Definitely seen your point about doing it right the first time. Cheap is sometimes more expensive...

BTW, at what point are forged pistons necessary? The number I used to see was 300 HP, but I read that a long time ago so I thought I'd ask.

sxoc had a few good debates of gt28xx vs 'old' used T3 turbos(mainly from cosworths). Short story..... those who actually ran both preferred the T3. A ford sohc 2.3 T3 with the 0.48 a/r rear housing for eg.
I believe both even ran the same 60 trim compressor wheel. So if u can literally match the performance for waaayyyy less than 1/4 of the price... why not? Nothin wrong with "cheap" if you do your homework.
Also, just gave an example of evo III 16g that would smash a gt28 at half the price
Look how many DSM street monsters wear rugged $200 used Holset diesel truck turbos
Some attractive, very satisfying low dollar options exist, once you're willing to do your research (and the effort to make them fit, of course)

I'd spend the money/effort on good tuning, and you might be surprised what a healthy stock ca18 bottom end withstands/produce
...as opposed to dumping money on "baller' parts, imho

dash wrote: Nothin wrong with "cheap" if you do your homework.

Exactly what I'm trying to do. Good reminder about the tune, and I agree about not cheaping out on one. Bad tunes have killed many engines...

Thanks for the info. May have to check SXOC sometime.

here us a good example of what a 'cheap' 2.3 T3 turbo does for a bone stock 1.6L honda civic. Just as good on CA18s

(save the image so u can view it bigger to read on your pc)

The gt series of turbochargers from Garrett are not what I would call modern technology. As you said, they run the same compressor wheel. All Garrett really did was change the CHRA for a BB. We all used to rage about them because the spool was faster, but that's like raving about how fast your new 15hp steam powered horseless carriage is compared to the single horse drawn carriage you had before. Hell if you want to stick with Garrett as a reference, they didn't redesign their compressor wheels until the GTX series. Show me a comparison of GTX turbo to that old T3 and I doubt you will find anyone who likes the T3 better.

Of course it can be done for cheap. And it will definitely work. You'll probably be happy with it. But that's because you've never experienced what it could be, so you don't have a point of reference. It's like driving a car that's faster than anything else you've driven. What you thought was great before, seems slow afterwards.

I think 300-350whp is a good estimate of what the stock pistons can take, but a good tune goes a long ways. Dee has claimed 536whp on a stock bottom end in a motor he has now run for more than three years. But that was also with NEW OEM 0.020" over pistons and it's my speculation the car doesn't see as much street time as many of our cars. Plus, Dee is a bit of an anomaly in of himself, lol. He's probably one of the best, if not THE best CA tuner in North America. Regardless, that 536whp figure is nothing to laugh at, so more than 300whp is attainable, but it's a good general figure for what the stock pistons can take.

What I can say for a fact is that, the sharpest, most talented & capable cats I know, u won't ever find on the net
"Best CA tuner in US" is anybody's guess.... as there have been a handful of CA mosters poppin up from way back.
I recall trading emails with Mark of Mazworx eons ago in his CA18 days. One glance at his sr20 forays would give u an idea of what level he is on.... just one example

Also, what a ca18 stock bottom end "can take" depends on a few variables. mainly the condition and how its used
Any 400+hp ca18 with a stock 5 speed behind it in a full weight s13, probably don't see much dragstrip/slicks action
In a lightweight hull like dhen's, a stock block(and oe 5spd) should definitely withstand enough power to scare you

Of course it can be done for cheap. And it will definitely work. You'll probably be happy with it. But that's because you've never experienced what it could be, so you don't have a point of reference.

and that is dangerous ground. That road is paved with misery, and it never ends. Just hope one has the pockets to match it
Once you set a goal, and are real with your expectations, you should be happy
Offered a diferent perspective, on how some ca18 were no less happier with a $100 junkyd T3 vs a $1000 GT, for a ~$300 hp target. Pretty much like how used holsets compare to $1200 Precision on a 600-700+ hp street DSM. For many, the latest $1700 turbo still may not offer enough of a performance advantage to sway them

Don't get me wrong, I love my CA, but these engines are 25 years old.

I've been looking into the Holset HY35. Undivided T3 flange, capable of a lot of boost, readily available, and easy to rebuild. It would be laggy, though, so it might not be worth it.

That's what research is for.

In such a small, light car, I would think responsiveness would be more important than ultimate power. Why not the tried-and-true S15 SR20 T28? That was honestly still one of my favorite turbos on this motor. Pretty quick spool, transient response was nearly instant, compact, and common, so there are plug-in ROM chips tuned around that turbo, a Z32 MAFS, and 550cc injectors.

I've got the SR turbo - T28, I presume. Perhaps you're right about sticking with what I have. My next project is to Megasquirt it, which will keep me busy for a while. The reason I'm asking now, though, is that if I have to get it tuned anyway when I put the new EMS on, I would rather do it once than get it running with what I have and then tune for a new turbo.

But I haven't experienced this car with max boost for this turbo, so maybe this is all I need. Decisions...

Is it the dual ball bearing turbo? There are a couple different SR T28's. S14 SR single ball bearing T28, I think there's a single BB S15 as well, then the dual BB S15. Which is the same as a GT2560R. I think those are good for, what, 18psi and 280-300whp? What sort of boost are you running now? I know that 3psi can make a huge difference. It certainly did in my Pulsar going from 7-10psi, lol.

Right now I'm running 12 PSI of boost, which I understand is the absolute limit without tuning.

I bought the turbo years ago before I knew what I was doing. The mechanic said I needed a new one, I read that the SR ones were "better," so I ordered a new one from FR Sport. I'm assuming it's the older version.

Here's a picture of the housing. I don't know if this helps ID which SR turbo it is.

That doesn't really help identify it. This is the exact turbo I ran, and I even bought it from FR sport; http://www.frsport.com/Nissan-14411-91F ... _1265.html

That turbo maxes out at about 18psi on a CA18. In that little car, I would be slack jawed if that wasn't enough power to make your car nearly useless.

Also, if that is the turbo you're running, and you're only running 12 psi on an un-tuned stock ECU you're giving up A LOT of power. When I went standalone I kept everything else the same so I could have a comparison. The difference in power that came from a ground up tune was HUGE. If you're running that same turbo, I wouldn't mess with trying to upgrade. Get your standalone on there and actually tune it.

My fellow boost-heads, what type of turbo that will best serve your application depends on your needs for performance from your engine. During my 18 years of tinkling on CA series motor (can't believe it's been that long), I have gone through many a tribulation as well as triumphs. And during that stretch was the changing of turbochargers. My complete lack of knowledge cost me a ton of money and a miserable car that lagged terribly. Coupled with standard or inferior tuning made it even worse. It is wise to invest in tuning equipment such as a competent EMS as that is the basis of your whole set-up. Failure to do that and you will experience what I use to experience in the form of blown engines or a complete lag monster.

Big turbochargers look pretty darn impressive, but if they are not closely or perfectly matched to your engine's modifications, then you've literally screwed-up the pooch and you are the pooch For Darian: I would put nothing more than a GT3071r with billet wheels on that puppy and not exceed a .63 on the compressor side. But before you do that, you must upgrade to an EMS that is extremely user friendly, yet powerful because even with the CA18, there are secrets to tuning these motors to make them appear bigger than they are. If your EMS does not have the capability to keep up with your needs, you've wasted your money, time and possibly have wasted a motor or at least the internals (Just saying).

And lastly for dash, the CA series motor is my specialty. I can build any motor and probably tune most of them as well, but there will always be someone who tunes a specific motor to a point where enthusiasts of said motor is impressed and probably say one tuner/builder is better than another. I tune for extreme reliability. I build engines for extreme longevity. I have built well over 50 of these motors and not one of them performed the same as another. I have built many customers motors and have yet to have one to come back and cry about me building them a bad motor. I don't compare me nor my work to any builder let alone any tuner, but I do know this, in the United States of America, I probably have built more CA18DETs than most shops combined. And if my knowledge serves me correctly, to date, Overboosted180s CA18DET produced the most HP on this side of the pond and it did not fly apart after producing more than 600+ whp. He has since moved on to an RB26 platform and sold his CA, but if he wanted to push that thing even more, it would've held-up just fine.

The engine in my S13 is nowhere near built to the specs of his with my bottom end being of OEM .020 over pistons, stock rods and well worked head with JUN cams in it. Coupled with a stock intake manifold, custom exhaust manifold, Garrett GT35r dual BB turbocharger, old school HKS 40mm wastegate, 1000cc injectors and an SDS EFI standalone, the car produces a comfortable 536whp while still retaining A/C and P/S. It drives very well off boost and comes onto boost like it means business. The difference in this car is, I tuned it for what I want it to do and not for bragging purposes. I wouldn't sell it just yet because I don't get to enjoy it. It is waaay too much power for the streets of Miami, so I turned down the boost to a modest 18psi and the car is still ridiculous. It's all about the tuning and matching of parts and a little bit of luck because the engine in my B12 sentra is better by a long shot, yet it runs horrible and I don't have the time to figure out why. Better engine, more coin spent, more R & D applied, looks fancier and still runs like crap compared to the cheaper motor. Oh yeah, the sentra has the same GT3582r, but with billet wheels, nearly the same heads, custom plenum, bigger and better bottom end (Pauter and JE 84mm slugs), polished crank and meticulous machine work, ring fitment, etc, etc. , but again, it's still not better. Hope this helps some in making informed decisions. I may not be the best at tuning all engines in the U.S. , but I do know what I'm doing when it comes to this one and I treat each and every CA18 engine as its own entity .

Thanks for letting bounce ideas off of you, everyone. I couldn't agree more about having the right parts matched up. Everything is a compromise. After reading this I'm definitely not going to change my turbo until I've maxed this one out. If I have to get it tuned twice because I later upgrade to another different turbo, so be it.

Totally agree about having a good tune, as well. I know some of you prefer SDS, but right now I'm really looking into Megasquirt. I think it would be fun to build one.

Having said that I don't want to cut corners...

If you already have a T2 journal-bearing CHRA that takes a 60mm compressor wheel, such as the S14 T28, you can make your own rebuildable journal-bearing 'GT28' for quite cheap.
The compressor housing and wheel can be purchased new for under 200$ total.

Then you have many options as for the turbine side, whether it be using the stock .64 or .86 Nissan SR20 housings to keep cost low, upgrading to one the actual GT28 housings and turbines, and then there also many specialty housings available, such as the T3-flanged ones in various AR's.

For example, here is a journal-bearing GT28 with a T3-flanged turbine housing, easily capable of 350hp. Yes the technology is a bit dated, but it works, and the availability of affordable components is nice.