mph gauge flutters when reved

[VeloceDrift]

Hey i just got done doing a blow through maf on my s13 and now when i rev when not moving my mph needle starts goin crazy> car runs great and i feel nothing wrong but still woundering why it is doing this.. any ideas??

[VeloceDrift]

[GTR PrYdE]

Mine does too

RPM gets shaky in higher rpms too... Haven't been able to find the reason- It wasn't like that before going turbo,

I'm thinking it's for lack of grounds- the engine isn't using the same ground as the battery is in the trunk

[VeloceDrift]

Right on! im not the only one then at least. Your theory sounds good and i have noticed that when i run my car really hard my rmp freaks a little as well. Oh well guess its no biggy