Jump to content
SAU Community

Recommended Posts

hi guys, I'm new to the forum, hi everyone :-) lol, I've got a rb25det s2 engine I wanna put into my r34 witch has a neo engine in it, was wondering am I able to use the 5 speed manual box from it and the diff and drivetrain? will be able to use the rb20det clutch I have for it on that box?

also wondering what else from the neo engine I can transfer , thanks guysguys

Link to comment
https://www.sau.com.au/forums/topic/420406-rb25det-s2-into-r34/
Share on other sites

Everything will physically bolt up, i.e. your current clutch/flywheel combo and gearbox will bolt straight on the S2 rb25 without any issues.

The electronics will be a different issue though, you will need to run all the neo sensors/manifold etc because they will be different.

hi guys, I'm new to the forum, hi everyone :-) lol, I've got a rb25det s2 engine I wanna put into my r34 witch has a neo engine in it, was wondering am I able to use the 5 speed manual box from it and the diff and drivetrain? will be able to use the rb20det clutch I have for it on that box? also wondering what else from the neo engine I can transfer , thanks guysguys

Why do you want to do it?

got the engine cheap so why not, ive just put the engine on, bolted up straight to the neo's gearbox and used the clutch/flywheel witch is excedy onto the s2, but ive come to the ecu loom wiring problem now, ive got a r33 loom for it, can I just take the r34 one out and put in the r33 one? what things will I have to wire up differently? thanks

ohk the r34 had a rb25de neo in it not turbo if you got confused, so id have to move all the sensors etc over from the neo to the s2, the injectors wont be turbo spec would they? and would the manifold fit on the s2? after ive done all of that do I just cut the plug off the engine loom and solder on the s2 det ecu or run the neo ecu? cause they both have different plugs..

Basically you need to run the ecu to match the sensors for the engine, if you want to run R33 sensors etc, then you need to run the R33 ECU which means re-wiring.

If you want it as plug and play as possible, then I would be running all the Neo gear on your S2 RB25, that way everything will just click together and it will start. I would avoid the rewiring path at all costs. The inlet manifold on the neo is interchangeable with the S2 engine, so its just a matter of unbolting everything and swapping it over.

The biggest issue you're going to have is that you're going to be running an N/A computer/injectors on a turbo set-up, which will limit what boost you will be able to run. It should run fine, but I wouldnt expect you to run much more than 10psi on the stock turbo before you ran into issues. Ideally, you would get the turbo ecu (or aftermarket ecu to suit an R34 so it was a plug n play job), upgrade the neo injectors and away you go.

Or better still, try to sell the S2 engine if you can and get a NEO RB25DET and then it will be much more plug n play.

ohk sweet as sounds good, apparently its running on 8psi atm so if i got it a tap for the gate i could turn it up to 10psi and see how well it goes, so im guessing if i put the neo inlet manifold on it, it will bring the injectors over as well? cause i hear the neo's are top feed ones? or bottem correct me if im wrong, also will it run the neo CAS? heard they are different on both engines?

The neo top feed injectors will need to come over with the neo manfiold because the injectors/rail are to suit that manifold only. R33 injectors are side feed and the rail also has different mounting points so it will only fit the R33 manifold, which is why you will need to swap the complete manifold/injectors over from the neo.

I forgot about the CAS.... The cam key will be different between the S2 and Neo so you will need to run the R33 CAS to suit the R33 motor. Hopefully the CAS plug on the R34 harness will fit the R33 CAS (not sure on this part), however worse case senario you will just need rewire the R33 CAS plug onto the R34 harness, which should be straight forward.

hey man we just took the intake manifold off the neo and found out the bolt patterns are different on the neo one compared to the s2 engine? and the injectors from the neo wont go into the s2 manifold either cause like you say they are different...what have I done wrong here? like you say they are interchangable but they arent witch is wierd, is it a different head on it maybe?

The only thing I could potentially think of is the N/A Neo head is different - which would strike me as odd..

The r33 na and turbo heads are idential, same bolt pattern and fully interchangeable.

The R34 GT-T head is a different set-up to the R33 heads, however the manifold bolt pattern (both inlet and exhaust side) is the same as the R33 heads so the manifolds are definitely interchangeable.

I've swapped all of the above over before, but must admit I've never touched an N/A Neo head before - I would have assumed that the N/A Neo head would have the same pattern as the turbo one because thats what it is like on the R33 engine... and its unlike Nissan to develop a completely different head.

Unfortunately, if the n/a neo manifold wont fit on the S2 engine, then its no longer a simple bolt in excercise with the gear you have..

I would still steer away from running the R33 gear and re-wiring your R34 to suit but thats me.

If it was me, I would look at three options:

-try to track down a standard turbo neo manifold for cheap and bolt that onto the S2 engine.

-If you can't get the stock manifold or if they want blood money for it, then buy an aftermarket top feel fuel rail and fuel regualtor so you can run the top feed injectors on the S2 manifold. A nice rail is around $180, $50 for fittings, then $150 for a regulator - so budject around $400.

-Replace the inlet side altogether with an aftermarket set-up. Get a new Greddy "style" manfold (or the genuine version if have the $$), get an aftermaket fuel rail and regulator to suit the top feed injectors for an R33 manfiold. This will cost anywhere from $700-$1300 depending if you get the genuine greddy gear or not.

  • 2 weeks later...

hey man, ive got a picture of the intake manifold bolt pattern, ive been doing some research and as far as ive got is thinking this engine may not be a rb25 but a rb20....it has red temp sensor on the radiator hose, looked up the CAS model number and its saying its an rb20 one...but it seems to be running indivdual coilpacks and I know the rb20's never had these, ive attached pictures of it, see what you think...

post-107952-0-97258800-1363755719_thumb.jpgpost-107952-0-37512400-1363755496_thumb.jpgpost-107952-0-50338300-1363755692_thumb.jpg

Yup that's definitely not an RB25 - the biggest give away is that it has no "bulge" on the timing belt cover where the inlet cam is - that's where the VCT should be. No VCT - no Rb25

I wouldn't be putting that into an R34. Sell it and get the right one.

hey man ive just ran the head and block numbers, the head has 08U writtten on it witch is the r32 rb25de head and it has 75T on the block witch is a r33 rb25det, so I do indeed have a rb25det in there, question is can I still run the rb25 neo ecu with it? cause it looks like its running the rb20 injectors etc...witch are top feed anyway

I wonder what has happened to this engine and where it has come from...

Is it a R32 RB25de that someone has just bolted a turbo onto or is it actually an R33 RB25DET that someone has removed the stock head and put a R32 RB25de head on it (if so, why - doesn't make sense??)

Anyway.. it all comes down to the head as that will dictate what manifold you can use and in turn what injectors/ecu/wiring. If its a R32 RB25de head then the inlet pattern is different again to the R33 25 manifolds so you're going to run the manifold that came with the engine as your R34 also wont fit (as you now know). The injectors that came with your "new" engine should work,because if they are R32 RB25de injectors they should be high impedance so your stock ECU should be fine. Basically, you will want to try and swap as many sensors etc off the R34 to the new engine so you keep it as "plug n play" as possible. You may need to rewire a few to suit if some of the sensors that aren't compatible (i.e. CAS, possible injector plugs). You also wont be able to hook your VCT up either because this engine doesn't have it.

I would still be opting out and look at selling the engine and getting the NEO RB25, but if you're up for a challenge and a bit of work theres no reason why you couldn't get this engine going in your car.


Good luck!

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

    • For once a good news  It needed to be adjusted by that one nut and it is ok  At least something was easy But thank you very much for help. But a small issue is now(gearbox) that when the car is stationary you can hear "clinking" from gearbox so some of the bearing is 100% not that happy... It goes away once you push clutch so it is 100% gearbox. Just if you know...what that bearing could be? It sounding like "spun bearing" but it is louder.
    • Yeah, that's fine**. But the numbers you came up with are just wrong. Try it for yourself. Put in any voltage from the possible range and see what result you get. You get nonsense. ** When I say "fine", I mean, it's still shit. The very simple linear formula (slope & intercept) is shit for a sensor with a non-linear response. This is the curve, from your data above. Look at the CURVE! It's only really linear between about 30 and 90 °C. And if you used only that range to define a curve, it would be great. But you would go more and more wrong as you went to higher temps. And that is why the slope & intercept found when you use 50 and 150 as the end points is so bad halfway between those points. The real curve is a long way below the linear curve which just zips straight between the end points, like this one. You could probably use the same slope and a lower intercept, to move that straight line down, and spread the error out. But you would 5-10°C off in a lot of places. You'd need to say what temperature range you really wanted to be most right - say, 100 to 130, and plop the line closest to teh real curve in that region, which would make it quite wrong down at the lower temperatures. Let me just say that HPTuners are not being realistic in only allowing for a simple linear curve. 
    • I feel I should re-iterate. The above picture is the only option available in the software and the blurb from HP Tuners I quoted earlier is the only way to add data to it and that's the description they offer as to how to figure it out. The only fields available is the blank box after (Input/ ) and the box right before = Output. Those are the only numbers that can be entered.
    • No, your formula is arse backwards. Mine is totally different to yours, and is the one I said was bang on at 50 and 150. I'll put your data into Excel (actually it already is, chart it and fit a linear fit to it, aiming to make it evenly wrong across the whole span. But not now. Other things to do first.
    • God damnit. The only option I actually have in the software is the one that is screenshotted. I am glad that I at least got it right... for those two points. Would it actually change anything if I chose/used 80C and 120C as the two points instead? My brain wants to imagine the formula put into HPtuners would be the same equation, otherwise none of this makes sense to me, unless: 1) The formula you put into VCM Scanner/HPTuners is always linear 2) The two points/input pairs are only arbitrary to choose (as the documentation implies) IF the actual scaling of the sensor is linear. then 3) If the scaling is not linear, the two points you choose matter a great deal, because the formula will draw a line between those two points only.
×
×
  • Create New...