[MBruns]

My .02, we ran those units when that was about the only reasonable choice for 911 twin plug, and they were pretty reliable, the sensors were problematic, the HPX units that replaced the HPV1's were junk ! The problems that I have seen time and time again with all of them is severe timing drift, which you won't find unless you shoot the timing while on a dyno. What you will see is say you have it set up to have 30 deg. total as the RPM gets beyond 5k the timing starts retarding anywhere from a few to 15 + degrees. what we would do to combat this drift was add the actual loss value to the adjustment that adds/removes timing and then it would give you what you wanted. If you can find one of these units that functions and is very cheap it may be fine for what you need, They no longer support/repair these units so keep that in mind.

Mike Bruns JBRacing.com