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I just bought a NVCS RB25DE and im going to bolt on all my RB20DET stuff...

my question to all the knowledgable gents out there in skyline land is:

What size are the stock side feed injectors and will my shit run lean if i use a RB20det computer with stock injectors?

also any helpful hints and tips you guys might have RE installing said motor.

CHEERS, ANDYLAUREL

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People in forums often take issue with NA+T. You'll find I'll arc up each time and say how wonderful it is!

I wouldn't run stock ECU mind you, especially with the massive change in displacement.

I would also use a turbo more suited to an RB25.

Besides that, no reason why you can't hammer out a good 12-14psi on a good tune. You'll see some good power from that and good response with the high comp.

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its been done. stock 25det computer and turbo. use the det injectors. the oil suply for the turbo needs to be taken of the oil pressue switch via a t peice.

the oil return is ok. just fit the turbo drain in the block (theres a bung.

the wiring is abit diferant. to what extent i dont know. but its defenatly diferant

ohh ok. the injectors are gonna be way to small.

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I've got a set of RB25DET injectors if you want them.

Oh, and a RB25DET Factory ECU

Maybe install those injectors and ECU, and you're good to go..

let me know.

oh, and you'll definately need a new fuelpump.

Edited by The Mafia
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i had a performance shop offer to install one of these into my car for $2100 (including swapping everything over and remapping my stock ecu) which i thought sounded pretty decent, but i was only expecting 6 or 7 psi because the compression is pretty high already. Without replacing anything bottom end to decrease compression, what sort of power would you be looking at with your setup? You can pm me if you like, i dun wana get your thread off topic.

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What size are the stock side feed injectors and will my shit run lean if i use a RB20det computer with stock injectors?

Again, I am saying NO to the RB20DET computer with stock injectors on that block. How on earth are its maps going to be correct on a 2.5L engine.

You need what The Mafia is offering if you don't want an after market ECU.

Edited by psybic
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wtf? You can't hook up a RB20 ECU to a RB25 motor...

my god..

Easiest fix - Install RB25 ECU, and injectors. Car would probably start fist go. And won't need to be re mapped...

anyway, don't say I didn't warn you.

Also, wouldn't the RB20 wiring loom be different to the RB25 loom?

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or just remap the stock RB20det ecu to cope with the extra demands :(

I'd do the same thing too...an rb25det ecu would probably allow you to run the car but i think the ignition timing maps might be too aggressive for the de+t...

Edited by limpus
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i was thinking that the stock RB20 ecu will be perfect to run the RB25DE because i will be using an RB20 AFM and the RB25de injectors are the same size as 20DET injectors...

hence when the engine is running, the AFM is metering a larger amount of air going into the engine (becasue its 2.5ltrs) and will add fuel accordingly... hence mixtures will be fine (at idle)

before you knock my block off, i understand that anywhere on boost, the 260ccs will not be able to supply sufficient fuel, but i think my metering hypothesis is correct...

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I've tried to use an rb20 ecu on my rb25. I was looking to do a remap. The rb20 ecu had the rb25 maps loaded onto it.

IT just wouldn't run. It idled like shit even with the rb25 maps. I remember reading somewhere before in the pfc threads that the ecus have slightly different wiring and require some modification.

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