My boss has an 85 200SX (S12) that he is looking to sell.

It has the CA18ET (the single cam turbo).

Does this engine have much potential? This car has had a rebuilt engine installed plus a rebuilt turbo (the turbo cost more than the engine).

What turbo did this engine use? (im guessing a T25 like the twin cam CA18).

would this car be worth picking up or should i just look for an S13 or S14.

BTW i dont know what he wants for it yet. as the car is in damn near showroom condition i assume hes gonna want a pretty penny

you could get a reliable 200hp out of the SOHC with judicious tuning. You could also yank it and bolt in a J-spec S13 DOHC ata later date without much drama. If the body is in great condition as well as the engine it would be a fun off the beaten track car. I could check if Nissan still has some "Gazelle" emblems in the parts bin for a JDM thing.

what would be a reasonable asking price on an 85 S12 turbo in good shape?

so the DET is pretty easy swap into an S12. thats nice to know.

would just need an IC for it since the ET doesn't have one.

how strong is the tranny? is it the same tranny that is used on the S13/S14? the car is a 5speed.

how close is the suspension to the S13/S14?

I think the suspension of the S12 is different from S13, but its more close to the Z31, there are some suspension parts that are interchangeable. This is a S12 specific site: http://www.club-s12.org check it out.

i think ill check it out

Hmmm showroom condition 200's are a rare find so kinda hard to price....but to give you an idea a rough but road worthy turbo should be in the 1000 to 1400 range.

It's actually a T2. 200's feel like a lot more motor than 120hp sounds like on paper, mostly because of their 4.11 diff. It's a good car to learn how to drift in as well.

great car to learn how to drift in huh:icesangel

sounds fun.

yes it does seem like a lot more than 120hp.

themadscientist mentioned that a reliable 200hp is possible from the single cam. is this with the stock turbo or a larger turbo?

any idea as to how much boost that T2 could take?

Red Lightning wrote:I think the suspension of the S12 is different from S13, but its more close to the Z31, there are some suspension parts that are interchangeable. This is a S12 specific site: http://www.club-s12.org check it out.

Yes it is extremely similar, I used Z31 front and rear hubs to convert my S12 Gazelle to five lug so I could mount the Skyline brakes on it. It should have an old type tranny, depending on the length you might be able to swap in a 240SX box. I am not sure about the U.S. version but my FJ had an old pin fulcrum shifted tranny but a Skyline GTS-T box with the ball fulcrum shifter dropped right in.

jmillheiser wrote:great car to learn how to drift in huh:icesangel

sounds fun.

yes it does seem like a lot more than 120hp.

themadscientist mentioned that a reliable 200hp is possible from the single cam. is this with the stock turbo or a larger turbo?

any idea as to how much boost that T2 could take?

A buddy of mine back in the day had one with a FMIC, subinjectors and SR20 redtop turbo that could sting S13 CA18DETs about half the time. I would go easy on that lil' turbo, leave it alone for now. If I had this car I would do this;

Rebuilt motor right? how long ago, couple of months? If it's a year or less you don't need to worry about the timing belt. Do a full tune up; plugs, cap and rotor, fuel filter, clean the throttle body and turbo pipes, set the timing and idle speed to spec and replace the O2 sensor.

Get a turbo timer and a boost gauge, you can now let your turbo cool down for longevity and monitor boost pressure.

Get the air moving; get a free-flowing exhuast, This is an old car so your selection is limited, you want at least 60mm pipe but get as big as you can find. Get a free flowing air filter, I recommend HKS or Blitz but any quality unit by K&N or other top-shelf company would double the flow of the stock unit.

You are going to notice a big kick in the pants now, likely about 20hp but don't go nuts and crank up the boost, you have to worry about fuel and charge temperature.

You will need to get an intercooler, the OE Starion/Conquest one would be perfect. It flows great is pretty efficient and is not too big so you won't lose a ton of response. For the SOHC @ 200hp I would suggest the shortest run of intercooler piping you can and use 50mm piping. A blow off valve should be included in that piping best mounted after the intercooler.

I don't expect this will give you a big jump in power by itself but it will allow you to run more initial timing and possibly increase the boost if the fuel will support it.

If you want to go further I would strongly advise purchasing a quality Air/Fuel meter and fuel pressure gauge, Greddy makes fantastic ones and those are the ones that rest on my dash, they have never let me down.

Next get a boost controller. You don't need the Bill gates electric light show GPS anti aircraft interceptor phaser model. High dollar boost controllers have their place. If you want one, get one but a manual knob type works just fine.

Monitor your fuel pressure and check that it is where it should be and watch your A/F meter. The stock computer is going to want to keep it at around 14.5:1 for clean emissions, that doesn't help you and could burn a piston. Normally I would say "slap on a SAFC fuel controller on it" but the car is to old, the computer won't work with it. So you are going to have to raise the fuel flow manually with an adjustable fuel pressure regulator. The problem with that is if you set it to give you a nice 12.7:1 under full boost at idle it might be way to rich and foul out your plugs in normal driving. Try and get it to see as close to 12.7:1 under boost and no richer than 14:1 at a low speed cruise.

If you start to see the mix go lean up top but the fuel pressure is good you have maxed out the injectors, if it leans out and fuel pressure drops to you have maxed out your fuel pump. If everything looks good you can start dialing in some more boost. I have no idea what the stock boost was on this car, it should be in a manual or wait until you have a boost gauge in to find out. I would think an old unitercooled Nissan like this would be around 7-9lbs. I wouldn't raise it very high no more than 12lbs, these cars were Nissan's first foray into turbo cars and the turbos weren't stunningly efficient.

Be very careful, check everything twice and go slow. You can have lots of fun with this car. You are going to have to increase the injector, fuel pump and turbo size to see 200hp but you should reach 150hp on the OE stuff with simple purposeful mods like I have listed.

the club-s12 guys all say that 10psi is about all you can manage with the stock injectors. if you add an extra injector you can take it up to 12psi and with a bigger fuel pump and appropriate size extra injector you can take the T2 up to 15psi at the max.

supposedly 15 psi on the ET will put you at around 250rwhp and 12psi is around 210-225rwhp and 10psi is usually 185-200rwhp depending on how far you can advance the timing without pinging.

this of course assumes an FMIC and upgraded exhaust and some type of cold air intake.

isn't the conquest a dodge? in that case it shouldn't be too hard to find one in the US. starions are about as rare as hens teeth in the US

It's a Dodge like a Probe is a Ford, they can be found. If you have the coin any decent size FMIC would work. Post a link to the S12 guys, I would like to see what data they have.

ok ill have to go hunting. its in one of their FAQs i think?

hard to tell of they are talking about US or UK spec cars at times. since most of club-s12 is from the UK

I dunno seems like there are a lot of U.S. cats on club-s12. The forums are here http://www.club-s12.org/. Damn mad what ever happened to your Gazelle? Sounds like a sweet ride. Any pics of your intercooler? I'm swapping a S13 ca18det into my 200sx and I'm trying to think of the best way to mount a fmic.

BTW jmill if you wanna go five lug, you can look around for a V6 200 and pull the hubs as they are 5's

its hard to tell on there. there aren't exactly a lot of people on club-s12.

i assume a 5 lug conversion allows the use of Z31 brakes (and aftermarket brakes for the Z31)

im guessing the 4lug s12 used that oddball 114.somethingmm lug pattern that early nissans used.

of cousre if it used 4x100 that would make finding rims easy

114mm lug pattern. If you use the five lug hubs you can run 300zx 4-pot calipers with the proper rims. I had GT-R ones on my old S12.

nice. i know that there are Z31s in the junkyards in cheyenne so it should be too hard to find the parts.

whats suprising is there there are probably less than 10 240sxs in cheyenne and about 3 s12s.

and only one of those 240s had had the SR swap done

Would the older S-AFC (not S-AFC II) work with the ET's computer? I'm told that the S12 does not have datalogging and you cannot tune it. When I'm done (a long time from now) with my car, I'm going to dyno tune it once, so no datalogging shouldn't be a problem? Thanks.

to the best of my knowledge no stock computer can datalog, that's a standalone thing. The S12 computer is so old I doubt highly you can tune it even if you have the facilities to burn your own chips. You could try running an engine harness and computer from another newer car, how about a pulsar? They are turbo, your S12 is turbo. They have a distributor, your S12 has a distributor. Your S12 has twin plug chambers though, I don't know how you would get around that short of plugging one set of plug holes and only running 4. I have seen these cars run on one plug per cylinder but they were not being run hard like you would.