RB20 on RB25 Power FC. questions for those who have done it.

[drifts135]

I would go some other route, but I have the PFC here with me. I know that it "can" be used by swapping two inj wires on the ECU plug, but my questions are....

Does the car start up and run at all (idle, accelerate enuff to drive to tuning shop)?

Are the few sensors that do not work gonna be the kinds of sensors that are gonna make the guy tuning it say NO WAY cause he isnt getting enough info from the PFC? (He is pretty laid back, but would it affect it enough to make it difficult to tune?)

As it stands, to run GTR 440cc inj on my rb20 with an SAFC, I have to use the dropping resistors, correct?. Do I need the resistors to run those inj on my 20 wih the rb25 pfc???

I jus need input from someone (Kamin? Carl H?) who has used one on a 20.

Please please please help me out here.

Plans are Z32 maf, 440cc gtr inj, RB25 turbo, 13ish lbs of boost.

Current mods are 3" from turbo back, Huge ebay FMIC, walbro, the usual apex filter, and TXS MBC.

If it matters, it is randomly really strong now, as in stronger than any of the other 4 RB20s I have had. (point is, Im workin with a really healthy engine that isnt on its last leg or anything)


One last stoooopid question to those who know the most... With a conservative tune, what should I expect with all of the plans completed on this thing? Is 275whp and 250wtq a pipe dream or is it likely?

[liv2drift045]

ive seen rb25's dyno 275 to the wheels w/ just a boost up so i'd say you'd be pretty close w/ the injectors and 25 turbine... u can probably reach the 300hp range too but u'd also probably be pushin that snail to its limits (don't quote me, just my own speculation)

as far as the PFC stuff.. i have no idea

[liv2drift045]

also if your tuner can tune fcon there is one for a rb20 on yahoo auctions (japan) just use rinkya and scoop that up... its @ 10,000Y right now... just a heads up

[MELLO*SOS]

I think you need to be asking this on Racebread or Nico/RB forum, I've seen a few threads on there recently regarding this subject.

IDK the resistance of the RB25 stock injectors, I would assume they're probably high resistance. In which case you'll need resistors to use on the GTR injectors. I don't think your PFC will be "missing" any important input, if anything it'll be the other way around -- you won't have some of the "outputs", like VVT or Boost control solenoid, etc. That stuff shouldn't matter though.

All the vital sensors should work the same (match up the ecu pinouts before hand). Double check the coolant sensor, RB25 may use a different one than RB20. Of course your fuel and spark maps are gonna be quite a bit off. Sounds like you're planning to take it to a tuner anyways so that shouldn't be that big of a deal for him to sort out. I think you might be able to get the engine to fire up on the RB25 maps, but I doubt it'll have a nice idle and it'll probably run rich as hell if you try to drive it.

With the basic upgrades you have listed there you should easily hit your goal; 250 to 300whp. It'll depend on your tuner. If the RB25 turbine still has the ceramic wheel you won't want to exceed 13 or 14 psi.

Can you post a picture of your swap? GL

[drifts135]

Thanks, you are right, I need to post this on Nico. I completely forgot their RB section, and well, Racebread is pretty much dead. No activity over there EVER.

Talked to the guy who probably will be tuning this thing today, and he sounded more excited than worried. He seems pretty psyched about the plan (if anyone uses the word anymore).

He also said that DSM 450cc inj are Low imp and that he thinks we can jus use those on my setup. He told me to double check to see which I needed cause RB20s arnt his usual fair.

Thanks again. I will continue to check this thread just incase someone has more rock solid input.

[liv2drift045]

i thought 4g63's were topfeed?? and im pretty sure the rb20 is side feed, so that wouldnt help at all (unless you have a topfeed rail for your motor already

[drifts135]

Five hours of searching resulted in finding out that the PFC will work great after switching some of the injector signal wires around and remapping the poo out of it.

RB20 is top feed high imp. (verified and locked in my brain to never be forgotten again...hopefully)

I broke down and bought some 440cc inj off of e-gay tonight, and a friend is loaning his Z32 MAF, so we will see how this goes.

Wish me luck on this thing. Im tryin' to buck the "pick two rule" by simply studying my way into a fast/cheap/reliable combo. Prob gonna backfire on me, but wooo it will be fun on the way.

Seems like the RB25 turbo is deff gonna be the new weak link.....

[MELLO*SOS]

Which 440s did you buy, the stock GTR's or the 7MGTE's? If the latter you'll need to pick up some new connectors. Otherwise how is it coming?