R33 Rb25det Series 2 Vs. R34 Rb25det Neo

[pricer-1]

So I have been looking into a RB swap for my S13 and I think I want to go with the R34 Neo but I have a few questions about differences between the Neo and Series 2 engines. When it comes to upgrades or even just OEM parts will the parts for a Series 2 motor work on a Neo? Physically what are the differences? Also what parts should I consider replacing before installing the engine into my S13?

[fergo308]

AFAIK pretty much nothing in the top end is interchangeable. the cams and injectors are different. exhaust manifold can be swapped though. ecu and loom are totally different.

Why are you putting an RB25 into an S13? it ruins the handling and all the hassle isn't justified for just a 25. if you're building a straight out drag car,go directly to an RB26,skip the 25,you'll never be satisfied with it.

Justin...

[Stinky Rooster]

and you put this in the Stagea thread because........?

[Lithium]

Why are you putting an RB25 into an S13? it ruins the handling and all the hassle isn't justified for just a 25. if you're building a straight out drag car,go directly to an RB26,skip the 25,you'll never be satisfied with it.

I couldn't possibly disagree with this all more. S13 + stock internal RB25DET with an upgraded turbo etc is a proven 10s combination at the drags. Even an RB20DET makes a hell of a fun car to drive, if its going into what was originally the CA18. Going by the fact you mention the handling, I am better you have not actually driven an S13 with an RB in it? It is a comment made often and I've never heard it made by people who've actually tried driving one. There are quite a few top NZ drift cars using RB powered S13s, even in Japan its done.

[fergo308]

I actually have driven an Rb20DET powered S13,and it was less than awe-inspiring. maybe back in the late eighties when an rb20 was a step up from the only engine silvias had,the CA18,it was worthwhile,but with the power SR20's can make nowadays,there's almost NO reason bar drag racing to go for the 6cylinder engines in silvias.

how many well-worked-over SR20 silvias have YOU driven? STANDARD turbo S15's are good for high 12's. throw the same money you'll spend on the conversion into working an original equipment SR20,and you'll see similar times as you would with the mildly worked RB.

Justin...

[joe26f]

Get an RS4 drivetrain and make an AWD S13

[petrolfix]

mate un less you want to track work or rallying of some sort i whouldn't worry about the extra weight of the rb. the rb has a shit load more torque and makes an s13 with one a hell of a lot of fun. keep it simple and stay away from the neo, i have one in the stag and as good as it is, the more i learn about it itis a very complex machine.+ the parts and power upgrades for the s2 rb25 are easyer and cheaper to get. have fun with it if you find understeering to be a problem then just put bigger tyres on the front then the back. then oversteer is your friend :laughing-smiley-014: . go over to www.silvia.com.au and there is this topic posted up numerous times.

[Baz]

AFAIK pretty much nothing in the top end is interchangeable. the cams and injectors are different. exhaust manifold can be swapped though. ecu and loom are totally different.

Why are you putting an RB25 into an S13? it ruins the handling and all the hassle isn't justified for just a 25. if you're building a straight out drag car,go directly to an RB26,skip the 25,you'll never be satisfied with it.

Justin...

Well because they are both RB25's, they are basically the same motor. AFAIK, the cams and injectors are very similar if not the same. The only reason I could see them being different is to reach the 206kw output of the R34 motor, compared to the 185kw (I think) output of the R33 S2 motor. ECU and loom are different because of a few added sensors to the NEO.

IMO choosing a neo when doing an engine conversion is to do with wank factor for it being a NEO and a funky engine cover. Sure they are an updated and newer motor with revised parts (Different intake, revised breather hose setup, added sensors, slightly larger turbo) but it just does not justify the extra expense that you require to fork out for one.

And if you know how to drive and how to setup a car properly, having a RB25 compared to an SR should barely affect the handling of the car at all. This obviously incoperates choosing the correct spring rate for the front to balance out the extra weight across the car.