RB25DET Neo Swap

[Tyler Elms]

Hey guys,

I'm planning on doing an engine swap of an RB25DET Neo into an R34 GT and  I just wanted to check I'm on the right track and not missing any parts! The engine I'm looking to buy comes with 

*Ecu 
*Complete uncut loom 
*Coils with inbuilt igniters 
*turbo and manifold 
*Complete intake including and injectors 
*J pipe 
*Alternator 

As far as i know all I still need is an intercooler and piping

[KiwiBoat]

Exhaust? Whats happening with your gearbox? Even if its factory manual you'll probably want a clutch. The brakes might need some attention too. 

 

I'm not too familiar with NEO but I believe they have a boost sensor that goes to the ecu, and of course you need the AFM.

[Tyler Elms]

Exhaust? Whats happening with your gearbox? Even if its factory manual you'll probably want a clutch. The brakes might need some attention too. 
 
I'm not too familiar with NEO but I believe they have a boost sensor that goes to the ecu, and of course you need the AFM.

Should've mentioned I'll be doing the clutch! Brakes are already bigger than factory too [emoji16] thanks man! Ahh exhaust, how'd I not think of that!

[Ben C34]

What is a j pipe?

[KiwiBoat]

4 minutes ago, Ben C34 said:

What is a j pipe?

The alloy 'J' shaped pipe that goes to the throttle body across the valve covers.

[GTSBoy]

Will need a gearbox.  The NA box will tap out after a year at the most.  Just not strong enough for the torque load.

Will need a fuel pump.

Will need an AFM.

Will need that boost sensor, but it should be on the engine.

[Tyler Elms]

Thanks for this guys, Fuel pump and AFM are added to the list!

Gearbox will come when this one breaks, sadly cant afford it all at once

[Dose Pipe Sutututu]

My advice is to sell your car, buy a GT-t

You'll save money, time, updating your registration with a new motor, etc.

But if you're dead set on doing the conversion then don't forget the boost sensor and popping in a better fuel pump.

R34 ECUs are retarded, without it the car runs like shit. Even when on Nistune, without it connected the TP Load Index goes mental, I found out the hard way when I tuned a customer's car. I disabled the boost sensor flags, upped all the voltage limits to avoid it trigger a DTC and guess what? Still went mental. Got in touch with Nistune support and they said it's paramount you connect the sensor regardless of boost or if it is disabled 

[Tyler Elms]

My advice is to sell your car, buy a GT-t
You'll save money, time, updating your registration with a new motor, etc.
But if you're dead set on doing the conversion then don't forget the boost sensor and popping in a better fuel pump.
R34 ECUs are retarded, without it the car runs like shit. Even when on Nistune, without it connected the TP Load Index goes mental, I found out the hard way when I tuned a customer's car. I disabled the boost sensor flags, upped all the voltage limits to avoid it trigger a DTC and guess what? Still went mental. Got in touch with Nistune support and they said it's paramount you connect the sensor regardless of boost or if it is disabled 

I thought about going this route but it seems to cost almost double in every situation considering it's about 22k+ for a gtt in NZ and 3.5 for an engine [emoji852]️, but thanks man fuel pump is definitely on the list and I'll make 100% sure about that boost sensor!

[Dose Pipe Sutututu]

38 minutes ago, Tyler Elms said:

I thought about going this route but it seems to cost almost double in every situation considering it's about 22k+ for a gtt in NZ and 3.5 for an engine ️, but thanks man fuel pump is definitely on the list and I'll make 100% sure about that boost sensor!

wow... they're like 12~14k here in Australia.

Just move over here, might be cheaper in the long run lol

[Tyler Elms]

wow... they're like 12~14k here in Australia.
Just move over here, might be cheaper in the long run lol

Hahahaha it's tempting! Could be worth an import! That's an insane difference though

[iruvyouskyrine]

Not to mention the price of fuel, even if we are getting fkd here in AUS right now by it.

[GTSBoy]

13 minutes ago, Dose Pipe Sutututu said:

wow... they're like 12~14k here in Australia.

Just move over here, might be cheaper in the long run lol

The hell you doing inviting more bloody Kiwis to move here?  Sydney is already Auckland's biggest suburb.

[KiwiBoat]

Wow didn't realise how much cheaper R34 were in aus, although its not quite that bad, you can pick up a coupe gtt here for 18-19k if you hunt around.

3 hours ago, GTSBoy said:

Will need a gearbox.  The NA box will tap out after a year at the most.  Just not strong enough for the torque load.

I disagree with that, I had factory manual R33 20e that had been swapped to rb25det and the gearbox was fine after around 10 years on the factory turbo. Plenty of people drift with the 20e/20det style gearbox with 300+kw and get decent life out of the trans.

[Tyler Elms]

Wow didn't realise how much cheaper R34 were in aus, although its not quite that bad, you can pick up a coupe gtt here for 18-19k if you hunt around.
I disagree with that, I had factory manual R33 20e that had been swapped to rb25det and the gearbox was fine after around 10 years on the factory turbo. Plenty of people drift with the 20e/20det style gearbox with 300+kw and get decent life out of the trans.

I haven't seen any that low in ages! I'm happy with an engine swap anyways [emoji16] and good to know about the box! Thanks dude

[iruvyouskyrine]

57 minutes ago, KiwiBoat said:

Wow didn't realise how much cheaper R34 were in aus, although its not quite that bad, you can pick up a coupe gtt here for 18-19k if you hunt around.

I disagree with that, I had factory manual R33 20e that had been swapped to rb25det and the gearbox was fine after around 10 years on the factory turbo. Plenty of people drift with the 20e/20det style gearbox with 300+kw and get decent life out of the trans.

I disagree with your disagree. It might live 10 years in might live 10 minutes, 20 box behind a 25 is a complete lucky dip.

[KiwiBoat]

11 minutes ago, iruvyouskyrine said:

I disagree with your disagree. It might live 10 years in might live 10 minutes, 20 box behind a 25 is a complete lucky dip.

Thats kind of the story with any used gearbox though, especially 20+ years old. If its in ok condition and you have some mechanical sympathy its not like they are made of glass.

On another note, Ive seen 25det boxes on here for $1000-1500 which is crazy, you are out about $2500-3000 in NZ for one.

[GTSBoy]

I disagree with your disagree doubly.  I have personally had 2x 20DET gearboxes suffer from input bearing death just with the increased torque load from a boosted 20 making only ~175rwkW.  My mechanical sympathy levels are off the fricking charts too.  I have also seen a large number of other 20DET and 25DE suffer short lives with 25 turbos in front of them.

The little gearboxes are not glass....they are rubber.  They are as flexible as a piece of boiled spaghetti and it f**ks about with the bearing life terribly.

[iruvyouskyrine]

I have multiple 25DET boxes, maybe I should start selling them to kiwis to turn a tidy profit! What's $2500 sheep dollars worth in AUD anyway

[dr phil]

The non turbo RB25DE AFM is the same as RB25DET, both pink label, same part number