Ignition lead diameter

[Robster]

XFlow, 1800 with Lucas Motorsport ignition kit (coil with amplifier). The ignition kit is suppposed to produce a belter of a spark! I am about to change the leads on the car, and notice that I can either get a standard set from my local autofactor, or an 8.5mm set from Burtons for around £30. Do I need the larger diameter leads, and what is the point of fatter plug leads?? Will the B8 spark plugs still do?

 

Thanks

 

Robster.

[Joe 90]

I can't think of a technical reason why you should need thicker leads, as regular ones have enough voltage breakdown capability. I suspect the more expensive (and hopefully better quality) leads are thicker so that it feels like you are getting more for your money. During normal running, more spark energy is created by a higher current or longer duration spark, not through higher voltage. The exception to this is the capacitive discharge ignition system, but I don't think they are very popular any more.

 

99,000 miles so far

[Graham Sewell]

I seem to remember an article in CCC a couple of years ago testing ignition leads, and the outcome was that, provided they were in good condition and up to OEM spec, they made no difference. So the snake oil merchants are potentially ripping you off! Nothing against Burtons, I buy some stuff from them and they have always been fair and given reasonable advice, but they will sell you exotica if you ask for it even if it doesn't provide more power...

 

Low tech luddite - xflow and proud!