Spark plugs with a resistor and Emerald ECU

[I.Mupferit]

Following on from my Iridium plugs thread, how important is it to use plugs with a resistor when you are using an Emerald ecu, and what would happen if you didn't? Would it damage the ecu?

 

Brent

(aka Arfur Nayo)

 

2.3 DURATEC SV You know when you've been AMMO'd 😬

R470.69 😬

[Rob Walker]

It will not damage the ECU but the EMR may cause interference and you may get misfires and corrupted sensor feedback to the ecu. NGK BR 7EFS work well with your spec of engine.

[I.Mupferit]

No they don't.

 

Actually that isn't entirely accurate, they work but seem to foul quite easily. If it is running at high rpm, all is well, but at town speeds, they tend to foul fairly quickly.

 

Brent

(aka Arfur Nayo)

 

2.3 DURATEC SV You know when you've been AMMO'd 😬

R470.69 😬

 

 

 

Edited by - Brent Chiswick on 21 May 2008 13:50:51

[oilyhands]

Resitive plugs are important on wasted spark systems since the firing resistance will be different between the compressed and uncompressed cylinders. The resistance of the plug brings both cylinders up to a common resistance rather than favouring the non compressed cylinder and causing a misfire on the compressed one. Non resistive plugs on a wasted spark system will cause a few problems that have nothing to do with RF interference.

 

Oily

[I.Mupferit]

Thanks Dave, that explains it. I have actually bought a hotter plug grade (NGK BR6EF) but just happen to have some in the garage one grade hotter than these but non resistive so was simply wondering if they could be used if it were necessary to go hotter still.

 

I won't bother trying then.

 

Brent

(aka Arfur Nayo)

 

2.3 DURATEC SV You know when you've been AMMO'd 😬

R470.69 😬

[Rob Walker]

Please explain Oily. Do you mean that the resistor acts as a current limiter so that the energy from the coil is evenly distributed between the two cylinders?

Brent,

As a matter of interest we ran Tom Hoods 280 bhp on non resitive plugs for 6 months and it ran sweet. It was Karl at Emerald that advised us to switch to resistive plugs as thay had problems with interference when using non resitive plugs.

 

Edited by - Rob Walker on 21 May 2008 22:08:29