Shifter cable insulation
 

I am just trying to sort out my second to third shifting issue while hot. One theory I’ve had enough for a long time is that the shifter cable run is squashed by the engine cover giving higher restriction when everything heats up. It may or may not be the case but I would like to slice the insulation down the middle or remove it completely so that the cable run profile is not interfered with. This would allow the cables to be flat rather than one on top of each other. You can easily see the imprint of the engine cover on the top part of this insulation material. Can this insulation material be removed without causing more problems? The sleeve has a complex air pockets structure sooooo likely it’s there for a reason. I went through the fire walk to have a look.

I happen to find this:
https://www.fvd.net/us-en/FVD424049I/shifter-cable-insulation-tubing-set-numeric-racing-reduces-interior-noise-vibration.html

In case any might have a need. They don't look to have much insulating capabilities and there is no information on the I/D. The stock stuff has nice air pockets

I've previously replaced my shifter cables and I cant see how the outer rubber insulation could possibly interfere with the run of the inner cable. The inner cable is encased in a metal sheaf and then a semi rigid plastic outer covering.

Hmmmm you may be right. But if you have installed/constrained and it's arc sticks up above the engine cover opening and then you crush it square with engine cover........?

I would imagine that some sort of binding would be possible especially when this heavily constrained system gets hot.

The outer rubber insulation in this case forces/routes one cable over the other pushing out of the engine bay

Maybe I am way off