bro , forget about using GSR, if you have more budget go for evo 4,5,6..... GSR is old engine, i mean in Japan that engine using for vehicles like wagon or carrier, that's why if u noticed that's NOT perfomance stuff produce by HKS, Apex'i , Tomei or dll..... for Gsr... if u want to BOT, that's good, but remember on Campro crank and conrod.. that's not suitable for BOT, maybe 1st year boleh la... but at the end you will know the cost.... BOT can't get higher boost, unless you change the piston, crank, and conrod.... happy mod...my suggestion..