Ignition Leads for MSD

[majordad]

I’m fitting an MSD Ignition, Coil and Tach to my 1973 2.7 RS engined 911. instructions say not to use the Porsche standard ( copper core ) leads. Why is this, and does it really matter much ?

[MikeB]

Dave

A Google search through up this reply to a query re solid core wires on another forum

"As I mentioned specifically in my last post "The solid core wires are noisy and will interfere with the MSD components" you will have problems with the solid core wires so stay away from them. It will not damage the ignition but it cause noise which can cause it to misfire etc. Mac_Winter is completely correct in his description and the problem he had with the solid core wires is common.

Thanks,

MSD tech4"

So there is a risk involved of the MSD not working correctly.

I have used Beru cables on MSD system in the past and the ignition worked, but I can't state whether or not it was letting the MSD work to its full ability.

[Jonny Hart]

This is due to MSDs stupidly high output voltage which would generate a lot of EMI using solid wires. As the MSD tech says, that interference can get back into the electronics of the MSD and cause misfires. The MSD also has a habit of burning out the original coils and the resistor in the rotor arm for the same reason. It's a great way to sell coils and ignition wires though!

Btw, there are no performance gains to be had with ignition leads of any one type over another. Just a question on quality (longevity) and suppression (interference).