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2.4 Rb20 Stroker Or Drop An Rb25det In?

Lukaz

By Lukaz,
in Engines & Forced Induction

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Lukaz Community Regular

Lukaz

Posted
Posted

Hey all, just after some advice.

Im chasing around 250rwkw in my r32 eventually, I already have gtr injectors, 500hp fuel pump and afew other supporting mod's on my rb20, altho still stock turbo.

My question is, should I ditch the rb20 and drop an rb25det in, or go for a rebuild and stroke the rb20 to the 2.4?

I figure it will be more expensive going the Rb25 route, but Id rather go that if it will handle the power better?

Im not sure how far I can push the 2.4 and also I hate the lagginess of the rb20.

I'd like abit more info on the 2.4?

Cheers.

legend01 Experienced

legend01

Posted
Posted

if you want what is the cheaper of the 2 go the rb25 .Building an rb2.4 is expensive and the rb25 will get you the power you want easy with out the lag

cheers Peter

Col-GTSX Grand Master

Col-GTSX

Posted
Posted

From my personal experience turning an RB20 into a Rb24 is not worth it...

Parts are expensive and you may as well just go to a Rb26 for the same money...

For a simple 250rwkw the Rb25 is the perfect selection. Most importantlly their cheap and the parts are cheap...

(When i say cheap, their cheap in comparison to other engines.)

Cubes Grand Master

Cubes

Posted
Posted

Its easy to get an RB25det reg'd in an R32.

Here in Adelaide they need to run the stock ecu, R33 GTST front brakes and thats it.

Unsure what the price of an R33 motor and ecu is worth these days but it 'may' work out better simply grabbing yourself an R32 RB25DE and dropping a set of aftermarket cast or forged (which ever your budget permits) pistons in it to drop the compression with a cheap refresh. For near the same cost (maybe +1k :ninja:) of an R33 motor and ecu you end up with a fresh 2.5ltr. ;)

The bonus of the R32 RB25DE motor is they are identical (sensor, plugs, injectors, bolt ups etc) to that of the RB20DET, so simply rip the rb20det out, drop the rb25 in, start it on the rb20 ecu and drive it to the tuners to ensure afr's are good, which they will be but MAY hit an early fuel cut as the ecu won't expect so much airflow at a lesser rpm.

FATAZZ Grand Master

FATAZZ

Posted
Posted

what about an rb30 btm end underneath the 20 head?

my tuner showed me one they put in a vl with a huge turbo

and ran 10z at its first meet.

not sure what needs to go inside the engine though,can anyone help on

whats needed inside the engine?

as id like to go this route to maintain the stock look.

Oblivion Grand Master

Oblivion

Posted
Posted
what about an rb30 btm end underneath the 20 head?

my tuner showed me one they put in a vl with a huge turbo

and ran 10z at its first meet.

not sure what needs to go inside the engine though,can anyone help on

whats needed inside the engine?

as id like to go this route to maintain the stock look.

wow they would have some good response...prob not as good potential as a 25 head....but the idea is there.

I like the idea of a rb24 just cause it is different, i mean it is more but then you could get 250rwkw without changing the internals on the 20, just mean some lag issues....but then again do you drift on track or anything? just dump the clutch again it if is slow :) The rb20 is still one of the strongest engines, dont want lag then pump fuel and a smaller turbo and or a different cam. Also you could commit suicide and put an sr20 wth a gt28rs in if you want balls.

Lukaz Community Regular

Lukaz

Posted
  • Author
Posted

Haha thanks for the response's guys, still undecided, at the moment my main game is drag, but I'd like to dabble in abit of everything. The idea of the R32 RB25 sound's like a good idea, I never thought of that, tho no VVT?

I thought the 2.4 might do alright with lag compared to 2.0l, figured it wouln't be too much different from a 2.5? but judging by the responses it sounds like it would be just as bad as a 20.

Cubes Grand Master

Cubes

Posted
Posted
Haha thanks for the response's guys, still undecided, at the moment my main game is drag, but I'd like to dabble in abit of everything. The idea of the R32 RB25 sound's like a good idea, I never thought of that, tho no VVT?

I thought the 2.4 might do alright with lag compared to 2.0l, figured it wouln't be too much different from a 2.5? but judging by the responses it sounds like it would be just as bad as a 20.

Yep no VVT. The head etc literally looks exactly the same as an RB20DET. The only difference is the side of the combustion chamber, valves and larger inlet ports.

With regards to the rb20 head on an rb30 in a VL running a 10. Thats no big deal.. An rb30et (SOHC) touch over 300rwkw, slicks, stally and an auto pulls in to the 10's with SOHC. :)

Beer Baron Grand Master

Beer Baron

Posted
Posted
From my personal experience turning an RB20 into a Rb24 is not worth it...

Parts are expensive and you may as well just go to a Rb26 for the same money...

For a simple 250rwkw the Rb25 is the perfect selection. Most importantlly their cheap and the parts are cheap...

(When i say cheap, their cheap in comparison to other engines.)

i'm keen to hear about your RB24 too.

I think the 24 would be a good option, and certainly more torquey than the 20 possibly about the same as a 25 even. and it will look stock. still have the same engine number, still run on the same ecu etc etc. it definately has some advantages. but i have to agree that the 25 will probably be cheaper.

Cubes Grand Master

Cubes

Posted
Posted
Can someone explain why RB20s scream and sound great, where as RB25s are a slightly flatter/deeper exhaust note? There is enough of a reason to keep the RB20 there :)

I do miss the scream and top end power feel where it doesn't simply nose over but just keep screaming. :)

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