Rb25 Neo Basic Rebuild For 350rwkw

[BaysideBlue]

Hi guys, thinking of rebuilding my rb25 neo to handle 330-350rwKW

what i have so far--> gt3240, external gate, 600cc injectors, pfc, fmic and all.

on the card--> tomei poncam, cam gear, custom plenum & throttle body.

whats required in a minimum rebuild to handle this sort of power? this is gonna be the last major mod for my car to keep me entertained till I have saved enough for a r34 gtr, therefore a basic rebuild is all im after.

many suggested forged pistons is a must. also metal head gaskets.

what about valve springs and retainers?

what else do you think i need?

thanks for the help.

Edited July 4, 2007 by BaysideBlue

[sinistaGTR]

if your rebuilding get some forged pistons, gtr rods, a good brand (ie trust) thick metal head gasket, n1 water and oil pump, acl race bearings, gates timing belt, oil cooler, q45 afm, decent ebc (not essential but with that power its great to turn the boost down when required). A decent clutch, maybe a diff, splitfire coils. thats just off the top of my head, still wanna go through with it lol. lotsa cash basically.

[Devils_Advocate21]

If intending to run more than say roughly 20psi valve springs as some have experienced valve float above, rods you can pick eagles up for cheap these days Diff is non-essential but wouldnt hurt, gear set some have seen past the 400 mark some havent its touch and go there add power increase wear. Part from that the above post is a good start its a fun and expensive game.

If you add the handling to it, theres more money and braking a little more money.

Cheers

[BaysideBlue]

A decent clutch, maybe a diff, splitfire coils

check, check, check. also already has greddy ebc and z32 afm. is q45 afm necessary for the power level?

and I thought r34 gtt came standard with gtr rods?

Edited July 1, 2007 by BaysideBlue

[N I B]

Still never pulled a NEO down with GTR rods,Every engine sofar has had std RB25 rods.Dont use R33 Forged pistons,Big mistake that I see from shops that should know better.

[R31Nismoid]

GTR crank, rods & forged pistons of some description

Either way there is no such thing as a basic rebuild when chasing 350rwkw

Its going to cost you around 6-7k.

[BaysideBlue]

I thought I have read somewhere in this forum that rb25 neo came standard with gtr rods, guess i was wrong then.

what about water and oil pumps? the standard ones are good for 300rwkw, do they really need upgrade for an extra 50kw?

Edited July 1, 2007 by BaysideBlue

[R31Nismoid]

i wouldnt be using stock oil/water pumps on a built motor dude.

[BaysideBlue]

GTR crank, rods & forged pistons of some description

Either way there is no such thing as a basic rebuild when chasing 350rwkw

Its going to cost you around 6-7k.

whats the breakdown for the 6-7k, including labour I assume? I already have all the external supporting mods as said above.

cheers

[R31Nismoid]

ye thats labour, motor in out etc etc. a 26 crank alone is ~$1100, pistons $1300, motor in/out $1000, so you can see the costs going up quite fast

Doesnt include tuning or any extra head work, just a light tidy up of the head and what not.

So if you wanted the extra gear like springs etc, then add accordingly

[discopotato03]

That GT3240 may be a bit of overkill and have manifolding issues because only HKS had exhaust housings made for them and they are 0.87 A/R and T28 mounting flange . A T3 flanged GT3037/GT3076R would probably be a bit more responsive for the power .

Cheers A .

[BaysideBlue]

ye I know its an overkill as I could only run low boost with standard internals, was considering down sizing for more response but want get the rebuild under way first and see how it turns out.

Edited July 4, 2007 by BaysideBlue

[BaysideBlue]

last question, which forged pistons on the market are suitable for my power aim? and work well with rb25 neo?

Edited July 4, 2007 by BaysideBlue

[sinistaGTR]

i got wiseco there sweet as i run them in my rex and skyline.

[Abo Bob]

Still never pulled a NEO down with GTR rods,Every engine sofar has had std RB25 rods.Dont use R33 Forged pistons,Big mistake that I see from shops that should know better.

If you are regularly pulling down NEO engines then why don't you take a pic of the rods you pull out, maybe put them next to some RB26 ones. Even better take some measurements.

You are the only person I know still saying that they don't have GTR rods in them. The part numbers are even the same for all the GTR's and the NEO RB25 in FAST.

I will have to admit that I did not personally view my own rods however I gave my engine builder some R32 GTR rods to replace them and he said that when he put them side by side they were identical. I can't think of any reason why he wouldn't use the GTR rods supplied if they were different.

As for putting on an oversize turbo then turning the boost down - have a think about what you're saying dude. 350rwkw from an RB25 is going to be laggy with the best possible turbo so why the hell would you introduce more lag deliberately. If your answer is "i'm getting a really good price" then sell it and get something more appropriate.

I can't comment on valve train because I only run about 19-20 psi but maybe you should look at some slightly bigger cams like the Tomei Procams.

I don't think you need a GTR crank as you can get a crank collar fitted to deal with the small oil pump drive issue which should be enough. Jun oil pump? (There goes a grand) N1 water pump.

Basic rebuild for 350rwkw? These two terms don't belong in the same sentence together.

many suggested forged pistons is a must

Bloody oath they are a must. I use Wiseco pistons because they are teflon coated from factory and have long skirts which I believe helps keep them straight in the bore thus less long term wear which probably doesn't matter to you. Any pistons for RB25 will fit the NEO.

If I was rebuilding again I would look at coatings for lots of the moving parts like bearings and so on.

A 3.5" exhaust would be helpful but a quality 3" one will do the job.

A good diff will be essential. What have you got?

Tyres?

What kind of intercooler do you have? Do you think it's capable of it's new job?

[hayden49]

Like many have said, there is nothing "basic" about building a rb25 to make 350rwkw.

Its not a matter of buying a bunch of parts and slapping them on and voila 350rwkw appears.

Your car will be off the road for some time and unless you can learn how to put an engine together yourself (its not that hard) dont expect change from 20-25k if your going to go all out.

And really, whats the point in under taking such a project if your not going to do everything the right way the first time?

[Rolls]

What's the point if you are going to buy a GTR? put the money towards the GTR, you'll have it sooner and probably able to buy something already built saving you even more money in the end.

[VB-]

seriously, consider a RB30 bottom end. you can get the motor built, then change it over later (less time off the road) and you can buy an RB30 cheap, and full forged rebuilds are cheap(ish) becuase everyone with a VL turbo has one. this owuld also do miracles for the larger turbo

[Adriano]

Agreed

" Any pistons for RB25 will fit the NEO" yes but they will give a much different C.R. to a non NEO rb25

[N I B]

I'll take photos of the rods next time.

33 Piston has a much higher dome than NEOs' I have a set of Venolias setup for a NEO if anyone wants them,New.