R32 Engine Swap Opinions

[Adz2332]

Hey all

i have a r32 gtst im about to pull down and paint. so while im at it will do work to the engine.

my pet hate is the gutless no torque rb20. was going to mod it but i dont think itll make up for the down low i like on the street. looking at roughly 300kws give or take

I then thought about putting a rb25 into it. i went out and got a rb25 turbo engine, which i have sitting in my shed at the mo, ready to be pulled down......

Then another idea struck. what about a 25/30? i know they wont fit under the bonnet as such but ill work around that.

Is it worth the hassle of a 25/30 over a 25 for modest street only car? I can get it regod with the 25 engine easily enough.

if i went the 25/30 route, if i got a series 2 rb30 block and 25 NA head would the head need to be modded to line up all the journals properly? etc?

is it right a 25 NA head all lines up with a 30 better and without modifying like a 25 turbo head will need to be?

Can i use a rb20 ecu and wiring with both engines? or will i have to rewire for either?

have a few more questions but will keep reading and update this thread as i need to

thanks

Adam

[GTSBoy]

If I were to put a 3L into an R32 it would have to be a VQ30DET. It might seem easier to stick with an RB because your gearbox problem is easier to solve, the mounts are easier, plumbing and wiring is easier, etc etc. But really, once you take that step to do the 25/30 you bring on all those other problems that you are aware of (trying to lower the engine height, actually modding the engine for the timing belt and VCT, etc). The effort spent on dealing with those things could be much better put into dealing with the tasks needed to get a VQ into it.

The only really interesting hassle with VQs is getting a suitable manual box. Now that 350 and 370Zs are older/more numerous/more present in wrecking yards, it's not as hard to find a suitable manual box and bellhousing as it was a few years back. And the adapter plate options to other Nissan boxes still exist. And I'm sure you could go the T56 route if required also.

[zebra]

LS swap

[Adz2332]

hahah id like to keep it ummmm legal ish....

as popping the bonnet with a 25/30 can still look standard... ish....

But thats also why im thinking just sticking to the rb25. fit a decent turbo low mounted, keep cross over pipe and be done with it?

[GTSBoy]

hahah id like to keep it ummmm legal ish....

as popping the bonnet with a 25/30 can still look standard... ish....

But thats also why im thinking just sticking to the rb25. fit a decent turbo low mounted, keep cross over pipe and be done with it?

Well, that's one reason why I went with a 25Neo transplant. And if you were going to do a 25 I would soooooo much suggest a 25Neo over an R33 25. Not least because the R34 ECU is natively Nistunable. It is also a newer engine with better power and torque and (possibly!) fuel consumption.

At the time I did mine it looked like a bit of hard work to get the gearbox problem solved, but I reckon that would be a lot easier these days.

As to legality, getting a 25 into an R32 in SA is piss easy - so long as the rest of the car will go over the pits without getting busted. All you have to do is put in an application for the modification and they will tell you the requirements. Those requirements will be bigger brakes (and R33 brakes will almost certainly be big enough for anything) and that all the emissions and engine management stuff for the new engine is present and working.

It would be exactly the same for a VQ30. The R33 brakes should be accepted. The VQ30 is rated at the same power level as the Neo anyway, so you're not going to frighten anyone at Regency.....and it's lighter. Oh and as a side benefit.....the engine is even newer than the 25Neo, and once you've done the conversion to VQ you make it much easier to grab hold of a bigger VQ later if that's what floats your boat. I think a low boost VQ37 in an R32 would be an excellent street car.

[bcozican]

rb25 with 3071gtx or equivlant hypergear turbo lowmount i/w on 18psi for 280 - 300rwkw? should carry 450nm and be all in around 3750rpm ?

injectors, fuel pump and basic ecu or nistune and get window switch for VCT if needed like oyu said keep crossover pipes etc for std look

people have different thoughts / feelings on response etc but wouldnt thought the above would be a good balance of all without too many dramas as its a pretty well troden path

[GTSBoy]

To be clear - I'm not recommending a VQ30 as your best option. I's saying that if you were going to go 3L, then it makes more sense than a dirty old VL motor conversion.

I also reckon you will achieve your aims with a 25, preferably Neo.

[zebra]

Isnt the VQ30 nearly as old as the RB?

but the VQ is still a much better motor

[Adz2332]

thanks guys!

a 25 seems to be the way to go. just with ease and also legality.

what are the neos worth to buy over a 33 25?

[Ke55pig]

U can get neo for 1000-1500 if ure in right place and time

[iruvyouskyrine]

RB30 conversion is piss easy in every way. People make it sound like a huge pain in the dick but it only requires 2-3 things more than a 25 conversion.

If you have a running 25 just jam that in then I wouldn't waste time tearing it down.

[niZmO_Man]

Isnt the VQ30 nearly as old as the RB?

but the VQ is still a much better motor

RBs came out in 1985. Are you talking about VG30?

[zebra]

Ahh sorry meant RB25det

[XKLABA]

If I were to put a 3L into an R32 it would have to be a VQ30DET. It might seem easier to stick with an RB because your gearbox problem is easier to solve, the mounts are easier, plumbing and wiring is easier, etc etc. But really, once you take that step to do the 25/30 you bring on all those other problems that you are aware of (trying to lower the engine height, actually modding the engine for the timing belt and VCT, etc). The effort spent on dealing with those things could be much better put into dealing with the tasks needed to get a VQ into it.

The only really interesting hassle with VQs is getting a suitable manual box. Now that 350 and 370Zs are older/more numerous/more present in wrecking yards, it's not as hard to find a suitable manual box and bellhousing as it was a few years back. And the adapter plate options to other Nissan boxes still exist. And I'm sure you could go the T56 route if required also.

This !!!, I was about to do this conversion to my 32 GTR then bought a 34 GTR instead

VQ30det with Z32 5 speed box and a cut and shut bellhousing which I still have sitting in the garage collecting dust

[AngryRB]

So does a VQ have lots of bottom end torque? last time i drove a VQ30dett there wasn't much happening under 4k on the stock turbo's, but a VL turbo was frying tyres from 2000rpm..

Love the dirty 30 for outright anger

Edited December 9, 2015 by AngryRB

[zebra]

No such thing as a VQ30DETT

Was it a VG30Dett?

[AngryRB]

twin turbo 300zx yes... although would be weight difference, didnt seem to be a bottem end torquey motor like the RB30, but whatever floats ya boat..

Edited December 9, 2015 by AngryRB

[GTSBoy]

VG != VQ.

VG30 is like 2x 3/4 of a CA18.

[niZmO_Man]

IMO VG is a bit underrated, no? I've seen one (single turbo) in an R31, it fits so well.