How Much Power Can A Standard Rb25Det Handle

[SimonR32]

Sam tuner, dyno etc etc

the motor is a "young" stagea 25 that was attached to an auto all it's life vs a very old skyline 25

Will post when I get to my computer

NEO's have a touch higher compression and better flowing cams/head which might be a better explanation for less boost, less timing and more power

[Decs31]

How you can do a proper temp correction on a turbo car is beyond me? It's not just a linear equation concerting the amount of O2 (like for a nasp) but complex shit involving intercooler efficiency and all sorts.

I wish peeps would just quote power at the wheels - on the day - and not the jiggery pokery of corrected this and that.

it just makes things a bit more consistent.

if you turn off all corrections, the car will make a minimally lower power figure but as it is displaying raw load on the hubs the numbers do drop slightly as after a few runs you develop a bit of heat soak in the engine bay. the temp probe picks this up and makes small adjustments to the numbers to keep everything more equal. it makes it easier to see if its what you just changed in the map that changed the power/torque or just the heat soak dropping it. its just a tuning aid.

i've said this a thousand times but numbers are numbers. in my experience hubs and rollers are very close, if anything mainlines read noticeably lower. who cares. its the quality of tune and how it drives that matters.

to be on topic a stock rb25 will take a lot, but it has to be treated with respect. good maintenance, safe tune, no limiter bashing and minimal rpm to achieve your goal. reving it to 8k will kill it quick smart.

[Simon-S14]

no limiter bashing?

do i know you?

[joeyjoejoejuniorshabadoo]

NEO's have a touch higher compression and better flowing cams/head which might be a better explanation for less boost, less timing and more power

Its from a s1 stag, so non neo

18 psi is achieved by ~3200 now

[Birds]

More power will wear an engine faster than the standard power, that's fairly normal. You're working outside the tolerances of what the engine was originally designed for, even if it was over-engineered in the first place.

[ARTZ]

Its from a s1 stag, so non neo

18 psi is achieved by ~3200 now

extra power wouldnt have something to do with this freezing winter air could it

i know the intake temps on my mazda have been 15 degrees lower than normal all this week, right now its on 34 2 weeks ago it was 56, its a big difference

[T.D]

extra power wouldnt have something to do with this freezing winter air could it

i know the intake temps on my mazda have been 15 degrees lower than normal all this week

Yeah that could be true but Joey mentioned that it made the power with less timing and less boost, so I'd rule out colder temps being the reason.

[ARTZ]

yeah its a fresh engine of course, but it all contributes and Id say the air temps in melbourne have been turbo heaven this week, I mean there is ice falling from the sky

[T.D]

Hahaha yeah that's true, the weather has been borderline Alaska. But yeah, if it was only air temp then timing would have changed as well as boost

[joeyjoejoejuniorshabadoo]

It's true that it was cold... 13c while we were tuning to be precise...

But the dyno has a correction for that and adjusts accordingly. Also 2 psi Is too much of a difference to be attributed to cold as the comparison tune was only done at around 20c anyway

[ARTZ]

yeah I may be wrong here but I beleive a dyno corrects for air temp, it doesnt dorrect for air density which is where you would get the extra power.. iE 18psi of dense air could be equal, or possibly better than 20psi of thin air

Add to that better compression, = less blowby pushing more exhaust gas giving you better spool times . Also better bearings and oil pump creating less engine drag. i also believe you are using a different oil now as well, what oil did you tune it on, the castrol edge or something else?

As i said ,it all contributes

[joeyjoejoejuniorshabadoo]

Old motor had nothing in catchcan and all piping was dry when we pulled it down.

Oil used for the tune was 10w60 as opposed to the old tune that was on 10w40 so of anything it would rob power.

Also re air temp.... My car has not been noticeably different in differing temps. Although many are?

[STATUS]

yeah I may be wrong here but I beleive a dyno corrects for air temp, it doesnt dorrect for air density which is where you would get the extra power.. iE 18psi of dense air could be equal, or possibly better than 20psi of thin air

Add to that better compression, = less blowby pushing more exhaust gas giving you better spool times . Also better bearings and oil pump creating less engine drag. i also believe you are using a different oil now as well, what oil did you tune it on, the castrol edge or something else?

As i said ,it all contributes

must decent dynos correct for most air conditions, i know our does full weather station not just temps..

[ARTZ]

Ok , i wasnt sure on that..but still doesnt answer the question why did it make better power?

Also do you think if you could dyno exactly the same car on the same dyno on a cold day and a hot day, correction would give you the same result?

[SoFreshSoClean]

I run a 252rwkw daily.. I've got a GT-RS sitting on 14psi, same as joeyjoejoejuniorshabadoo I've got nothing in the catch can, motor is 103xxx kms.

Will be seeing how much more I can get out of it (18-ish psi) in a few months

As people say it depends how you drive it, honestly driving it to work/shops I'd be surprised if I'd ever utilise more than 5k RPM, probably only ever puts out 140rwkw max

[ARTZ]

yeah but joe flogs his and I know mine hits limiter everytime its out of the shed and the can is dry as well. Doesnt necesarily mean compression is perfect and there is no blowby. Or does it?

[ARTZ]

lightened flywheel?

[joeyjoejoejuniorshabadoo]

Mine? No

[ARTZ]

so do you know the answer?

Or is there no actual answer?

[joeyjoejoejuniorshabadoo]

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