# rb25det in a 1990



## fenix3069 (Oct 19, 2004)

i've heard from multiple sources that putting and rb motor in a 1990 240sx is going to be harder then putting one in a 91+.. anyone have any information about this? the reason i ask is because i found a perfect 1990 for 700 bucks and its begging for the the swap and i now have the money to do it. should i wait and find a 91+? or does the year matter? any help is greatly appreciated.


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## azRPS13 (Jun 7, 2003)

HUH? I dont see why it would be harder, considering its the same Chassis... Go for it man 700 is a good price. You might want to ask whoever you asked why it would be harder. With other swaps like the SR or CA its just a few more steps than the 91+. But Harder? NOPE! Ask Opium, He has swaped in a RB.


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## drift240sxdragqueen (Oct 23, 2002)

harder? no.
more time consuming? yes.

or for me it would. i'm slow.


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## Kelso (Apr 29, 2003)

actually with a CA youd want the 89 or 90. with the sr you want 91+ and for rb's i dont think it matters much


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## Nismo1997 (Dec 26, 2003)

the only resson its harder is bc of the power steering..other then that its the same..id buy the 240 for 700 :thumbup:


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## fenix3069 (Oct 19, 2004)

whats more time consuming? and are u talking abnout the power steering interfering with the exhaust manifold?


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## augimatic (Mar 23, 2004)

RB or SR into a 90 will cause you either way to get a new Gauge display, and power steering lines as well as AC. Not that big of a deal. But the RB has it's own head aches weather or not you have a 90 or a 91. Is there a reason you want the RB aside from just being different? Cause you can get 400 hp out of an SR if you build it right. And it'll be easier.

For me I'm having my own headaches with just an SR swap no way I would be even thinking RB.


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## azRPS13 (Jun 7, 2003)

Kelso said:


> actually with a CA youd want the 89 or 90. with the sr you want 91+ and for rb's i dont think it matters much


Why do you think this?


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## augimatic (Mar 23, 2004)

azRPS13 said:


> Why do you think this?


In the 89 and 90 RPS13's/Hatch or 180SX they were made for the CA18DET, but the Silvia or Coupe got the SR20DET, so when you swap the CA into the Hatch you don't have to change the gauge display, power steering lines or AC, it bolts right up. But in Japan after 91 all Silvia's and 180sx's got the SR20DET motor. So you don't have to change anything for those swaps.

180SX was called that because it used the CA18DET.....hence why the USDM model is called the 240SX, KA24E(DE)


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## azRPS13 (Jun 7, 2003)

Sorry... thats wrong... Yes the 88-90 silvia's and 180sx's did come with the CA18DET... But that would not make a 89-90 240sx ideal. The reason a 91+ 240 would be ideal for a CA or SR swap is the fact that they came with a DOHC engine... The SOHC engine has the PS line, resevior and pump on the opposite side. Not to meantion the SOHC tach is useless to any DOHC engine. Trust me... I am having to get custom PS lines made up because they original lines were bent (causing a Kink in the line)to be used on my CA. Also i need to open up or even make new holes in my engine bay to bolt up the PS resevior and Ignitor chip (which was also on the opposite side). So to put this to an end... If you are putting a DOHC swap into the 240sx a 91+ will be Ideal. If you dont have a 91+... no biggy... Just a little extra work


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## azRPS13 (Jun 7, 2003)

augimatic said:


> In the 89 and 90 RPS13's/Hatch or 180SX they were made for the CA18DET, but the Silvia or Coupe got the SR20DET


Like I said 88-90 180sx And Silvia had the CA18DE/T...Don't believe me? Clicky here . And back then they were called *S13* and *RS13*... The *"P"* means SR20DE/T. Hence the title under my screen name.

EDIT: Im bored at work:

S13/RS13- CA
PS13/RPS13- SR
MS13?/RMS13?-KA

K= 4 wheel steering Ex. KS13- Silvia CA18de/t HICAS
N= AWD Ex. BNR32- R32 Skyline GTR RB26DETT AWD
___________________________

Here are some hybrids i put together, like I said I'm bored:
HS13/RHS13- RB20
ES13/RES13- RB25
BS13/RBS13- RB26

You may now bow.... J/K man  GOSH!!! Im bored!!! Someone please kill me...


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## augimatic (Mar 23, 2004)

I stand corrected, I never looked deeply into it cause I went SR all the way anyway.


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## fenix3069 (Oct 19, 2004)

im going with the rb motor because its an inline six turbo from a skyline.... and to get 400hp from it it will cost me less overall
also an s13 with an rb25det has pretty good resale value hear in CT. im gonna chop the ac anyways and changing the power steering lines isnt going to break my back. ive heard the gauges will be off but can b fixed through the ecu with a computer tuner and theres a shop down the street that will help me out.

would i not have to change power steering lines and gauges if i use a 91+?


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## Nismo1997 (Dec 26, 2003)

fenix3069 said:


> im going with the rb motor because its an inline six turbo from a skyline.... and to get 400hp from it it will cost me less overall
> also an s13 with an rb25det has pretty good resale value hear in CT. im gonna chop the ac anyways and changing the power steering lines isnt going to break my back. ive heard the gauges will be off but can b fixed through the ecu with a computer tuner and theres a shop down the street that will help me out.
> 
> would i not have to change power steering lines and gauges if i use a 91+?


For a tach, just get a Autometer..i would want a better tach for that motor.


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## kaptainkrollio (Jul 29, 2003)

damn, those silvia k's were light.


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## OPIUM (Aug 18, 2002)

fenix3069 said:


> im going with the rb motor because its an inline six turbo from a skyline.... and to get 400hp from it it will cost me less overall
> also an s13 with an rb25det has pretty good resale value hear in CT. im gonna chop the ac anyways and changing the power steering lines isnt going to break my back. ive heard the gauges will be off but can b fixed through the ecu with a computer tuner and theres a shop down the street that will help me out.
> 
> would i not have to change power steering lines and gauges if i use a 91+?



I say just get the 90. If you are afraid of a lil work then no swap is right for you. For the tach on an RB just swap the RB tach into your existing gauge cluster. Custom a/c lines and ps lines are only a couple hundred bucks anyawys. Just put that into your budget as well. Other things your going to need for the swap is some electric fans, and fuel pump on top of many other misc things like belts, hoses, fluids, etc etc.


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## fenix3069 (Oct 19, 2004)

azRPS13 said:


> Like I said 88-90 180sx And Silvia had the CA18DE/T...Don't believe me? Clicky here . And back then they were called *S13* and *RS13*... The *"P"* means SR20DE/T. Hence the title under my screen name.
> 
> EDIT: Im bored at work:
> 
> ...


 im not useing any of those motors im useing the rb25det from an r33 gts-t


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## Kelso (Apr 29, 2003)

he was proving a point to me and somebody else. i thought it would have been easier for a CA in an 89/90 but apparently not.

but why are you so biased towards the rb25? not saying its a bad motor or anything its just you seem kind of closed minded about it


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## Nizmodore (May 9, 2003)

Kelso said:


> but why are you so biased towards the rb25? not saying its a bad motor or anything its just you seem kind of closed minded about it


Well compare it to a RB20DET, it has far more potential, and is a much nicer motor to drive around town (well to my driving style....it has torque! A much better mid range), when you really start playing with the RB20DET (well compared to the bigger RB's) you find you run out of head room real quick, with smaller exhaust/inlet ports.....

Still in a Silvia, it doesn't matter. They are very light and you can get good ratio Diffs (final drives) for them.......

But motor for motor, I'd take the RB25DET anyday....

There is no substitute for cubes when talking about powerbands, boost can only do so much (sadly)


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## fenix3069 (Oct 19, 2004)

no bias just the fact that the rb25det is better then the sr20det and only one thousand dollars more and u will deffenitley get more bang for your buck. the sr20det is a good motor in a four cylinder class but the rb is a good motor in the six cylinder class which is pretty damn good :thumbup:


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