# CA18det questions



## NissanCA18DET (Dec 15, 2004)

I recently did a CA18det swap in my 240, and it lacks power up to 4000 rpms, i think it might be the timeing, but i would like an expert openion on this. I am also having some trouble with the boost, it goes to 10psi untill about 6,000 rpms, where it slowly drops.. any help would be appreciated. thanks again


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## NissanCA18DET (Dec 15, 2004)

i forgot to mention, it idols at 650, and it sounds like it misfires once in a while, and it is running extreamly rich. thanks again


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## b310turbo (Dec 14, 2004)

previously what engine were running in ur 240 and its cc??


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## kaptainkrollio (Jul 29, 2003)

I'm guessing it would be the 2.4l KA, considering it is a 240sx....
And rough idle would probably due to a vacuum hose leak I think.


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## 180SX-X (Sep 21, 2003)

do you have an aftermarket BOV? check it if you do, check all vacuum hoses, make sure all your grounds ore clean, and so on..


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## aldyno - S13 (Jul 7, 2004)

*Higher octane*



NissanCA18DET said:


> i forgot to mention, it idols at 650, and it sounds like it misfires once in a while, and it is running extreamly rich. thanks again


Change the fuel to a higher octane one or add octane booster to the fuel tank, it will help with the running rich thing.


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## aldyno - S13 (Jul 7, 2004)

NissanCA18DET said:


> i forgot to mention, it idols at 650, and it sounds like it misfires once in a while, and it is running extreamly rich. thanks again


As higher you have compression into an engine, higher you need the octane in the fuel. So, when you raise boost (as I believe you´ve done -10PSI-) the vulnerabilty to explotion of the fuel becomes higher because of a higher compression ratio. The normal fuel explodes easier and the mix becomes rich. Higher octane = higher resistance to higher compressions, explodes less and works better for the aplication we´re giving to our cars :thumbup: 

that´s why you need a higher octane fuel.


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## bessell (Feb 16, 2005)

aldyno - S13 said:


> As higher you have compression into an engine, higher you need the octane in the fuel. So, when you raise boost (as I believe you´ve done -10PSI-) the vulnerabilty to explotion of the fuel becomes higher because of a higher compression ratio. The normal fuel explodes easier and the mix becomes rich. Higher octane = higher resistance to higher compressions, explodes less and works better for the aplication we´re giving to our cars :thumbup:
> 
> that´s why you need a higher octane fuel.



standard boost on the CA18 DET is 10 psi so you should be ok on regular fuel


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## aldyno - S13 (Jul 7, 2004)

bessell said:


> standard boost on the CA18 DET is 10 psi so you should be ok on regular fuel


10??? mine came only with 6!!!!!   

well, I initialy used the regular one (82 octanes) and there was always a high mix, I switched to premium (94 octanes) and the difference is viewable! and I haven´t raised boost. 

Here in Dominican Rep., CAs are not so famous, the streets are full of SR20s, 7Ms, ZCs and 2JZs, that´s a point against me because everyone knows at least something about SRs and when they see under my hood, they get surprised.


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## bridrive55 (Aug 26, 2004)

aldyno - S13 said:


> 10??? mine came only with 6!!!!!
> 
> well, I initialy used the regular one (82 octanes) and there was always a high mix, I switched to premium (94 octanes) and the difference is viewable! and I haven´t raised boost.
> 
> Here in Dominican Rep., CAs are not so famous, the streets are full of SR20s, 7Ms, ZCs and 2JZs, that´s a point against me because everyone knows at least something about SRs and when they see under my hood, they get surprised.


10psi might be enough pressure to experience fuel cut. An FCD or any piggy back system, or aftermarket (chipped) ECU will remove the fuel cut.


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## bessell (Feb 16, 2005)

aldyno - S13 said:


> 10??? mine came only with 6!!!!!
> 
> well, I initialy used the regular one (82 octanes) and there was always a high mix, I switched to premium (94 octanes) and the difference is viewable! and I haven´t raised boost.
> 
> Here in Dominican Rep., CAs are not so famous, the streets are full of SR20s, 7Ms, ZCs and 2JZs, that´s a point against me because everyone knows at least something about SRs and when they see under my hood, they get surprised.


the handbook says you should be running 95 octane (that is regular fuel in the uk sorry for any confusion) the fuel cut doesnt work until you have more than 15 psi of boost i will be upping the boost on my one soon and changing the ecu also i already have a blitz air filter and a full mongoose exhaust system with all of these mods i should have around 200 bhp! i hope this helps :thumbup:


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## aldyno - S13 (Jul 7, 2004)

So, With a decent FMIC, could I raise boost to 15 PSI with no problem?

Wouldn´t I need ECU upgrade, a piggy back, injectors or any other mod related?

Sorry if my question seems stupid, I just don´t want my car to spit the pistons through the Catback.


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## bessell (Feb 16, 2005)

aldyno - S13 said:


> So, With a decent FMIC, could I raise boost to 15 PSI with no problem?
> 
> Wouldn´t I need ECU upgrade, a piggy back, injectors or any other mod related?
> 
> Sorry if my question seems stupid, I just don´t want my car to spit the pistons through the Catback.


you could i will be changeing the ECU so that i can do other mods look at www.norrisdesigns.com to see what is possible before internal mods are needed if you raise the boost to 15 psi you have to adjust the timing i will find the figures and post them here :thumbup:


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## aldyno - S13 (Jul 7, 2004)

bessell said:


> you could i will be changeing the ECU so that i can do other mods look at www.norrisdesigns.com to see what is possible before internal mods are needed if you raise the boost to 15 psi you have to adjust the timing i will find the figures and post them here :thumbup:


I saw the site, and I have already installed a manual boost controller, but wanted some good info before turning the knob.

I hope you find those diagrams of the 15PSI timing.

Thanks in advance


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## azRPS13 (Jun 7, 2003)

No! I would not recomend taking the stock turbo to 15psi! The CA's T25 would not last at 15.... maybe the SR T25 can do it or the T28 can definately do it, but not the stock CA T25... Even with ECU and FMIC. And stock is not 10psi...


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## aldyno - S13 (Jul 7, 2004)

*Turbo kit for CA*



azRPS13 said:


> No! I would not recomend taking the stock turbo to 15psi! The CA's T25 would not last at 15.... maybe the SR T25 can do it or the T28 can definately do it, but not the stock CA T25... Even with ECU and FMIC. And stock is not 10psi...


please check ebay´s item number 7961261512 and give me your opinion please

If I install this...

what else do I need to don´t blow the engine?
maximun PSI recommended is...?
FMIC size?

any other thing you think I should know?


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## bridrive55 (Aug 26, 2004)

azRPS13 said:


> No! I would not recomend taking the stock turbo to 15psi! The CA's T25 would not last at 15.... maybe the SR T25 can do it or the T28 can definately do it, but not the stock CA T25... Even with ECU and FMIC. And stock is not 10psi...


The SR20DET and RB20DET T25 with ceramic wheel are just as vulnerable as the CA18DET turbo... Steel wheel is what matters.


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## azRPS13 (Jun 7, 2003)

Very true...


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## Joel (Jun 11, 2003)

Very untrue. The T25 and T25G from the CA18DET and SR20DET have both steel compressor and exhaust wheels. Only the RB and the VG have ceramic exhaust wheels.
Series 2 R33 even came with a plastic compressor wheel!

The boost fail (drop off after 10psi at high rpm) is caused by the inefficiency of the tiny T25 (small compressor housing and small small exhaust housing). It just cant produce that kind of boost at high RPM.


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## bridrive55 (Aug 26, 2004)

Joel said:


> Very untrue. The T25 and T25G from the CA18DET and SR20DET have both steel compressor and exhaust wheels. Only the RB and the VG have ceramic exhaust wheels.
> Series 2 R33 even came with a plastic compressor wheel!
> 
> The boost fail (drop off after 10psi at high rpm) is caused by the inefficiency of the tiny T25 (small compressor housing and small small exhaust housing). It just cant produce that kind of boost at high RPM.


So if they aren't ceramic, why are the Nissan T25's so notorious for sucking at high boost? A friend of mine runs 1.1bar on a Mitsubishi stock T25 (TD05) all day with absolutely no problems. My TD04, which is really really tiny, can even take .75 bar at least without massive suckage. How come you can't do this on a Nissan turbo? I just naturally assumed that Nissan used a ceramic compressor wheel or something like that that made the turbos incapable of sustaining such high boost. 
Maybe I have too much faith in Nissan, and wanted to blame bad ceramic parts for their turbo-suckingness. Then again, Mitsubishi turbos do completely and roundly OWN.


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## bessell (Feb 16, 2005)

azRPS13 said:


> No! I would not recomend taking the stock turbo to 15psi! The CA's T25 would not last at 15.... maybe the SR T25 can do it or the T28 can definately do it, but not the stock CA T25... Even with ECU and FMIC. And stock is not 10psi...


on uk engine's 10psi is standard as stated on www.norrisdesigns.com (see boost upgrdes) :cheers:


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## bessell (Feb 16, 2005)

aldyno - S13 said:


> I saw the site, and I have already installed a manual boost controller, but wanted some good info before turning the knob.
> 
> I hope you find those diagrams of the 15PSI timing.
> 
> Thanks in advance



if the boost is set at 15 psi then the ignition should be set to 13 degrees BTDC for use with 95 octane fuel but if you are using 97 octane then ingnition should be set to 14 degrees BTDC. i hope this helps. :thumbup:


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## azRPS13 (Jun 7, 2003)

Haha! here in the US our highest octane is 91 and our lowest is 87... Theres the rare stations that sell 101 octane for a ungodly price...


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## bridrive55 (Aug 26, 2004)

azRPS13 said:


> Haha! here in the US our highest octane is 91 and our lowest is 87... Theres the rare stations that sell 101 octane for a ungodly price...


Yeah, I know, and gas is like $2.05 today! Murder. That's the highest I've ever seen it here.
Some people in town with heavily modified cars have to add octane booster to every tank... Ouch.


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## aldyno - S13 (Jul 7, 2004)

bessell said:


> if the boost is set at 15 psi then the ignition should be set to 13 degrees BTDC for use with 95 octane fuel but if you are using 97 octane then ingnition should be set to 14 degrees BTDC. i hope this helps. :thumbup:



Sure it does dude!!

THANKS A LOT!!


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## aldyno - S13 (Jul 7, 2004)

bridrive55 said:


> Yeah, I know, and gas is like $2.05 today! Murder. That's the highest I've ever seen it here.
> Some people in town with heavily modified cars have to add octane booster to every tank... Ouch.


You shouldn´t complain, here in Dominican Rep., we pay US$3.23 (regular)and US$3.50 (premium) per gl.


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## azRPS13 (Jun 7, 2003)

what's the octanes level in Dominican? Reg-87 plus-89 and premium-91. Here in AZ Im paying 2.29 for 91 octane... Plus $5 for octane booster


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## Joel (Jun 11, 2003)

bridrive55 said:


> So if they aren't ceramic, why are the Nissan T25's so notorious for sucking at high boost? A friend of mine runs 1.1bar on a Mitsubishi stock T25 (TD05) all day with absolutely no problems. My TD04, which is really really tiny, can even take .75 bar at least without massive suckage. How come you can't do this on a Nissan turbo? I just naturally assumed that Nissan used a ceramic compressor wheel or something like that that made the turbos incapable of sustaining such high boost.
> Maybe I have too much faith in Nissan, and wanted to blame bad ceramic parts for their turbo-suckingness. Then again, Mitsubishi turbos do completely and roundly OWN.


The problem with the ceramic wheel is that at high boost the glue that holds the wheel onto the metal shaft breakes down and your exhaust wheel goes shattering through your cat - common on skylines and Soarers. Steel wheeled turbos do not have this problem. The problem with small nissan T25's is exactly that - they are small and are simply not designed to spin fast enough to produce high boost. They are however quite efficient at lower boost which makes them good turbo upgrades for smaller engines like the E15T. 
The nissan T28 for example has a larger compressor housing and different wheel sizes and trims to the T25 and can happily hold over 1.0bar all the way till redline because its designed to operate in this boost range. Try to jack it up to say 22psi though and it will behave in the same way - hit the 22psi but drop off after a certain rpm limit. Its all about the turbos range of efficiency. I would say the same thing is apparent between the TD04 and TD05.


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## bridrive55 (Aug 26, 2004)

Joel said:


> The problem with the ceramic wheel is that at high boost the glue that holds the wheel onto the metal shaft breakes down and your exhaust wheel goes shattering through your cat - common on skylines and Soarers. Steel wheeled turbos do not have this problem. The problem with small nissan T25's is exactly that - they are small and are simply not designed to spin fast enough to produce high boost. They are however quite efficient at lower boost which makes them good turbo upgrades for smaller engines like the E15T.
> The nissan T28 for example has a larger compressor housing and different wheel sizes and trims to the T25 and can happily hold over 1.0bar all the way till redline because its designed to operate in this boost range. Try to jack it up to say 22psi though and it will behave in the same way - hit the 22psi but drop off after a certain rpm limit. Its all about the turbos range of efficiency. I would say the same thing is apparent between the TD04 and TD05.


Thanks for the infos. None of us can ever forget why you're a mod.
I love the Mistubishi turbo's, and they're all over the place here. I'm actually thinking of getting a 16G turbo, but I don't know what turbo would be best for a KA24DET project. There's a "disco potato" kit for sale in town here, and I think a ball bearing Garrett T28 would rock...


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## bessell (Feb 16, 2005)

aldyno - S13 said:


> You shouldn´t complain, here in Dominican Rep., we pay US$3.23 (regular)and US$3.50 (premium) per gl.


here in the uk we pay $1.20 a liter roughly or $4.80 a gallon for 95oct or $6 a gallon for 98oct :thumbdwn:


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