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R33 Rb25 Loom On R32 Rb26

SKiT_R31

By SKiT_R31,
in General Maintenance

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SKiT_R31 Experienced

SKiT_R31

Posted
Posted (edited)

Hey All,

Long story short, I want to put an RB26DETT into my R33 GTS4. What issues am I likely to have running it on the RB25 loom? Can I just use all the rb25 sensors (inc afm which i can adjust using SAFC), idle gear, ignitor and just swap the injector wiring harness and run the RB26 ecu? Any issues with ATTESSA or variable steering on the different ECU?

What other changes would be required...?

Also, GTR sump the same bolt pattern as GTS4 RB25DE (which is same as stagea afaik).

Ta,

-Dan

Edited by SKiT_R31
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https://www.sau.com.au/forums/topic/343154-r33-rb25-loom-on-r32-rb26/
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payback21 Community Regular

payback21

Posted
Posted

To be honest, i think you would be better to change all the wiring loom and ecu with a R33 GTR wiring loom and ecu.

What i did with my R32 GTS4 was get a R32 GTR half cut, having all the wiring loom, ecu, motor, dash, intercooler, piping etc and then just swap it all straight into my GTS4. It was so much easier to do compared to chopping the original 20 wiring loom to suit the 26. Also by doing this, i was able to change the dash harness to the GTR one allowing me to use the triple gauge cluster in the center of the dash.

You will also find that things like power steering pump / reservoir tank, air con pump etc will also need to be changed if you wish to use the twin turbo setup.

Get yourself a R33 GTR half cut. Its way easier and you wont have the headache to go with it.

Heres a link to my engine conversion. RB26DETT Into A R32 Gts-4 Conversion

mad082 Grand Master

mad082

Posted
Posted

some of the sensors might not work/fit on the 26, so it would end up being more of a nightmare than it's worth. plus the fact that the r33 ecu is probably going to need more than just a safc to get it to run right. i'd go the rb26 loom and ecu route.

SKiT_R31 Experienced

SKiT_R31

Posted
  • Author
Posted

ugh...

Cheers for the info on power steering and other clearances, didnt even think of accessories - do these all bolt up? I have a complete RB26 in mind, I am aware that running the loom is the best option but it is not the path i want to take, I'd rather leave an rb25 in it rather than change the loom and wiring.

Running the RB26 ecu, I cant see what is different... The ignitor is the same (yes the plugs are different but wiring matches), afaik all the idle gear operates the same, cas the same? Only differences i can tell are the injectors (which i will replace that section of loom) and the AFM, which is fine as i have a single Q45 wired in, which the safc can convert into 2x rb26 afm signals.

I run an RB26 microtech in my RB25 R31 with an RB25 loom, I jsut cant see what is different... I will probably fit an RB26 powerfc at some point also.

With clearances, is it the factory piping that is the issue? Turbo inlet or outlet? I'm pretty handy with a welder and can make my own piping...

payback21 Community Regular

payback21

Posted
Posted

Everything bolts up the same. Its the pipe work connecting to the power steering pump and air con pump that is different.

Also you have to remember that the plum back system on a RB26 is way different to the RB25. Another thing different is having 2 O2 sensors on 26 dump pipes. Accelerator cable is also something else that needs to be changed from memory. The list goes on...

I totally recommend you go with a R33 26 loom and ecu. Your asking for a big headache using the 25 loom.

mad082 Grand Master

mad082

Posted
Posted
ugh...

Cheers for the info on power steering and other clearances, didnt even think of accessories - do these all bolt up? I have a complete RB26 in mind, I am aware that running the loom is the best option but it is not the path i want to take, I'd rather leave an rb25 in it rather than change the loom and wiring.

Running the RB26 ecu, I cant see what is different... The ignitor is the same (yes the plugs are different but wiring matches), afaik all the idle gear operates the same, cas the same? Only differences i can tell are the injectors (which i will replace that section of loom) and the AFM, which is fine as i have a single Q45 wired in, which the safc can convert into 2x rb26 afm signals.

I run an RB26 microtech in my RB25 R31 with an RB25 loom, I jsut cant see what is different... I will probably fit an RB26 powerfc at some point also.

With clearances, is it the factory piping that is the issue? Turbo inlet or outlet? I'm pretty handy with a welder and can make my own piping...

the tune is probably totally different between a 25 and 26 computer and the safc isn't exactly a highly adjustable unit. running an aftermarket ecu from 1 model to the next is different from running a factory ecu, since the aftermarket ecu can be tuned to suit.

you may have issues with the throttle body voltage as well. i'd say that you will more than likely have issues with hitting ecu protection even at relatively low boost levels, which you can only prevent for so long with a SAFC.

you also couldn't use a factory rb26 ecu because of the fact that the rb25 loom is missing a few sensors, such as the air intake temp, so if you did, it wouldn't run 100%

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