ok is it possible to run an aftermarket comp (dfi) and retain the stock gauges? oh and this is a lt1 car, not sure if that matters?

 

I'm presuming you want to eliminate the stock PCM from the car and just use the DFI unit. The fuel, oil pressure, water temp and voltage gauges are not PCM dependent. They are controlled by their respective sending units. The tach sigal is generated from the stock PCM, but an aftermarket PCM will also have a tach output signal. The speedometer is a little more tricky as it gets its signal through the PCM as well, but you can purchase a signal convertor to drive the speedometer directly from the vehicle speed sensor. Dakota Digital makes a convertor. The biggest problem in wanting to remove the stock PCM all together is when the car has an automatic trans...but this doesn't seem to apply in your case.

 

thanks, but could i use the stock pcm just for the gauges and just piggyback or use the dfi to control the engine?

 

Yes, you can use the stock PCM to continue drive the stock tach and speedometer. I run the stock PCM in parallel with my MoTeC ECU. As noted in the earlier response, the other gauges have NOTHING to do with the PCM.