exact differences: rb26 vs rb25

Post by **dreamsOfSkylines** » Wed Jan 15, 2003 7:45 pm

I know the 26 has individual throttle bodies and the 25 does not (i think it was night who was talking about putting them on his 25) . Other than that I've heard vague claims of "better flowing heads" and "stronger internals". Does anyone have specifics? Was the .1L gained from stroke? Could the crankshaft be switched? Sorrry if this is a dumb post...

Post by **YamaOni** » Wed Jan 15, 2003 7:45 pm

The stroke is increased from 71.7 to 73.7 on the RB26.The intake manifold is more direct on the 26.They have the same bore size 86mmRB26 has solid lifters I think the 25 has hydraulic ones.Some of the latter RB25 engines had VVT on the intake side and I think that the NEO25 has it on both the intake and exhaust, As far as the 26 goes I dont think any of them have VVTThe R33 RB26 Crank has a larger key way for the oil pump.Hope this helped

Post by **dreamsOfSkylines** » Wed Jan 15, 2003 7:45 pm

thanks alot for the info. Is much, if any, custom work required for switching the heads/throttle bodies? Since the crank can be switched you could even use Rb26 stroker kits too right? Why would anyone go through all the extra effort of installing the 26 if you can do just as much with the 25? (i'm looking at you daunt) thanks again.

Post by **Nif** » Wed Jan 15, 2003 7:45 pm

Off the top of my head I remember some of the 25's having the 12mm head bolts. Also the 25's have a hydro cam bucket where as the 26's have a solid type.

Hey Night when does the new turbo get in?

Oh, the rb26 has a bit different bolt pattern on the intake, a bit of custom (ooh the dreaded custom word) work is required. Not anything to prohibitive though as this conversion has been done before.

Hope this helps.

Dan RushingSub-ZeroPerformancehttp://www.sub-zero.com.au

Post by **Nif** » Wed Jan 15, 2003 7:45 pm

its the oil gallies IIRC the conversion is pretty straight forward, never heard of an adapter plate, also if you drill out the block for bigger bolts/studs don't use garden variety heli-coils spend the money to get Kingserts they are much better for that application.

Night: if you need a turbo still, e-mail me with your spec's and we can brew something up for you

Thanks,Dan RushingSub-Zero Performance

Post by **TIM996** » Wed Jan 15, 2003 7:45 pm

ok so is the rb26 really better than the rb25,what is the safe rwhp limit on each? if the sr20 safe rwhp limit is 400 than the 25 should be at least 100 more. who has done the rb26 swap into a 240sx,it has twin turbo,right,if so does it have 2 wastegates,and with the turbo's up top what about the clearance between the shock tower or thye downpipe and the steering shaft? I am really thinking of getting an rb over an sr because I to want be different. do you think its cheaper to get a 25 and upgrade the turbo,or get a 26,if the 26 will fit. thanks for all the info that everyone has given.

Post by **Nif** » Wed Jan 15, 2003 7:45 pm

Don't forget to get the oil pick-up if putting the rb25 oil-pan on the rb26dett also I would suggest having baffels welded into place to help keep the oil where you want it;)

My e-mail is [email protected] for anyone interested.Night shoot me an e-mail with all of you current specs and where you want to end up and I'll get back to you with a good snail.

Thanks,Dan RushingSub-Zero Performance

Post by **Redline240** » Wed Jan 15, 2003 7:45 pm

Can't the RB26's twin turbo's be pumped up to close to 400rwhp? also, Nif are those mods to the oil pan and steering very difficult? Would an engine shop have any trouble with this? I thought it would be as easy to drop a RB26 as it is for a RB25, not that i'm saying it's easy......

Post by **Nif** » Wed Jan 15, 2003 7:45 pm

The baffeling is just a suggestion, not something that is required. There has been talk of oil starvation under hard launching but I don't see it being a problem for most people. Baffeling also helps to reduce windage which frees up internal losses. I personally would prefer a single turbo set-up but I'm developing a kit to install the rb26dett into the s-chassis, thats the reason for the steering mods. So no none of it is overly difficult, but none of it is like walking in the park.

Dan RushingSub-Zero Performance

Post by **Redline240** » Wed Jan 15, 2003 7:45 pm

Nif wrote:The baffeling is just a suggestion, not something that is required. There has been talk of oil starvation under hard launching but I don't see it being a problem for most people. Baffeling also helps to reduce windage which frees up internal losses. I personally would prefer a single turbo set-up but I'm developing a kit to install the rb26dett into the s-chassis, thats the reason for the steering mods. So no none of it is overly difficult, but none of it is like walking in the park.

Dan RushingSub-Zero Performance

What would be included in the kit? And any idea how much it would cost? I would be very interested in purchasing it.

Post by **Nif** » Wed Jan 15, 2003 7:45 pm

I will say nothing about the kit as it is not completed yet. It would be unfair to say it going to be one thing and at this price only to change it later. When I have the kit tested and ready to sell I will be happy to tell you all about it. I just wouldn't want to misslead anyone who might use the idea for themselves only to have the concept ultimately fail. But soon enough my friend I will have an economical kit.

Thanks,Dan RushingSub-Zero Performance

Post by **Redline240** » Wed Jan 15, 2003 7:45 pm

Ok, well can you at least give me a time frame cause i'll be installing it next winter. So any chance in having it done by then?

Post by **Nif** » Wed Jan 15, 2003 7:45 pm

Absolutely! Hey if my last post seem offish that was not my intent. Just reread it and it seemed a little harsh. But yes it will most likely be done by summer.

Post by **dreamsOfSkylines** » Wed Jan 15, 2003 7:45 pm

So night are you going to stroke it? (the engine sicko)

Post by **Redline240** » Wed Jan 15, 2003 7:45 pm

Nif wrote:Absolutely! Hey if my last post seem offish that was not my intent. Just reread it and it seemed a little harsh. But yes it will most likely be done by summer.

Awsome, that fits into my plans perfectly. So will it aleivate all clearence problems with the steering?

Post by **Nif** » Wed Jan 15, 2003 7:45 pm

Patience my friend I'm working on it. Just be patient and we'll cook up somthing delicious for you. In all hoesty though I've been working about 17 hours a day trying to get the Indy Cars together. I've also e-mailed Mick to get his input, you'll get an e-mail soon though.

Post by **Nif** » Wed Jan 15, 2003 7:45 pm

Oh, yes clearance issues will be resolved.

Thanks,Dan RushingSub-Zero Performance

Post by **Redline240** » Wed Jan 15, 2003 7:45 pm

NightXCZ77 wrote:So you're making a kit for the 26 swap with no steering issues? This is a Single turbo kit?

I hope not, the engine is expensive enough as it is, if it's just a single turbo kit then i'm not interested....i'll just have to try to manage to get the twins in there, i'll find a way, it's been done but i've never seen it....

Post by **Nif** » Wed Jan 15, 2003 7:45 pm

Although we do offer a single turbo kit for the rb26 and its in my opinion that single is probably the best way to go our kit will be made to accomodate twin turbo.

Thanks,Dan RushingSub-Zero Performance

exact differences: rb26 vs rb25

exact differences: rb26 vs rb25

Nissan Forums

Infiniti Forums

Datsun Forums

Technical Forums

Classifieds / Marketplace

Nissan Motorsports

General Forums