Shielded Wire for EFI

[chimpvalet]

Nearing completion of wiring up for an EFI conversion and dealing with low spec wire provided in the aftermarket harness. I've got several shielded, multi-conductor cables rated at 80 deg C. and plan to replace with better spec extending into the engine bay from Deutsch connectors but am not sure of best way to bond the earthing braids together when using this approach. Advice please.

[dannobee]

https://workmanship.nasa.gov/lib/insp/2 ... rimps.html

There are splice sleeves made for that. If you're asking if you should ground on both ends, well, it's a bit more complicated. Grounding both ends can create a ground loop, but old school best practices was to ground both ends. Personally, I ground one end at the engine block.

If you're asking about wire, Spec 44 (150C rating) or Spec 55 (200C rating), or 27500 (Mil spec, 150C rating). All of these are better than the 80C rating on what you have. Spec 55 is the "go-to" wire for very high end motorsport harnesses, but Spec 44 is still way better than what most OEM's use. Insulation is better and thinner than the PVC normally used by OEM's.

[chimpvalet]

Thanks Dannobee, once again you come through for me. I would ground only one end of anything intended to drain EMI, in this case at the ECU as intended by the manufacturer.

Looking at coils for this CNP installation, liking what's been OEM for 5.3 LS powered vehicles 2014 onward. seems the plug wires are typically shorter than what I wish to use and I see unfamiliar boots at one end. My on hand set are native to a '90's CNP Delco ignition system, any idea if they'd connect reliably to the recent coils?

[dannobee]

I know of the different length spark plug wires for the later CNP's, but I know nothing of different end terminals. I was under the impression that they were all similar, less length and sometimes a heat shield on the plug side. It could very well be different at the coil as that's about the time that I stepped away from the dealership circus.

[blwilliams]

If you ground both ends of the shield, the shield just becomes another wire.

[chimpvalet]

I understand the point of grounding a shield wire at one end only, thanks. Resolved the plug wires handily enough once I got on with purchasing the LS2 coils and reviewing the subject. Turns out the wire set I'd purchased on spec years ago was for coils with male HT terminals, just like a spark plug. Now have a set of wires suitable to the coils I'm going with.

Advice appreciated.