Quote:

Noise can be a problem on any EFI car, but you add noise to the incredible cylinder pressure that you have in some of these cars that make 3000+ HP and you have a SERIOUS issue.

This is a typical thing we see, especially on THIS site. Guys have always done things a certain way, it works OK and when something different is suggested, they attempt to shoot that theory full of holes. Just because you have always done something a certain way, does not make it the right way for EVERY car out there.

I changed the way I wired cars, because I DID have issues on some high HP EFI cars with intermittent noise. So common sense tells you that if the changes were BETTER for EFI cars, they were better in general. At least that's how I looked at it, plus to me the "floating ground" deal is clean and easy. So what you have to string a couple extra wires. It makes trouble shooting SO much easier, because things are contained in a specific area.

As far as factory cars........who cares......I don't, because we are not talking about factory cars. Plus, when I worked for Dodge, I know our ECUs were directly battery grounded. Are they still??.........don't know, don't care.

So, you want to ground your whole car through the chassis or sheetmetal...........fine, no problem, but no need to try and prove it's the ONLY way or best way to do it

Oh yeah, forgot something and this is FACT not here say. The Holley Dominator ECU is capable of running factory LS coils. Millions of cars out there with LS coils. However, in a HIGH hp application, with high cylinder pressures, the "flyback" voltage from the LS coild was horrendous. Bad enough in fact, that we had to put a stupid amount of filtering in our boxes to keep the junky coils from smoking our boxes. So the point......what the factory cars have don't mean squat in a race car

Monte



Monte as much as I respect your knowledge sometimes I have to disagree. So the fact that a race car has more cylinder pressure make the injectors need a floating ground? Really? I agree that cylinder pressure could be an issue with spark. But what in the heck does cylinder pressure have to do with injector firing or coil triggering? Nothing that I can think of. I will go tomorrow and get some straight facts and report back. If I'm incorrect I will post that as well. The bottom line is that every electrical circuit needs correct sizing. Clean tight connections. And correct routing . We fight noise issues all the time. Fixes involve different routing, shielding and yes moving the feed or ground circuit to a different power or ground location. But saying "grounding at the frame/cage" (which was the original question in this post) won't work is a catch all, and I believe incorrect.
Doug