Wire insulation for harness extension - lots of questions!

I have decided to extend the 1jz-gte wiring harness to allow it to fit in my usdm ma70 body. The knock sensor wires leading into the ECU seem to be insulated with PTFE insulation. I have read that these signal lines are susceptible to noise, so they require special shielded wire for the extension; people typically use USB2.0 wire, apparently.

It seems like the shielded usb wire is way overkill for this application. Furthermore, the USB wire is actually 4 individually wrapped and super thin wires. How does this even work? Do people just use the shielding and run an extension wire through it (pulling out the 4 smaller wires in the bundle)? Do they then ground the shield?

If there are no problems with just using standard wire, I would be inclined to do that. Has anyone heard horror stories about using standard wire? On paper, extruded PTFE wire insulation has the same dielectric strength as standard wire. Maybe toyota used the PTFE for its better thermal resistance since the knock sensors are right by the block? If this is the case than it's pointless to use anything other than standard wire for the extension.

Thoughts?
 
waltma70;1859365 said:
I have decided to extend the 1jz-gte wiring harness to allow it to fit in my usdm ma70 body. The knock sensor wires leading into the ECU seem to be insulated with PTFE insulation. I have read that these signal lines are susceptible to noise, so they require special shielded wire for the extension; people typically use USB2.0 wire, apparently.

It seems like the shielded usb wire is way overkill for this application. Furthermore, the USB wire is actually 4 individually wrapped and super thin wires. How does this even work? Do people just use the shielding and run an extension wire through it (pulling out the 4 smaller wires in the bundle)? Do they then ground the shield?

If there are no problems with just using standard wire, I would be inclined to do that. Has anyone heard horror stories about using standard wire? On paper, extruded PTFE wire insulation has the same dielectric strength as standard wire. Maybe toyota used the PTFE for its better thermal resistance since the knock sensors are right by the block? If this is the case than it's pointless to use anything other than standard wire for the extension.

Thoughts?



WOW, I am an idiot. I actually cut the wires, and there are several bundles (3 bundles of 2, 18-gauge conductors) that are in fact shielded. Just had to begin cutting the harness to find out. There are also 2 individual single conductor harnesses that are shielded. I am assuming these are for the knock sensors.

In any case, I found shielded multiconductor wire for sale on mouser. It shouldn't be too bad.

Sorry for the confusion.