Jump to content
SAU Community

Recommended Posts

Righto , it seems that RB26 heads and inlet manifold systems are the best available from the factory so assuming R33 GTST owners like myself can get them what would be involved in applying them to the single turbo R33 and its RB25DET . Actually I'll go one further and say that most would have either a PFC or some other tunable computer to start with .

The problems I can forsee are :

1) Dfferent coolant/oil passages at the front of the block/head .

2) different sized stud holes (larger) in RB26 heads .

3) Fitting issues ie will the 26 IAC stuff fitt in with the 25DET water/oil cooler .

4) If required fitting the RB25DETs single turbo exhaust manifold .

5) Wiring loom mods to connect sensors in places foreign to an R33 GTST .

6) Sensor compatibility .

7) Injectors - all high/low impedance and top feed rather than side feed issues .

8) Water plumbing issues ?

Anyone done this conversion or nutted out the fixes , cheers A .

roy pose's a very good point.

IMO this is the line where u say its too expensive for the gains. sure putting on the 26 plenum and throttle setup to the 25head is quite expensive, but i reckon the extra work required (as stated in the first post) would be the killer and make it far too expensive, even for the 'backyarders'.

1-Pretty sure there will be minimal water passage dramas, you may need to tap and grubscrew the oil feed to the VCT. Dont forget to fit oil restrictors.

2-Simple, use rb25 head bolts, the head is located by the dowels

3-The rb26 also uses a water/oil heat exchanger. I would say both the 25 and 26 IAC would be pulse width modulated, so there shouldn't be too many dramas there.

4-Two options here, aftermarket single turbo rb26 manifold, or an adapter plate. I would avoid modding the head. Cheap rb26 staino manifold would be my choice, just brace it and the exhaust. Or a good aftermarket one-your choice

5-TPS isnt too far from the original, IAC will need lengthening, CAS, water temp and injectors are in the same spot. May wish to add wiring for the Air temp sensor. Will need to change injector plugs, and add a resister pack if you want to use the rb26 injectors.

6-You may have to fit rb25 water sensor, as i said not 100% sure about IAC though

7-As said above

8-Water plumbing for the turbo will be very similar betweent the two, a few hoses to nut out, but nothing too complex

Righto , it seems that RB26 heads and inlet manifold systems are the best available from the factory so assuming R33 GTST owners like myself can get them what would be involved in applying them to the single turbo R33 and its RB25DET . Actually I'll go one further and say that most would have either a PFC or some other tunable computer to start with .

The problems I can forsee are :

1) Dfferent coolant/oil passages at the front of the block/head .

2) different sized stud holes (larger) in RB26 heads .

3) Fitting issues ie will the 26 IAC stuff fitt in with the 25DET water/oil cooler .

4) If required fitting the RB25DETs single turbo exhaust manifold .

5) Wiring loom mods to connect sensors in places foreign to an R33 GTST .

6) Sensor compatibility .

7) Injectors - all high/low impedance and top feed rather than side feed issues .

8) Water plumbing issues ?

Anyone done this conversion or nutted out the fixes , cheers A .

I think Adz here on the forums has on on his 25,shoot him a PM.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Didnt realise RB's had more then 1 head.
    • I'm normally copping my own abuse from neglecting my daily drivers. "Those suspension bushes will last a bit more", "Don't worry about the oil leak, just keep topping it up". The project cars I'm always doing things slowly on them as I'm wanting them to be done better, and neater, and nicer. Luckily I don't have to deal with 18 year old Matt's "Learning to wire" stuff in the project cars. And there's only one piece of wiring I'm displeased about in the Landcruiser, and it's about to be cut out... However, the box loads of parts that have been going through this place lately for the Landcruiser... Brake pads Brake Rotors Full handbrake overhaul Wheel Bearings Seals Swivel hubs Steering Boxes Half the suspension joints Shocks Air bags (Ones to go in the rear springs for towing) Water pump Timing kit Lower timing case Harmonic Balancer Radiator Lots of other little seals and shits Gas struts for the bonnet New power window switches And god knows what else I've forgotten... Ha ha ha I have my fingers crossed the pinion seals don't start leaking on the diffs, that the transfer case doesn't leak, and the gearbox input shaft doesn't leak, nor the rear main seal. As they're about the only seals I haven't replaced in the driveline! I'm seriously eyeing off buying new caliper rebuild kits front and rear brake calipers... I'll probably recheck all the valve clearances soon too, and hopefully, it should be all good and sweet to haul some long distance trips again!
    • Every time I pull my 3x gauges out of the console and see the crack-addict way that I did the wiring, and I just can't bring myself to tear it all apart and "make it nice", because it is currently working. In fact, the last time I was in there I probably made it worse.
    • The best part is when you own the car long enough that you look back and find your OWN ham fisted amateur shit!
    • The annoying part about neglect, is when you start to replace one thing, and find ten more broken things. Ham fisted monkey repairs you normally only find out about when trying to do something unrelated! Ha ha   Neglect you can kind of anticipate the huge costs to fix it all. Ham fistedness is normally a shock the first time your work on a new old car, as everything "looked" good before.
×
×
  • Create New...