Bolt in A/C for RB swapped S14 and now S13!!

Discuss the RB20, RB25 and RB26 series engines.
rixskyline
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*UPDATE* .....free how to info below, this is my gift to you nicoclub....thanks for all the free info over the years

Hey guys, my name is Rick and I do a lot of junkyard research to find out things that work best on rb powered cars. I have recently found a bolt in a/c solution that uses a complete under hood all nissan a/c system. The compressor bolts to the rb bracket, the lines are the right length from wall to compressor, the condenser is a bit larger but fits great.

This a/c solution plumbs all of the pipes in the driver side instead of being in the way of your intake, intercooler pipes, battery or radiator hoses like on the pass side.

I have this system in my wifey's s14 rb25, have pics of the install for test fitment.

Anyhow here are 2 install pics, one with the turbo on and one without, all lines are driverside with no cuts or bends to fit around any other accessories.

I am more than willing to share this info

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Last edited by rixskyline on Sat Jul 06, 2013 5:02 pm, edited 2 times in total.


platez808
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i'm definitely interested!

rixskyline
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Im working on it, Ill add more details this week as I figure a few more things out. All the accessories fit nicely around the a/c like stock!

here is a stock s14 setup, red lines indicate low side, blue is high, compressor and drier are the grey thingy, and yes the line placement drawing is spot on.
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almost done with my girls car, a/c complete, the drier lives right next to the compressor
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this is the connection side to show how nice it clears the rb25 starter even with the in line drier on the a/c line itself, can't see it?? thats the point!
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moar....look for the line...follow it
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yes, its outer space painting on the covers and bay...spray paint art lol
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godzilla_753
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Joined: Sat Jan 27, 2007 1:55 pm

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Very cool!! Im also definetly interested. Im currently trying to get a/c working in my car as well, I went the rewelded lines route but have yet to hook everything. If this bolt on stuff is easier might go this route. Any idea how to trigger the IAC to raise the idles on NEO rb's? The ECU controls it in instead of the chassis on my s13 and im stumped on how to get it to bump up the idle **sorry not trying to thread jack!!

rixskyline
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so run the a/c relay signal from the dash switch into the ecu and it will kick out a signal to your fast idle control...I wired this car from both diagrams and they are shockingly similar. I made sure to wire up the hi pressure switch on the dryer so the a/c will cycle on the temp switch too instead of being on all the time.

platez808
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i really hope this applies to s13s too..

Darius
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Car: RB25DET S14 - 665 WHP (SOLD)
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This will be interesting considering the S13, S14, and S14a all have different AC fittings.

rixskyline
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Well darius considering how many components change over I will be looking more into the S13, I dont have anyone local willing to try any a/c work that I can use as a test bed...well RB guys, but I can tell you that you delete all of your fitting issues with other bolt in lines on the S14, I have done this on my 98 RB25, and my wifeys 95 RB25 with no issues.

I am still figuring it out but so far it all works on the s14, and s14 s*** works with s13 on many levels, and even if I have to get creative I think its time someone came forward with good a/c solutions

rixskyline
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anyone have measurements for the S13 condenser?

From looking at just pictures I am going out on a limb to say it but I bet I can make this work easily....the s13 and s14 only differ in the nose on the a/c, the dryer has the same 10mm bolt in small high pressure line and the low pressure side is the same size at the firewall as the S14.....which I intend on replacing all of it from the firewall forward with this setup anyhow so all the under hood fittings don't matter.

I will need to physically put something into a S13 before I can claim that but I damn sure will. I just need a lab rat....

Darius
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Car: RB25DET S14 - 665 WHP (SOLD)
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Yep, the cold side of the condenser to the evaporator is not the issue. The fitting differences lie in the low-pressure fitting at the fire wall and the hot side of the condenser. I've sunk a ton of money into designing and manufacturing fittings to fit the S14 and S14a (for the RB25 compressor) and I offer a $300 kit. But if you come up interchangeable Nissan parts for less, then more power too you!

rixskyline
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well all I know is keeping the rb25 compressor is half the problem, Ill do more digging on the S13 side of things but I cannot imagine them being too far off from being a bolt in affair with a change or 2.

Darius
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Car: RB25DET S14 - 665 WHP (SOLD)
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That's the problem, they aren't far off at all but they ARE different. The low-pressure fitting out of the evaporator is only off by like 1mm between the two S14's. It totally pissed me off when I had to order a new set of custom hose ends for the larger diameter too. Why the hell Nissan would think making that small of a change is a good idea is beyond me...

RRRRB
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Car: 98 RB powered S14
Location: WA

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what we need is a USDM ac compressor retrofit so we can all source none JDM compressors that have been sitting open forever...


What did you do on the 98 to cycle the compressor? how are you keeping the evaporator from freezing?

Darius
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The wiring is in a comprehensive A/C thread already. I will try to find it. But basically the pressure is being controlled by the triple pressure switch on the dryer. When the pressure rises too high, it opens the circuit and the compressor clutch disengages.

rixskyline
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this compressor is a US model, off of a very common car that bolts right on.......

RRRRB
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Darius wrote:The wiring is in a comprehensive A/C thread already. I will try to find it. But basically the pressure is being controlled by the triple pressure switch on the dryer. When the pressure rises too high, it opens the circuit and the compressor clutch disengages.
well here is what i have read... I havent personally verified anything besides what i have actually performed on my car.

The 95-96 240sx models have a evap temp sensor in the evaporator which is what cycles the ac compressor clutch relay in reference to evap temp

The 97-98 models dont have one... ( i have a 98 i didnt see one, nor was it in the wiring diagrams i have) I also read that the ac compressor on the 97-98 runs constant and the refrigerant flow is controlled by a TSV (throttle suction valve) like most others most, pretty much all ac systems have pressure switchs, ive always assumed they were just for safety as pressures change dramticly with amibient tempature so regulating evap temp with pressure would seem dificult and inacurate..

Basicly i got ac to work in my car, but it wouldnt ever shut off and would eventually freeze the evaporator... the Rb compressors arent designed to continuesly run so i installed a thermo switch from a honda evap box i had laying around and put it inline with the ac compressor clutch relay, and i no longer have any issues...

rixskyline
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Ok so today I figured out I use parts that went through the same changes as the s14 a/c fitting wise, the low side is different in years as well and its all def compatible in the s14 and s14a for sure.....thanks for pointing that out.

Ill post thermometer pix in the vents tonight, no heating up issues on the wife's 95 RB25 with this setup...if it makes it to the 2 week mark then Ill figure out a way to start getting my hands on a bunch of these "kits" and sell a few cheap ones to kinda see how other people like it. Cheap I mean like $250 shipped? That is the full a/c under hood setup to re route the lines all on the driverside.

condenser, compressor, all lines, drier w/pigtails....this clears all of out p/s and radiator

You can also opt to buy just the bolt on high pressure line, compressor and bolt in low side and run your stock condenser and high pressure lines and drier...

I will be buying up more parts to try the top mount turbo setup on another 95 s14 RB25 this week to see how well it clears.

godzilla_753
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all this a/c stuff .....god. its been awhile since i felt this clueless with something car related :crazy:

but good job guys, seems like there some options out there for everyones setup, I am gonna go look at mine and see if I cant figure it out.

and rixskyline, my only concern with hooking the relay up to my ecu directly is that what if it blows something up? I dont know how many amps the switch requires, and dont know what that specific circuit in the ecu is made to handle. Unless I have it wrong?

I just like to triple check before I start wiring up stuff to that computer, finding another [affordable] neo stagea ecu would take eons lol

rixskyline
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I also have setup a way to use just my US compressor and 2 main lines off of it with all the other stock s14 a/c stuff....if you wish to keep the drier on the passenger side.

wiring is simple, grab a diagram and look at it, you would be surprised how easy it is..

Im going to try all sorts of setups to see what works best.

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uber95
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On the S14 have you checked these components/set-up with an aftermarket header or you are just using the stock exhaust manifold?

rixskyline
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it clears both so far

godzilla_753
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So I have a quick question guys, Ive got the NEO rb25, got A/C working on my car thanks to my awesome little bro who is a wiring guru, only thing is we need some kind of refrigerant pressure sensor switch. Anyone know of one thats cheaper than 50 bucks and has 3 wires coming off of it? We found one of the 02-04 Altima's (2.4 4 cylinder) but couldnt find one in the junkyards, and dealer wants 50 bucks.

mailman31090
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rixskyline wrote: Ill post thermometer pix in the vents tonight, no heating up issues on the wife's 95 RB25 with this setup...if it makes it to the 2 week mark then Ill figure out a way to start getting my hands on a bunch of these "kits" and sell a few cheap ones to kinda see how other people like it. Cheap I mean like $250 shipped? That is the full a/c under hood setup to re route the lines all on the driverside.

.
Well when ever your ready to ship the "kits" please contact me. I'm ready to purchase.

RRRRB
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Car: 98 RB powered S14
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godzilla_753 wrote:So I have a quick question guys, Ive got the NEO rb25, got A/C working on my car thanks to my awesome little bro who is a wiring guru, only thing is we need some kind of refrigerant pressure sensor switch. Anyone know of one thats cheaper than 50 bucks and has 3 wires coming off of it? We found one of the 02-04 Altima's (2.4 4 cylinder) but couldnt find one in the junkyards, and dealer wants 50 bucks.

whats wrong with the factory switch?

rixskyline
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I have decided I am just gonna tell you guys the whole deal, so this way you can do your own setups and try new things and make this swap s*** easier and cheaper for us all in the long run......Just dont forget who told you guys about this. The items you need to do this swap:

junkyard j30:

different years have different fittings, same year 240-J30 or close will bolt in. 93-96 j30 = 95-96 240sx, 96.5+ = 96.5+ J30

all j30 a/c under hood

lines
condenser
compressor
dryer
ect.

J30 compressor bolts to RB brackets
J30 lines fit around turbo and bolt into car like stock
J30 condenser can be used t put dryer out of way of aftermarket intakes and i/c pipes
J30 dryer same as 240

Dont forget to replace your seals, charge, wire and go!!

rixskyline
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as far as s13 goes....I am still waiting to find a test car to try stuff on

The setup I have now is setup just like the way you would find it in the j30, no thermostat in the coolant system, dual "12 fans push/pull, aluminum radiator....and highway speeds results in frosty white air, in florida heat and its been summer now for a while so I would rate this idea 8 outta 10......try it!!

speakeasy
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Joined: Sat Oct 30, 2010 11:40 am
Car: 1991 240sx Coupe RB20DET

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I have an S13 with an RB20, but I don't have any of the A/C parts installed. Would doing this be the easiest way to get A/C working in my car?

rixskyline
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this setup so far is for S14's only, I am looking into getting a rb s13 guy to see what works and what doesn't...when I figure it out Ill let ya know.

rixskyline
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still working great on our rb25 95 s14 :) hope this thread helps!

speakeasy
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Staying tuned for the S13 version :)


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