Originally Posted by Element Tuning
Yes this is the most common sale for 02-05 WRX customers and Hydras. So AVCS heads or full STi LB swaps are no problem. Keep in mind this is a custom Hydra so make sure you call me and don't just order the 02-05 WRX unit as it's not capable of closed loop AVCS. What you'll need is a hybrid STi/WRX Hydra.
I've got a Hydra 2.5 setup for an '02 WRX cable throttle + AVCS. How bad is the upgrade path? Any way to update the 2.5 to a 2.7, or am I looking at a whole new unit?