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Sense, Spend Money On Rb20 Or Rb25?

335

By 335,
in Engines & Forced Induction

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335 Rising Star

335

Posted
Posted

Hello

I am deciding what to do with the parts I have.

I have a R32 GTS-T with these mods, twin front pipe, cat back exhaust, fmic, pod. Will buy a boost controller soon and I have a RB25 turbo. For now I am happy to put on the RB25 Turbo, find a computer and maybe even get aftermarket cam gears and maybe Tomei Pon Cams. Later I want to have 350 hp, but for now the power from the RB25 turbo and later a ecu tune will be ok.

But I have access to a 5 year old, R33 RB25 s1 engine. It was ordered new from Nissan about 5 years ago by someone who used it in their R33. The engine has less than 10,000km on it. The engine has now a aftermarket head gasket, (not sure the thickness the man who owned it is gone), a GReddy forward facing penum, and no throttle body. I forget if the injectors are aftermarket or not. I also have access to a PFC for the engine and a Nissan stock RB25 ecu. I do not have a engine loom.

Should I use my money only for fixing the rest of the RB25 engine or do the light upgrades to my RB20 first(boost controller, maybe ecu, maybe cam gears, maybe Poncams) and than work on the RB25 engine?

The RB25 is from my friend who is willing to sell me the engine, PFC and front penum for cheap.

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The Mafia Grand Master

The Mafia

Posted
Posted

The RB20 is what you scientifically call a "Boat-ius-anchor-ous"

Throw it away and put the RB25 in there.Cheaper power and much more torque.

That is where your money is better spent, guaranteed.

The RB20 loom can be adapted to the RB25 fairly easily I think. There are plenty of people that have done it around here.

R32Abuser Mentor

R32Abuser

Posted
Posted (edited)

Can it become legal in anyway? As in insurable?

Here in SA it can be, and has been done.

Since an RB25DE was offered in the R32 GTST, correct me if I'm wrong, but any engine with the same engine code as an RB25 can then be installed into that car legally if the following is carried out:

  1. Emissions Test (forgotten the test number). Maintain the stock RB25DET intake side (plenum, injectors etc.) and exhaust side (turbo etc.) and you are fine. Obviously there are extenuating circumstances to allow for where worn components will cause a motor to fail an emissions test
  2. Upgrading of brakes to suit increased power. Upgrade to R33 brakes and you are fine.

Bare in mind, this is working on SA's rules and regulations.

Edited by R32Abuser
KiwiRS4T Grand Master

KiwiRS4T

Posted
Posted

If you search you will find pages of argument on "should I do up my RB20 or get an RB25" but in your case its more shall I do up this old rb20 v install a near new RB25 that comes with a load of goodies - there's no contest!

toffy Veteran

toffy

Posted
Posted (edited)

I'm nearly as big of a fan of the little 20 as Roy , but honestly , if i had the choice to buy a low klm rb25 in good condition , id put the 25 in , sell the 20 to make back as much as i can and enjoy the slight increase in torque . Note : the best part about the lil 20 is the way it revs all day if in good condition , 25 won't take stupid limiters set at 8500rpm for very long from my experience . If the 25 was just another wrecker motor that you didn't know the condition of , i would suggest the 20 all day

Edited by toffy
discopotato03 Grand Master

discopotato03

Posted
Posted

Possibly the easiest option is just to sell the R32 and buy an R33 . You can spend a lot of time and money building an R32 GTS25T - or you can buy one with all the factory parts supplied in an R33 . And its complied and insurable and legal .

I know everyone likes to turn cars into projects but theres nothing wrong with starting out with the closest basis to what you aim to end up with . The R32 wont have the right gearbox , diff I don't know and etc etc etc . The complete conversion (everything the 33 has) would cost a bit and its doubtfull your going to get it back later .

Anyway your call , I went with a 33 because it was the simplest most problem free option .

A .

GTScotT Grand Master

GTScotT

Posted
Posted

I do agree with Disco but in this case having ready access to a fresh RB25, I would just roll with it :)

You wont need much just a minor rewire, intake bits and a window switch for the VCT. Leave all the R32 wiring in place and just put the thing in there. Harmless!

Rolls Grand Master

Rolls

Posted
Posted

Can it become legal in anyway? As in insurable?

Yes do an application to modify vehicle, go through a full inspection with R33 brakes installed and voila, legally registered r32 with an rb25det.

Do it and don't look back, the rb20 sucks, lower compression, no vct and half a litre less capacity.

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