S12 ca18det conversion brief pointers
 

This is a list of pointers for someone who is familiar with basic mechanics


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When fitting the ca18det into a ca18et s12 you can use the:-
same s12 gearbox and bell housing,
same s12 engine mounts in exactly the same location.No mods needed
same s12 car loom.
You need the s13 ecu,loom and loom ancileries ie dropping resistor for the injectors and a s13 power transister for the coil packs which you also need and the 3 green top relays from the s13 engine bay to join your car harness to the ecu harness. These relays are used for the fuel pump and ecu.
s12 power steering and alternator can be used. Cut a chunk out the s12 power steering pump bracket to clear the wider det head or find a s13 bracket
The s12 exhaust is compatable. Use the s13 manifolds and turbo & downpipe. You could use the s12 turbo and downpipe but it really is too small#

When wiring in the s13 ecu loom you will see that there is a big plug spare by the ecu and another further down the loom near the air flow meter.These used to connect to the s13 car harness.You need to reconnect some of these to your s12 system.

The connections you need to make are listed below with there wire colours.
BY AFM

Black / Pink stripe
Fuel Pump Relay

Red / Black stripe
ECU Relay

Red
ECU Backup Power

Black / Red & Blue / Red (Note: connect 2 wires to 1)
Main Ignition Power

Black / White stripe
ECU Power

Brown (to O2 sensor)
O2 Sensor Power
Any 12v switched source

white plug

Yellow / Red stripe
Tachometer signal

Orange
Ignition start

Black
Ground


Blue / Black stripe
Water temp signal

The s12 and s13 have 2 looms. A engine loom and car loom. all you essentially are doing is swapping the engine loom over and then powering it up.
You can use the s12 fuel pump but its advisable to uprate it as it will probably run lean under load/boost. You need to change the wiring for the pump round so that it has the new ecu + feed via a green relay and a constant body earth rather than the old s12 wiring that was earth switched.

good job !
Thank you pukka ;)

i still cant get the s12 tacho working in mine. my tuners tried everything.

had to use an after market rev counter.


any ideas...

use the S12 gearbox ;)

the gearbox has nothing to do with the tacho toytoy, thats the speedo :D

Rev counter
 

I assume its the Rev counter your on about, excuse my lack of tech jargon. If this is the problem then its a sensor located just by where the air intake pipe joins the air flow meter. there is a sensor attached to the loom here & it tends to get corroded. Check this or replace, I think this should cure your problem. I think Silviagod has a pick of this somewere on his web pages.

this was posted by Sam on club-s12 and we both need help.

If somebody could provide us with a pinout instead of colours, that would be very much appreciated.

I really cant understand all this Jiberish.

What wiring have you got left to do exactly? Thats all you need to say

no worries jon, we've got it sorted out.

basically, the wires for the ECCS relay, IG power, etc.. aren't on that white plug you were describing. They're on the two plugs that are in the engine bay.

The white plug only has the start signal, and the wires for the gauge cluster sensors.

1st place i have looked to do ca18det conversion and there is so much info here!! good job

leo

Think you read my it wrong.It says there are plugs by the air flow meter location and on the white plug near the ecu :p

My installed Relays are in the engine bay rather than attached to the old s13 car loom socket


So is your car running now Indy>?

soon.

I only have a few more things to do. Wiring is finished, I actually cranked the engine :o Just waiting on the damn dropping resistor from the engine importer still..supposed to get here last friday..but nope...

Then just gotta do the intercooler piping, boost gauge source, blow off valve, and plug off all other intake stuff and connect some sensors (neutral switch, reverse switch, oil pressure sender unit, knock sensor) and I can start her.

I dunno if my pump is working, I'll be checking for fuel pressure today.

Well don't use the S13 wire to try to get it to work, only aftermarket gauges are sensitive enough to pick up the signal.

I got it working on my mates bluebird. You'll need 4 thick diodes from maplins. The smaller ones allow the current to go the other way and the car won't start.

Tap a wire into each coilpack. There are 3 wires, when looking at the back of the plug, its the left one you need. From each wire put in line a diode so the current can only flow away from the coilpack. Then join all 4 wires together into one and take them to the original wire that feeds the rev counter. This could be found behind the dash (don't know the wire buts it probably blue) or if you still have the original section of loom in the car take it to the connecting plug that connects to the S12 coil earth. Its a single wire plug, the wire is blue.

can u not just swap the loom over, will it work like that

No, unless you change the gauge as well. But for the sake of buying 4 little diodes and 20 mins soldering, its no big hardship.

Can anyone write this up in plain English and add some pics including wiring in the Relay's ;)

Come and look how I did it, dont live far from you. Once you see the method I used to get the engine running you'll wonder what the fuss is all about.

Now i have a little problem here.
Obviously as my s12 was fj20, the engine mounts are different and dont realy fit that well.
So i got my self a couple of s13 engine mounts, but they dont fit the travers (or whatever you call that thing that they bolt to). So now the milion dollar question: are the mounts different and do not bolt up (so i just need a couple of s12 mounts) or is the travers (or whatever it is called) different on the fj and ca cars? Anybody knows?

I used S13 mounts on an S12 subframe, but I used the S13 brackets (which are required to match the mounts). Benefit of S13 brackets is they bolt to the block via 3 bolts per side (not 2 like on the S12).

Thats all well and good, and you can mount the engine BUT I would like to point out a potential flaw.

I can not tell you if the engine will sit at a different height or not. Whilst this sounds trivial it may effect the angles on the prop shaft and therefore you could experience vibrations due to larger angles on the UJ's. It may be fine (in fact the difference is probably minimal) but I have to point this out as you could find youself with a problem.

I didn't have a problem as I was independantly setting the height of the engine, box and setting the angles up on the Datsun anyway. Only reason I used S13 mounts was coz I wanted to fit nice solid nismo mounts.

the fj20 mounts are oblong and about 47mm with the engine sat on them.

I am using the s13 brackets, because they came with the engine, so i never even checked if my fj brackets would fit (i just asumed they wouldn't).
Now the thing is that the s13 mounts dont just bolt to the subframe (thats the thing that i was refering to as "travers" :D ). Seems that i would need to drill a little hole in the subframe, for the little thing that aligns the mount (its closer to the bolt then on the fj mount).
If the left and right mounts are different in this aspect i might have to of the same side. Ill look into this today, maybe make some pic's to make it all clear.

When i fitted my det on the mounts i cut the little locater off my nismo mounts :)

Just rotate the mount 90 deg's, the dimple is supposed to sit in the same slot that the bolt goes into. I would also recommend not tightening them up until you got the engine in place as you get a degree of flexibility from where they can move up and down in the slot

Allright, ill see what can be done, when i get back home.
Thou i would have a prob with tightening the mount, once the subframe is back in the car. Basicly theres no room to reach that bolt, i guess i would need some sort of a smart wrench, that i dont have :D

if you have the fj20 mounts, could you measure the thickness of them in mm please as i was told they where about 47mm with the engine on them, thanks.:)

Yeah you need to smash the spanner up a bit with a hammer.

This image shows visually how the dimple should sit

http://i6.photobucket.com/albums/y21...h/DSCN1176.jpg

who's engine is that mart ?

Nothing to do with me, its just a pic I found.

Thanks for the help 30psi. Got the mounts in today, everything looks fine for now ;)

would standard auto box take the power of a det?

Depends how hard you treat it,

A standard manual apparently can't withstand sustained abuse from a standard ET

http://www.nissansilvia.co.uk/vbb/sh...?t=3037&page=2

good point...

I think I read somewhere, (here or zxoc) that a standard auto should be good for upto 350hp under "normal" conditions

Not sure if that's true though

i think the silvia god says around 200bhp before it starts to slip, my auto box must be shot as it slips @ 12psi with just an airfilter mod :o

who ever started that rubbish off either has never checked/serviced there gearbox oil and cant change gear properly.

Also i have never read anywhere about an s12 autobox handling 350hp. I would trust silviagods experience here. sorry if this sounds rude,i dont mean it too be

i shall also then! Cheers

TBH my autobox couldn`t handle 200bhp :( . The gearbox couldn`t cope with the kickdown. I had the box fully reconditioned too and it still let me down.

I would definately go the manual route, if you are looking at higher power outputs.

Regards,
Ian.

well im hoping 2 do the sr20, sometime in the future, but 2 save hassle felt like doing the det conversion 4 now, with auto as i can get nearly everything 4 free or very cheap. And do the manual when i do the sr,

I guess if the parts aren`t going to cost much it`s not too bad if the autobox goes boom ;) ...LOL... As long as you are careful with the kickdown, you should be okay. My box used to expire when I got to eager with the right foot...LOL....

Regards.
Ian.

Power transistor?
 

I never hear anyone about the power transistor (DIS-4 modulle)
I found out that its not on the engine loom but on the chassis loom.
Cant figure out how to hook that up.