tach help

i installed an aftermarket digital tach from deft racing, a 52mm. it looks clean but the reading seems off from the stock tach. ex. whne im at 3k the digital tach says 5k, its weird. i need to get a shift light also but i want the digital one to be right on the money. my friend hooked it up and he said tomm hell mess with it. he connected it to the ecu. can someone tell me what wire or pin to connect it to in the ecu, that would make things hella easier, thanks

search on stealth316.com for how to install safc.. that should help

Jason

ok new problem, we though we had fixed it, we mess withit and connected to what we thought wa sthe correct wire, it was accurate at idle. but when i get on it, its wayyyyy off, but when i go back to idle, its better again, i dunno wtf. the gauge it self is set to 6cyl on the back on it. is there a connectection on the cpu thatll give me some of those symptoms?

I don't have instructions to hook up an aftermarket tach, but my guess would be to connect it to the RPM wire going into the ECU, or the pin labeled TACHO at the power transistor unit. ECU pin numbers and info on the PTU can be found on stealth316