Megasquirting a NAPS-Z

[ketshy]

I got tired of the finicky carburetor and just plain gutlessness even on a fresh rebuild of the Z22 in my '82 720, so I'm in the process of installing Megasquirt. I've been taking pictures and plan on documenting as well as I can. So here goes, I guess.

First the components:You can source a manifold from an '80 to '83 200sx, I got lucky and found mine on Craigslist with injectors and a bunch of extras. I've also heard of a modified KA24E manifold working, which makes sense given how related the engines are. And of course you could always go custom.Heres a stock 200sx manifold:As you can see it's pretty straightforward, the plenum bolts right on and has mounting locations for all of the stock components. The injectors mount in plastic housings and bolt straight to the manifold, they are not held in by the rail. The coolant temperature sensor is a standard GM sensor and the one recommended on the Megasquirt website, it threads in to the manifold right where the vacuum switch went, or I'm pretty sure would fit in the stock location. I kept the stock sensor to run my gauge off of. Right below the sensor (Yellow and black wires on the right) is the mounting location for the fast idle valve. Seen Here:When cold or off it lets air through, when the engine is running it receives a constant 12 volts and gradually closes. Its a pretty basic setup and doesn't allow for idle control so that has to be set by the throttle body stop.

If you noticed the odd port off to the left of the manifold you might be wondering what it's for, and to be honest I'm not really sure. Here's a better shot of it and where it goes with the manifold flipped over:My best guess is that it was EGR but I don't have a stock valve to see if one would fit, I just plugged it and called it good. However it does have some good potential it seems, something along the lines of water injection or nitrous maybe.

There appears to be two different kinds of plenums (and I would assume manifolds, then. Though I only have one) one has coolant passages and the other does not, I chose to use the one without (on the bottom):It's hard to spot the coolant passages on the other plenum because that's a lousy picture but one is on the top by the left mounting hole. For the intake air temperature sensor you can again use the standard recommended GM sensor, it will thread right into a couple different locations. There are 4 or 5 total holes in the plenum, I use one for the air temp sensor, one for the brake booster vacuum line and one for a fitting that feeds two different size vacuum lines (for advance and the fuel pressure regulator) and takes the hose from the fast idle valve. That leaves at least one for PCV if you feel it is necessary.

The stock injectors are JECS top feed low impedance and the fuel line attaches straight to them with hose clamps. This makes fabricating a fuel rail quite simple if you need to, and it's just kind of nice to not have to deal with O-rings. I haven't done much research on where to get these but Napa lists them on their website and Google says that quite a few other Nissan motors used the same kind. Google also says that its a 180cc/min injector and has an opening time of 1.2ms, both of which worked for my setup with some fine tuning. Sorry no pictures of the injectors, only what I'm assuming is the stock fuel rail:

Now I'm ready to assemble. The head doesn't require any modifications to make the manifold bolt on, but injector clearance looked scant to me so I decided it couldn't hurt. There is a small half circle taken out of the top of each port that lines up with the injector, I ground each one a little taller to make it line up with the manifold with no overlap. Heres a picture:The one on the left has been marked with the manifold in place so thats how much it needs to be ground. The one on the right has been ground already. It's a good idea to stuff a paper towel or rag down the port while you're grinding to keep the shavings out of the cylinders.

That's it for now, I'll have pictures of it as a running setup probably by the weekend. Feel free to ask questions or ask for more/better pictures.
Modified by ketshy at 10:05 PM 11/19/2008

[nismopu]

Sounds good! Hope you have more fun with megaturd then I did, lol. Yes, many engines use the 180cc injectors, including old L-6 EFi engines. Sourcing the parts can be difficult these days but if you have trouble I know of a few board members on other sites that have this stuff. you can email me about it since theres no PM's on this site. Also, ka24e turbo manifolds from JGstools.com work on the Z-series heads. something to think about eh?

Dont get frustrated with the guys on the megasquirt boards, I suggest asking friends in your area who they know thats good with the system. A friend and I recieved little to no help on those boards. We learned on our owns and currently my friend has an 85 turbo 528 BMW that waxes STI's. peace.

[ketshy]

Alright I kind of missed the updating soon thing... Oh well it's up and running and I have pictures now so I'll update. Thanks for the offer and words of encouragement nismopu.

[FricFrac]

Just curious how this went. NAPS-Z/Mega Squirt hasn't really been done.... doing something similar myself but boosted as well

http://www.vanisledatsun.com/forums/ind ... 0/all.html