RB25 NEO VS RB25 SERIES 1 AND RB25 SERIES 2

[craz4240]

Hey guys,

Just trying to clear up what parts are similar between these 3 motors.I recently sold my rb20 frankenstein motor to a friend and am swapping in an RB25 neo in the months to come. Car is a 1995 240sx.

Wondering if anyone can confirm these are the same as the earlier rb25's (series 1 and 2)

1.) Timing Belt2.)Tensioner3.)Idler4.)Water Puump5.)Oil Pump6.) Gasket Kit7.)Intake and exhaust manifiolds (flanges to head mostly)

Problem is none of these parts that I have searched out list the NEO motor,I assume they are the same but need for sure input if you guys can help.

Harness will be done by carl HUsing R33 Crossmember and Syko mountsBully Clutch Being installedClutch fan retrofitGriffin RadOther things I think I have the basics covered as this is not my first RB swap.

And I'd use my FAST program but for some reason I can't add the JDM files to the USDM version I have on my laptop...and for now I need the USDM program more.

Thanks a mil guys hope to see this thing turn out over the next year.

[S14-NEO]

yes to all of the above...welcome to the small NEO family..hehe, your in for a treat..

[Carl H]

hg may be different and the intake manifolds are definately different but the head flanges are the same for both the r33 and 34 heads.

[Thanielson]

ya it always is a challange.

[neonbomb]

Your life just got ****tier! Getting a neo was my worse decision everrrrrrrr

[S14-NEO]

oh blah , blah , blah....you guys sounds like a bunch of whinners ..i have not had one issue that you guys are thinking of that i couldnt get around...you guys just have to investigate things like i did thats all.

[Coolwhip]

as mentioned before, all are the same as x-ref parts.

However, thought the head flange for the intake manifolds are the same, the throttle body gasket is different along with the throttle body. The AAC /IACV is different including it's mounting flange. The injectors and rail is different from the S1/S2 to the NEO.

[Coolwhip]

Your life just got ****tier! Getting a neo was my worse decision everrrrrrrr

plain and simple, NEO's rock!

[craz4240]

Awesome info guys so far.

I was aware the intake mani was different however I was mostly asking to gauge how useful a full rb25 gasket set would be on a neo. I am sure the MAFS is the same as series 2,CAS is different then early rb25's but same as later ones?? Little things just getting the ducks in a row cause this swap is gonna be a slow and very attentive build.

[craz4240]

yes to all of the above...welcome to the small NEO family..hehe, your in for a treat..

Thanks alot man....I am very excited to start this journey.

[Coolwhip]

out of the gasket sets available the RB25 set is the one you'll use, (and only few inbetween gaskets won't work but you'll be fine).

CAS is the same as the R34 RB26, thats it.

[S14-NEO]

i could be wrong but i believe the NEO MAF is also just for the NEO engine. i never used one on my setup cause i have a power FC and im rocking a Z32 MAF so i didnt have to worry about the fact that my engine didnt come with a MAF cause i already a Z32 MAF anyways.as far as the throttle body is concerned, its the same style throttle body setup used on some Q45's with the funky traction control system that uses a secondary throttle plate in order to modulate the amount of incoming air to keep the power down when the TCS system is on.

[Carl H]

neo maf = s2 rb25

[S14-NEO]

neo maf = s2 rb25

well there ya go

[jbracy7]

what is a rb25 neo

[Cjmartz2k]

I'll assume that's a joke. You wouldn't want to catch the internet beat down you would receive for not typing "RB25 Neo" into google before asking such a stupid question. Like I said, I'm pretty sure that's a joke, right?

[S14-NEO]

what is a rb25 neo

you have got to be freakin kidding me..

[craz4240]

Awesome...info here guys. I appreciate it alot it is clearing up some of the grey area ideas I had. For those wondering there are no huge plans for the swap to begin with...just get it in and running real strong for awile prolly a year or 2 then down the road I plan on with some research of course begginning my journey to 450whp.

Any more info on parts for the neo we can put in here the better so if you have anything to add for those interested such as myself please do.

[jbracy7]

Im sorry i dont type everything i see into google . flame if you wish but im clueless about all the RB's im just a ka-t guy trying to step my game up a lil

[Coolwhip]

for the best source for NEO info is reading through the build threads of the NEO guy's themselves. They have actually had their hands on these motors, tried to fit parts that didn't fit or work, as well figured out what does.

That's the research part

[craz4240]

Indeed it is......I just happen to know a couple guys on here have done the swaps very successfully and initially speaking I just want to confirm some things i already believe are true/false. Whiten up the grey areas a bit.

Thus far I know

Series 2 rb25 MAF is the same as NeoRB25 Gasket set works for the most partRegular RB25 Exhaust Mani will work fine when the time comes to change up the snailQ45 or something similar TB gasket should workTiming Belt,Tensioner and Water Pump on the neo is the same as the RB25CAS is the same as R34 RB26DETTAnd the wiring I'm not doingOil Pump is the sameSplitfire makes coilsAlot of clutch companies make clutches

I say this is enough info to start a sucessful swap.The rest I should be able to bumble around/research on SA or some other similar forum Nico.. But feel free to continue compiling in here if you like I sure will.