RB25DET Neo into a R33 Gtst with 33 box

[BundyBear]

RB25DET Neo into a R33 Gtst with 33 box

Hey Guys, My mate and I have just finished converting his R33 GTST to a RB25 Det Neo, so I thought Id doc the process and what we used of each car

Block, head, sump is all Neo

Inlet manifold is s1 with a cut n shut top half including throttlebody

exhaust manifold is aftermarket from the s1

enginemounts, we used the R33 ones but neo are the same

alternator, power steer, A/C are all s1 including the brackets

thermostat housing we used the 33 s1 part so we could use the same bottom hose but if u use the neo housing then just use a neo bottom hose

coilpacks we used the s1 packs as their only a few months old but they do not fit in the head valley so we made a bracket and mounted them elsewhere

 

WIRING CHANGES

vct plug needs swapping to a neo one or EV1 injector plug I beleive is the same

CAS wires need to be swaped...ie 1234 becomes 4321

thats it....because we used r33 stuff everything else stayed the same

 

pics to come

 

 

 

Edited November 14, 2016 by BundyBear

[discopotato03]

Just for the record does anyone know if the VCT switch/valve is the same R33/R34 - aside from the electrical connection ?

Just may save some work if its a simple swap .

From the above I gather the coil and injector loom plugs are the same R33 to R34 .

 

Cheers A .  

Edited November 15, 2016 by discopotato03

[BundyBear]

Just for the record does anyone know if the VCT switch/valve is the same R33/R34 - aside from the electrical connection ?
Just may save some work if its a simple swap .
From the above I gather the coil and injector loom plugs are the same R33 to R34 .
 
Cheers A .  

Na we originally looked at pics in a few parts catalogs amd they look quite different. Our tuner also confirmed their not interchangable.. i just went to my local wreakers and snipped an injector plug of an old pulsar that had a dammaged harness (i dont like cutting plugs of a harness someone could use one day but if its Already munted then snip away). I wired it in leaving the old plug just incase but we wont go back to non-neo so the old one could have been cut off

[discopotato03]

Did the R34 injector sub loom plug into the R33 main harness . I know the coil one does .

Cheers A .

[BundyBear]

Did the R34 injector sub loom plug into the R33 main harness . I know the coil one does .
Cheers A .

We used the inlet manifold, injecters and harness of the 33 so we minimised and wiring issues. I think my mates still got the neo inlet manny so we should be able to check the plugs

[AngryRB]

I used the R34 intake mani, had adaptor plate made for the iac stuff, throttle body vacumn channel welded up.  Theres a vacumn line from underneath that needs an extra fitting tapped into the neo plenum. The  top feed rail is obviously a bonus and the plenum gasket is better than the r33 one.

[BundyBear]

We already had an aftermarket top feed rail. So there was no great advantage we could see to running the 34 plenum given the extra work involved in using the 34 one.. which plenum gasket is better in the 34? The one between the two halfs or manny to head?. Did your injector harness plug straight into the 33 harness?

[AngryRB]

Yeah between the two halfs, and the top feed rail on a r33 job is pita so wasnt keen on that.

Cars at tuner, not sure on the injector harness yet..

[Dale FZ1]

Good to see you lads having a go.

Apart from "because we can", what's the driving force for running a Neo 25 in the earlier chassis?

[BundyBear]

Neos are more efficient and definatly stronger than a s1 25. Ringlands, oil pump issues have been fixed (im sure neo arent perfect but better than the old ones). Were suspecting thr neo block is lighter as the car seems to sit a tad higher amd seems lighter in the steering. But thats pretty subjective...hopeing to get her on the rollers monday to get some numbers

[Dale FZ1]

Sounds good enough.

I hope there's either a turbo change or a dirty 30 bottom end in the pipeline for this thing.

[BundyBear]

Well the old girls been dyno'd. seems we lost 40kw peak power but gained 40kw through the mid range. A bit disapointing but the extra mid range will make up for it in driveability. not sure why weve lost peak power as on paper we should have gained. compression is 150 across all 6 (dry and warm). Ive heard people say (since building it) the neo has slightly a slightly different intake diamiter so were planing on doing some measurements and maybe swapping the lower half of the intake to a neo and matching the cut n shut 33 top half and see what that does

 

[Scott Black]

oil pump issues have been fixed (im sure neo arent perfect but better than the old ones).

Definitely not fixed at all, oil pump engagement still to small with poor clearances still lots of failures just not as common as a slightly newer car