I have the CTR on my car. You can find the reducer at any hardware store. if you modify the water pipe you do not need the reducer. Keep in mind the installation is not complicated if you have everything you need. Be ready to do some work. Also, that if you are not buying the CTR intake you will have to modify your original intake. It will not fit the CTR. In addition, the down pipe needs to be upgraded to the CTR or a PRL and do not forget that you also will need a tune. Those are the lessons I learn when I did the work. Good luck.