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r32 mines ecu with gtr injectors do i need to add the resistor?


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Hi all, i am buying a mines tuned ecu for very cheap aswell as some gtr injectors and z32 afm i was told the ecu has been tuned for 444cc gtr injectors 18psi and a z32 afm so i was wondering if the injectors as i read somewhere that i need to add a resistor would i need to add that to my current loom if the ecu is already tuned for gtr injectors?

 

thank you very much

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9 minutes ago, BK said:

GTR 440cc are low impedance, hence need dropping resistor pack. I have a spare GTR injector resistor pack with the plug cut off if you need to splice it in.

yeah that would be awesome is there a tutorial on where and how to wire it in? or can you pm me? thank you

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Yes there is. What motor is this, RB20 I take it ?

See Roy's instructions below. Let me know if you need the pack from me.

On 26/01/2005 at 11:42 PM, Roy said:

Shopping around for injectors you often see GTR owners selling their 444cc injectors cheaply. I have seen them from as low as $200 up to $400.

First thing, whilst this can make for a cheap injector upgrade, i would hope you spend the extra cash on getting the injectors cleaned and flow tested just to make sure the 2nd hand bargain doesnt turn into protracted suicide:)

So first things first. The injector itself is identical to the injector used in the std RB20DET silver top engine. If it wasnt for the injectors being different colours then you could make the mistake of re-installing the original injectors. (red v yellow)

So if you can remove/install the std injectors then you can install the GTR injectors. No changes required to plugs, mechanically they are identical:)

The only problem is the resistance of the GTR 444cc injectors, and the difference to the std RB20DET injector. From memory the GTR injector is around 2.5ohm. The std RB20DET injector is around 12ohm. So running the the re-written ECU or an Apexi Power Fc with the injectors will damage the ECU unless the impedence differences are addressed.

Funnily enough the GTR ECU also needs to see a high impedence just like the RB20 ECU. However it gets away with using the low impedence 444cc injectors by using a ballast resistor from the factory. If you want to use the GTR 444cc injectors with your RB20 then you will need to get your hands on this ballast reistor as well.

So the installation of the injectors is a cake walk for most ppl mechanically minded. The surprise is its also very simple to wire in the ballast resistor which will mean your R32 ECU will happily run the larger injectors.

I strongly recommend you get your hands on a copy of the R32 GTST/GTR wiring diagram. The fact that the two engine types are on the one wiring diagram makes it very easy to suss out the wiring. You can get the diagram from rb20det.com or megalla.com

Following is a bit of a punch list/photos to help with the wiring of the ballast resistors. It can be done with the wiring loom on the car, in fact it is easier. The photos are with the loom removed because i was replacing mine meaning i had to once again wire in the resistor pack into my new harness.

How it works

Effectively the injectors are turned on / off by the ecu. All injectors are fed by a common 12V power. The injectors are then wired to the ECU independant of one another and are switched/open - closed by the ECU in order to fire the injector as required

So in order to cheat the ECU you need to be sure that the power supply to each injector passes firstly thru the ballast resistor

Resistor Pack and Plug.

462RB26_Inj_Resistor_Plug.JPG

You can see that the plug that goes to the resistor pack has 7 wires. The red wire is the 12V power supply to the ballast resistor. The 6 blue wires are the new power wires to each injector. ie remember that the injectors are all fed from a common 12V power wire, so all we are doing is taking the existing 12V power wire and diverting it to the ballast resistor, and using the 6 blue wires to go to the injector.

The Wiring

So once you have removed the RB20 injector and installed the GTR injector, you will need to wire up the resistor pack. So prior to re-connecting the plugs to the injector you need to identify the appropriate wires.

462Std_RB20DET_Inj_Loom.JPG

Here you can see the injector plugs taped as per std. The looms std 12V power wire feeds the front 3 cylinders directly, then goes into a plug above the thermostat that doubles back along the fuel rail supplying the injectors for cylinders 4 thru 6. The above pic shows the plugs for the front 3 cylinders, but is the same for all:)

462STD_RB20DET_Stripped_Inj_Loom.JPG

Here you can see the injector wires without the electrical tape. In the bottom right hand corner of the pic you will see where the 3 wires are spliced into one another. So this is where the common 12V power wire is spliced to feed all the injectors. You can also see a wire running off to the left, that is the common 12V power wire running off to the plug that feeds power to the rear 3 injectors mentioned earlier.

462RB20DET_Inj_Loom_Cut_I.JPG

So being sure you have identified the wire that is common to all the injectors, then feel free to cut the 12V power wire and seperate the wires as per above. Against the cardboard in the middle of the packign tape (just below the texta mark) you will see the cut 12V power wire that use to feed all the injectors. Connect this wire to the red wire to the resistor pack.

Effectively the power wire is now going directly to the resistor pack. In the above pis you will see that the wires have been curled up, we now connect a blue wire from the resistor pack to these wires. 6 injectors, 6 blue wires to solder together.

Solder them together in a neat orderly manner, and wrap them carefully with electrical tape to be sure that the joints will be free of moisture and unable to short out. And you are done:thumbsup:

So thats it. From parking the car to remove the injectors, to starting the car with new injectors and resistor pack will take about 6-8 hours being methodical and checkinng twice before cutting.

Note: You may not need the ballast resistor if you are running an aftermarket ECU that runs a range of different impedenced. For the record if you have a re-written std ECU or PFC then you NEED the ballast resistor. You will also need to get the ECU re-written to suit the larger injectors, other wise the engien will run very rich if at all:(

 

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8 minutes ago, Dose Pipe Sutututu said:

You can make it.

However, I suggest you avoid that MINES ECU junk.

 

Yeah, more reason not to buy it

why do you suggest that? i have already purchased the ecu and gtr injectors i got it for $100 which is the price of a rb20 ecu anyways.

 

im not after anything great its just i have a 34 neo turbo and the car already runs rich so im hoping this ecu will fix that and also have some power gains due to gtr injectors 

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1 minute ago, Ben C34 said:

Is a lucky dip, chances are it won't be the same, it will be better or worse 

I guess worse

i got it 2nd hand and the setup will be the same and the guy who had it before me was using it for ages, are they that bad? guess ill find out when i set it all up

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2 hours ago, Sirsyorrz said:

i got it 2nd hand and the setup will be the same and the guy who had it before me was using it for ages, are they that bad? guess ill find out when i set it all up

Problem is you can't tune it so its a lucky dip. You won't know if its good or bad unless you dyno the car.. Better to get a Nistune chip.

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11 minutes ago, KiwiRS4T said:

Problem is you can't tune it so its a lucky dip. You won't know if its good or bad unless you dyno the car.. Better to get a Nistune chip.

noone where i live tunes nistune otherwise would have been first choice, guy who had the ecu before me used it for 2 years ill get a afr gauge to make sure it doesnt run lean and just see how it goes

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@Sirsyorrz as soul crushing as this sounds, sell what you've bought to someone else

Save your money, get a standalone ECU or at the very least get a SAFC II or NEO and a decent wideband, retard you base timing about 2~3 degrees, hammer more boost and tweak your AFRs till it targets about 11~11.5:1

If you start to run out of injector, add in a FPR and bump the base pressure to about 3.5bar.

But, get a standalone (best option)

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1 hour ago, Dose Pipe Sutututu said:

@Sirsyorrz as soul crushing as this sounds, sell what you've bought to someone else

Save your money, get a standalone ECU or at the very least get a SAFC II or NEO and a decent wideband, retard you base timing about 2~3 degrees, hammer more boost and tweak your AFRs till it targets about 11~11.5:1

If you start to run out of injector, add in a FPR and bump the base pressure to about 3.5bar.

But, get a standalone (best option)

the guy before me had it running for 2 years on 18psi trying to blow his engine as he had a 25 to drop in, i got gtr injectors and the ecu for a total of $212 just cant afford a standalone ecu atm, i will eventually get a haltech

 

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