Hello, with compression ratio are you running you engines? I have A3 1.8t AGU with stock CR 9.5:1 which i am currently rebuilding as one of the rods have bend. Currently i have chinese hybrid T03/T04e turbo at 1.2 bar getting 325 bhp and i plan to use it until it broke. My ecu is 3.8.2 and i don't plan to use aftermarket ECU. The idea for the next turbo is GT2871R or G25-550. 1. I have to select Pistons and i'm in doubt what CR to select? 8.5:1, 9.25 or 9.5? 2. What size of injectors i would need for GT2871R or G25-550? Currently i have 440cc 3. What size of intercooler would i need for GT2871R or G25-550?