hm....2000 Si should already have a DOHC B16a yea?so why swap it? Sounds like you need to do alot more research. Racing alone is very expensive not to mention the cost to build a race car. I have friends with race/street cars and believe me - thousands of dollars! Not to mention track costs, and maintanence. Try www.Tuner-junction.com for some info. I am on this forum (hondaguy1122)....great site.build the motor. what type of racing do you want to do?! autocross? drag? track? different set-ups...