rb25det potential vs. rb26dett

[jollygreen]

I am curious as to what the rb25det is capable of if built. i'm aware of the differences between the 2 engines and i'm wondering if it's really worth spending the extra money on a rb26dett. if both engines are built do they have the same potential?

[Spazz]

its been discussed many times on here, use the search button ( the one on the tool bar that flashes) the rb26 is far more superior than the rb20/25.

[PalmerWMD]

But he did say <if built>...

[Yellow4g63]

I would have to say the 26 head blows away the Rb25's by far.

[sean8564]

the rb26 is the easy way to go Rb 25 a little more difficult to get.

[SeVa-S13]

They're limited to 3 and 4.2 bazillion horsepower, respectively.
Modified by SeVa-S13 at 4:39 PM 9/5/2005

[onefastrb26]

The 26 head flows a lot better than the 25 head. If the bottom ends are build, the 26 will still rev higher, so it will make more power. If the heads are built and ported, the 26 will still outflow the 25 head. The 26 has more potential...

[jollygreen]

i understand the 26 head is better, it has itb's and flows better. but for the cost of a 26 swap you could swap a 25 and build it if you assemble it yourself. is the 26 THAT MUCH better to justify the extra cash?? i don't really care about the wow factor, i just want the most cost effective way to achieve 500whp on pump gas.

[Joe]

a 25 is all you need if you are going after 500whp.

[sean8564]

I agree with Kamin You can Make that easy with the 25.

[jollygreen]

would you need to rebuild to make it reliable? or could a stock 25 with bolt-ons safely make 500whp on 91 octane??

[Joe]

personally i would rebuild it.

id rather have the piece of mind having a properly built engine that would run forever, vs. a stock one you are bringing near its safe limits. im not saying a 500whp RB25 wont make it, but its an intelligent idea to build it.

[jollygreen]

thanks for the feedback, i appreciate it

[nissanparts.org]

personally i would rebuild it.

id rather have the piece of mind having a properly built engine that would run forever, vs. a stock one you are bringing near its safe limits. im not saying a 500whp RB25 wont make it, but its an intelligent idea to build it.

I smell a tomei engine

[Joe]

not on my RB25 lol. tomei = overpriced

and hey your in scottsdale?

i need a CAS for a R33 RB25, part number: 23731 08u00, this is also on the CAS d6y91-02 5202. email me [email protected]

[RB26-S13]

Umm... the 26 will make 500 hp .. like.... extremely easy, very little mods at all.... The turbo's crap out at about 450-500... replace them with a pair SLIGHTLY larger... boom.. 500 right there.

[eh?]

RB25 NEO........ solid lifters, rb26 rods, much cheaper than RB26.

[themadscientist]

26 has better head bolts too. for 500hp the 25 is up to the task. rebuild it though. these are used motors boys and girls! would you take a junkyard KA and try to produce double the power without a rebuild?

[Nameless EJ6]

Umm... the 26 will make 500 hp .. like.... extremely easy, very little mods at all.... The turbo's crap out at about 450-500... replace them with a pair SLIGHTLY larger... boom.. 500 right there.

lol. You make it sound much to easy.

The RB26 isn't gonna make 500 'extremely easy'.. no motor will.

You gotta have the fuel and tuning to support it. The RB26 will SUPPORT 500 'extremely easy'.. but who wants to run 500whp on a stock RB26 all the time? Or an RB25. It's silly. Wear and tear starts as soon as you turn the boost up, upgrade the turbo, etc.

Building the motor is the only reasonable way to go if you want a reliable 500whp motor.

And if you only want 500whp, there's no reason for an RB26 unless you love to run that much power without knowing whether or not the motor is happy supporting that much power all the time. Build it, do it right.

RB25 for 500whp. RB26 for over 500. Both built.

And for 500whp, you're not gonna necessarily need to worry about head flow. You really need to worry once you get over the point where you stop making more easily when turning up the boost while tuning it. Headwork is usually done AFTER building the bottom end... unless you're using pistons that would require headwork. You're gonna need head aftermarket head bolts for 500whp as well. Cams will help with headflow as well. Max out the headflow with aftermarket cams and that's when you need to start working on the head.

[eh?]

Do you have any sort of experience with RB's to be saying any of that?

[Phat_Optimo]

The RB26 is the better engine... hince it has more potential... duhh. It also has tons more aftermarket support. Just look at the OE charge piping and intake manifold setup compare them. That should tell you something

[jollygreen]

so what is the 25 capable of if built with a mild port/polish and valve job??? can it produce numbers similar to a built 26?? also, since it's slightly less displacement does that mean less reciprocating mass and therefore if balanced could rev higher then a 26??

[Joe]

so what is the 25 capable of if built with a mild port/polish and valve job??? can it produce numbers similar to a built 26?? also, since it's slightly less displacement does that mean less reciprocating mass and therefore if balanced could rev higher then a 26??

your asking 2 different questions

in 1 post you say all you want is 500hp, in the next you say you want numbers similar to a built 26

i think your missing the point that you need to pick a hp number, then pick an engine to meet that number. you arent going for max power so it really dosent matter wich one you choose. to be honest i dont think you realize how much eithre are going to cost you to build; not only the engine, but a car capable of 500hp. the engine is only half the battle.

and reciprocating mass has little to do with rev limit. also rpm does NOT equal horsepower.

[sean8564]

ok the rb25 and 26 blocks ar the same minus a few oil lines here and there

[Joe]

ok the rb25 and 26 blocks ar the same minus a few oil lines here and there

hmm im gonna disagree with you on that, they are close, but not the same

if they were the same a 26 head would bolt onto a 25, and thats far from true.

[sean8564]

well now if you use the 26 crank and rods with 26 pistions this ups the displacement to the 2548cc like the 26. Well noe exactaly the same as far as VTC oil lines the RB25 oil cooler lines RB26 Head bolts But From what I understand they are the same Cylinder Bore. Correct me if I am Wrong

[jollygreen]

500whp is my goal, i was just wondering if once built a 25 would be able to hang with a 26. i know i can reach my goal with a 25 and that's what i'll be getting. i'm just wondering what it would max out at because after a while i may want more. btw i know reving higher doesn't make more hp, and that it's going to be expensive to build a 500whp street car.

[DriftingisLame]

Build an RB20 and blow us all away..

[themadscientist]

ok the rb25 and 26 blocks ar the same minus a few oil lines here and there

they share some base measurements but there are notable differences. you can drop a 26 rotating assembly into a 25 true, the assembly sans 86mm pistons will go in a 20 too. They are totally different castings.

[Kansei240sx]

If anyone wants to see what a properly done RB25DET can do, Go to this website....

http://www.G3POWER.COM

Its in japanese but you can still navagate through the pictures, and its ****ing awesome, some of the work they do to thier cars are sweet as hell.