Some easy CA18 Questions

[02 Black Spec V]

I hope to get a 240 soon and then Ill swap a CA18DET into it. So I have some questions. I searched but came up with nothing.

How much boost will the stock CA handle. How much boost before you need to replace the ECM? And are there piggy backs you can use for that?

What do I need to do to get to the 250-275 HP mark? I heard that the ARC side mount, S14 T28, 550s or DSM injectors, and full exhaust will get me there. what about the S13 T25? Also, are there any other manifolds besides the SS Autochrome? Is the SAFC a good means for tuning the CA or is something else needed?

Are there any parts availible for the CA18 transmission? I can rebuild transmissions, and if it went out I dont want to buy a new one. Also, what are some good cheap LSDs? Is the J30 an acceptible one?

One more question. After reading I see alot of people think its better to recirc the BOV. How is this done and what exactly is the benifit?

I know I have a ton of questions, but thanks to any and all people that help me out. NICO is the best source for CA stuff so Im always on here to try and learn more. Thanks again.

[rico05]

1. Some folks pump up the boost pretty high, but I will leave it to them to tell you how far/what they did to get there.

2. for 275rwhp, I am doing:-S15 T28 (getting soon)-460cc RX-7 primaries (Series 4 TII) (have)-ARC SMIC and custom pipng (have/soon to)-Headgasket (soon to get Nismo)-Head bolts (ARP soon to get)-Custom tuned EPROMSAFC is good, but if you have the dough, get a Apex Power FC (eBay) or a stand alone. I am getting the hardware to flash my own ECU chips, or you can always get one made (several folk here can do that for you: T88lexus, etc) I have a SSAC mani (about to sell, but plan on getting another one when I actually need it) but to be honest: for a Garret T2- family turbo, just keep the stock cast mani. Less bling but longer lifespan. DON'T FORGET: 275hp is about 300 at the crank or more than 125 than Nissan designed the car to have. You really should invest in things like an aftermarket cooling system and things like better brakes/tires to handle the power. I did my brakes/suspension Stage 1 tuning first so that I knew I had a car that was ready for the boost of ~70rwhp over the KA24DE I left behind.

3. You can use any S13 transmission as long as you use the CA bellhousing (ie Trust or OS Giken gear sets for SR transmission) J30 VLSD is a bad idea since it is geared so tall. I am hunting for a CA VLSD (4.36 gears!!!!)

4. YES. Recurric the BOV> Mine is vented and it runs so rich, I have to change/clean my plugs once every 2 weeks just to keep it driveable (did it yesterday). You simply plumb the outlet of the BOV back into the intake tract after the MAF and before the turbo. You do this b/c the MAF reads the volume of air and tells the ECU that much air is on the way to the cylinders therefore the ECU doles out that much fuel for that much air. When the BOV discharges, some of the air is lost, but the ECU does not know this: therefore the ECU runs the motor rich, but it does not realize it! The best is to get a MAP sensor setup (HKS VPC...good luck finding this as the CA ROM was discontinued years ago) or a stand alone.

I have a T25G (SR20 turbo) and at 9spi, my butt dyno tells me I am about 200rwhp. Turbo is good until 15psi, but not for long. At that boost level, with supporting mods (I/H/E, fuel, light tuning) you could see as much as 225-230rwhp.

[02 Black Spec V]

thanks alot for the info, its really good an just what I was looking for.

I have a few more questions though.

you say your stock T25 is good for about 230HP and 15PSI? Is the SR T25 any different than the CA? Im sure the T25 spools up quicker so that would be a plus.

The head gasket and head bolts are cool since ill rebuild my motor before putting it in. Ill be good with stock internals at 250-275 hp?

When I get the injectors I might as well go ahead and get SAFC or other tuning because it will run too rich without right? Also, did you go ahead and get a walbro to run with the CA?

How could I get a ECM that can be flashed? And how can I get the stuff to flash them myself. Whats involced with that process?

What trannies are geared best for use with the CA? I dont want to swap to a crappy unit and kill my performance.

Are there any other good LSDs to get as well? Is the VLSD that came on some USDM S13s good?

Thanks alot for your info, you have been a big help.

Also, I know I need to upgrade suspension and tires and brakes and all that. I am just trying to figure out how to get my engine where I want it, and the rest I have already figured out.

[redamnavit]

I skipped the areas that others would better respond. BTW, you can search for all of these answers if you want more info.

you say your stock T25 is good for about 230HP and 15PSI? Is the SR T25 any different than the CA? Im sure the T25 spools up quicker so that would be a plus.

The SR T25 has a larger exhaust housing, so yes its an upgrade. The SRs also had BOVs, so their turbos are often in better shape the the CAs. If you're looking for options that are a step up, search on this board for the multiple GT25R vs. T3 discussions.

Quote »The head gasket and head bolts are cool since ill rebuild my motor before putting it in. Ill be good with stock internals at 250-275 hp?[/quote]Not a problem.

Quote »Are there any other good LSDs to get as well? Is the VLSD that came on some USDM S13s good?[/quote]What do you want to do with the car? If you're autox-ing or just using it as a street car, a VLSD is a good upgrade over the open rear end. Beyond that you've got clutch diffs (Kaaz,Cusco,ATS,OS Giken) or a helical/torsen (Quaife). Those start at 800 and climb from there. Anything that fits an R200 rear is technically applicable.

Have fun, and welcome to the group.

[r34 gtr]

your car WILL run too rich if you dont use some sort of piggyback or stand alone fuel management unit.

yes, you will need a walbro 255 or equivalent (z32, gtr, etc.) fuel pump

to be able to tune your stock ecu, you will need to socket it to accept new chips. its not too tough but it is a bit unnerving. to get all the stuff you need, i would ask jon, t88 lexus or someone.

all the trannies for the s13 are geared the same, so you cant pick a "bad" transmission.

hope this helped,

- tim

[02 Black Spec V]

yeah you guys have helped alot!

I belive I will be going for the S14 T28, but I might just get a SR T25, im sure it will be cheaper to start with. I have also heard alot about Z32, or KA24E MAFs. Why would I need to upgrade as compared to a CA?

Also, I am just building a fun street / occasional strip car. No real purpose as far as racing, I just want an overall fun car to drive. A normal VLSD will be fine, I dont need anything too fancy.

[rico05]

I will be selling my T25G for hella cheap to a fellow CA'er here soon (like January when I get my T28BB) so I might could hook you up in that way. The KA24E MAF is slightly bigger but the main reason is because many motorsets (like mine) don't come with the MAF so the KA one is the easiest find (and CHEAP. I got 2 for $20) The Z32 is nice and I am batting the idea of getting one myself, but just to let you know: the ECU will need to be reflashed for it. Here is some basics on flashing CA EPROMS and tuning in general:

http://www.boostcruising.com/silvia/epr ... ob/ecu.htm

[rico05]

Oh yeah: My buddy with a ~250rwhp SR S13 that is his dedicated "Drift Whore" has a VLSD in it. It has lasted him about 20 AutoXs and prob 8-10 drift competetions and COUNTLESS late nights sideways. HE BEATS on his car (He has a soon-to-be-TT Lexus SC300 as well) and it is only just now dying after 2 years of abuse. So you can always get a VLSD and save your milk money for a "real" LSD for later.

[02 Black Spec V]

what kind of condition is the turbo in? T25G what does that come from? Forgive me but I am pretty new to all the turbo stuff.

Also, will you need to flash for the KA24E MAF?

So there really is no real big reason to get a different MAF besides if you putting up huge numbers? With what I want Ill be fine stock right?

[Xracer]

this is definatly a good thread. i didnt have had to the balls to ask that many questions so i searched for ever and found most of that stuff but still learned some stuff here.

anyways, how about motor mounts? i know you can use the stock KA mounts but did any of you upgrade? how good are the nismo mounts?

[02 Black Spec V]

I know I was planning on using KA nismo mounts, but Im sure i could just as easily get CA nismo mounts from the parts dept at the delaership i work at....

[rico05]

If you can get Nismo CA mounts, HOOK US UP. I am using stock KA mounts, and SR Nismo mounts will work, but put the motor up a bit and apparently it will rub the hood. No need to flash the EPROM for KA MAF. Negligible increase in flow, so actually leans out the mixture a bit (which is good since CA runs rich stock) The T25G is off of a SR20DET (T25 is off of a CA) compressor A/R is .80. I am not sure about price. I could let it go for under $150, but I am still considering using it as a decoration on my desk

Never be afraid to ask us info. There are really only a handful of us with running CA swaps here on NICO so we are really tight knit and love to increase our numbers!! boost_boy (Dee, God of all things CA) is a little harsh sometimes, but he knows more than you ever will so take it with a grain of salt and use the Search button and he will be your best pal!! Plus: He can hook you up with most any OEM or aftermarket part you could need. Me? I am just a tool that reads a lot and spends more time online that outside so I seem to absorb a lot of info But it is not always right Hehe
Modified by rico05 at 9:33 AM 11/23/2004

[02 Black Spec V]

I can see if I can get CA mounts from nismo through work. Maybe see if I can get cheaper prices if a few people buy them?

What is the A/R on a turbo? Can it be changed? Or is that how that turbo is stock? What would be the benifit to changing the A/R?

Remember Im still learning alot on turbos, so any help you have is better than what I got now....

[c-rad]

What is the A/R on a turbo? Can it be changed? Or is that how that turbo is stock? What would be the benifit to changing the A/R?

Remember Im still learning alot on turbos, so any help you have is better than what I got now....

A/R = Area/Raduis ratio. It has to do with the area of the scroll of the turbo divided by the radius of the center section or some garbage. Anyway, the A/R is predetermined on both the turbine and compressor housings. When selecting an A/R, people (on here at least) are usually talking about the turbine housing. The smaller the A/R, the better low end response. The higher the A/R, the better the top end performance. The goal is to match the compressor with a good A/R turbine so you keep the turbo in it's efficiency range without stress. Keep in mind there is always a trade-off though. The smaller the A/R, the more top end you lose. The higher the A/R, the slower the spool.

[float_6969]

Tim, I've giving you a cookie! I have absolutely nothing to add to this thread as Tim and the others have done a marvelous job of answering the questions presented here. Thanks guys, makes my job much eaiser! Plus my girlfriend doesn't get mad when I don't spend so much time on here, hehehe.

[Dattebayo]

What do they mean by this on that site you gave us?

"Also, if you have an R32 Skyline (rb20det) than all the CA programming principles are the same, ie, no need for a daughterboard (like the sr20) etc.."

does that mean you can just put a IC cage right on the motherboard?

[ca18detizzle]

nice thread... answered alot of "noob" questions i dont know about and was also afraid to ask. anyways.. ERRRR IM SO MAD! hah (off-topic) i need a CA motor, i asked NWN sponsor DDX for one and he didnt have one!! =/

[c-rad]

What do they mean by this on that site you gave us?

"Also, if you have an R32 Skyline (rb20det) than all the CA programming principles are the same, ie, no need for a daughterboard (like the sr20) etc.."

does that mean you can just put a IC cage right on the motherboard?

I believe they are saying that the RB20 ECU is like the CA where both can be socketed and edited with the ROMedit software. Apparently the code is very similar as well which I wouldn't doubt as they are from the same production timeframe.

[GotBoost4Yall]

Thought Id peep in, havent been around in awhile. So the search begins for a CA LSD......

I've had plenty of good races but it seems after 3rd gear there is no more, had a good race pullling on a slight modded VW Gti and a local guy with a quick SR20VE. My car is decent quick but gearing seems to suck, I pull good until 3rd gear.

[02 Black Spec V]

A/R = Area/Raduis ratio. It has to do with the area of the scroll of the turbo divided by the radius of the center section or some garbage. Anyway, the A/R is predetermined on both the turbine and compressor housings. When selecting an A/R, people (on here at least) are usually talking about the turbine housing. The smaller the A/R, the better low end response. The higher the A/R, the better the top end performance. The goal is to match the compressor with a good A/R turbine so you keep the turbo in it's efficiency range without stress. Keep in mind there is always a trade-off though. The smaller the A/R, the more top end you lose. The higher the A/R, the slower the spool.

So how do you pick a good A/R for the CA? Im guessing that since the SR T25 is what alot of people go for the .80 is good because you get a wide power range.

[02 Black Spec V]

OK so after doing alot of searching a reading I have another question.

If I were to get say a Z32 MAF and 550's, plus I want the boost cut and speed limiter removed I need to socket my ECM and have someone make a chip. On top of that it would be a good idea to still get a SAFC and fine tune the fuel. Is what Im thinking correct? I really just need a base map for the new injectors and maf, but for tuning I could use the SAFC???

How do I socket the ECM? Ive been searching and havent found anything. And im not nerdy enough to make my own chips, Ill just spend alot of money and not know how to do it, so ill leave that up to someone else.

[redamnavit]

If I were to get say a Z32 MAF and 550's, plus I want the boost cut and speed limiter removed I need to socket my ECM and have someone make a chip. On top of that it would be a good idea to still get a SAFC and fine tune the fuel. Is what Im thinking correct? I really just need a base map for the new injectors and maf, but for tuning I could use the SAFC???

That's a reasonable approach; I'm tentatively planning on using an eManage to do the same thing.

<long-winded>Technically you could do the whole thing with just the SAFC but its a bad idea. The ECU uses air flow to determine how much timing to pull; more boost = more retard. If you're using the SAFC to show the ECU less airflow than is really coming in, its naturally going to pull timing based on that lower airflow. For small corrections that's no big deal but it can add up when the boost gets high. This is likely academic for you considering your power goals are pretty reasonable. If you find you're getting a bit of detonation though you'll either need to adjust to run a little richer, or possibly adjust the CAS to retard timing across the board. Of course with a socketed ECU you could just have someone burn you a new chip with some more timing retard up high. </long-winded>

Quote »How do I socket the ECM? Ive been searching and havent found anything. And im not nerdy enough to make my own chips, Ill just spend alot of money and not know how to do it, so ill leave that up to someone else.[/quote]You'll need the appropriate socket, solder, a soldering iron and a solder extractor. Open the ECU and pull out the mainboard. flip it over so you can see the back side of the chip. You use the soldering iron to melt the solder at each of the chip's pins and the extractor to remove it from them as you melt it. Do this to all the pins and the chip is loose. Put the socket in where the chip was and solder each pin to the board. Clean up the old chip's pins and put it in the socket and, if you did everything right you've now got a socketed, stock ECU.

Having said all that, I'd pay some professional at the electronics store to do the job for you if you feel at all uncomfortable with it. Or buy a spare ECU off of ebay if you like to fiddle with things like I do.

[c-rad]

So how do you pick a good A/R for the CA? Im guessing that since the SR T25 is what alot of people go for the .80 is good because you get a wide power range.

There is a formula they use that involves the displacement, volumetric effieciency, intended boost level, etc. From what I have been seeing on this board and elsewhere, a 0.64 A/R turbine housing is "probably" about as high as you would want to go. A 0.48 would give you great spool, but would most likely kill the performance on a lot of turbos like the gt25r and gt2871r where their effieciency is in the higher boost levels (15-20+ psi). I plan on running a 2871R (.64 A/R) @ 17-18 psi with a beefy headgasket, ARP head studs, 550s, Z32MAF, and base mapped EPROM. I think that with that setup it will be a nice little warrior.

OK so after doing alot of searching a reading I have another question.

If I were to get say a Z32 MAF and 550's, plus I want the boost cut and speed limiter removed I need to socket my ECM and have someone make a chip. On top of that it would be a good idea to still get a SAFC and fine tune the fuel. Is what Im thinking correct? I really just need a base map for the new injectors and maf, but for tuning I could use the SAFC???

How do I socket the ECM? Ive been searching and havent found anything. And im not nerdy enough to make my own chips, Ill just spend alot of money and not know how to do it, so ill leave that up to someone else.

Well, with the Z32 MAF, essentially your boost and fuel cut will be removed as it is highly unlikely you will outflow it. A SAFC would still be a great idea as it will allow you to fine tune it using a wideband O2. The base maps are just that...base maps. You will still want to lean it out if you are not maxing out your injectors, which you shouldn't be anyway....

There really isn't a "how-to" just for soldering a zif socket. You just desolder where the eprom sits on the PCB and then resolder in a zif socket. If you are not comfortable with it, go to your local college and ask one of the electrical engineering students to do it for you. It will take him 5-10mins. Luckily for me there is a guy just down the road in Orlando who sockets and burns eproms all day long. Mostly for DSMs but he has done plenty of other cars as well and is considered the "ECU man" by the Orlando DSM Club.

[rico05]

One of my best friends is an EE major, so I got the hook up;)

[Nunook]

Srry Long post:Just find someone to put the socket in good and u can switch chips whenever u want. Thats wat im doing. The socket stays in the ECU and u never have to worry about soldering another one in. The guy that did mine gave me back the original chip that was in there so if i wanna put the stock settings, cuts and stuff all i have to do is open the ecu and stick it back in.

Now i have one question (still almost noob) on the t25G can i pull the compressor housing off and switch it with a .64 housing from something else? If i can wat turbo would i get it from? Also what size is the exhaust side?

EDIT: maybe not that long...

[02 Black Spec V]

If you can get Nismo CA mounts, HOOK US UP.

OK I talked to my parts dept today and we can get the Nismo CA motor mounts. It will be $270 for the set (both engine mounts and trans mount). If anyone is interested I can get you the info of the guy to talk to so you can get them.

Should I post this somewhere else too, to get the word out?

[02 Black Spec V]

so from reading the stuff on the A/R you can get a pretty much stock turbo, and change the A/R by putting different housings on it? Is that how it works? Does anyone know what the stock SR T25 and S14 T28 A/Rs are?

[rico05]

SR20DET OEM turbo Specs:S13 T-25: 60 trim 56mm BCI-1 compressor 53.8mm 62 trim T-25 turbine, .64 A/R turbine housing. Journal bearings.

S14 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 T-28: 60 trim 60 mm BCI-1 compressor in T-04B housing, 62 trim 53.8mm Inco turbine .64 A/R turbine housing. Ball bearing center section. *cast divider wall between turbine discharge and wastegate.

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

Just in case you cared about the rest.

[02 Black Spec V]

cool thanks. Also, whats the difference in the turbine and compressor A/Rs (other than one is for the compressor and the other for the turbine of course) Basically what difference does each make in turbo selection?

also what does all this mean: 60 trim 56mm BCI-1 compressor 53.8mm 62 trim

im about to stop asking questions hahahahaha

[float_6969]

The A/R is still the same principle with the compressor and turbine housings. The larger the #, the more air it will flow, but the slower it will spool.