When the first brushless (BL) speedos came out it was assumed that they simply delivered the required firing for the three coils in the motor. As early as 2006 at major events speedo manufacturers were starting to play with adjustable timing in the speedo.
This 'playing' carried on behind the scenes until first Black Diamond and then Tekin came out with speedos that could be programmed to deliver timing adjustment on the fly. A DC electric motor's timing retards under load due to the interaction of the permanent magnet and the electromagnetic fields. If you were able to advance the timing as the motor accelerates then this would negate the loss of performance. That's exactly what Black Diamond and Tekin did, and so the programmable speedo was born.
This meant you had to have an in-depth knowledge of how motors work, as well as a laptop with the latest software and firmware for your speedo. People liked it at first, but it fell into disrepute because motors were going off like grenades in the hands of the inexperienced, and the cars became so fast they were almost undriveable by those below the top ten in a National.
In order to return some sanity to the situation, someone came up with the idea that speedos would be programmed to have zero timing advance to the motor and was locked into that mode to prevent fiddling at trackside. To signify that an LED blinks when the speedo is in neutral. Hence the term 'blinky mode'.
It has done wonders for participation at all levels. It means everyone can buy a speedo, set it in blinky mode, and then race with everyone else without worrying whether they have the latest software, the right timing setting to bring in their turbo or whether their boost profile is the right one for the track... or indeed whether their motor is going to last the whole five-minute race!
However, even with that fairly tight set of rules in place, it is possible to get more motor performance from other settings that are not in the rules, and indeed which are difficult, if not impossible to measure. Then there's the circuit board design, the quality of the FETs and the style of firing the FETs.
In short, different speedos deal with the 'blinky' mode differently, some better than others. It is a small difference, but for drivers with the right skills it is there to be felt. Hence the phrase "some speedos blink faster than others!" HTH
