MSD 6A vs. HKS Twin Power

[Barry Bordes]

Originally Posted by classicauto

Nice info Barry!

What plugs were used on the runs? You don't happen to have figures with NO amps whatsoever do you?

Classicauto,

I am using BUR9EQs all around.

Without an amp the spark would blow out with about 8 psi. and would not rev to 6000 rpm without a heavy stumble.

When I first put the Twin Power on I was amazed at how smoothly it ran.

Maybe if three MSD 6As were used, one for each coil, it would be comparable in power and smoothness.

Barry

[RICE RACING]

The reason the twin power idles so well is because it uses a transistorized ign circuit for the lower rpm ranges (which has a far longer burn period compared to CDI) even when CDI is utilizing multiple restrikes at stupid high current and voltage it will never match the clean burn and stable burn ability of Transistor ign system and especially boosted ones.

Here is a plot of a custom CDI system I engineered/tested, its of massive output and specification, but still a smoke packet sized HKS unit outshines it at low engine rpm


Burn time is roughly 420us or .4 milliseconds and there is 6 separate restrikes at 1000rpm over roughly 5 milliseconds per cycle. System pulls about 25 amps of first spark and 13 amps for the restrike sparks.

Even at high rpm's and mid range the only time the CDI will shine is under high duress (heavy AFR and water injected for example), though many people can complain of a power loss on CDI systems. You only need to look at current F1 technology its a 50/50 split between CDI and Transistor systems! The HKS box employ both systems in their tiny case.

It is s great unit.