[Catalin Balcescu]

Hello guys,this coils are 5v tiggered?

[pani]

yes

[jozo]

i cant get them to fire when i put the jumper to 5v.. i used a circa 300ohm resistor in series to the coil signal and 12v ignition output on speeduino and they give spark.. its circa 5.5v on the resistor that means 6.5v trigger when you subtract from 12v battery voltage

will this kill the coils or speeduino.. what should i do

they are ngk u5014 for r8 i think 115E

and my board is smd diy efi 0.4.4b

[PSIG]

It sounds like your resistor value is too high for the type of transistor in the coil. Some coils use IGBTs (voltage control), and others use transistors (current control). I don't know the specific values for your coils, but some similar Bosch-design coils need 5V with 60 to 90 ohms resistance (1/2W). The reason it's working on 12V is that the higher voltage raises the current through the 300 ohms to the point it will trigger the transistor.

[Piotr Rogowski]

I've tested NGK U5014 260N with 12V (14.5V) trigger signal for a while and everything is still alive