SR20DET Engine Swap

SON240sx Automotive
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This thread is for the purpose of providing answers to FAQ on this popular engine upgrade for the 240sx.

If I make any mistakes, please correct me, and I will fix them in this write up, I’m sorry if it’s not perfect, but I am basing it on my knowledge and the research that I am doing while writing this.

SR Swaps:

Basics: Know your engine:
S13 red top, S13 black top, S14 engine, which engine to chose and which engine is most suitable for which car? First off, the s13 in japan came with 3 engines, CA18DET, sr20det red top and then sr20det black top. The reason why people prefer SRs over CAs is because there is a lot more aftermarket support for them, SR is really the cheaper way to go to make more power and have a more reliable engine (to make things simple)
People who want to go CA to be unique, have fun, I recommend the SR way.

I, myself, have an s13 black top SR, if someone can please specify the years the red-tops and black-tops came, it would be great because I always get confused over those numbers. The red top was produced from 91 to late 94. The black top was produced after that. (s13s were in production in Japan at the same time as the s14s due to their popular demand) People say that it makes no difference what kind of engine you buy, but I personally think that blacktop is a better engine to get for an s13, simply because it’s newer and ECU is slightly different.

Here is the difference between turbo’s for SR’s. (Courtesy of Freshalloy.com)

SR20DET OE turbo variations:
 S13 SR20DET: T-25, 60 trim 56mm BCI-1 compressor, 53.8mm 62 trim T-25 turbine, .64 A/R turbine housing. Journal bearings.
 S14 SR20DET: T-28, 60 trim 60 mm BCI-1 compressor in T-04B housing, 62 trim 53.8mm T-25 turbine. .64 A/R turbine housing. Ball bearing center section.
 S15 SR20DET: Same as S14, but with Inco turbine wheel (instead of GMR), cast divider wall between turbine discharge and wastegate.
 Pulsar GTi-R: T-28, 60 trim 60 mm BCI-1 compressor in standard T-3 housing. 79 trim 53.8mm Inco T-250 turbine wheel .86 A/R turbine housing. Journal bearings.
 BB SR20DET: T-25. Basically, the same as the S13 Silvia.

Now back to the topic: SR-swaps. People say it’s overplayed, but I still say that it’s the cheapest, easiest way to make your little slow 240 into a fire breathing dragon.

First you need to find the engine, the more complete it is, the cheaper it will be for u in the long run. When choosing the engine, these are the things you need to look for:

  • The harness has to be complete and uncut (mine came with a cut off ignitor chip plug)
  • Make sure your crank angle sensor isn’t cracked
  • The ECU has to have no physical damages (I am assuming that it’s the right ECU for that engine)
  • Check the whole engine for visible damages, including the throttle body, and the fuel rail (make sure it’s not bent)
  • Hope that your oil pan is not bent, if it is, you can knock it out, or you can purchase a new OEM one ($139 USD) or Greddy Aluminum Oil Pan ($289 USD) from srswap.com
  • Make sure your tranny is manual, and check the tranny sensors for visible damage.
  • Check it has an ignitor chip, if it doesn’t have it don’t worry ($250 USD) from srswap.com
  • Does it come with a SMIC (Side Mount Intercooler)?

I got my engine for Tiger, usual price that you will find is $2000 CDN and up depending on what the engine comes with.

When you get your engine, these are the other things you are going to need, you can cut some corners, but I will explain you need them, and why I chose these for my car (I have to say thanks to Sasha and Andrew who have helped me find the best parts and provided me with explanations of why they are the best when I was doing my swap)

MAFS, if you have SOHC then your problem is solved, u can use your SOHC MAFs with your SR, if you have DOHC, you have to find one in a junkyard, or order one online.
Intake, I have Blitz LM ($125 USD), any generic intake will do, but you need to purchase an adapter for your intake to work with SOHC mafs.
Walbro Fuel Pump – Heavy Throttle - 119$
You need a new fuel pump, yes z32 fuel pump will work, but you might want to get a walbro right away because you will only need to replace it once.
Blitz Downpipe – Heavy Throttle – 189$
Blitz is stainless steel, which means that it doesn’t rust, which means that it’s a very good bargain. You can also look into other downpipes like Trust, or even Heavy Throttle custom made downpipe (to save you some coin)
Exhaust – you don’t need an exhaust for your SR to run (you can use stock exhaust), so I’m not going to talk about it.
Hotpipe. The easiest option for a hotpipe for you will probably be HT Hotpipe – Heavy Throttle – 139$. Since I got a Greddy BOV, I got a Greddy Flange on the hotpipe right away. There are different flanges available, such as Blitz, etc.
BOV (Blow Off Valve) – This is a whole separate discussion, but I chose Greddy Type-R Bov (Heavy Throttle – $215) because it has a very stiff spring which prevents boost from leaking at idle.
Intercooler. Most engines do not come with a stock SMIC, so instead of you wasting your time, cutting metal, and making your own piping, it would be a wiser idea to just purchase a FMIC. I have GREDDY RSPL on my car, it comes with all the couplings (including the ones for your hotpipe). I personally really like the unit, it comes with great instructions and it’s good quality.
Radiator. Lets face it, if you are going to run stock rad., your car WILL overheat, so why not spare yourself some time and get an aftermarket rad. right away.
KOYO Rad – Heavy Throttle – 479$ - comes with fans.
I chose this one because everyone who has it, likes it, so I decided to get it as well. *Note: make sure you get the SR KOYO rad., because they also come with an inlet on the left side instead of the right side.
Nismo Engine/Trans Mounts – Heavy Throttle – 275$
If your old engine/trans mounts are crappy, just replace them… it’ll save you money and time in the long run.
Heater Hose Kit – Heavy Throttle – 35$
This is a must. You need this kit to make your heater work, and u need to put the lower hose on the engine BEFORE you put it into the car.

There are a few other things that you’re going to need when doing the swap:
Synthetic Motor Oil (Syntec 5w50) – 20$ (4L)
Nissan OEM Oil filter (SR20DE) – 10$
Coolant – 20$ (4L)
Spark Plugs (NGK V-Power Cold Range 7) – 20$ (4)
Tranny Fluid – Castrol Syntec 75w90 – 20$ (2L)
Nissan OEM Fuel Filter (300ZX TT) – 20$
Fuel Hose (Filter>Inlet) – 10$

You will need to purchase those items as you’re doing your swap.

You will need to rewire your harness (since Japanese cars are right-hand drive), it is not that difficult and you will be able to find all the wiring diagrams online. www.srswap.com has a great FAQ section which is what I used when doing my harness.

Your lower harness from your KA will have to be reused, so be careful with it, you will need to wire in your MAFS plug (and extend it), you will need to extend your O2 sensor, and you will need to connect your lower and upper harness. (as I said, you can find all the instructions online) You will also need to wire in your speed sensors, tach, etc. near your ECU and once again all the instructions are online.

The usual SR swap takes about a week time, the 3 SR swaps that we have done so far ranged from 6-7 days. (I don’t mean that you will be working 8-9 hours on your car a day) but expect it to be around a week. Make sure you get a few guys to help you out, who have already done the swaps and will help speed up the process. If Sasha, Andrew (iQuaBob) and Mike (Bomex) wouldn’t help me with my swap, then it would definitely take me a lot longer to research and to do everything by myself. So thanks again guys.

I hope this write up helps anyone who is thinking or planning to do an SR swap in the near future. If someone would like to add anything to this, please do so.

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It’s very good,

only comment’s i can think of right now are that:

You can run the stock rad and not overheat, i know andrew and I are, and aslong as you have a strong fan you should be good … oh and also if you keep away from hours of stop and go traffic.

Gauges, If you were running a SOHC before hand, you will not be able to have your tach, so either get one from a S13B / Silvia or RPS13(japan), or an aftermarket one.[Note the proper SR tach goes from 0-9000 unlike the S13B]. Another very useful gauge is a boost gauge, it is very easy to install and extremely important to see how the turbo is acting. You DO NOT need to buy a really expensive boost gauge to get an accurate reading, all it is, is a air pressure mechanical gauge, get one from princess auto ect. if you don’t care about asthetics, oh and price, for example i have a $9.00 boost gauge that works extremely well!!

If you have the SOHC beforehand you will have a problem with power steering, there are a few solutions; you could find the DOHC lines and resivour from a yard, or buy them new, also you can get your old lines extended professionally, There is still the option of no power steering which i am currently doing (it has it’s +'s and -'s).

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Red top is 1991-1994(S14 was released in 1994, thereby signalling the end of the redtop) and the blacktop was produced from 1994-1998.

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Andrew is running a stock Silvia rad, it’s a bit thicker than the stock one. When Mike was running a stock rad he was overheating a lot, and so do all the guys on FA, so i still stand by my comment that you need an aftermarket rad. But thank you very much for you input on SOHC –> SR swap.

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Mike wasnt running a fan thats why he kept over heating.

The KA rad is sufficient, but again I would strongly reccomend a larger Rad with hipressure Silicone hoses.

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Some things you might want to know:

Power steering isnt your only problem on the 89-90 models, you also have a problem with a/c. The a/c pump in the early models wont fit witht he engine, so make sure u get a 91 up pump aswell.

And powersteering as well, just like Racer 240sX mentioned earlier, you can do this in a snap. Disconnect all hoses, and turn ur wheel left and right and left and right, alot of fluids will leak on the floor and then presto! Manual steering.

ECU and wiring is also a bit of a problem with the early models. The ecu on the 91-up model can be used for the swap, but u must rewire the hoses, if u need a diagram, email me and ill get you one. you must also rearange the wiring on the car to fit with into the harness properly.

The best thing on the 89-90’s model is that the MAF sensors fit with the SR20 engine, but the 91-up MAF sensors do not.

The ignitors on boths cars are good for nothing, you will need either a SR20DET ignitor or get it from a 92’+ Q45 or 300ZX(Z32). If you need the wiring charts from these ignitors, email me aswell.

Relocating you battery to the back is a very smart move, if your planning to upgrade from the stock intercooler to a front mount intercooler. The battery will get in the way.

You should also do somethings if you want your sr engine to last for more than just safe speed limit crusing.
Some include:
-Removing Heatshield(if you turn really quickly, you steering shaft will contact with this possibly causing it to lock)
-Clutch/Flywheels replacement(Any Maxima Clutch)
-Fuel Pump(you feel like you car is sluggish if u compare it to other Sr cars)
-Radiator/Intercooler(big problem with Sr engines, when suficient cooling isnt provided.)
-New Injectors(I’m aiming for 300ZX injectors)
-Brakes!(big thing, more power, you want it to stop faster, especially if you had the KA engine for a while, you will need the brakes. Try for -300ZX brake conversion, if your planing to do this, email me, ill help you out. $1300 could get you a good front Z32 brake conversion.

Any questions or if you are doing a swap, email me, cuz i might help you out.
-Art

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Just to clarify:

S13 Red Top: 1991-1994
S13 Black Top: 1996-1998
S14 Black Top: 1994-1998

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i know this a little off topic but since the sr suffers from a very poorly desinged water pump. (thats part of the over heating problem because it runs in to cavatation at high rpms) has anyone tried installing an electric water pump there was a great how to on zilvia for the ka24de though just an idea. sory for the off topic

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i think the water cooler is fine, no point converting it. most overheating problems come from the small radiator used with the stock SR20. Getting a bigger one will reduce ur engine heat drastically, but if your paranoid, just run it with heat on full blast.

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No, actually above 5000rpm the SR tends to overheat quickly. Thats why people buy the KOYO rads… and fans

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? your agreeing with me, why are u saying no?

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? your agreeing with me, why are u saying no?[/quote]

Probably cuz in your previous post you called it a water cooler lol. He just assumed you didnt know what you were talkin bout and just ignored the rest of your post.

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cuz this guys talking about a water pump. isnt he refering to the air water cooler?

my bad, i was thinking of the wrong engine.

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Honestly i dunno much about technical stuff. But i’ve never heard of a water cooler, maybe im wrong too.

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I like men too but the overheating is due to the SR’s small water pump
and it be comes inefficient above 5000rpm. Koyo rads flow better so it
puts less strain on the engine/water pump at higher RPMs. The only
problem with the KOYO rad is it runs too cold if you’re using the stock
clutch fan which most people don’t use anyways.

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ya, i was thinking of the subaru WRX’s water cooler, thats that little sprayer it has so it cools down the radiator and intercooler. i was planning to build that for my sr20 once i get it.

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That’s water injection. SAAB’s also have it too.
Water injection helps suppress detonation, and gives the combustion chamber a nice steam clean.

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No he’s talking about a system similar to the N-tercooler… except instead of spraying nitrous on the IC or rad, they spray water…

It’s quite effective…[/quote]

OIC, sorry about the little confusion.

I still believe that water injection or nitrous injection would be more beneficial.
Radiator cooling can be handled simply by upgrading the thermostate.

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I heard using the stock ka rad or sr rad is good enough if you are using a larger fan then stock. Im running a stock 240 rad with an aftermarket fan, I dont remember what size it was, but it’s large.

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Continuation of BrandonC’s finding at Megacity scrapyard:
http://forums.son240sx.ca/viewtopic.php?t=4478