silicon or teflon coil stalks preferred?

Hey gang, we are looking to install a R35 coil conversion, the market has kits with silicon spark plug stalks and teflon versions as well. Which material would be more ideal for trouble-free use and/or performance? Would silicon be better suited for periodic removal/re-installation, for avoiding damage to the surface, ensuring a consistent proper seal?

Good question, and something new to me, so take my comments as potential discussion points, rather than hard 'facts'.

From what I understand, the teflon version would be expected to have a maximum temperature range to around 400f, and potentially start deforming (softening and 'melting') from much lower temperatures. The silicone insulation is good to around 530f and won't melt.

I don't know how resistant to wear/abrasion or other damage the teflon is, but I have found some silicone leads to be soft and easily torn - but only to the fibre-glass outer braid.

There are special boot pulling tools available - don't know how much clearance you have for the hooks/forks, but may be an option*. Another option is to dab a little high di-electric (fancy name for non-conductive, or insulating, material) grease, which most high performance companies sell, on the plug/boot to help it slip off without sticking.

Something like this https://www.ebay.com/itm/313817308947 would be the cheapest, and depending on the depth of the boot, the angle, and the plug bore diameter, there are more expensive 'plier' versions.

@Gord, he is talking about the coil on plug "stalks", not leads.

@Bobby, I suspect either material would be totally fine, assuming the design of both is adequate. The design in terms of fit/thickness and spark leakage litigation are probably going to have a much greater influence on the ultimate breakdown voltage than the material properties in this case I think. The important property to prevent sparks jumping to where they shouldn't be is the "dielectric strength" of the material. Although extruded PTFE (teflon) dielectric strength is initially higher than typical silicone rubber, it does suffer more from "dielectric fatigue" so will breakdown more over time. Silicon would typically be moulded Vs PTFE machined so potentially the Silicon could have a tighter design in terms of leakage.

I blame a brain fart/old age/tiredness from staying up for the F1 and Indy races/something else.

Yeah, for some reason I had the idea he'd changed the coil-on-plug to external coils :-(