Sparkplug extensions

[glynlucas]

What are the potential problems of not using the sparkplug extensions? Are they to stop emi from interfering with the ECU?
I read in another posting that some people have removed them as they eventually break down and reduce spark effectiveness by arcing across to the cylinder head. What do the experts say?

[RCA]

I would have thought it is a heat issue more than anything else. Without them I would guess the leads would not last very long. Could be wrong mind you!!

[griffter]

The original extensions are suppressed and as you suggest, ought to supress EMI interference. The non-suppressed extensions which are available from ACT and Magnecor serve only to distance the HT lead from the manifold to reduce heat damage. These should be used with suppressed leads (eg Magnecor).
I don't know if the original HT leads were unsuppressed ie copper core? Anyone know? - Doon't s'pose there are any originals left!

[glynlucas]

I recently replaced my HT leads with some Bosch ones from Halfwits. These were standard Range Rover types and it did say they were suppressed. If this is the case then I ought to have the non-suppressed extensions. Thanks for your help.

[david beer]

I may be wrong here but did not this come up and was also to do with spark "length". I have to say that mine went and i removed them only to be reminded by the dealer at service time, didnt actually notice anything though, cant believe i just said replace them.