oh no my ECT is 5 degrees off...
you should be worried about repeatability.
auto gauge isnt cheap, theyre just low cost.. Ford Racing sources their gauges through them.
sure you can get re-calibrating digital stepper motor gauges for $350 each, but in many cases theres just no need and a mechanical or air core gauge will do what you need for a quarter of the price.
wouldn't you want to go pneumatic ? to get a correct reading of whats actually leaving the turbo, rather then off the ECU like cobb. or by electrical are you meaning kinda how defi does there gauges with a box they all plug into
I dont know what peoples aversion to mechanical gauges is. Pinching lines maybe?
the three main types of gauges are as follows:
mech-> pressure of a fluid physically travels to the dial face, where it acts against a spring which moves the dial. extremely simple. 2 types: fluid filled and air filled. The fluid acts as a damper against micro fluctuations (as can happen with pressure readings near a pump outlet)
eletrical air core -> a "sender unit" takes the pressure in the engine and converts it to an electrical signal (electrical resistance). This is sent to the gauge via wires where it powers two perpendicular electromagnets, generating an electrical field which "rotates" and drags the needle along with it.
digital stepper -> little less sure here. A digital "blip" rotates an electric motor with the needle on the end a precise number of degrees. requires a microcontroller to output digital blips. This is why tachs cost so much and why yours is driven by the ecu (unlike most other gauges in your dash)
edit: i take that back. all dash gauges that "sweep" are stepper motor gauges. without the sweep it wouldnt know where the start and end of its path lie and it also wouldnt know where it started, so it re-calibrates max blips, min blips, and current position every time you start the engine. My car, being older, has all air core gauges except the tach. my truck has air core except the tach and the speedo, which is mechanical (actually run by a rotating cable from the trans output shaft).
