If u have already ordered your pipe, you can still get some bottom end power by using harder springs on your clutch setup. I have an RB S7 engine which is more of a high end power engine but I do manage to get very good acceleration by using 1.1mm springs and a 13-t clutch bell. So don't worry if u already ordered the 'wrong' pipe. Have your clutch set-up right and u can have all the bottom end power that u you'll need.