Yup, it was better than getting socks and more Drambuie (much as i love Drambuie !)
The first thing i did was open it up, expecting to see a resistor.....then, because it was advertised as being 'digital' I expected at least an 8-bit microcontroller, but neither of those are in there. It's two LM324 quad op amps, resistors and plenty of diodes providing small voltage offsets.
Without load it runs at about 6mV offset. When accelrating the ECU increases rail pressure and injector timing to deliver more fuel. (Obviously if the rail pressure is artifically manipulated the mpg gauge is incorrect so I need to do a brim-brim to see how it's affecting.). As the rail pressure increases the offset slowly increases too, to make the pressure a bit higher than was requested. Then when the injector fires it delivers a bit more fuel than it really thinks it does, due to the higher rail pressure.
It seems that if the rail pressure increases slowly from, say 600Bar to 900Bar, the added offset is small and steady, but if the rail pressure rises quickly between 600 and 900Bar the applied offset is larger. That just means that when you demand brisk acceleration you get it, and when you want steady acceleration you have a bit more than normal but not to the extent that it becomes uncrontrollable. The throttle still controls the speed, rather, the driver does. There also seems to be reasonable limiting to the amount of offset it will apply in any situation and it never allows the rail pressure to climb above 1600Bar, which is the limit the ECU works with too so some effort has been made to shape the output. (I measured the pressure sensor output both with and without the box)
It's never going to be a remap, but I like driving with torque at low revs and it has just lifted the car out from the zone when you wonder if you should really change down a gear. I only have it set to about it's 25% setting, I think at it's higher settings (above 60%) it can start to become a bit lumpy and you'ld only tolerate it if you were looking for continuous hard acceleration, such as race conditions, but it would certainly be great for that although probably a bit jumpy in traffic at those higher settings.
I've still got a few days to go before I lose the chance to return it for a refund and I'm hoping to get a few longer drives in, but at the lower setting it is adding just enough to make the car feel lighter without it being unpredictable or 'boosty'.
I know I probably shouldn't think it is doing anything but damaging my engine, but now I've done the basic checks I am able to do I can't see anything becoming unduly stressed because notihing is having to operate beyond the existing limits which already apply.
I'm not going to pretend it's a quality product, it has no weather sealing, no cable strain relief and no conformal coating on the PCB...it might be great in Italy but we have over 90% humidity for days on end. If I decide to keep it I'll definitely be applying some spray on pcb coatings !
I don't have time or the inclination to do any more logging because my electric motorbike project is dragging me in again
so I think I'll just run with the box for now, and might even turn it down a little bit more.