Syvecs Forums

hi iam new to the forum , just a question about using 3 wire denzo coils with the s8 am i right in thinking that you have 12 v ign live.an earth and trigger to ecu ,is this correct .thanks in advance .steve

Not necessarily.

If it's a recent S8 you can choose whether the coil output is high or low level. High level will drive a coil directly without an amp, or can drive coils with built in amps by connecting the +12v and signal input together, and connect the ECU output to the coil ground.

Or you can use a coil with built in ignitor in a conventional manner with +12v and ground to the coil, with TTL signal from the ECU. Beware that some coils (like Chevy LS7) will require a pull down resistor of around 200ohms from the ignition output to ground so that after the ECU has pulled it high (to 5v or whatever) it gets pulled hard to ground to give minimal coil delay.

What coils are they? For example R32 GTR coils are 3 wire Denso but do not have built in ignitors whereas R34 coils do.

thanks for reply coils are from honda type r

Do you know if they actually have built in amps? They probably do, in which case I would connect them to ign 1-4 on the ECU with those outputs set to TTL, and use some 200ohm resistors to ground. This will stop high currents and buzzing up and down the ignition wires and reduce electrical noise as a result.

ok thanks.and can the s8 drive low impedance injectors without the need for ballast resisters

It can, but I've not had much success with it and it caused more grief than it was worth so ended up back with a ballast pack. However If you are speccing new parts I would honestly avoid low impedance injectors as modern high impedance units are considerably nicer (for the most part) and achieve low lag times and good flow.

If you do decide to try running the low imp injectors direct I would add some anti flyback diodes across the outputs as the PWMing of the "hold" phase seemed to cause problems.

thanks again , have already got eight injecters so looks like we will be using a ballast pack(will be back on here asking about ballast packs at a later date ) cheers

What injectors do you have exactly?

1200rc injectors on first bank and2600 mike morans on second bank these might seem big but we are running methanol

forgot to say 2nd bank r mike moran injectors