005 Acura RSX Type S. The goal was specifically to increase lateral front tire grip for autocross competition. My control arms substantially increase caster and camber angles to suit modern autocross tires and autocross style courses. The reason that Honda did not engineer the car with these angles from the factory is because they will reduce tire life during normal street driving. One really has to be driving like a maniac to make use of a lot of negative camber.
I have mixed feelings about this project. On one hand I am happy because they worked and made the car faster. The nature of the manufacturing technique meant that the fitment was absolutely perfect. On the down side the arms are heavy (2 lbs. more than stock), and that really violates the spirit of automotive engineering. The use of fasteners like this is also tacky for a racing part. The ones I used in particular are of high strength and have precision ground shoulders so they also act as dowel pins. I suppose it is tempting, if the only tool you have is a mill, to treat everything as if it were made of billets. It’s time for me to learn some new techniques…
Here’s some pictures. The stock black arm is for comparison. The project took about 2 months from conceptualization to testing on the car.
Below is a link to a video of the fun part, testing the finished product at a competition. In autocross you usually get 3-10 runs on a course made of up pylons that are set up in a new arrangement for each event. The only practice you get is walking the course. The rules that I follow only allow minimal modifications to the car, so my engine is stock and the differential must remain open (non-LSD). I just started developing this car’s suspension last fall. In this particular video the club is called NTAXS. You get 8 runs with NTAXS. The course is the bus parking lot at the Texas Motor Speedway and it is known for low grip. It was a particularly cold day which hurt grip more but I can assure you the car would understeer like a pig without these control arms.