Thinking of going RB26.............

[Imissmyturbo]

Ok. I am at a point where I am thinking of selling my RB25 setup and putting an RB26 in it's place. I have a friend who will buy my RB25 without Harness or ECU to put in his 280Z. This will leave my with my PFC to sell and an RB25DET transmission. (He will use an RB20) As my car sits right now I think it should be able to make 375-400 WHP with tunning and more boost. The RB26 appeals to me because I can make those power numbers without running the engine on the edge of it's limits. Also the RB26 will have a wider power band then I currently have and in time if I want to make more power I can get a set of N1's or 2530's and that will keep me happy for a while. The one thing that scares me is I know my RB25 is in great condition where as I would be buying an RB26 that I don't know what I may be getting. Also I hear so many different power #'s for the RB26 swap. 280 hp is stock rating. It has been said it makes 280 WHP in stock form. So you make it 2wd and it should make about 300? Add 3" exhaust and turn the boost up and 340-350 is possable? What point to the stock turbo's run out of steam. I have heard 380-400 whp. Also I did a google search and I can't find any stock RB26 dyno's that arn't in KW's.

[Nameless EJ6]

Bad idea.

For one, you never really know when you're on the edge of limitations untill problems start to occur. What problems are you having so far?

Actually.. I'm not going to sit and try to convince you of why I think it's a horrible idea. All I can say is that you seem worried.. and in the back of your mind there is a neon sign flashing "RB26DETT".. not a good combination.

If I were in your shoes I would keep what you have now.. keep toying with it, I bet it'll open up a lot more than you'd expect.

[Imissmyturbo]

Problem I have right now is a heat issue. The car runs hot. I know it's because of my FMIC. Before I had my sidemount my water temp would hold steady at 87 degree's C. Now it will go to 92 and creep up slowly. It then takes for ever to come back down. My FMIC blocks the air flow to my radiator. I have a larger on to put on which will let more air though but If I put it on I will have no way to run my charge piping. My new intercooler is too tall let the pipe cross back over in the bumper. So I need to either make a new intake or get a greddy. With the RB26 that won't be an issue. I know I can sell everything I have and do the RB26 without spending much additional money.

[kouki-gymkhana]

Don't swap it out for an RB26 which will likely be older and in worse condition than the RB25 you have now. I didn't realize the tuning potential of the RB25 until I went to a shop down here in FL this past Sunday called Drag International. These guys have at least 5 RB25 swapped s13 and s14s that over the 450whp mark with stock internals. They are all running electromotive TEC3 standalone systems with no problems whatsoever. With a bigger turbo, a better standalone system (I'm not really a fan of the PFC), and excellent tuning you could easily meet the same power output you seem to be looking for from an RB26 for a modest investment. Hey, do what you want but this is just my $0.02.

[Nameless EJ6]

Going with the RB26 is pretty extensive. So, if you don't mind undergoing the extra work like modding the oil pan, wiring, and all that jazz.. then hmm.

Still, I think it's not such a good idea. The heat issue you're having could be fixed relatively easy, as well as the piping. You don't have to route side by side.. you can feed it from the top of the engine to the other side. That's cake.

As for the heat buildup.. what fans are you using? With good fans there shouldn't be any problems if they're running constantly, regardless of the intercooler. There's a lot of options that can clear up heat probs. As in modifications for extra air flow. I'll be cutting extra vents in my bumper when I do mine.. so I'm not too worried about it.

If you can manage to get 6-8k ready for the changeover.. I think you might as well. You'll like it more. But that raises a new question: Do you need the RB26? The powerband is taller, but it comes quickly. So IMO, that shouldn't be a decision factor. I've worked with Hondas for years.. trust me, I'm familiar with tall powerbands and turbo's =p. That'll boil down to personal preference.. because you can easily get more top end from the RB25 if you chose to keep it and modify the head/intake manifold etc.

I'm pretty sure the RB26 will put down 260-300whp stock depending on engine/turbo condition and efficiency. Upgrading twins is also expensive.. as you've probably noted.

Anywhoo.. I'll chime back in if needed.

[Wulfgang]

If I knew that I could afford to take out an SR, an RB20, or an RB25 and replace it with an RB26, I would do it in a heartbeat. But that is just my opinion.

Sure you can get the RB25 up to those hp goals, but the RB26 is already there. Also remember that 280 hp is Nissan's quote, which is supposedly very conservative. You start with a better engine in every way, better intake routing, nicer looking engine, and twin turbos. And 400 whp is mickey-mouse on an RB26 (or an RB25 for that matter).

Anyway, there are always arguments going for the RB25 vs RB26, but I would go for an RB26. But then that probably will just make your cooling issues worse....

Also, 1 hp is 746 W or 0.746 kW.

[gawdzilla]

i say go for it. you clearly have experience in the swap. if you have the money and time, do it. just keep in mind you'll need to make a new harness, oil pan mod.

if it blows up while you're running it, rebuild it. if you're getting an early 32, just don't rev it past 8 grand and it should be fine. if you buy the motor and its dead, (like me ) go fully built

[goofynick6]

For some reason I always thought you had an rb20..I always was wondering why your car seemed fast for the mods..heh.

Nick

[BoostFab]

since you'll be keeping the transmission (driveshaft is good to reuse), all you need is a RB26 long block and the wiring. you're already 1/2 way there. remeber the r32 and some r33 rb26 have oil pump drive colar issue taht need to be addressed.

[enginerd]

Personally, I would say stick with the RB25. You may want to redo your intercooler and radiator setup to ensure proper cooling efficiency. Remember, bigger isn't always better. You may be able to find a more efficient, smaller FMIC that will allow better airflow for your radiator. You could always change the end tanks on the FMIC to allow for different piping too. It may not be much mor to get the RB26 swapped in, but the power upgrade parts are really pricey. Take a look through the parts cost because you may be able to achieve the numbers you want with the RB25 with just a little more money.

As far as power difference for RB26's, here's a dyno chart I posted in an older thread that shows the difference between the R32, R33, and R34 motors. There are several reasons why the power is different. If you need to conver the kW to hp, use 1 kiloWatt = 1.34102209 horsepower.

[Wulfgang]

390 rwhp on an R34 RB26??? Is it really that good, or were those GTR's not stock?

390 rwhp is Z06 territory. No... in a 240SX that's closer to Viper territory.

[enginerd]

390 rwhp on an R34 RB26??? Is it really that good, or were those GTR's not stock?

390 rwhp is Z06 territory. No... in a 240SX that's closer to Viper territory.

Each car was tuned on 98-octane premium unleaded (in Australia) using a Power FC with an aftermarket exhaust. The R34 does make significantly more power for several reasons (better turbos, redesigned head, better cams, better dump pipes, better intercooler).

[biglipzit]

wow exhaust and tuning is all it took to get up to 390HP on all stock parts... I am impressed.