To
get a decently calibrated speedometer, I bought a simple Bike-computer
(Sigma Sport Terra) and fitted like this. Works great, now with lighting
added. Also works as a trip computer, will show average speed and max
speed for example.
This
is the WIKA boost gauge, liquid damped and with a small "blue"
LED at the bottom to light it up.
The
red dot is the LED that lights up when the Saab APC system detects knock.