R32 Rb20Det To R33 Rb25Det

[StevenCJR31]

Hi, finally killed my 20DET in my R32 and now going to put in a RB25 out of a S1 R33 as a replacement,(going to a 25/30 later) using a nistuned 20 ECU/my existing loom (already have engine/ecu laying around from other projects)and independant VCT controller to run the 25, my question is has anybody reading this has done this conversion and what headaches/ problems did you have with this conversion?i know i will have to change injector plugs (mine are crispy anyway)and that the 25 injectors are different impedence . .. . . have i missed anything?any good suggestions appreciated

[DVS JEZ]

Not too hard buddy.

U will also need to use the rb20 tps otherwise send the ecu to nistune to get it reprogrammed to suit the 25.

What happened to the 20?

[StevenCJR31]

i cooked it,Have you seen the amount of hoses running under the intake manifold!? the previous owner had done a bypass on the heater hoses (heater core had let go)and it was one of those that split and dropped all my coolant out, i was busy (ahem)racing with a WRX at the time and didnt see the temp gauge go up to "H" before i shut it down. . . . .i reckon the rings have lost their tension as once i fixed it all and went down the road in the car as soon as the engine was at running temp (id changed the oil)i was leaving a blue smoke screen behind me that looked like something outta summernats. . .(the engine wasnt blowing any smoke before that)thanks for the heads up regarding the TPS , not sure whats been programmed into the 20 ECU (been told its a 25 map)regarding sensors n stuff as i got the NISTUNED ecu secondhand but will get a workshop here in Perth to check it all (including AFRs) once i swap out motors

[TTT]

I paid someone to do mine.

20 out, 25 in, stock 25 ecu in, AC regassed, PS pump cut across from 20 to 25, new radiator and hoses (mine was coocked and gooped up too).

I kept the 20 box

edit - the heater hoses are different size.

and mine were made back in 1989 so fell to bits.

Currently bypassed till I can find replacement ones.

Edited April 15, 2012 by GTST

[StevenCJR31]

Hose sizes are different? bugger. . . i got myself a bunky 20DET for parts and was hoping to use the heater hoses off that ,once ive replaced the heater core(dash out job from what ive read )

[TTT]

yeah fairly big difference..

research this forum and all posts will say that people make a small adapter and just force it on.

but the hoses are so old that as soon as you try to put it back on they split.

well mine did.

no biggie though... just no heater for winter.. not such a problem for Brisbane.

[StevenCJR31]

im not keen on an adaptor so i might go a different way with mine . . .seeing as i gotta pull my heater core out anyway i can get larger inlet / outlets welded onto the new (or reco) tanks , that way when i win lotto and replace all the hoses i can get a complete kit for a S1 R33 RB25DET, very very unlikely that the 20 will go back in

[51NNA]

easy as swap, started it sat morning and had it running 10pm sat night, also u need the r33 throttle cable, 32 one is too short =)

[StevenCJR31]

easy as swap, started it sat morning and had it running 10pm sat night, also u need the r33 throttle cable, 32 one is too short =)

thought that might be the case . . .throttle linkage on the 25 looks very different to the 20 . . . did the 33 cable go straight onto the 32 pedal or needed a bit of persuading? will hit up my local nissan guy for a price on the 33 cable, it MAY not cost me my left nut!keep the above info coming guys MUCH appreciated, i want to get this conversion right. . ^^^ well done on the quick turn around on your swap

[51NNA]

Went straight in without a problem, think i had too swap some rubber from the 32 one to the 33 one, you shouldnt have too pay anymore then 1500-1650 for an engine, all up it cost me 1800$ that includes

RB25 S2 80k kms

set of spark plugs

fuel filter

r33 throttle cable

oil

i used the 33 loom and ecu, then decided too buy a microtech and made a new loom so that added 1500 more too it haha

[StevenCJR31]

Went straight in without a problem, think i had too swap some rubber from the 32 one to the 33 one, you shouldnt have too pay anymore then 1500-1650 for an engine, all up it cost me 1800$ that includes

RB25 S2 80k kms

set of spark plugs

fuel filter

r33 throttle cable

oil

i used the 33 loom and ecu, then decided too buy a microtech and made a new loom so that added 1500 more too it haha

i paid $900 for the S1 25DET (ks unknown)with auto/ECU/AFM, BUT it was missing the wiring loom/coil packs etc, no biggy as im going to use new after market coils (and new O2 sensor)and use the 32 wiring loom, sticking with the NISTUNE ecu as my car is auto and in about a years time i will drop in a 25/30 as ive got a 25 head modded and ready for my rebuilt 30 bottom end, i would put it in now but dont have the $$$ to buy the bigger injectors and turbo etc i will need for this

[51NNA]

nice! mine was a complete engine, no G/B, even came with a dinted sump yet too fix it though haha

[StevenCJR31]

nice! mine was a complete engine, no G/B, even came with a dinted sump yet too fix it though haha

Ha! i like the dented sump! ive lined up a ASR baffled/deep sump for the 25/30 . . . along with that and some oil restrictors for the head i SHOULD be able to fang the car around without starving the bearings of oil . . . .