I recently got into an accident where the front turbo gonna need replacement. So naturally I gotta upgrade. One of my friends suggested that I only upgrade the front and leave the stock 9g in the back. I was wondering if anybody has tried this. Theoretically it would be benefitial because the smaller 9 g would spool up for initial boost and the bigger 13g or maybe 15g would provide power for the upper rpm band. The only problem i can see is the back pressure on the 9 g when the 13g is pushing with all its force. Any comments or ideas would help. Thanks!