Vampire speedo

[gav4wd]

Hope someone can help, I have the vampire +sr speedo reedy lipos tekin 13.5t motor and whatever I do the car has no punch or good top end power.
Tried sensor wires,
Gearing up and down
Every setting on speedo and timing on motor
None of above gives anything different in peformance.
Could it be the spedo is not suited to stock racing or is there something I am missing.
Any advice much appreciated