“Vitek” brand wires are generic wires fitted with braided fiberglass sleeving (intended for abrasion resistance). Although braided fiberglass sleeving can reach 1,200 degrees F without destroying itself, the same can’t be said about the cable inside the sleeving.
In their advertising, Vitek only claim that their braided fiberglass sleeving will resist 1,200 degree F. Unfortunately, in extreme situations where there is little or no airflow, braided fiberglass sleeving can almost reach the temperature of the heat source and cook the cable inside, and for this reason, tight fitting braided fiberglass sleeving fitted over the cable jacket is virtually useless for heat protection.
For heat problems, our customers have reported that loose-fitting reflective coated fiberglass sleeves slid over spark plug boots can help in some cases. Thick loose-fitting “fire sleeves” fitted over the spark plug wires are very effective on race engines, but generally it’s bulk makes it impractical for use on a street engine (and unsightly on a well presented street car engine). By far the best solution for heat related problems with all engine wiring is to shield, wrap or coat the heat source itself, and to introduce more airflow around where the spark plug wires are located.