only person i've heard of tune an F-con V is Susumu Koyama from Jun in japan. He came over to tune a few cars including a R34 GTR over in perth. Software is supposedly in japanese only and you have to be certified by HKS to have access to the software.
well ask him if he knows how much boost the HKS car runs, if you push as much boost as the HKS GTR is running then you'd want to rebuild the turbo as often cos seeing it go pop half track will be very expensive
Just asking for people to share their experiences with either company with relation to their differentials as mine is on the way out and im thinking about which one to choose.
Thanks
rb26 conversion prolly cost more than what sydneykid posted, not to mention the lag before boost then stupid amounts of torque and power through the rear wheels when on boost. Try driving that every day.