Notes on Autocross & Track Setups for the Civic Si/SiR|
The Civic Si/SiR is a great platform for one to dive into the world of autocross, a.k.a. Solo II. No, it is no Miata or Type R on the auocross course, but for the money you get a great performer while still being a versatile, reliable daily driver.
For those just starting out, keeping your car stock can be benificial to the learning curve vs. chasing suspension setups instead of learning driving technique. With a stock suspension system, tire pressure is pretty much the only variable to be played with from run to run.
For tire pressures I run about 39 to 45 psi front to prevent excessive rollover onto the sidewall, and 45 or more psi rear to reduce traction to get the back end to rotate. The tried and true white shoe-polish-on-the-sidewall trick to see how much you are rolling over onto the sidewall works great with most street tires like the Toyo FZ4 (my previous tire) or T1-S. Just put a stripe of white shoe polish starting about an inch in on the tread, down the sidewall an inch or two. Do this on all four tires, two to three places on each tire, for the overall picture. After your run, examine the polish to see how much is rubbed off. If the polish is completely rubbed off the sidewall as well as the tread, it means the tire is rolling onto the sidewall during hard cornering (not good for best traction). Increase tire pressure incrementally to reduce this tendency.
In my case, I found that even with the more neutral handling afforded by the SiR over my old Si (made possible by the rear swaybar and stiffer springs and shocks, standard on the SiR but not the Si), the car still understeered when pushed hard. Advice from my clubmates led me to try higher and higher tire pressures for the rear tires, to the point that traction was reduced, allowing the car to rotate a bit better when flung into tighter corners.
As for driver skill, get as much seat time as possible. A car control/autox school before my first event helped me immensely. Plus, having a great club to hang with (HADA: www.hadamotorsport.com) makes a BIG difference.
There are a couple of other little things, like removing any heavier objects from the car (bass units, for example), removing the spare tire and jack for even more weight savings, and trying to make sure the tank is as empty as possible. More serious competitors will remove all passenger seats and go on crash diets for that extra edge... :D
Also, make sure to remove all loose things from the cockpit, and make sure your buddies haven't turned on your A/C as a joke...
Seat position can make a big difference as well. I autocross with my seat-back as upright as possible without my neck getting too crammed from my helmet hitting the roof, and I have the seat pretty much as far forward as possible while still being able to operate the pedals. Also, twist the seatbelt a couple of times so the lap belt and shoulder belt twist around each other and pull it real tight when you buckle it up - it keeps you in place better that way. The recent addition of an Integra Type R driver's seat means far better side bolstering - an upgrade I highly reccommend.
Obviously brake pads and tires are going to take a beating, but it's the price you pay for having so much fun! Hawk HP+ pads are a great improvement over stock, although they dust and squeal a bit too much for everyday use (IMO). PBF ULX Ultimate Ceramic pads are also a great pad, but are not quite as powerful as the HP+. They are less expensive and do not squeal nearly as much, but they do, however, dust as much as the HP+.
After all is said and done, the single best modification you can make is to the nut behind the steering wheel - seat time, seat time, seat time... Have fun!