Putting Rb25de Into R32 Gts

[i want a skyline]

Hi guys,

What is involved in putting an RB25DE into an R32 GTS?

I know I'm going to need:

Engine

Gearbox

ECU

Loom

Anything else?

Pete

[driftrx]

tailshaft to suit as well, im not 100% sure but the RB20 one might do,

everythings pretty much plug/bolt in and play.

pretty straight forward to do yourself over a weekend.

if theres anything else someone else on here will pick up on it lol

[G0DZLR]

what generation of RB25DE are you talking here?

1st gen without VVL, 2nd gen, or neo head?

[SKiT_R31]

as above, if your just putting an rb25de from an r32 into your car, it will all just bolt up to your stock rb20de gear, including with wiring loom (will bolt straight up) only other thing you'd need to change would be ecu.

[G0DZLR]

to make things easier try and find a manual block with the gearbox attached. correct me if im wrongbut there are slight differences in block size between autos and manuals. itl just make things easier...that is presuming you want a manual...

and going by the laws of physics, unless the RB20 and RB25 tailshafts are the same, an RB20 tailshaft wouldnt be able to handle the increased torque from the extra capacity from the 25 for long before snapping :S

[SKiT_R31]

hang on, wait what?

is he manual converting it as well or...?

i'd just leave your gearbox in the car, just out with the old engine and in with the new, change the clutch while your at it t5o somthing a bit better tho. The tailshaft is same afaik, and the rb25de doesnt really make much more power than the 20 anyway, and people get away with turboing them (or dropping in turbo donks) with no issues.

[G0DZLR]

vote 1 for moar info needed in first post

[i want a skyline]

Sorry guys, I should have been more detailed.

Car previously had an RB20DE in it with manual gearbox.

Car now has no engine or box. It still retains the loom.

I'm going to hunt around the traps and see if I can find a Series 1 RB25DE without VVL, as I don't really want the associated wiring headache of the VVL function.

[Eug]

a small number of R32s came from factory with the RB25DE. it should be a walk in the park.

the R33 RB25DE uses an R32 RB20DET gearbox so I don't see much of a problem with mix-and-matching - and agree with skit.

[SKiT_R31]

Sorry guys, I should have been more detailed.

Car previously had an RB20DE in it with manual gearbox.

Car now has no engine or box. It still retains the loom.

I'm going to hunt around the traps and see if I can find a Series 1 RB25DE without VVL, as I don't really want the associated wiring headache of the VVL function.

no worries. Since the box is already out, you may aswell bolt it to your new engine and put them both in at the same time, make things easier.

You can get an R33 engine, and everything should still pluging ok, most sensors are the same you'd just need to swap somer plugs over, i think the idle gear and the injectors are all thats different. As for the VCT - it doesnt have to be connected but you could just run a seporate plug and wires to the ecu, would be pretty easy.

i've got a cut R33 RB25DE loom you can have cheap if your interested

I dunno how compatible the 32 is with the 33 wiring, but i would avoid completely changing looms if possible, not my cup of tea anyway

Edited June 20, 2008 by SKiT_R31

[i want a skyline]

Thanks for the replies.

At the moment, the plan is as follows:

R33 RB25DE with VCT (as R32 RB25DEs without VCT are very rare)

R32 RB20DET gearbox

R32 RB20DET tailshaft

R32 RB20DE loom adapted to suit RB25DE

If necessary, VCT function on a switch

Is this feasible?

[SKiT_R31]

should be all fine, providfing you get the complete rb25 engine (inc afm etc) and dont forget the ecu

Your clutch will fit, but its its a stocker, i'd change it. Exhaust manifold will also fit.

edit: ive put an r32 engine in an r33 (r32 spec rb30det) just so you know it is possible, all worked fine, as i said before only differences are the idle gear and injector plugs, you'll have to use your own rb20 ignitor, cas is the same, etc

Edited June 20, 2008 by SKiT_R31

[Eug]

you are missing ECU.

why VCT on a switch? an RB25DE ECU will handle things.

check differential bolt pattern, i have heard some are 6 bolt some are 5 bolt.

if the R32 RB20DE loom and sensors will work, ok. if not buy an RB25DE with loom and ecu

should be do-able and should be a very very fun car.

[i want a skyline]

you are missing ECU.

why VCT on a switch? an RB25DE ECU will handle things.

check differential bolt pattern, i have heard some are 6 bolt some are 5 bolt.

if the R32 RB20DE loom and sensors will work, ok. if not buy an RB25DE with loom and ecu

should be do-able and should be a very very fun car.

Because if I run an RB25DE ECU, I need to rip apart the dash and swap ALL the wiring over don't I? which will be a kent of a job to do!

I'd rather get the loom adapted to the SII RB25DE and leave the R32 RB20DE ECU in.

[daisu]

I'm pretty sure an RB20 ecu won't run an RB25 engine as the fuel and ignition maps would be different, you'd have to get it remapped.

You don't have to rip apart the dash to use a new loom, there is only 1 or 2 plugs next to the ECU that may need modifying (not sure on R32/R33 differences).

[SKiT_R31]

yeah theres nothing that has to be ripped appart, you simply have to unplug the old ecu and plug in the new, its like 2 screws to get to it (passenger side kick panel) and the plug bolt. No cutting of wires.

you could get the rb20de ecu to work, but i dont think the injectors are the same (if not you'd have to swap them or run a safc) and you'd have to run all the rb20de gear (afm etc) and as daisu said, all your fuel and timing maps could be out of whack, especially if you get the r33 engine (plus no vct), swapping ecu's is definately the way to go - and a 25de ecu is worth sfa.

[dori34]

pete!

if you want a r32 rb25de motor PM Me, i know a local wrecker to me that has it complete in a half cut with loom ecu etc..

now.. if you get the r32 rb25de without vct it will be a piss easy job with wiring.

all r33 rb25de's have vct..

im not sure about the ones in ceffies/laurels??

if you do get a r33 motor,

get the complete loom & ecu

it can be done as what was done to my car and the vct works fine.

rb20 box & tailshaft will bolt up just fine.

however the gearbox mount/cross member; two holes will only line up so a bit of fab work here to make the other two line up.

if you use a rb25 box & shaft, the tailshaft has to be modded coz its longer then a rb20 one.

[GTS4WD]

umm.. just one question..

Why are you changing gearboxes? Are you going to be going turbo?

The only reason you would need to change the NA box is because its weaker than the turbo version and you need the strength because your pushing more power through it.

Do you need the extra strength?

[SKiT_R31]

rb20 box & tailshaft will bolt up just fine.

however the gearbox mount/cross member; two holes will only line up so a bit of fab work here to make the other two line up.

if you use a rb25 box & shaft, the tailshaft has to be modded coz its longer then a rb20 one.

wtf!? the rb25de box is exactly the same as the rb20de, or even the rb30e. Getting an rb25det box would just be retarded and completely un necesary = waste of money (plus adds weight to car)

as i said before, you do not need to change the loom for the rb25de R32, just the ecu

[i want a skyline]

Hey Elvis I'll probably give you a call later re: half cut.

I'm aiming to just get an R32 RB25DE (from factory) now, would make things a lot quicker and easier.

Once again, thanks everyone for your replies. I will keep you updated!