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hi, im brian
I'm buying a s12 ca18et tomorrow and a uninstalled t25 turbo.
I have alot of questions.
Like where can I get a good cheap exhaust/intercooler?
what are some quick cheap upgrades?
what is the max boost with everything stock?
what limits the boost at this point?
what are some common problems with this motor/chassis
I'll be searching around this forum but i'd like to set this up so I have all this info in one place.
Pics will be posted soon.
Where You Located ?
Welcome! You have come to the right place. Lets see some pics
I'm in newburgh IN right outside evansville.
I can't seem to figure out how to upload the photo
Post Merge
and one more question in good running condition what is this 200sx worth to you?
The ca18et is a waste of time to modify unless your only looking for a relatively small bump up in power. The ca18et is an archaic 2 valve per cylinder engine that doesn't move air efficiently at all. A ca18det with the same exact mods as a ca18et will always make way more power simply due to the fact the 4 valve head is much more efficient at getting air in and out of the engine. On top of that most ca18et's are in need of a rebuild, especially after 30 years of non intercooled boosting. Much much more cost effective to simply upgrade the engine with something more modern. I replaced mine with a ka24de.
The value of s12's is one of the more hotly debated issues on club s12. A lot of members have acquired their s12's for very cheap (under 1 to 1.5k) so the general consensus seems to be they are not worth very much. The SE is widely regarded as the most desirable and valued stock s12 but even then most members won't pay much over 3k for a nicer one. If your planning on modding your s12, like most vehicles that are modded, don't expect to get a lot of your mod investment back if you want to sell it down the road.
^^this guy always puttin down the 18et lol. Its a good motor not really any after market most stuff has to be custom made as far as cheap ebay intercoolers are fairly cheap. If you plan on upping the boost you need to take off the pop-off valve located on the pass side rear of the intake manifold hell even if your not upping the boost get rid of that thing its safety measure its like boost cut prevents the motor from grenading in the case the wastegate takes a shit. But its old as hell and probably venting sooner than it should now. Also if you do plan to mode for power your going to need injectors you can find a set like ours with hose barb fitting on a old mercedes 1976 mercedes 600e or something like that. They are rated at 450ccs which should be more that enough unless you plan on going with more than 200hp. Also get a walbro 190lph fuel pump anything bigger and youll need a fpr (fuell pressure regulator). I'm probably the only person your going to find here that like the single cam ca. Feel free to pm me anytime with any questions you may have.....
Here we go again. Sideways_s12 vs Redneck ca18et debate battle number 1,000,000 haha. The ca18et is never going to be able to hold a candle to the modern Nissan engines with 4 valve heads in terms of performance. When it was new, and in its time, I'm sure the ca18et was a decent engine. 30 years later, especially after all those years of hot intake air being directly plumbed back into the engine from the turbo, it just doesn't make financial sense to put money into them. And for any serious power increases you have to rip into the bottom end because the rods are not all that strong. Keith bent one in his fresh remanufactured block at like 160whp? After Keith bent the rod on his ca18et he got a ca18det, swapped over all his ca18et mods, and was making 220whp. 60whp increase and the only difference was the heads. You can say I'm always puttin down the ca18et but it isn't like I don't have evidential reasons to support my claims. Newer members especially should be aware if they are going to stick with the ca18et it isn't going to be a cheap or easy path for significant power increases.
Hahaha, goddamnit guys.
Redneck on 06:50:18 PM / 15-Feb-13The ca18et is never going to be able to hold a candle to the modern Nissan engines with 4 valve heads in terms of performance.
Any motor can be built its like sayin i can build a g13b metro motor but its not really a good idea. The money it cost isnt really worth it
Redneck on 06:50:18 PM / 15-Feb-13Here we go again. Sideways_s12 vs Redneck ca18et debate battle number 1,000,000 haha. The ca18et is never going to be able to hold a candle to the modern Nissan engines with 4 valve heads in terms
sr all the way ^_^
I do like that color blue on the s12 tho....
i feel like ive seen that blue s12 before
Maybe. its in southern indiana. I'm getting an sr swap in the summer. I was just wanting to know what I can do in the meantime.
think 2500 is too much for this one?
By most used car standards, I'd say it's not bad, nice wheels, decent paint, just needs the turbo hatch spoiler if you ask me, but yeah the S12's tend to go for less than most people would expect, around the $1500, hell here in BC Canada the last 3 that I saw ran just fine, but they went for under $800. I'd say you'd be better off in the $1800-$2000 region but meh, it looks clean as hell. Depending on how you see it, could be worth the extra $500.
actually it does come with that spoiler.
but back to the questions like how far can i push it with just a boost controller?
Not very.
Let me interject here because I'm not Redneck, nor am I sideways_S12. I'm Arro, and I've owned one of those CA18ET's, was good friends with someone who pushed one pretty far, and also have moved onto a more modern engine (KA24DE). I have a more rounded opinion perhaps. No offense to either of these two chaps, both with lots of knowledge in their own right, but they have each picked a "corner of the ring" if you will, and I'm still somewhat in the middle of all that.
Now sideways_s12 hates to read, so don't worry, he won't have much to say about particular points in what will probably be my long post. Redneck probably will, but I suspect he'll agree with most of my latter comments.
SO... Here is what I think. Notice I said "think". As in "opinion".
You need to know what some of your immediate hurdles are to performance, then you need to know what some of your more distant hurdles are. The first hurdles are easier to overcome than the farther away ones.
First off, this is a relatively low-compression engine, as turbo engines go. Most turbo cars in the 80's run 8.5-to-1 compression ratio, which is lower than a non-turbo engine of the same vintage (9:1). This is for longevity under the stress of boost among other reasons too complicated to get into now, but understand that compression ratio affects power output in a turbo engine just like it does in a non-turbo engine. Yours is .5 lower than most turbo engines of its time. The only way to make up for that lacking is to either change the pistons or turn up the boost. We already know you're going to prefer the latter of the two.
So then what about that, turning up the boost? Well, your stock turbo is a T2. This is a rather tiny turbocharger. I have a picture of a T2 versus a T25G on here:
GARRETT Turbocharger Component Options
It's noticeably larger, the compressor housing... and the compressor wheel is, too. That little T2 will just be making heat when you go to anything past 7 or 8 psi. They are sprung from the factory at that, 7 psi... but the spring in your OEM wastegate actuator can is probably old and tired, and more than likely you are opening the wastegate flap up closer to 5 psi. Don't trust the factory "gauge", because it's digital and known to be inaccurate. It's just useful to show you that you're getting *some* boost. The factory gauge uses a cheapo MAP sensor.
A T25 is better turbo, but it's only a little larger... so after 10-12 psi, it's just making heat. Now, you might wonder what that means. It means that the compressor wheel is spinning so fast to make that extra boost that it's generating heat from all the friction of the air.... that heat means that by the time it gets into the outpipe, the hot air has already decompressed some... re-expanded, meaning it's less boosted. A larger turbo spins less to compress the same air, and therefore creates less heat. This means the boost it makes STAYS compressed better. An intercooler helps, too... but a tiny turbo with a big FMIC is a bad idea because it's unable to pressurize the extra volume in the IC as well as a better sized turbocharger.
Which is why I like the T25G. It's a bit bigger than a T25. So that means it's significantly larger than a T2. And THIS is your best bet for your CA18ET. You can get 15-18 psi out of it with the right intercooler setup. It's been done many times. This is good. Anything more than this, and your engine would need severe improvements. As it is, at 15+ you probably want a fresh head gasket with ARP head studs to hold it together properly. Not super expensive but that means obviously you're taking off the head.
So then what's the first step?
BUY GAUGES! DO NOT TUNE THIS CAR BEFORE YOU DO! You need (at least) an O2 meter (also called an air/fuel meter). It doesn't have to be a wideband, and in fact it's probably better it's not for mild tuning. You also need a quality boost gauge, one that shows BOTH vacuum and PSI. No, you don't need an Autometer 30-0-30. You will never be pushing 30 psi in this silly SOHC CA engine :P So a 30-0-25 is fine and is cheaper.
Why do you want gauges before tuning? It's called "baselining". Read about it in this article:
Tuning 101
And in fact, that should get you going with some good information. You need to understand the tools of the trade. I wrote that with CA18ET tuners in mind, but it applies to any turbocharged engine. So read that article.
Aside from baselining your tune... Get a T25G. Install a medium-sized FMIC and piping, with a BOV. Install a good, but MODEST pump like a Walbro 190 liter-per-hour, because larger pumps will overrun your stock fuel pressure regulator. Don't listen to anyone who says it won't. Your fuel pressure reg's spring is just as tired as the one on your stock turbo wastegate can. And 190lph is enough to support ~250hp judging from other people's results on 4-cylinder 1.8 and 2.0 liter engines.
Rewire that fuel pump on a relay. Install a SuperAFC and an SR20DET MAF. Or run a home-made extra injection setup and MONITOR FUEL MIXTURE.
There was a guy on here who managed to get his CA18ET S12 into the high 12's at the 1/4 mile dragstrip, so that should give you an idea of what kind of power you can make on a stock longblock. He had an unported head and stock pistons. His only problem was he blew the head gasket on the next run after the 12-sec run. We figured that with a fresh gasket and some ARP studs to hold it firm in place, it could have done that again and again. We have no idea how much power he was putting down, but the butt dyno hinted that it was around or a bit over the 200hp mark.
This engine has some serious flaws. One of them is in the rod design. The rods are thin on both the CA20E and the CA18ET. The CA18ET's rods are a bit better than the CA20E rods but only because they aren't quite as long, so the length to width ratio is a tiny bit better if you can understand what I'm saying. The longer the rod at the same length, the easier it is to bend/break. It's easier to break a toothpick at full length than if I cut the toothpick into a 2mm long piece and handed it to you to try to break. Make sense?
Anyways, even tho the CA18ET rods are a bit better than the CA20E rods, they're still thin. And there's one risk. You can get custom forged rods.... $$$$.... or run CA18DET rods which are a bit beefier. Okay more than a bit. But you still have thin sidewalls on the block.
Now, to date, nobody I know of has blown a hole in the side of the block. Oh wait, I did :P Yes, I threw a piston out the side of the CA18ET block. Now, I'm not saying it wouldn't have happened to a different engine that suffered the same failure, but I suspect I might have survived the event if it had been a different engine, yes.
So then what else to worry about? Well, the fuel issue is one of the closer hurdles to deal with. The fuel pump and Super AFC is half that equation. Running 91+ octane and larger injectors is another. Now some people just say "run huge injectors and if you run a lotta boost and don't blow, it's tuned!". That isn't true. Too much fuel might help cool the air temps, but it also washes out the cylinder walls. This means they aren't oiled properly. Means they cause friction. Means wear and tear on cylinder walls and pistons. Also means that if by chance you DO have some detonation, what might have been minor is now a damn powderkeg, waiting to puke engine internals all over the pavement. This is why tuning properly is so important, especially on a CA18ET. As opposed to something I've jokingly called "t00ning".... because that shit only works in a cartoon world where physics and chemistry don't apply :P
Here is some information on injector options:
Injector Comparison List
You also have to contend with the stock turbo manifold. Which sucks ass. Which is an understatement. Now, a T25G will be a direct bolt-on with that manifold, which is good. But the manifold itself isn't the best design. Nobody makes a header for these engines (anymore). So you're stuck with it, unless you have a buddy who can make you something better.
Then there's portwork to consider... the SOHC CA heads have terrible port design, and will be your BIGGEST restriction to more power (aside from strength issues). Porting will help A LOT... but even then, you're limited to how much you can do, because the water jackets are close to the ports and too much porting will breach the jacket and ruin the head.
NOW... that's how you make power. But is it worth it?
This is the Redneck side of things. As in the person, not as in just how rednecks tune shit lol.
So there's all this concern about the engine's strength... but then there are also a number of performance limitations like the head design, the manifold, and the fuel system is weak sauce. The last one can be addressed, but still... What Redneck is thinking is that for all the money you'd spend to make a little bit of power, you could do something easier like swap in a KA24DE, and have more power. More reliable power. And still, later, be able to push 5-7 psi through the engine, using any number of cheap and plentiful Ebay turbo manifolds and a T25G. Plus more modern electronics that are easier to tune.
That, and even if you never get around to turbocharging it, you enjoy more HP and torque than you ever had in the CA18ET, without the complication of a turbocharger... and with a more linear power output (no lag), so it's more predictable. And beefier rods, and a beefier block. And a better flowing head design. And with newer wiring, and probably an engine with less mileage on it. And with newer engineered parts that hold up better over time and abuse. And so on and so forth... plus installing something like a KA is easy. And KA isn't your only option, either... there are a few alternatives that literally "drop right in" to our engine bays. Take a look here and read up on the pro's and con's of them:
S12 Engine Swap Guide
I personally ended up ditching out my blown-up CA18ET for a KA24DE.... which then ended up being transferred into another S12 that originally had a CA20E. I think if I ever find a clean CA18ET S12 and have the cash for it, I'll restore it to clean stock, then just mildly tune it up a bit. 175 hp on a stock but freshened longblock is IMO reasonable.
Anyways, I've given you four valuable links, some additional suggestions, and some thoughts on the good and the bad. Which now looking at it, is mostly bad :P BUT... if you want to restore it to a vintage look under the hood, but still urk out a little extra power, there are options. Just don't expect much in terms of results without serious commitment, serious cash, and more risk.
Arro, I always enjoy your long and informative posts. Think you need a weekly tv show
Red
What I need to do is write more article-style posts and just link people back to them. Most of the past stuff I've written is with input from other people on here who knew a lot in their own right. I just bring it down to earth as best as I can, but thanks for the compliment.
Brian, lemme hit the first questions you posted...
Brnlxndr on 12:22:26 AM / 14-Feb-13hi, im brianUnless your T2 is failing, just sell the T25 and get a T25G, for the reasons I previously stated.
I'm buying a s12 ca18et tomorrow and a uninstalled t25 turbo.
I have alot of questions.I like you already :)
Like where can I get a good cheap exhaust/intercooler?Intercoolers... ebay, but check for leaks and have a radiator shop fix leaks as needed if you get some. Cap the ends with rubber-bands around some seran wrap, then submerge in your bathtub to see if you get bubbles (leaks). Check for Keith on here, his cardomain page is in his signature and shows his intercooler install. IMO the size and shape he chose are perfect.
what are some quick cheap upgrades?There's no such thing with this car and engine combination. Well, maybe ditching out the airbox for a cone filter, but even then, your stock mass air flow sensor is horribly restrictive. Remove it and see immediately why that is.
what is the max boost with everything stock?I covered enough info above to give you some idea, but not much boost is the general answer!
what limits the boost at this point?Also covered that above ;)
what are some common problems with this motor/chassis
I'll be searching around this forum but i'd like to set this up so I have all this info in one place.
Pics will be posted soon.
yea thanks. it was quite informative.
its coming with a boost gauge and I have a a/f gauge ready to install. I'm getting the t25 turbo with the car and later this summer I might get a cheap sr from a friend which I will need an intercooler and bov for anyway.
I already have a vr4 which I've messed with a bit. Is there a pretty reliable max boost out of the box or do I just have to watch my a/f gauge and adjust?
I know everybody with a vr4 tells you not to go past 14lbs of boost on stock turbos.
rednucleus on 07:59:47 PM / 18-Feb-13Arro, I always enjoy your long and informative posts. Think you need a weekly tv show
Red
Brnlxndr on 08:11:44 PM / 18-Feb-13yea thanks. it was quite informative.
its coming with a boost gauge and I have a a/f gauge ready to install. I'm getting the t25 turbo with the car and later this summer I might get a cheap sr from a friend which I will need an intercooler and bov for anyway.
I already have a vr4 which I've messed with a bit. Is there a pretty reliable max boost out of the box or do I just have to watch my a/f gauge and adjust?
I know everybody with a vr4 tells you not to go past 14lbs of boost on stock turbos.
I skimmed through most of your post and agree with most of the points you brought I like how you worded it you didnt shit on the motor the way redneck did. Its not the greatest motor but also isnt the shittiest and can be played with if done right....
Yep.
Anyways most of that shit you've already read over the years, dude :P
An inexpensive way to help flow and facilitate the install of a front mount intercooler would be to get a CA20E intake manifold from a part out here. Upgrade your fuel system and route some piping to a fmic and you have something more potent already. You already have a T25 so upgrade the fuel accordingly to the boost you want to run.
That's pretty much all I know about the ca18et :P never had one but I sold my old ca20e mani to a ca18et owner.
Arro on 03:47:57 AM / 19-Feb-13Yep.
Anyways most of that shit you've already read over the years, dude :P
Well I'm gonna need a front mount and a boost controller either way so I guess I can go for just that. Might find that CA 20 mani in a scrapyard. I'll probably be on here in a few months trying to sell this CA18et whenever I'm springing for my sr.
Where are you located?
Paki may have that mani for sale. I have the pipe, but have read that it's difficult to get a used pipe back in w/o leaking. Apparently a new pipe is rare to no longer available.
newburgh, close to evansville. How much?
Brnlxndr on 01:21:03 PM / 20-Feb-13newburgh, close to evansville. How much?
what state lol
Post Merge
I don't understand why the pipe can't be re-sized & reused
It's just a coolant pipe. If it don't fit just sligthly bore the hole, spread some JB weld around the pipe where it goes inside and let it cure in place. It'll be a permanent fit but it will be leak free.
are you sure about that because I believe iggy did the same thing and it leaked like 2 weeks later...
Are you guys talking about this? The big hose with the white smear on it?
Rockauto has them for less than 10 bux shipped. I'm sure the other favorite parts sources have them for similar prices.
Here's some more reference pictures I took of my old CA20E intake manifold:
You have more to worry about then just the upper radiator hose. The vacuum lines are different, and depending on if your CA20E intake manifold comes from a Mark I car (1984-86... SOME 86), or a Mark II car (1987 and 88), your idle air motor may be different. In Mark I there are minor changes between 1984 and 1985, and some 1986 are spec'd out like 1985, some are spec'd out like 1987 Mark II. The differences are minor but if you aren't comfortable with reading a vac diagram from both your car's year and the year of the car the CA20E intake mani came from, then this isn't a good idea.
I do think it's a good idea for someone who wants to stay CA18ET, but again I think tuning this car is kinda pointless when you're going to swap in an SR20. You're just wasting money you could be spending on the SR, which is far easier and cheaper to modify with bolt-ons, and has far more potential.
Also, it's hard to offload a CA18ET to anyone nowadays... most people simply don't want it, and chances are the people who do won't live close enough to you to make the sale worth it for them. Nobody's gonna pay to crate a CA18ET, at least for a long time. Maybe Vegas Jason(sideways_S12) but right now his finances are as tied up as the rest of us, both with life and his current project. Like the rest of us :P
So take a long hard look on how you plan to spend your money, unless you make enough to throw some of it away on an engine you're gonna ditch out and have a hard time selling to someone else. Just doesn't make sense to me.
negative its the pipe on the block thats directly under that...