How Much Power Can A Standard Rb25Det Handle

[ssxRicho]

I thought it was the NOS kit and stand alone engine management system fitted to the new one that made the extra power?

[ARTZ]

Yeah, old motor was tired... New motor is not.

thats a lame answer Joe

[ARTZ]

dp..

Dont be a smart ass John btw that radiator shroud you sold me was broken.

But basically what I said before about low comp and excessive piston blowby was right. Probably worn valveseats and springs as well but in Laymans terms, yes engine was tired..

Just the way you were talking I thought there was something you had changed but werent telling us what it was.

[simpletool]

If you cleaned up the carbon deposits on the valves and gave it new valve springs the old motor might have done alright

[joeyjoejoejuniorshabadoo]

Except for the big end bearing that lunched itself

Nah, setup is exactly the same. I was jus making the point that my ol motor that had held ~ 300rwkw for 3 years was getting on.

There is no definatel answer as the old motor hasn't been pulled down yet.

[joeyjoejoejuniorshabadoo]

Big power from a stock motor is great... But it won't last forever... IMHO 3 years at that power level is pretty good

[skylinecouple]

I'll chime in here. Since I've had my car for 300,000k's I think I can answer this often repeated question. How much power can an RB25 make ? Anything from 250 to 300rwk. However, Ask more the question, "how hard do I drive", "who tuned it", "what's my setup and how many short cuts did I take ?"

I've been through a couple of engines now and I know when I pulled apart my first it was as clean as a whistle inside apart from bent valves, a long story. It had been caned. Unichip and usual mods at 215kws.

Motor number two is still in the car and also around the same kay's on it. Still strong but tuned it myself and though it has some track days under it's belt it has an easy life now.

Both motors are stock internally. The secret I think is that both motors have never been beyond 6,800rpm. They had their oil changed every 5,000k's. Fresh plugs and coils if there was any doubt at all if they needed replacing. I had set the rev limit low because I was never going to have a turbo that would make power in the top end. Mind you 268rwkws is enough anyway.

I don't where everyone gets the impression these motors are indestructable as they pop on a regular basis especially with the home mechanics that make the dumbest mods then thrash them without so much as a run on the dyno. They are just another motor, better than some but not as good as some others.

[ARTZ]

who runs around on full boost and who turns the boost down with EBC when they dont need it and will this make it last any longer anyway?

[joeyjoejoejuniorshabadoo]

18 psi run

[boostn0199]

18 psi run

Not running it on ethanol anymore?

[joeyjoejoejuniorshabadoo]

not at the moment...

will go back there soon with a vipec and a content sensor.

my laptop wont recognise my datalogit, so changing maps is a PITA atm... when i have the time i'll get it sorted again

also... a mega responsive 280rwkw is easily enough for a 33gtst

[ARTZ]

nice, its also made peak power 500rpm earlier and more torque, is it a full new tune or just a rework of the old one?

[joeyjoejoejuniorshabadoo]

rework of the old one...

car is nicer to drive all round... even idles better

haven't got the boost graph on USB, but i have the printout and 18psi is just nudging 3200rpm

[ARTZ]

yeah i bet it does, once your valve springs get sloppy it all falls to shit really, allthough it was still in pretty good nick considering. Would be interesting to know what the comp was like too. would be cool to see how your car goes against Kris with the 3076 and 280kw..

[HEKT1K]

not at the moment...

will go back there soon with a vipec and a content sensor.

my laptop wont recognise my datalogit, so changing maps is a PITA atm... when i have the time i'll get it sorted again

also... a mega responsive 280rwkw is easily enough for a 33gtst

awesome

You are making 18psi 4-500rpm before me, and 10kw up on me everywhere..... fag.

[joeyjoejoejuniorshabadoo]

yeah i bet it does, once your valve springs get sloppy it all falls to shit really, allthough it was still in pretty good nick considering. Would be interesting to know what the comp was like too. would be cool to see how your car goes against Kris with the 3076 and 280kw..

Interesting you should say that... I have driven both cars and they are actually very different for what is exactly the same power.

Kris's is much more linear and slower to build. Feels a lil doughy after mine. You can definitely notice the difference with the bigger turbo. Having said that however, kris's car could be seeing 20rwkw over mine if he pushed it a lil more.

[Tangles]

Im was running with 240rwkw at 1bar thru auto on my S1 rb25det Stagea. Bottom end has finally let go after a handful of trackdays, compression in cylinder#5 is v.low.

Looking to rebuild the block in a few months time with N1 oil & water pumps, a fresh nismo timing belt kit, wiseco 87mm pistons with manley rods, arp rod bolts & main studs, acl race bearings, a fresh full cometic streetpro gasket set, extended crank collar, & honing the block to suit. I'll be upgrading the 450cc S15 injectors to 600cc and installing a Nistune Z32ecu to replace the Toshi remap and AEM Fic-8 piggyback ecu.

The head has been ported a few years ago, setup with tomei cams and springs, etc. Turbo is a GT3076iw. Everything already done is strong and ready for a forged bottom end.

What Im not sure about is whether I should get a Ross harmonic balancer and under-driven pulley set, and whether I should bother thinking about a reimax N1 oil pump gearset or a different oil pump altogether such as a Nismo oil pump for around $1100del. Engine would probably not see track work again, but I would like to up the power by around 30rwkw for an end result of at least 270awkw from 16-18psi from the auto/awd stagea.

[STATUS]

^^ swap the wisecos for... anything else im a wiseco fan (all my bikes run them) but not a fan of their rb pistons.

[Tangles]

^^ swap the wisecos for... anything else im a wiseco fan (all my bikes run them) but not a fan of their rb pistons.

cheers for that info - it'll be CP pistons then with either eagle or manley rods then.

probably will keep to stock balancer, and standard N1 pumps to keep the costs down a bit.

[Lithium]

18 psi run

Got a boost plot for that?? If its full boost at 3200rpm, I'm curious to see why the torque curve climb like its spooling until 3600-3700ish rpm?!