rb26dett or rb25det please help

[llucky13]

hello everyone. i'm debating on either the rb25det or the rb26dett for my 89 240sx. i have done my research so please bear with me.
1 i know the 26 has more power than the 25 but can the 25 be built to be equal to the 26?
2 what parts are swappable with the 26 to 25?
3 can i use the internals from a 26 and put into the 25?
4 what needs to be done to drop the compression ratio?
the reason i don't really want to go with the 26 is cause it's a little bit more money than what i have.
thank you guys for your help.

[TheSparo]

the 26 will have to have a turbo taken off, no room, and a 25 will be plenty of power, plenty, just make sure you do it right, dont bother with the rb26dett in my opinion

[cooldill]

well if its out of your budget i think you should go another route.. There are always little things/expenses that pop up, and you wouldnt want to have to leave your project undone cause you cant fund it...
btw..Where in Hawaii are you?

[Grumpy]

A lot can be done to the RB25DET to make good power. I have seen HP numbers up around 700 for the RB25DET. But these are pure race cars not street cars.

Some parts from the RB26 can swap into the RB25. Not alot!!!

The RB26 can be fitted with the stock turbos on the car.............

RB25DET........
http://www.imagestation.com/picture/sraid65/p5ac647272e3f096e6ddc0f7372c6a8b1/fbecfd83.jpg

RB26DETT in a S14 240sx...........
http://www.imagestation.com/picture/sraid65/p09fa28ff73067ae061271f6f5b64c8e2/fbecf85c.jpg
http://www.imagestation.com/picture/sraid65/p11f118a8296f28a424cc3fe3d4663d60/fbecf867.jpg

Grumpy

[misnomer]

rb motors are generally the choice when money is not a consideration :P

Regardless, unless you are looking at becoming a drag queen, either motor will be just as effective. What power levels were you hoping to reach?

I don't know what internals are shared between the engines. Compression ratio is dropped the same with any other engine, usually new pistons. But, do you really want to lower compression? It's already a turbo-built engine, lowering the compression may allow you to run more boost, but it will effect the RB's great torque levels.

Either engine is not a "plug and play" swap, but you've done your research so you know. The rb26 will have trouble clearing the steering column with it's twin turbos.

[llucky13]

i'm located off of nimitz highway in military housing. as far as dropping the compression it's to match the rb26's at 8.5 to 1

[DuffMan]

I would think about it this way. Find out the total cost difference between the two, and then decide whether the natural advantages of the 26 in whatever internal improvements it has is worth more power than the same money sunk into improving the 25.

It really depends on things like what your plan for build up is, like turbo sizes, what kind of power band you want ect.

[wpayne]

The RB26 is by FAR superior to the RB25. Yes, parts are swapable to get the RB25 near where a RB26 but it'll probably cost you more than just getting a RB26 in the first place. The RB26 crankshaft and conrods are the main advantage over the RB25 as they're built a lot stronger and also the slightly larger capacity and twin turbos. RB26 internals are extremely expensive.

Also, installation is not a problem with the RB26. Just need to get the cefiro/laurel engine mounts and use them instead.

[Jim96SC2]

Just get a single turbo kit for the RB26 and you should be ok. May need to screw with the turbo extension and DP to clear the steering though.