SRT8CUDA Build
Making some revisions to the main positive and negative power connections on the SRT8CUDA. On the
FAST XFI 2.0 User Support Facebook page, I've seen several posts about problems that have been traced to poor wiring installations - especially concerning grounds. I e-mailed David Page (Fast Technical support) to get his perspective on my wiring and he said that I definitely should make some modifications. In particular, he did not like the fact that I was using the chassis for my main ground path - and- also that I did not have the ground wires from the XFI and XIM boxes going directly to the negative battery terminal. This is what he had to say:
Our recommendation is based on practices that have consistently resulted in noise and interference free operation. ALL ground wires from the XFI or XIM MUST GO DIRECTLY ON THE BATTERY NEGATIVE TERMINAL.
I also strongly recommend that you run a negative cable from the engine block to the battery negative terminal equal to the size of your positive battery cable. This will minimize the current spike and voltage drop while cranking the engine. Using the body or frame to carry this ground is a bad idea as they are subject to change conductivity with age, temperature, and degradation due to oxidation and corrosion. In other words, just because it works fine now does not guarantee that problems will not arise in the future.
So based on what you are indication, I would strongly recommend moving the XFI and XIM ground wires directly to the battery negative terminal and installing a ground cable from the battery to the engine block.
The first photo shows how it is currently wired and the 2nd shows the proposed new wiring.