infernosg's S5 N/A Build

[C. Ludwig]

Originally Posted by infernosg

The only specs I can find on the coils say 19 A max but I think that's for the internal ignitor to the coil and not the external power draw. I've read a single 20 or 25 A fuse is suitable for four coils. The 18 AWG sections are short - 12 in. at most. The 16 AWG portion is the longest being something like 6 ft.

Four of the IGN-1As will draw around 5 amps at idle with a charge time of 4.5ms in direct-fire mode. As the revs go up and duty cycle increases, the amp draw will go up a bit to around 8-10 amps. This is on a 12V system. I've had one guy use these on a 16V total loss system and he had to build the circuit to support 30A max to run 4.5ms charge time. He's also getting a good bit more mJ out of the coil at that voltage and charge time than one would with a 12V system.

I build our harnesses with a 14G feed for primary + and - that's spliced down to 18G 10-12" from the coil. This is using M22759/16 wire. If I were using standard auto hookup wire, I'd probably go up one size.

[infernosg]

Originally Posted by C. Ludwig

Four of the IGN-1As will draw around 5 amps at idle with a charge time of 4.5ms in direct-fire mode. As the revs go up and duty cycle increases, the amp draw will go up a bit to around 8-10 amps. This is on a 12V system. I've had one guy use these on a 16V total loss system and he had to build the circuit to support 30A max to run 4.5ms charge time. He's also getting a good bit more mJ out of the coil at that voltage and charge time than one would with a 12V system.

I build our harnesses with a 14G feed for primary + and - that's spliced down to 18G 10-12" from the coil. This is using M22759/16 wire. If I were using standard auto hookup wire, I'd probably go up one size.

This is good information. I definitely think at least part of my harness needs some reworking at this point. Just to be clear you are using single 14 AWG power and ground wires for four coils that are split near the coils? I think it was you who also said to ignore the grounding instructions from AEM and just to ground everything to the engine. Would there be any benefit or detriment to following AEM's instructions?

I assume my wiring for the injectors is okay at 16 AWG splitting into 20 AWG? Injector Dynamics says their resistance values are in the 8.5-12 ohm, which gives a current of 1.23-1.65 A for a single injector. Multiple that by two and it's 2.45-3.29 A. Does that seem about right?