Injector wire size??

[50RTD]

G'day gents,

Im wiring up a set of Bosch/Delphi Low Impedance injectors at the moment and need to change injector plugs to Bosch EV1 style plugs. While these are available from places, i have heaps of them floating around, however they are all fairly small guage wiring, unlike the factory 1JZ injectors with fairly sizable wires...

I dismissed this idea until i looked at the factory BMW injector plugs which (using EV1 plugs) have quite small wiring and are also low impedance... This got me thinking if i could use the plugs i already have... This will not only save $50 or so, but the wires are fully shielded and ooze pure sex....

Question is. will the smaller guage wiring present an issue on a batch fire, EMS ECU controlled 1JZ with low impedance 750cc injectors???

Cheers

-Dan

[oldcorollas]

low impedance = max abotu 4amps each during opening, then hold at 1amp or less, so average curretn is probably more like 2amps at WOT?
this is per injector.

if you have seperate wire for each injector then 5amp capable wire would be heaps.

if you are batch firing 2 at a time, then each power and ground wire will need to carry about 4 or 5 amps max

[50RTD]

Thank you sir, that will help greatly...

Any rule of thumb for wiring size current handling?? Like whats a 1mm diameter copper wire rated at?

Cheers

[oldcorollas]

nfi

depends on strand size and number of strands?

[50RTD]

Yeah probably material too, copper and aluminium would be different....

As big as possible sounds like the go!

[thechuckster]

just use what came with the bmw injector plugs or scab the injector wiring out of an existing loom.

No need to go too large as you then end up with stiff and over-sized wiring looms.

handy reference:
http://www.powerstream.com/Wire_Size.htm

Also has a calculator at the bottom to estimate voltage drop.

[hks7mgt]

Can you have any technical issues running thicker wiring for the power to the injectors (4mm cable for example)? Like too much resistance. I have already partially wired my bay car using 4mm cable for all the power feeds to coils, injectors, VSS, thermo fan and its all taped up but might be better to revert now rather than later, if neccessary.

Shouldn't be an issue here??

[oldcorollas]

4mm diameter copper???

no problems i think, thicker will have less resistance and less voltage drop. only downside is higher cost

[RA35GT]

No issue in running too big a cable, it should have less resistance than smaller cable. (Think of resistors in parallel)

I run automotive 4mm cable on my injectors and thermos.

OK I lie, the only issue is the physical size of the cable LOL.

[RA35GT]

Oh yeah, OC is right, it does cost more too haha

[oldcorollas]

yeah, packaging too...
manufacturers moved to smaller wire for reasons of both cost and packaging.. but increase in quality of the conductors (and finer strands) AND the insulation allow both to be thinner and have thinner overall wire that is still capable.

[Rhyno]

Apart from the above, another obvious but important point is that the extra copper equals extra weight.

Not much of an issue in a daily driver, but oversized wiring can end up costing you a fair bit of weight in a track/drag car. The same applys for OEM wiring that is not required...

The next time you are at Jaycar grab one of their cataloges, got plenty of wire volt/amps/resistance data in there with an easy table to use.

Just my 5 cents worth!

[50RTD]

[hks7mgt]

Thanks guys. I didn't expect a response as grand as that. Another credit to the forums!

I noticed the 4mm cable i bought was rated for 15amp - does this sound about right? Considering the OldCorollas first post it seems its not an issue unless you're running multiple circuits off the one power feed.

[Rhyno]

Hi hks7mgte,

4mm Outside Diameter or Wire Diameter?

If OD 15 amp is about right, if 4mm is the wire diameter it should be higher, like 50 amps.

O and 50RTD...



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