Computer questions for the CA20ET project

OK, I know I'm gonna end up sounding like a real idiot here, but all my life I've messed with carb'd V8's, and I'm still learning all this EFI stuff. I have a pretty good grasp on how the stock system works, and all the sensors involved, but I'm not sure how much a stock system will take. My original plan was to go standalone, but the way my money is, I can usually only buy small things at a time, it'd be near impossible for me to save up $1200-$1500 for this, then another $500 for a decent used laptop.

So here's what I'm thinking. I know the stock CA20 electronics are pretty much junk with the trap-door MAF and whatnot, so should I try to find a KA harness and ecu? I know they're pretty easy to find, almost bought one on ebay last week for $20 (without the ecu). Or should I try and track down a CA18ET harness and ecu? Which one will give me more flexibility? Can I just use the stock computer with a SAFC or what?

Sorry I'm such an EFI dummy, I'm trying to learn... :slap:

well any ecu or harness that you get from another car thats na you will run into the same probs you need to find a system that has positive pressure to begine with.. your best and safest bet is a ca18et ecu and partial harness

http://www.sdsefi.com/

I've been looking into this company for standalone engine management. I've heard it's not the best, but it's affordable and programmable, and you don't need a laptop. Any opinions about SDS?

Only thing holding me back from a CA18ET setup is I've heard the MAF is super restrictive...

Well, the top of the line SDS setup with distributorless ignition is $1249, so it's pretty comparable to the other systems except without need of a laptop. With a MSD box is $1007, and fuel only system is $841. Oh, and another nice thing about them is they come with their own harness. So, it's definetly something to think about. Thanks for the link... :D

The MAF is restrictive ... but it's way less of a restricition than the ca20e one.

With an SAFC, I'm pretty sure with some smart fiddling. you can run the ca18et MAF in a Cobra Mustang (85mm) MAF housing.

Then you just have to richen everything up an "X" percentage all the way across the board.

They go for about $200

I was wondering how hard it would be to swap in another MAF. I guess just figuring which wire goes where and you could use just about any unheated MAF...

So the CA18ET ecu and harness with a SAFC and a bigger MAF looks like the cheapest and close to the best way to go...

I was wondering how hard it would be to swap in another MAF. I guess just figuring which wire goes where and you could use just about any unheated MAF...

So the CA18ET ecu and harness with a SAFC and a bigger MAF looks like the cheapest and close to the best way to go...

yes just get a z31 maf they are rated to about 350-400 and wil be alot cheaper then z32 mafs in a yard.. while you are at you might as well get some injectors maybe 370cc with the maf that way your air and fuel is taking car of.. and you just need a s-afc to control the new maf and larger injectors

Just FYI ... most Nissan's use the same hotwire MAF. It's the housing that is different. ECUs are calibrated with that information.

(X) amount of temperature drop (translated as a signal from 0.1 to 5v) x MAF volume = air coming in

Because the MAF itself ony sees a small sample of the air coming in, you need to make up for all the air the ECU doesn't perceive.

The ca18et MAF does fit inside the Cobra housing, you just need an SAFC to compensate for all that extra air.

agreed there matt... but our hotwire maf isnt as accurate as the z31. the z31 has a much longer hotwwire then ours which translates into more accurate and quicker readings... and heck i got my z31 maf at a yard for 25bucks i know the cobra ones run for alot more

OK, so I'll grab a z31 maf, that's easy enough to do... As far as the injectors go, what can I get them from? VG30? Should I buy new ones? Thanks for all the help so far guys...

Try and get a set of CA18DET injectors these are 370's. I not too sure how common they are over there though.

LOL... Not too common at all... :-?

What about the SR20DE's? They came in the SE-R's and newer 200SX's...

Do the CA18DE's use the 370cc injectors, or just the DET's? I know I could find some DE's...

We just don't have enough turbo vehicles over here. :laugh:

well you need to make sure the injectrs are the right resistence either around 4ohms or 16i believe.. eitther way you will more then likely find some that are top feed that require a new rail, whcih i just finished so i 'll show you some pics of it.. im using the 370cc from the det cause they are the right ohms

Yeah, I'm definetly wanting a new rail too. The stock one is pretty freakin puny... I'd be interested in seeing what yours looks like...

well you need to make sure the injectrs are the right resistence either around 4ohms or 16i believe.. eitther way you will more then likely find some that are top feed that require a new rail, whcih i just finished so i 'll show you some pics of it.. im using the 370cc from the det cause they are the right ohms

Ive made a new rail too but one of the injectors i got is broken as i dropped it and now the needle is stuck inside the housing! (GRRR!!) I just need to find one more injector and Im ready to go. Apart from I need a new boost gauge that goes higher than 1 bar i'll have to keep looking on ebay.

ok, let me try to clear up the injector mess...the injector you need is a low impedence top feed injector. If it was me, I'd find myself a nice set of stock DSM injectors (450cc) which can be had for $50 easy and would be abit more fuel than the stocker 270s. They can still idle very well and get good gas milage on a good tune.

Ive made a new rail too but one of the injectors i got is broken as i dropped it and now the needle is stuck inside the housing! (GRRR!!) I just need to find one more injector and Im ready to go. Apart from I need a new boost gauge that goes higher than 1 bar i'll have to keep looking on ebay.

Higher than 1 BAR?

Jim ... what are you up to?

:twisted:

Yeah Bart ... add me to that list, I'd like to see what you did for a fuel rail