i have had experience with the HDI, the blitz and the greddy units. i still stand by the "sell it and get a better one" statement i made earlier. as i said before. the HDI ones dont have a proper gain control. so managing boost is never easy. if youre spending good money on a turbo motor, why skimp on one of the most important pieces of kit? i have used a Greddy profecB2 (on my starlet) and it was great, held boost perfectly and i was running more than your average levels of boost. the blitz item is also good, i have the DSBCR on my s15 and i know of other people who use it and its really bloody good, better than the greddy even. with this in mind. think about your options. is a potential engine rebuild worth the 50 quid youre saving by using the HDI?