RB series stock hp - mid - full modify.

[w00t_Masta]

What potential do these engines have??? Im sure its a ton since umn......Skyline. But i've heard they are powerful and only seen a few posts about the actual power. about 240-280 stock from rb25-26tt. But how many mods will it take to get a lot of hp. And what would a s13 w/ a rb25/26 run stock? 1-more thing what do these engines weigh??? I've looked through the thread about weights.... but no specific lb is posted. Also the weight of a SR/CA would be nice to compare.

[SpeedRacer1]

It would cost alot more than you have to spend to get 800+ hp out of the RB's. Im not sure what that one S13 w/ RB26DETT ran in the 1/4 mile in Japan but it hit 200 mph.

[s14=pimpin']

Yes, Skyline parts are very expensive and the HP ratings are underrated due to Japan's 280HP limit, all the big manufacturers rate their HP at 280 max in Japan. You'll just have to wait for dauntt to get his motor in, then all the answers will come.

I'm very curious myself to see whether swapping to an RB is worth the coin.

[ninjak84]

Japan's horsepower limit is 276 to be exact.

[s14=pimpin']

Japan's horsepower limit is 276 to be exact.

I played gran turismo back in the day as well

:rolleyes

[Siddhartha]

There is no actual limit. This limit is a gentleman's agreement between car companies in Japan to avoid a horsepower war. All cars at or over this limit are rated at around 280 hp.

[777aaron]

It would cost alot more than you have to spend to get 800+ hp out of the RB's. Im not sure what that one S13 w/ RB26DETT ran in the 1/4 mile in Japan but it hit 200 mph.

It ran 7.19 against the turbonetics celica.REAL F@$#ING FAST!:D

[95exludesi]

what is the celica hitting now? last i checked it was at 214mph

[95exludesi]

Japan's horsepower limit is 276 to be exact.

there is a dog, driving your car, might wanna catch that... *points at link in sig*

[RedStage]

RB20DET - From A31 Cefiro or C33 Laurel are rated at 205PSRB20DET - From R32 Skyline are rated at 215psRB25DET - From R33 Skyline are rated at 240 or 260psRB25DET - From R34 Skyline and C34 Laurel are rated at 280ps

RB25's are not all that popular with tuning. Something about internals being too weak. Buddies R33 GTS25T blew a piston shortyly after getting a boost up tune........

[240sxTurbo]

***not intended as a personal attack on anyone****

<rant mode on>

can't blame the owner when the tuning wasn't correct for the situation.

I personally find it hard to believe the RB25 is any weaker than any other RB. The only factor that lends itself to the belief the RB25 might be any bit weaker is its 9:1 compression. That merely means it more likely to want to detonate before say a RB20. The key to fighting detonation is tuning and running the proper gas and keeping those AF ratio's in check, no detonation means good power and safe motor.

We have plenty of KA24DET turbo cars here in the US running 9:5:1 stock compression, stock bottomend, running on JWT setup with 50lb injectors, FMIC, fuel pump, and cobra MAF and they are running 15psi and makine 350RWHP. There is no reason why the 2.5L RB shouldn't be similar in nature, the KA I can promise has much weaker factory pistons than the RB does, yet we manage to keep them together on this side of the pond so what gives.

I"m not saying anything bad about the RB's, just that it seems a lot of the AUS web boards I read there is a lot of skeptics on the RB25, when in reality the only thing that proves true in most cases is, with proper tuning a meltdown could of been prevented. Are they scared to tune em up, or what, seems like they are.......inexpirience??? what gives??

Sorry to rant, but I for surely hope to prove all this RB25 stuff just a myth when I start tuning on mine with a T4, 50 or 72lb injectors and a ECU tune. I will break 400WHP on the stock Head gasket and stock bottom, maybe more, cause I know for a fact that motor is a helluva lot stronger than a KA, and those guys are getting dam close to 400WHP on stock internals.....on a 4 cylinder.

<rant mode off>

thats all.......

[APEXi240]

I thought the 280 thing was Japanese law...I don't know where I got that from....oh well.

[battle D]

when did the rb26 powered s-13 race the celica and where, and arnt they getting rid of the v-8 pro class

[APEXi240]

It raced over the past summer, the celica was slightly faster, not that it IS faster. I don't remember what event or anything...i don't really keep track of drag, i saw it in a mag.

Yes they are getting rid of the v8 pro class. the only ones in it were paisley, the celica, and blast racing (which didn't really run a full season)

[RedStage]

I checked with some shops local to me and they told me that the pistons have a tendancy to melt when the engines are set past the "stock" settings.

My buddies R33 had this happen. All he had done was ECU tune to up the boost to 1.0 instead of the stock 0.7, larger intercooler, air intake, full exhaust.

Like said, RB25DET's really aren't that popular here in Japan for tuning. If they were already in the car that's one thing, but dropping in an RB25DET into a R32, A31, C33.....not that popular of a choice.

More often than not an SR20DET will go inplace in the A31's and C33's. (Cefiro and Laurel)

280ps by factory was an agreement between the car manufacturers supposedly.

[meggala]

As redstage said they are fragile if you aren't carefull fuel is the main issue cause they run out of injectors and afm at 380-400 hp.with sensible tuning bigger afm and injectors 450 is achiveable for more you would be wise to lift the head off and fit a thicker head gasket or rb26 pistons to reduce the compression. with stock afm and injectors mid to high 12's are common with rb25's in s 13's etc.for those think bout the rb 26 swap save your money with a carfully planned rb25 build you can get up to 700 hp and believe me you really dont wont more than that unless its a drag car only. most of the rb 26 internals fit into the rb20 and 25 blocks cause the only real difference is deck height. MY web page will be having a guide to tuning rb's over the next few months which should help you guys out.cheers meggala

[Max240]

sounds good, I am really looking forward to learning more about these engines and the ultimate swap for s13's.

[chin suru]

the Veilside R34 Street Drag in SCC or SS a while back had 1326hp. Lots of Ti parts too.

-Andrew

[s14=pimpin']

more RB25 info please!!!!!

Would a S14 with a RB25 motor be a good autoX/road course car? Or is it strickly drag racing? Would an RB motor throw the balance of the car right off, even if the motor was installed cleanly and weight reduction was done to the front end?

thanks

[WDRacing]

I've come to find most small cube engines, lets say under 3liters, are just about modifiable to the same point before requiring serious block and balance work.

The Rbseries is no different. I took my Skyline (RB20DET) to 28psi with a stock block. The only other car that has done that is the MK1V Supra, but I also had a stock fuel system.

I used an Alky Injection kit to add fuel and keep the combustion charge at a reasonable temp. But it took me 5 engines and I lost track of how many cam/head combos to get it to hold under 28psi. Anyone who hasn't driven a car running that much boost has got to try it.

If I can find my Dyno slip I'll post it, but it goes a liitle somthing like this. It builds up to 187rwhp at 4300rpm, then you come on boost, by the time you hit 8000 your pushing out 497 hp.

But my friends 180 with the SR20 beats me every damn time. Only cause he come on boost so much faster and is lighter. I'm catching him by the time we hit the finish, but catching isn't winning.

I guess my point is this, the RB20DET is a blast to work on if you have the parts. That goes for the rest of the RB line except for the RB26DETT. That thing will put 700rwhp down with stock internals and a good fuel system.

WD

[themadscientist]

have been in Japan a while? I don't know about mainland but down here in the sticks the new crop of kids buying Skylines are pretty stupid. They like to explain to me how the RB20 is **** and they can't wait to swap in an RB25, yadayadayada.I remember back in the day when the RB20 and RB26 was it and there were dozens of 400+ hp RB20s schooling the then new GT-Rs. I like the RB25 but the 20 is a stronger block and a lot more forgiving. I would like to bolt a 25 head on though, those puppies look like they have a lot more flow. Did you try that combo in your experimentation.

[WDRacing]

No, I sure didn't, there aren't that many RB25DET's lying around. A few na versions, but...

I have been porting heads for a few years now. Since the RB20 is so cheap I could afford trial and error. There is a ton of room for port work on the RB20DET head. The exhaust side has huge restrictions from the manifold studs. You have to be careful but you can remove all the excess. My engine was designed for a higher rpm. Since my laggy T04E didn't spool till 4300 or so. So Porting the hell out of the head didn't really matter since my bottom end wasn't going to making any power anyway.

WD

[meggala]

yeah I like the rb20 they are nice here is mine in action

[mattback]

hey meggala. how much do RB30 commodore short blocks go for in Aus ??? do you nkow who sells them out there ?