I have the EFR on mine...nothing that I know of comes close. Good for 530 bhp at full chat on the smallest twin scroll, mine did 420 on low boost and 470 on high and that is on a bog standard engine...it is lag free and feels worlds apart from my T34 that I had.
Last edited by Caddyshack; Nov 12, 2014 at 11:12 AM.