Well dont race it completely stock, just add the racing exhaust that sounds scary at 5000rpm and below, racing chip, the engine modifications, MAYBE a bigger turbine, and just a sports intercooler. I definately would reccommend leaving the LSD, and VCD alone. Why? because the ATTESA-ETS AWD system in the R34 Skyline GT-Rs are the most advanced LSDs you can get out there (for circuit racing anyway), also the torque is distributed very nicely, probably perfect. The suspension is up to you, you dont need to change it, I liked it stock, but I still put the Racing Suspension in there, but set pretty soft. I also only put in the racing susp. was because I didnt want the car to dip so much or crouch during high speeds. The clutch, flywheel, and carbon driveshaft you should get, as well as reducing weight. Skylines are notorious for being heavy. You really don't need a spoiler on the Skyline. Actually, you dont need to install a spoiler on ANY car, unless it already comes with one (race cars)