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Upgrade - N/a Rb25 Or Rb25det

huddy

By huddy,
in Engines & Forced Induction

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huddy Veteran

huddy

Posted
Posted

have a ceffy and i want more torque...

i have heard of people putting in a N/A rb25 completely standard with a turbo bolted on and making big numbers and minimal lag... also being able to run it off of a rb20det computer

i was also considering - if i was to go this route to use turbo pistons and an aftermarket metal head gasket to lower compression. the n/a has no oil squirters which could be a problem (so i've been told) but also been told that can get away without them and its not a major issue...

does the N/A 25 have to be NON - VCT to be able to utilise the rb20det computer still?

OR

go the rb25det route - i already have a rb25det gearbox installed so going for engine/box package doesnt make much sense unless its cheap and i sell the spare box seperately...

i'd also have to change the loom/computer - is there anything else i'd have to change?

-------

mods included to be bolted up are - hks2530 / hks fcd / ebc / fmic / pump... currently i am making 236rwkw @1.2 out of the rb20det so i'm not after more power really, just more down low torque...

thanks.

BTW - i know i could just rebuild my own motor to 2.3etc... but i may decide to do that aswell over a slow period of time.

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https://www.sau.com.au/forums/topic/108241-upgrade-na-rb25-or-rb25det/
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tigermm Apprentice

tigermm

Posted
Posted

Hey mate.

Yeah I think it would have to be a non VCT one to be run by the R32 ecu, or you'd have to lock the cam in one position (adjustable cam gears?).

If you use the factory R32 sensors on the new motor, i cant see why it would have a problem running with the factory ecu.

Im looking at doing the same swap into my GTS4 and it just seems like a lot less hassle than rebuilding or making an RB30/22/24

ellie Proficient

ellie

Posted
Posted (edited)

Or when your talking about putting in headgaskets and such you have to pull the head off. So why not go the rb25 combo for the R32 using an RB25det bottom end with the N/A RB25 head off the late R32's. This Gives you An rb25 but you can use your standard loom, computer (remapped of course) and all your auxillaries (manifolds etc,etc.) will bolt straight up. That is the basic idea to my understanding and if you love your car enough, give the motor a freshen up while its appart to give you 200,000kms solid service instead of ?unknown Kms before you have issues.

May be some one who has actually done this combo could offer a more accurate account of what is required

But it would seem that this would be much more appealing than a full engine, loom and computer conversion

Only an my oppinion to give you some alternatives :O

Edited by ellie
huddy Veteran

huddy

Posted
  • Author
Posted

hmmm very interesting

well its going into a cefiro... and the current computer actually says c33 on it - so i'm guessing laurel computer :S

just seems not many ppl have done it yet... all your opinions / alternatives are welcome as i would just love to get some more torque out of this car...

possibly - i might be able to purchase a rb24 tomei motor - but it needs a rebuild/freshen up... would this be a good option? as then all i would need to do is remap the comp and everything else would be exactly the same...

also add cams / h.gasket aswell into that...

1400r Veteran

1400r

Posted
Posted

good plan ellie but the cost to source the 25 na head and then a 25 turbo bottom end would out way the postives I think you would only go that way if you already had some of the parts.

24's already running a remaped ecu Im sure it would be sold with the engine then you've just gotta check to make sure it's still suitable with any extra mods you do.

ellie Proficient

ellie

Posted
Posted (edited)

Valid point 1400r but to stroke the RB20 is also a massive cost if done correctly even if you're in the industry. Add on top of that the dismal flow the RB20 head has compared to an RB25 so even with extensive head work and CA18 valves (1mm larger) you could only expect close to 85% of the flow of a standard RB25. add to that again the price you would pay even at mates rates for the head work = $1000+. So yes getting the RB25 together may cost you extra up front but with a light freshen up being cheap as chips compared to borring the block, all balancing, grinding clearance on cranks and big doolar head work to get a decent result worth the time and effort, I feel in the long run you'd be better off going an RB25 or as has been suggested every time this subject has come up for around the same cost build an RB30DET weapon that any one would be affraid to line up against.

Of course these are only my opinion and should be seen as such :O

In the end you should see if someone would take you for a spin in there car that has not just what you want but what you can afford. So then it becomes a matter of what YOU want!

Edited by ellie
ellie Proficient

ellie

Posted
Posted

I know personally, dispite the cost, i'd love to have a crack at an RB24 just to have something a little different and from 1400rs' account of how it drives it sounds like a barrel of fun!!!

See if I lived in adeliade, I'd be hitting 1400r up for a ride in a heart beat to experience the motor and see if it's what i really want.

huddy Veteran

huddy

Posted
  • Author
Posted

well i'm not really interested in 'lining people up'... so maybe the rb30det wouldnt suit...

i have driven the white ceffy 2.4 that ryan is talking about and its nuts... so much torque down low... but still rev happy... this looks like it is going to be the winner...

ellie Proficient

ellie

Posted
Posted (edited)

Not my primary objective either as i couldn't give a rats ass what my car runs down the 1/4 mile but being interseted in performance cars and being willing to take on an engine build i would assume that you wouldn't mind beating the guy next door. I'm not a cruiser or a street racer but it sure is satisfying when a V8 pulls up and lets a snide comment slip your way (JAP CRAP!) and you absolutely obliterate him. That was all i was implying by my comment, that with an RB30det you could knock most anything flat that came before you for what by many accounts is a cheaper and more rewarding build

As i said in the post above, i would love an RB24 and wish you all the best !

On a side note: This subject comes up a lot so maybe you could document your build and any problems along the way which would give people a much more definitive idea at what is involved and things to look out for. Even if you don't i'd love to see how it turns out so post up some results etc.

P.S. 1400r: have got your set up posted somewhere or could you post it here cause i'd would most appreciate it

Edited by ellie
1400r Veteran

1400r

Posted
Posted

Yo my 32's setups in my sig

the 24 ceffy is works car it was fairly stock apart from remap when it came into the country has had cooler and turbo put on

but excess boost (1.5 bar) has reduced the comp in cylinder 6 so its coming out for a rering

so either Im buying the whole car will a rering (if mine sells) or Huddy can buy just the motor

ps Huddy's ceffy is a track bitch so no V8 traffic lights grand prix

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