Rb26 Forged Vs Rb25(neo) Forged!

[GreeceS13]

What to choose guys?

Don't think the money... only the result!

If I have the same forged pistons and rods (e.g. wiseco+eagle) either on rb26 or rb25 what I will have better if I choose rb26 engine?

The power that I want is 500-600 for now but I want to know the power limits of the engine for later...!

[R31Nismoid]

Pretty open ended question

500hp? rwkw? rwhp?

[GeeTR]

Theres no debate, if money is no question, I cant think of any benefit of using an RB25

[R31Nismoid]

Agreed

[GTR-80Y]

i assume he meant 500-600hp. Rb26 for sure!

But i must say i really do miss a responsive 200rwkw on the streets.

[BLK33T]

RB26 for sure

shorter inlet track (no over the top plenum)

higher capacity 2.6l as opposed to 2.5l (as we know there really is no replacement)

better flowing head

six throttle bodies = excellent response

this list goes on and on

don't kid yourself even thinking about a RB25 if money is no object.

then again if you got a big budget why don't you look into an LS1 or an LS2 conversion ... I assume you aren't wanting or don't have ATTESSA so you could go down this route.

benefits include.

50kg's + lighter than RB26 and its shorter in length than RB26 which equals better weight distribution.

virtually indestructible bottom end that will support upwards of 400rwkw's standard when boosted.

minor mods to head will see the motor sit on 7000rpm all day everyday.

mountains of torque will see you frying tires in every gear.

simple, less complicated design would suggest that less chance of mechanical failure.

standard ecu is very advanced, easily chipped/ tuned and will support anything you throw at it

huge power-band

etc...

that should rattle some peoples cages now let the flaming begin

[r33cruiser]

hmmm.. rb26, spins 4 wheels.

hmmm..rb25, spins 2 wheels.

i know what i would go for

[BLK33T]

ohhh and depending on how much you throw at an RB26 you can make upwards of 1000kw's ... look at some of the drag gtr's around they make close to or above this figure

[R31Nismoid]

RB26 for sure

shorter inlet track (no over the top plenum)

higher capacity 2.6l as opposed to 2.5l (as we know there really is no replacement)

You know the RB26 isnt a "true" 2.6ltr yes?

Its approx 50cc's more if that

ohhh and depending on how much you throw at an RB26 you can make upwards of 1000kw's ... look at some of the drag gtr's around they make close to or above this figure

Im sure with the money spend to get a RB26 to 1000kw, you could do the same with RB25

[sloutch]

definitely go for the RB26. Bigger capacity is already a plus point.

[discopotato03]

Neither , RB30E cheaper and not really any weaker . If your up for aftermarket RB rods and pistons I'd start with an RB30 . Being a "Mk 1" block ie non VCT its very easy to bolt the RB 26 top end on it . Do the rest as per RB26 and have the bottom end with .... bottom end . For the money I'd do the crank collar just because .

Cheers A .

[a20089]

then again if you got a big budget why don't you look into an LS1 or an LS2 conversion ... I assume you aren't wanting or don't have ATTESSA so you could go down this route.

benefits include.

50kg's + lighter than RB26 and its shorter in length than RB26 which equals better weight distribution.

virtually indestructible bottom end that will support upwards of 400rwkw's standard when boosted.

minor mods to head will see the motor sit on 7000rpm all day everyday.

mountains of torque will see you frying tires in every gear.

simple, less complicated design would suggest that less chance of mechanical failure.

standard ecu is very advanced, easily chipped/ tuned and will support anything you throw at it

huge power-band

etc...

that should rattle some peoples cages now let the flaming begin

NO flames yet :-)

Any hint of the price for the engine, then the fitment, then possible the twin turbos just so you get the power you need.

[GreeceS13]

Guys thanks for your replies!

But maybe you can help me more if I tell more about what I have to choose!

Also I am from Greece... I don't know what is LS1 and 2 and sure I cannot find it easy.. also I don't want rb30!

RB26DETT from Greece 5.000AUD

Condition"

It has problem at crank(stock oil pump and hard driving )... it needs rebuilt..!

So I can buy from AU or UK a second hand crank and forged pistons-rods, stock gasket kit, acl bearings!

PROS

Also it has twin plate hks (unknown condition but new discs aren't very expensive right? )

It has repaired turbos with steal wheels and I can sell them!

He said that it has something like extra ecu, bullshit sure but I can remap the stock ecu as far as I want!

CONS

IT HAS RB20 GEARBOX!!! :| :| :| :|

I can sell it about 500-600aud I think here in Greece at 200sx boys and then I can buy one rb25 gearbox for 1100AUD

RB25DET NEO from UK Including 4.100AUD+300Shipping

Condition:

Mint condition stock

I have bought greddy intake with 90mm q45 throtle body and stock gasket kit (but I hope that I can sell them if I choose 26)

I also will need pistons and rods and bearings as the 26 to have a safe motor!

PROS

RB25 Gearbox

NEO engine!! Fresh and better than r33s!

CONS

NEO engine have some incompatibility with r33 aftermarket parts!

TARGET

For now 500-600HP!

But potential for quite more..

I don't want never to spend money for the head.. no cams, no headwork, nothing at all!

The "house" of the RB will be my 180sx S13 everyday car but I love Drag Strip and I want to see my car to run high 10s!!!!

Sorry for the gabble! Hehe my target is high 10 and I don't mind for hp!

Can I do it with stock rb25 gearbox?

I don't want weight reduction!

I have Hoosier Drag Radial 225-50-15 and I don't want to spend money for larger tires.. I want to do high 10 without crazy low 60foots!

Think that I did 2.0 with 350hp and toyo r888 225-45-17!

Edited December 21, 2007 by GreeceS13

[illusiVe]

I have a R34 GTT and im thinking about 500-600hp engine or wheels either is good. (i know i know, big difference)

I know the huge advantage of having an RB26.. but is it worth the COST difference to either rebuild my busted RB25, OR just sell the RB25 and buy an RB26DETT + mod it..

(just adding to this thread hopefully not stealing it)

(oh and id def not rule out RB25/30 or 26/30......im more wondering cheapest way to make the best 500-600hp RELIABLY and properly, not an engine that will last half a week)

Edited December 21, 2007 by illusiVe

[R31Nismoid]

Good lucky making 370-430kw on a stock motor.

Wont last forever.

So if you dont wanna spend money on the head etc, then get a more realistic aim.

[GreeceS13]

I told that both 25 or 26 will be with FORGED pistons and rods and full rebuild!

Ok RB26 have huge advantages..! But what they are?

Let's start a list:

-Better flowing head

-6 throtle bodies (lest the q45 will be good too?)

-intake manifold (rb25 with greddy intake will do the same job)

-Remappable ecu

-They have the same block?

-What about electronis?

-Ι don't mind for 50cc more of the 26

I don't think that the advantages of this list are HUGE! We don't compare stock engines... we compare tuned engines!

I know that 600 engine HP can handle a stock 26 but the 26 that I find to buy will need full rebuild for sure work!

I will do whatever you say me

I told you above the prices and what exactly I will get with 26 and with 25!

If 25 and 26 have really HUGE differences I will go for 26 but I want to know the HUGE differences to know what I do

Edited December 21, 2007 by GreeceS13

[R31Nismoid]

If your going to build a bottom end dude, you'd be extremely silly not to put some effort into the headwork required.

Thats arguably the most important part.

[GreeceS13]

Just I don't want to spend money in the head...! Only I will change seals and I change what ever is worn! No cams no headwork!

If after some years I want extreme power I will spend money and at the head!

For 500-600 engine hp I know that stock head both 25 and 26 is enought, right?

But my problem is what to choose... not if I do somethin with the head..!

Come on guys!! Please help me with your knowledge

Edited December 21, 2007 by GreeceS13

[BLK33T]

you need less work to get the RB26 to the power level that you are chasing ...

RB26 has more after market support overseas than RB25 has

if you are going to rebuild either motor my advice is to go with RB26 ... if your going to drag race get a big single ... if you are building it for the street or track go with a twin setup like t517z 0r 2530's turbos <--- correct me if I'm wrong but these turbos with a forged engine should see a very responsive 500hp with the right supporting mods and tune.

and yes it is true that you can get the RB25 to the same power levels but you will need to lean on it harder to make the same power.

you'll need at least cams and upgraded valve springs to reach the power levels you are looking at you will also need injectors 740cc or bigger and a massive fuel setup i.e. twin pumps, surge tank etc you'll need to revise the ignition setup too with upgraded coil packs etc etc.

The bonus is that you don't need to port the head because it flows very well as standard 1000hp + is not a problem.

if your going to rebuild the motor consider a stroker kit like HKS or Tomeii to make the capacity either 2.7 or 2.8L this will place less stress on the engine because you won't need to rev it as hard to make the power that you are after.

anyway you look at it you are going to have to spend big dollars getting the whole setup reliable.

my advice ...

if your going to do it ... go all out and do it right the first time

it might cost in the beginning more but it will save you lots of headaches in the long run

perhaps you should make a call to a company like CRD or the like and ask them their opinion because they are very well respected over here and will be able to give you the right advice ... they are the experts after all.

[turboedsloth]

you want to forge a bottom end but not spend anything on the head? in my opinion your wasting your time an money on the thing. do it right the first time with watever motor YOU choose to go with