Rb25det 4wd- Auto -> Manual Question

[Chris Rogers]

I ahve bought one of these as a engine/box/harness combo out of a 09/97 C34 Stagea. eninge has 109K on it. I am ditching the auto box and dropping the 5sp box and front diff from my GTS4 onto the RB25.

questions:

balancing of this engine - internally balanced or externally balanced?

I am trying to work out if I need to retain the crank pulley off my RB20 or not.the rb20 flywheel is a given.

my knowledge of balanced engines relates to small block chevs and those were a mixed bag. some had harmonic balancers some did not. I do not know a lot about the nissan engines.

starter - same as manual or different?

I know that subaru swapped starters across various engines in the EJ range - are these the same or does one size fit all.

ECU - is there a manual and auto version?

if so what pin on the 'auto' ECU do I need to fiddle with to make the ECU think its 'manual' ?

temp gauge sender - same as RB20 or different?

I have kept the RB20 one. the ECU one I'm not worried about.

anything else that I may have missed fell free to chime in.

[KiwiRS4T]

I'm not sure what you mean by internally or externally balanced but the RB motor does have an harmonic balancer on the front pulley. The engine should run OK with the auto ecu - in the Stagea you short out the fuses below the battery to enable it to run with a manual box so don't know how to do it at the ecu. You will have to connect up the wire for the reversing lights. Have you got a S1 Stagea pinout? If not give me an email address and I can send it to you as an attachment.

[Chris Rogers]

I'm not sure what you mean by internally or externally balanced but the RB motor does have an harmonic balancer on the front pulley. The engine should run OK with the auto ecu - in the Stagea you short out the fuses below the battery to enable it to run with a manual box so don't know how to do it at the ecu. You will have to connect up the wire for the reversing lights. Have you got a S1 Stagea pinout? If not give me an email address and I can send it to you as an attachment.

crank balancing - you have answered my question in a roundabout way anyway. I either need to get a RB25 manual flywheel or keep the RB20 pulley and RB20 flywheel so the engine doesn't shake its self to bits. ( you are essentially telling me that this one is externally balanced.)

re diagram for the ECU - no - need one please ([email protected])

reverse light input to ECU - weird? any idea why?

I know that stop lamps go into most of them when in auto guise so it unlocks the torque Conv.

I requested the FULL front/dash harnesses of the C34 when I ordered it (engine/box is at a mates yard in osaka.) so I should have everything. that said I can work out what I need to change on the ECU once I have a pin out on it.

do you have a rough diagram of what you are shorting in the fuse panel area and if you are shorting it to ground or to +12v.

ta!!

[Chris Rogers]

I should also add that the only part of the C34 harness that I'll be using will be the ECU harness the rest will be R32. having a quick read elsewhere it looks like the wires that are being fiddled with are for the starter lockout. am I correct?

[QWK32]

hey chris. for that year model stagea they are all auto's, so there is only an auto version for the ecu. but one thing to keep in mind, the ECU programming/mapping is the same as a S2 R33 but with a R34/S2 style ecu plug. the pinouts aren't the same as an R34/S2 ecu and to complicate things there were 3 different ecu pinouts over the S1 stagea range. so it can be hard to sort out an aftermarket that isn't full wire in. some guys get lucky and an R34 powerfc works just by swapping a couple wires around. but i think is was Duncan who had a lot of trouble getting it to work. nistune is out of the question.

something that i thought may work is to get your hands on a S2 R33 engine harness and ecu and use that instead of the stagea one. all the engine plugs should be the same (eg, cas, injectors, coils etc), ecu pinouts are available and accurate, and there are more options as far as aftermarket plug in ecu's including the popular nistuned Z32 ecu plugin.

temp senders for all rb's i thought were the same but i'd retain the RB25 one for the ecu just in case as thats the important one. i'm 100% sure the reverse lights don't go into the ecu and there is no pin on the ecu to make it think its a manual. the auto inhibitor is external to the ecu and because your car started as a manual you wont have to worry about it.

i wired up a S2 RB25 conversion into a VL the other week, apart from making sure all your ground, constant 12v, and ignition switched 12v feeds are hooked up. there is also a cranking signal so the ecu knows when your trying to start the engine, the fuel pump signal, a tacho signal, the temp wire for the gauge cluster. i think that was all we hooked up for it but there were others like the A/C request, power steering idle up, hicas speed sensor, engine check light and probably a couple more that would be a good idea to wire up.

all of these wires can be found a plug or 2 about 300mm back from the ecu plug, it links the ecu loom to the cars loom. on the S2 R33 it was one big black/white plug, and from memory the R32 as 2, a blue plug and a white plug. don't know what the S1 stagea's is.

also thinking about chris, i'd use the harmonic balancer that cam with the RB25 as its balanced with the engine. aren't flywheels balanced themselves? so it shouldn't matter putting your RB20 one on.

Edited November 27, 2010 by QWK32

[Duncan]

Re factory balancing, I think nissan just make stuff the same in the first place (unlike the yanks ). Plenty of people replace flywheel and balancer without resulting balance problems

Re ECU, the auto one is a little sensitive to change (ie goes rich very quick compared to skyline with mods) but the only real difference in the auto is it retards timing on auto gear changes. Since it will never get that signal again there are no problems. Ash Josh mentioned I had heaps of pinout trouble with my ECU. so be careful if you change to aftemarket one.

starter is same same. no issues.

Re wiring, I doubt you will have the auto cutout wiring issue since you have gts4 body loom. Probably a bit of stuffing around ahead matching stagea engine loom to gts4 body loom but I'm sure you are up to it

[rb30dett]

RB20 flywheel & clutch should be ok.

Don't use the Stagea harness use an r33 ser2 harness & ecu that way all upgrade options are available.

What QWK32 has suggested is all correct and would be your best option.

[kidafa]

Chris have a look in here Manual Convervion Findings

[dirtyRS4]

Chris have a look in here Manual Convervion Findings

Thanks for the pm RB30DETT for the info on the loom and ecu side of things. This thread is interesting. Cheers kidafa. Have found a few discrepancies though.

33 loom should give you more options. Bob, I think reverse is wired to the gearbox? Been eagerly watchn your build Mr. Rogers. for a cheap way out. lol

Edited November 28, 2010 by dirtyRS4

[KiwiRS4T]

re diagram for the ECU - no - need one please ([email protected])

reverse light input to ECU - weird? any idea why?

Sorry - confused you by stating the bleeding obvious - reverse light needs to be connected to gearbox, not ecu. Pinouts sent!

[Chris Rogers]

Thanks for the pm RB30DETT for the info on the loom and ecu side of things. This thread is interesting. Cheers kidafa. Have found a few discrepancies though.

33 loom should give you more options. Bob, I think reverse is wired to the gearbox? Been eagerly watchn your build Mr. Rogers. for a cheap way out. lol

yep from what I can see quite a few people seem to be watching what I am doing. that car is a LONG way from moving. its a case of panel/body first then electrics once it goes nback together.

[Chris Rogers]

Sorry - confused you by stating the bleeding obvious - reverse light needs to be connected to gearbox, not ecu. Pinouts sent!

thats ok I done a few swaps in my time - kinda worked out what you meant. ta for the pinouts!

[Chris Rogers]

hey chris. for that year model stagea they are all auto's, so there is only an auto version for the ecu. but one thing to keep in mind, the ECU programming/mapping is the same as a S2 R33 but with a R34/S2 style ecu plug. the pinouts aren't the same as an R34/S2 ecu and to complicate things there were 3 different ecu pinouts over the S1 stagea range. so it can be hard to sort out an aftermarket that isn't full wire in. some guys get lucky and an R34 powerfc works just by swapping a couple wires around. but i think is was Duncan who had a lot of trouble getting it to work. nistune is out of the question.

something that i thought may work is to get your hands on a S2 R33 engine harness and ecu and use that instead of the stagea one. all the engine plugs should be the same (eg, cas, injectors, coils etc), ecu pinouts are available and accurate, and there are more options as far as aftermarket plug in ecu's including the popular nistuned Z32 ecu plugin.

temp senders for all rb's i thought were the same but i'd retain the RB25 one for the ecu just in case as thats the important one. i'm 100% sure the reverse lights don't go into the ecu and there is no pin on the ecu to make it think its a manual. the auto inhibitor is external to the ecu and because your car started as a manual you wont have to worry about it.

i wired up a S2 RB25 conversion into a VL the other week, apart from making sure all your ground, constant 12v, and ignition switched 12v feeds are hooked up. there is also a cranking signal so the ecu knows when your trying to start the engine, the fuel pump signal, a tacho signal, the temp wire for the gauge cluster. i think that was all we hooked up for it but there were others like the A/C request, power steering idle up, hicas speed sensor, engine check light and probably a couple more that would be a good idea to wire up.

all of these wires can be found a plug or 2 about 300mm back from the ecu plug, it links the ecu loom to the cars loom. on the S2 R33 it was one big black/white plug, and from memory the R32 as 2, a blue plug and a white plug. don't know what the S1 stagea's is.

also thinking about chris, i'd use the harmonic balancer that cam with the RB25 as its balanced with the engine. aren't flywheels balanced themselves? so it shouldn't matter putting your RB20 one on.

sounds like a plan. I have a mate with a S2R33 so I/m going to compare notes once this engine lands. my harness has the same setup as what you describe so builiding the 'new' harness should be a piece of cake. I have to worry about ABS and the wipers but thats it.

RB25 ECU temp sender - yep keeping that one . I was referring to the gauge one. all the essential wires will tie to something as I want everything on this car to work as it did from day one, albeit with a few changes for the better. looks like I spend a bit more time talking to osaka again..

Re factory balancing, I think nissan just make stuff the same in the first place (unlike the yanks ). Plenty of people replace flywheel and balancer without resulting balance problems

Re ECU, the auto one is a little sensitive to change (ie goes rich very quick compared to skyline with mods) but the only real difference in the auto is it retards timing on auto gear changes. Since it will never get that signal again there are no problems. Ash Josh mentioned I had heaps of pinout trouble with my ECU. so be careful if you change to aftemarket one.

starter is same same. no issues.

Re wiring, I doubt you will have the auto cutout wiring issue since you have gts4 body loom. Probably a bit of stuffing around ahead matching stagea engine loom to gts4 body loom but I'm sure you are up to it

yep - kinda what I do for a living so no biggie

balancing was the key issue I thought was going to be a problem. turns out that it may not be now. ECU - yep I understand the 'rich' problem - 33 seems to do the same thing.

33s2 harness looks to be the easy way out so I may as well do that. I'm not one to swap things around too much but it's nice to know I can if needed.

RB20 flywheel & clutch should be ok.

Don't use the Stagea harness use an r33 ser2 harness & ecu that way all upgrade options are available.

What QWK32 has suggested is all correct and would be your best option.

understnd a bit more about it now - TA!!

[Chris Rogers]

looking at the pinout this thing also runs the trans!!

definitely using a different harness now. I can se this turning into a lot of fun of I use this one.

[rb30dett]

looking at the pinout this thing also runs the trans!!

definitely using a different harness now. I can se this turning into a lot of fun of I use this one.

The stagea harness = mine field there are several different versions of the harness and only 1 pinout diagram for ser 1

That said I would buy the Stagea harness from you if it is the 1 I need (ecu mod #?)

There are no plug in ecu options or Nistune available for the Stagea harness thats the main reason I suggested r33 loom

The factory gauges will all work on your dash with the rb25 sensors & harness no probs

[KiwiRS4T]

The fact that the Stagea ecu runs the auto is not a problem - it works perfectly well on a manual but the fact that it has 3 rows of pins is a bit of a problem - R34 ecu doesn't work so yes look for a S2 R33 loom and a z32 ecu.

[Chris Rogers]

The stagea harness = mine field there are several different versions of the harness and only 1 pinout diagram for ser 1

That said I would buy the Stagea harness from you if it is the 1 I need (ecu mod #?)

There are no plug in ecu options or Nistune available for the Stagea harness thats the main reason I suggested r33 loom

The factory gauges will all work on your dash with the rb25 sensors & harness no probs

unsure of ecu model. I do have the chassis number of the car it came from though so I can derive the part number of it.

The fact that the Stagea ecu runs the auto is not a problem - it works perfectly well on a manual but the fact that it has 3 rows of pins is a bit of a problem - R34 ecu doesn't work so yes look for a S2 R33 loom and a z32 ecu.

Z32 - if I want tuning capability - yah? the ECU harness I understand.

[QWK32]

unsure of ecu model. I do have the chassis number of the car it came from though so I can derive the part number of it.

Z32 - if I want tuning capability - yah? the ECU harness I understand.

yeah the Z32 ecu comments are in relation to Nistune, as there is no option to nistune a R33 ecu you can either use a Z32 ecu or a R32 ecu. the Z32 ecu is prefered as it will operate the VCT where the R32 ecu will not (an external rpm swtch is needed to activate the VCT). you need to do some minor modifications to the Z32 ecu to get it to work properly Link for Info.

but if your not looking to go down the nistune route than any aftermarket R33 plugin will obviously work if you use a R33 harness.

[darrinspencer]

Spotted this for you

Series 2 harness

http://www.skylinesaustralia.com/forums/Se...om-t345989.html

[Chris Rogers]

Spotted this for you

Series 2 harness

http://www.skylinesaustralia.com/forums/Se...om-t345989.html

ta! I'll wait for his reply.