While foam is a cheaper alternative, it's messy, time-consuming and permanent; the beauty of Carbing's bars is that you can remove them whenever you want, but you also benefit from them greatly while installed. The ultimate reason for reinforcing the chassis is to tighten it up against the added twisting and lateral g-forces while allowing your suspension to become more efficient.
Carbing offers a multitude of chassis bars for the STI, but Subaru made some chassis adjustments to the '07 models. The sub-frame replacement and front strut bar pictured were not used, and Carbing is currently redesigning these pieces to fit onto '07 STIs. We were, however, able to install the floor support bars, which are mounted along the frame rails to help stiffen the chassis for longitudinal g-forces from hard acceleration and braking. To help assist with the latitudinal g-forces, we put on a Tein front strut bar, Carbing rear cross bar and Carbing rear strut bar. Surprisingly, the unit that helped the most was the Carbing rear cross bar. This piece is installed in front of the rear seats and connects to the factory seatbelt bolt. This really helps stiffen things in the C-pillar area, but lets you retain the back seat area.
WHEELS AND TIRES
The most fun part of setting up a track car is picking wheels and tires; not only will they help handling, it's also something that makes your ride stand out in a crowd. We decided to go with the new Gram Light 57 Maximums in 18x8.5 with a +45 offset. This gives us a wider track and still clears the factory Brembo brakes. Since we wanted a representation of a true street car, we went with the 235/40R18 Advan Neova AD07 tires. At the Willow Springs Super Lap Battle qualifying round, we were lucky enough to get Katsuma Nakai, the head engineer from Tein USA to set up our suspension. He beat up on the car all day long in the 115 degree heat and remarked on how these tires still held their grip throughout the day.
WHAT NOW?
Subaru STIs out of the box are a contender, the AWD system is great for handling, the stock Brembos give you more than enough stopping power, and the 2.5 liter turbo motor puts out a nice 300 hp. In stock form, this car is great for the street and even light track duty, but knowing us, we need more upgrades to be competitive for the Super Lap Battle Finals. Now that we have the suspension set up with the right wheel and tire combination, we'll be looking to add some power with the help of A'PEXi and Crawford Performance. Be on the lookout in the coming months as we follow the build up of Super Street's Track Super Star.