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Also be very careful about using the tach adapter. I believe the stock Z guage wants a 12v signal but if you have an autometer or other aftermarket tach that wants a negative pulse as the signal then you don't want to use a tach adapter. basically the tach adapter takes the negative signal and converts it to a 12v signal. his autometer wanted a ground as the signal so before i read up on the tach adapters job i actually fried out the 52 ohm resistor in his ecu for the tach signal, which left me pissed about how the hell he was gonna get the safc2 tuned without the safc being able to read rpm. at which point i ran the safc2 to the 120degree cam angle sensor ecu pin, which there is 2 of, either green wire should work but i believe i used the 40 something one, i think it's 41 but i don't feel like checking the pinout right now. discarding the tach adapter altogether i spliced in his autometer guage and safc's green tach signal wire into that 120 ecu pin and voila. my caution is to see if your particular autometer tach wants a 12v as the signal or a ground, cause i'm sure they make both. in the guage box there should be instructions that'll tell you. his had something on the back of the instructions that said "for old style ignition systems" and it had a picture of the signal wire going to the negative post on the external coil.

Chris, We discovered one of his coil packs wasn't working. And being a series 2 it doesn't already have an external ignitor, so I wired in a PTU from a Z32 and wired in a Grand National Coil /w msd ignition cables. I've noticed all the guys in Australia with 800+hp run this wasted spark set up, if you're interested in how to do it, I'll let you in on it since you've been such a help to me. Thanks again David

, it's a matter of opinion really. to each his own, none of the motors are bad, there's pro's and cons to every motor. like now you see the ka-t craze going on my last sr20 with stock injectors, ecu, and t25, just a front mount, 13psi, and a lightweight flywheel ( i think it was a jun it definately wasn't aluminum crap ) i put 238.9 rwhp and 260.9 rwtorque. i have to say i definately wasn't impressed with the rb20's 187 rwhp, but the fact that i could go from 4th to second and take off like a rocket with the 3.5 r200 rear end really made me happy LOL the thing revs like a rotary(my rb20 came with an Access tuned ecu they had bumped the redline to 8500) they're both great motors, as far as reliability i'll say sr20 > rb20 no question. the 6 sounds way better than a 4 no doubt about it. i never disliked any sr car i had and i i've had 3 this is my second rb20 car which by the way i just cracked a ring land, which is what they do LOL, so i'm keeping the rb20 tranny and putting my 25 in it, then since i'll have an extra 25 tranny i'm putting a 26 in my widebody 240z which was going to get my 25 once it's done being painted. for a 240sx i'd go sr20 before i went rb20. for a Z i'd go rb20 before i went sr20, but in either scenario i'd go rb25 before i went 2.0. i'm finishing up my friend's rb25 in his 72 240 this week, saturday we're shooting it to the dyno, then i'll have my xmas labor $ which is paying for the 26. ^^ that sr does sit nicely in your Z btw, i didn't think it'd work but i was wrong LOL so gj

dumb question but has the gas in the tank been sitting for 25 years? LOL seriously though i'd lean towards contaminates in the fuel system if all the ignition components looked ok, ie no cracks/hot spots in the cap, and the rotor button looks good. it'd be a good idea to do it anyways so i'd give the thing a major tune up and definately flush the fuel lines out, replace the fuel filter, and if you're still having problems THEN i'd check the distributor and see if the vac advance is working etc. at least you have compression

sr20's are front sump 2 piece oil pans that even if you did sit the motor really far back the cross member'd probably be directly underneath the oil pan. you probably wouldn't need a drive shaft you'd just need to saw off the collar on the 240z's considering rb20's, ka's, and sr20's (except s15) all have the same transmission and just different front belhousings (tip if you blow up your tranny *wink) if you get a motorset it should come with the ecu and harness, make sure you get ignitor, mass air flow sensor, and cam angle sensor as they like to leave out those parts. 240z fuel return line is pin hole size you really just need to tap a bigger nipple on the tank and run a hose/line from the tank to the fuel rail. you don't need stand alone. i agree with the guy that said it'd be gay to put a 4 cylinder in a z car, rb20's sound way better than sr's and everyone and their mom's got an sr nowadays. my first sr i paid $1000 for a black top s13 sr20 and it came with everything even the side mount intercooler and piping. that was a good while ago though. there's nothing wrong with sr's except the floating valve train problem which rocker arm stoppers help. they're stout engines, but in all honesty (and i'm far from a purist) i'd rather see a 240z with a 1g-gte than an sr20 in it or any other 4 cylinder for that matter. rb20's are like half the price of an sr. i started my rb20 in my 78 280z saturday afternoon, i had the car running sunday night and drove it to work monday morning. later that day smoked my boss's 2002 vette (automatic) by 3 cars, won $50 for the bet, then dyno'd at 187 rwhp. i spent $950 on that rb20 motor set, it came with a blitz bov, and all the intercooler pipe and down pipe which i just cut it an inch below the flange and turned it a couple degrees then welded it to the rest of my exhaust. i used the 1jz-gte intercooler i had laying around and routed it to the stock over the valve cover intake. rb20, the motor mounts you can use, the trans mount from the 240z bolts right on, the driveshaft is usable, you have to do 3 wires, then just change the alternator/starter plugs/connections cause they're smaller/different on the Z, then start that ♥♥♥♥ up (that's for a 280z though). what i'm saying is the most expensive part of that swap besides the motor set itself was the rear sump oil pan. think about this too stock redline on an sr20.... ?? ~7200? rb20...~8200 sr20 $1700-2200 rb20 $850-1400

i did my friend's z31 vg30e into an 87 rx7 but that's definately a swap i hadn't thought about, nice job man

well....with no intercooler piping, no mass air flow, no radiator, no exhaust, no 02 sensor and the fuel return line going into a gas caddy the rb25 started right up. we got more to do but at least we know the motor'll run and idle on it's own. thanks a lot Chris for your write up, it helped immensely, and all my questions got answered as i went on. thanks again cause as soon as i'm done with my friend's i can yank out my rb20 and do my 25 swap in a day or two

ya i saw where you wire it in to the black/white ign switch wire. i'm almost done, i did the regulator conversion last night, and i just need to swap the alt plugs and wire in the fp relay then tape it all up.

sounds like you're on the right track. the r180 is a pretty weak differential and it would be a great idea to put a r200 in it so you don't have rear end problems, you also need a rear mustache bar off like a 78 280z if you get an r200 cause the holes are bigger and if you drill em out bigger you're gonna make that mustache bar very weak, check out the mustache bar on www.arizonazcar.com it's so sexy!! before i'd worry about chassi flex i'd be worried about how i'm gonna stop this car with single piston front calipers and small rear drum brakes LOL lemme know when you get started on yours cause i'm gonna do the same. i have a 78 280z with rb20det, and i have a widebody 71 240 that's got no rust, roll cage , and beefier frame rails. as soon as my friend's done with the body work i was gonna put my rb25det in it but i cracked a ring land in cylinder #6 on my rb20, so i'm gonna put my 25 in my 280 and use the rb20's transmission. that'll leave me with an extra rb25 tranny and no motor for my sexy 240z platform. so i'm gonna get an rb26 for that one. so when you start on your project lemme know cause i'll either be doing it right there with you or already be done with it and i don't mind helping if you run into some issues. good luck David

preciate it , i'm almost done with it, tonight i just need to wire in the fuel pump relay, and convert the lower harness, then tape everything up and i'm done. thanks again

i was finished with this guy's s14 sr20 and he was still waiting on the ecu, so he borrowed one of my friend's and i finished and everything worked, then my friend needed his back so he borrowed one of his friends...when i hooked up his friends ecu it wouldn't start, it wasn't getting any fuel, but i know everything was correct because with my friend's ecu it started right up, so i called the kids friend and inquired about the shop that did his swap, did they hard wire the fuel pump into ignition, and he said they did, anyways, the fuel pump circuit in the ecu may be fried, you can see if when you power up the ecu (turn the key on) the fuel pump wire get's a ground, or see if you can borrow a friend's ecu, if not try hardwiring your fuel pump

thanks well...on to series 2 variation number 2. the thin grey wire that goes to the 8 pin skyline plug off the maf harness doesn't have the grey wire in it to feed ignition power to the fuel injectors from there. So i'm just gonna tap into it at the injector goofy lookin 8 post plug cause it does have the wire there. i pulled a green efi relay from one of my old 240sx's and i'm gonna use that for his fuel pump relay and wire that in tonight as well as bypassing the voltage regulator. then all we have to do is recirc the heater hoses, and do all the intake hose routing (he has a jun intake manifold) then we'll sit the motor in, get the fluids in, and crank it up. he's running a t3/to4e which is already on, and he has some 550's but for now i left in the stock injectors so we can just make sure the thing idle's and such, he still needs to get a z32 maf and i've already wired in the safc2, but the car should still start up without a maf. oh i have one more question, i've heard you wanna disable vtc after 400hp...did you already post how to wire that in though? *i'm being lazy thanks for all your help.

yeah, thanks chris . i've been making headway on my friend's wiring he has a series 2 rb25det, ours with the 1 external ignitor is series one, these both have vtc, the neo motors as far as i understand came out of r34's and have a bunch of plastic crap on em, like popping the hood on one of today's newer nissans here, that's the answer i got when i was asking some jdm engine venders if they've ever came across a 25 like my friend's. so far as far as the dash plug goes the only wire that's not there is the solid big red one that goes to the ignition relay because he only has an ecu relay. we're gonna cut a bigger hole through the firewall tomorow and feed the ecu harness through then get started on wiring it to the ignition switch etc. but so far since i'm not just reading, i'm doing as you're explaining, everything's running smoothly and it makes sense EXCEPT for what's making me smoke more cigarettes than usual LOL, the external voltage regulator removal. the reason why is everyones' plug in the world is round except his, he's got the bastard child rectangle plug which was throwing me off and as it is this is my first external VR project. honestly, tonight is the first time i've been able to find a wiring schematic for the theory and operation of the thing so i can comprehend it and not just pray as i take his rectangle plug and wire the thing based on wire color while imagining the plug is round lol. So now i'm in the "ooOOOOo i c" process and it's making a lot more sense. This is the first place i've seen mention of the rectangle plug, check this, tell me what you think. http://www.atlanticz.ca/zclub/techtips/alternatorswap/index.html the only thing i'm still searching is cutting off the T shaped plug on the alternator and splicing in the rb's without mixing up the wires (i think J Soileau is seeking the same info), or checking voltage with a volt meter to determine which goes where when the car's not running in the first place lol it's only 2 wires i know someone here knows it right off hand LOL, basically the rb's plug has 2 wires, one is white/red stripe the other is blue & something i forget, and i'm searching for the answer ie "white/red goes to "S" and blue goes to "L" <----[that's my guess. i'll check my 280z rb20's plug/wire colors tomorrow and pray the 25 has the same colors] Can anyone confirm that though? Once i get that confirmation i commence "I GOT THIS! WHO'S YOUR DADDY" phase ^.- all in all so far so good though chris, i really appreciate all you guys helping and so does my friend. David

if you were to take a test light and hold it to the soldered back of the ignition switch or go even from the ignition switch's plug and go from wire to wire and turn the key to run position you'd see a couple of em get hot, but when you go past run into the start position you see it's no longer hot, that's not the ignition wire you want, that'd be something you'd want for like the radio, so it wouldn't pull any voltage when you're cranking the car but soon as you're done cranking and the car's running it comes on, what you want is a true ignition wire which will stay hot even in the start position. double check your ignition source.

well i came home to my rb25 after looking at my friend's coil packs, and there's definately an extra hump over each of his coil packs, so it's looking good as far as the harness only having one relay and each coil pack having it's own ignitor theory. i just wonder what kind of car his 25 came out of *shrug, tomorrow i should make some headway on his dash plug/ignition switch wiring, i'd like to be able to start the motor or at least compression test the thing before his warranty is up. tomorrow i'll call jarco or jhot and ask em if any of their 25's only have one relay.

there's only one relay, i've inspected this whole harness, even on the small harness that runs off of the coil packs there's no lead or plug for an ignitor hehe. but anywho, i looked at the "dash plug" with my 25 harness next to me as a reference and i'm tracing back some of the wires off of my second relay, and there's no wire in the terminal on my friend's dash plug ( the white one that snaps over ). i'm pretty sure one relay is for the ecu and the other's for ignition etc, well IF his motor has built in ignitors on each coil pack then perhaps his ignition is completely ecu controled therefore not needing a separate ignition relay...... this whole thing is strange but i'm gonna make it work

another crazy thing, i'm looking at the main harness and i don't see any plug for the ignitor, and the short harness off the coil packs doesn't have a pigtail for it either....i believe i was glancing at something and it mentioned rb25's with internal ignitors on the coil packs....but anywho i'm gonna get back to work and make some sense out of all this LOL.

every rb i've ever swapped had nasty plugs in it, take a look at ur plugs

I'm doing an rb25 swap in a friend of mine's 240z, and his wiring harness is a little butchered but i'm inspecting this thing and i only have 1 relay on the harness by the ecu plug. so i take it home and set it next to my rb25 harness. mine has both relays, i've stripped down the insulation on his harness and i can't see any cut wires where maybe someone cut the other relay out. both our 25's are the neo motors with the vtc hump on the passenger side timing cover. any ideas?