After going back to review the equipment installed, I see why they chose to run the Haltech and stock ECU together. 1300cc injectors would be not so nice at partial throttle, unless your tuner took a lot of extra time and gave special attention to the cruising range of cells with UPREV alone. Did you really need 1300cc injectors or was it for an added safety margin? My build had 1000cc injectors and it would stumble at about 3.3-3.5k RPM at partial throttle.
I would rather pay for extra dyno time than purchase the Haltech to be used as a piggyback system, but that is just my opinion. I think you will be able to use the Haltech unit exclusively in the near future. There are some smart people working on solutions for the drive by wire x2 issue. With that being said, my setup was running solely on UPREV for management and in the right hands is all you need. The Haltech unit has some beast-mode features though.
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 2007 350Z NISMO #0618: Zerolift | UPREV | F.I. | Greddy | Competition Clutch | Injector Dynamics | Aeromotive | Pioneer | JL
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