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Hi Guy's,

Theres a couple of things I really need to find out before my car goes into the mechanics on Monday.

I need to know if there are any complications to take care of when doing the conversion.

Things like: Air Con Compressor hosing

Belts

Power steering

Clutch (will my current Exedy clutch work and fit with the rb25 fly wheel???)

Although I am aware that the tail shaft requires shortening and balancing I have taken that into consideration and it will be taken care of.

All advice and help very much appreciated as the work starts Monday!!!

Thanks

Mark

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Been there, done that.

The steering pump may be different, but the R32's will bolt onto the side of the RB25, but then requires a totally different belt. The A/C compressor will also bolt straight up, using the same belt. Clutch / flywheel is the same.

But basically, the RB25 drops straight in.

Should I just use the steering pump that comes with the rb25???
The RB25DET I got was from a Stagea, and the P/S hoses had different connections (angles) onto the pump.

Using the R32 one means you don't have to disconnect and bleed the P/S system. Separate the P/S pump, on its mounting bracket, from the block before removing the engine.

But the 25's P/S pump would have been nice, because it's much smaller, and easier to adjust the belt tension.

R31, depends if you get the engine with a half cut or not (mine was simply an engine on its own). I found out after I'd wired in a Wolf 3D that I could have left the loom in place and plugged in a GT-R version of the Wolf (bloody 20-20 hindsight!)

The only difference with the belts is the RB25 uses a 3 tooth belt for power steering rather than the 4 belt that the rb20 uses. I just used a 3 belt to fit the crank pulley and fitted it on the rb20 power steering pump.

Dunno about the rb20 loom being fully compatible with the 25. I swapped in the 25 loom. From what i have gathered for my swap you wouldn't have either factory boost control or idle speed control. You also wouldn't have the idle step up for the AC on (you have to wire it separately anyway when swapping into an r32.

Also (though this may be an error in my info) there a a couple of injector and ignition pin outs swapped around. Otherwise looks alot simpler than using rb25 loom as i did.

About the only thing you may need to do to use an rb20 loom is extend the wires for the auxiliary air control valve and swap the injector plugs for rb25 ones and wire in the vvt.

It's worthwhile swapping the oil pressure sender and temp guage sender too just to make sure they work properly with the r32 dash.

Good luck with the swap.

Some quick notes;

R32 has hydraulic HICAS and R33 has electric, most Stageas don't have HICAS at all (hooray). So you can't use an R33 or Stagea power steering pump in an R32 with HICAS.

What are you doing about the VVT?

You will need R33 loom and ECU for it to work.

Boost Control?

I would suggest using the R32 wastegate actuator (no RB25 parts)

Sump?

Oil pickup?

Is it a 2wd RB25 or 4wd?

What ECU are you using?

What dashboard?

If all R32, then use ALL R32 sensors off the RB20.

Tailshaft?

Does that mean you are swapping to an RB25 gearbox as well?

Then you will need to make up a hybrid speedo sender, using RB25 internals and RB20 cable connection (RB25's have electronic senders). There is a thread on how to do it.

What exhaust?

The exhaust bracket at the gearbox is different, it will need to be modified. Don't leave the weight of the exhaust hanging off the turbine housing, it will break.

That's all I can remember, hope it is of some hlep:cheers:

Hi Guys,

Thankyou soo much for your help!

Cars gone in this morning.

I have:

R33 loom and factory ecu

It has a 2wd sump

R33 Gearbox

Exhaust joint next door to the mechanics they will find a bracket for me.

I also have a power fc and blitz spec r boost controller going in.

I should have the car back next week.

thanks heaps

Mark

Hi Guys,

Thankyou soo much for your help!

Cars gone in this morning.

I have:

R33 loom and factory ecu

It has a 2wd sump

R33 Gearbox

Exhaust joint next door to the mechanics they will find a bracket for me.

I also have a power fc and blitz spec r boost controller going in.

I should have the car back next week.

thanks heaps

Mark

OK R32 chassis (instruments) with R33 wiring harnes and ECU, from memory......

The speedo is a problem, but you know about that

The tacho is OK

The boost gauge needs its own vacuum hose from the plenum

I think it is R32 bottom radiator hose and R33 top hose

The fuel pump will need a separate relay, R33's have low and high voltage switching from the ecu

We always find it easier to put the engine and gearbox in together, getting at the bell housing bolts with the RB25 gearbox in the R32 firewall/transmission tunnel is way too hard

If I think of anything else I will post it up.:D

  • 1 month later...

There are a few wires that need to be run from the ECU side of the Car to the engine bay loom.

The injectors need power.

Window wipers need re-wiring also to work :rofl:

SK, the R32 has a voltage switch on the fuel pump also doesn't it? I never installed another relay for the fuel pump.. just hooked it up. Not probs.

If you are keeping the fuel pump speed control then you need to wire in the dropping resistor.

Power for the injectors can be picked up by one of the 2 relays near the ecu. I think factory it comes from the big ugly plug in the front corner of the engine bay

Wipers can be done easily by stripping that part straight out of the r32 loom and adding it to the r33 loom

Hi Guys,

The mechanics put the r33 loom in my car and it wont start.

Thankyou for the feedback, im a little lost on the situation.

What do I need to do to get everything to work and the car to start?

Chasers can make the loom work although thats $800. I dont know whether I should just do that.

All your advice is much appreciated :)

Thanks

Mark

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