Chris Boots

OK, Lets start with front to back:


MAF/AFM: You're gunna need a 87-88 Turbo MAF/AFM (mass air flow meter) N318 i believe . The car Will start and run with a Non turbo MAF but it will run rich. the turbo's have a stronger spring in them.

TID: (turbo inlet duct) a black rubber duct that goes from the MAF outlet to the turbo inlet. Some people have made them from home depot's turbo and intercooler etc. section. The stock ones are kinda known for cracking right on the turbo inlet end right where it goes over the turbo inlet and it clamps on. Or if you already have an after market cone filter and MAF adapter you can make an even easier inlet duct out of intercooler piping and a 3in to 2-2.5in reducer for the MAF to pipe and a standard connector to hook it up to the turbo. I can take pics if you have no idea what I'm taking about...

BOOST SENSOR: Get a Turbo II boost sensor #318. If for some reason you don't have one by the time you are going to fire her up you can do two things: (And I know its not right guys so don't flame me for saying these things...) 1. leave your NA boost sensor in and just don't hit boost until you get one. If you do it will boost up but will stutter really bad unless you floor it then it will accelerate sorta normally. I'm not sure if it runs lean or rich when you floor it so just don't do it unless you Really have to. 2. Unplug it completely. The ECU will set the Boost sensor parameters at a preset level and leave it there (sorta like S4 limp mode kinda). With it unplugged you can drive the car normally but it will run rich (bad gas mileage) and your "shift up" light won't work. I know it runs the engine rich because I checked the stoich (Air to fuel) level with my Wide band meter on one of my TII's when I unplugged the boost sensor. (again flame on if you think I'm wrong, this is just a temporary suggestion guys there's no substitute for a real turbo boost sensor)

ENGINE: Where you get one I don't care. I'm not gunna recommend any japan importers except maybe "japan2la" To make things easier just get a S4 turbo engine. Although I got a S5 and converted it to work with my S4 chassis, thats a whole different thread though. Above it all I built my S5/S4 engine so I had to get the little things like: all the top mount intercooler piping (which isn't alot). You'll probably get all that anyway from where ever and who ever you got your engine from.

I blocked off ALL the emissions on this engine so I'm not going to go into emissions stuff AND i disabled the twin scroll system when it had a S4 turbo setup on it.

WIRING HARNESS: either harness needs a few mods to make them work perfectly. The original NA harness in my opinion was the easiest to mod. I haven't had to mod a Turbo harness to make that work but some people have... search. I can't remember which wires you need to trip but I know one of the NA wires that go to the power steering goes to the knock sensor system on the TII's so... not fixing the wire problem means when ever you turn the wheel your ECU will retard the timing 20 degrees. The knock system works about the time you start to here big noises and you have realized to let off the throttle (its pretty useless and leave out that system in your swap) There's another wire that on a TII goes to a fuel pump resistor but not on a NA so disable that wire too. I'll check one of my swaps to verify the wire numbers like 3B etc.

You have to lengthen your harness to alow it to plug into the BAC and sometimes its not long enough to plug into the TPS. Easy and straight forward stuff though.

INTERCOOLER: you have 2.5 options really: 1. get a front mount setup. 2. get a TII hood. .5 the stock top mount intercooler will fit under your NA hood and allow it to close BUT you're pretty much cooking your air instead of cooling it then. I saw temps of up to 120 degrees intake temp on one of the swaps i did where we left the NA hood on and ran a TMIC TEMPORARILY. You can however just leave the NA hood off with the TMIC and then it works to an extent but not as good as a TII hood setup or going with a FMIC.

BLOW OFF VALVE/ BAR: (BAR= bypass air return) if you don't have a stock TID then you need an actually atmospheric blow off valve like a Blitz DD BOV , otherwise the stock BAR plugs into the TID from the turbo outlet pipe. BOV's are easy to hook up though. just plug them into a place after the turbo outlet and not too close to the intake and give it some vacuum and you're good to go.

THROTTLE CABLE: Simple, get a TII throttle cable

BRAKE BOOSTER VACUUM LINE: Lengthen your existing one to your original pipe if you can.

TRANSMISSION: You have a few options on this.
1. use your NA trans and upgrade your clutch to hold the extra power, but in the end you're gunna wish you did a full turbo drive train conversion cause the NA system works but isn't the strongest.

2. Use a turbo trans S4 or S5 and use a turbo clutch setup, turbo slave cylinder, starter and... get a custom drive shaft. There's ways of doing that, the easiest way is to buy Mazdatrix's custom TII to NA shaft which is basically a NA shaft with a turbo Trans connector and a NA rear end connector. You can also find a good drive shaft shop and take them a NA drive line and a TII drive line and have them switch the ends. Thats cheaper and works just as good. I'm only going to mention the words "NA Automatic Trans driveshaft" ... (I'm not recommending it in any way, don't flame) The NA auto shaft has in a sense a turbo front and a NA end BUT its a little shorter so you could strip your turbo trans's outlet if you run that shaft hard (boost) this shaft will get you by as in you car use it to move the car and maybe take it on a short test drive... thats all.

3. Turbo drivetrain setup, you will need : the turbo clutch setup, turbo slave cylinder, turbo starter, turbo drive shaft, turbo rear end and turbo half shafts and a few nuts and bolts here and there. Its all or none with this setup so you're either going this way or not but you can use S4 or S5 parts.

FUEL PUMP: You can use a stock turbo fuel pump, a S6 (3rd gen) fuel pump, a walbro 255 replacement, or if you're really desperate you can use your NA to start and drive the car and NOT BOOST. It will lean out if you use a NA pump and thats bad news.

EXHAUST DOWNPIPE: there's a few things you can do, get a stock TII precat/downpipe and mid pipe which bolts it up to the main cat OR get a aftermarket downpipe or custom one. You'll see the problem when you get to that point and you'll find its not too much work to make it work. Oh that NA exhaust system is kinda restrictive so redoing the entire system is advisable or it will effect your boost.

ECU: Get a N332 or N333 ECU, these are turbo ECU's and you need one. then along the way you can do what ever and maybe get a RTEK 2.1 or Apexi power FC, or a Haltec blah blah blah

BOOST GAUGE: Don't think you can just throw a turbo gauge cluster in it and the stock boost gauge will work, it won't unless its a S5 car. those are interchangeable and are plug and play. You can make the S4 stock boost gauge work but then again anything is possible and its not worth the trouble. Get a aftermarket boost gauge and mount it where ever.


There's a chance I could have left something out maily because I'm a little tired or its small enough that I just didn't remember it so if you have any questions and no flames just ask. Oh and pics on request.

I didn't include prices for everything cause they always vary and most times you get a "great deal" on a part so its your job to find this stuff. It may seem like a lot but its way worth it.

Any questions, comments, or corrections go ahead and reply or shoot me a PM.

I originally posted all this in a poll but this title is more straight forward in the case that someone searches with the key words: Swap, NA, Turbo, or S4
Enjoy

RotaryRocket88

iTrader: (7)

Nice writeup. I don't think we can ever have enough threads on this subject since it comes up so often. I just wanted to add some wiring details:

When using the NA engine management harness, The wire running to Pin 1R needs to be cut or wired up to a knock box. Personally, I just cut it and taped off the ends. I agree that the knock box is useless.

Pin 2K is for the split air solenoid on NAs, but for the twin-scroll solenoid on turbos. If keeping emissions, a J-spec ACV does not use a split air solenoid, which will free this wire up for the twin-scroll system. I suggest using the S5 turbo and manifold however, so you can forget this system altogether.

Pin 3D is for the fuel pump resistor/relay on turbos, but is unused on manual NAs. However, on Automatic NAs, it runs to the inhibitor switch. But lets face it, no ones converting to turbo and using an AT transmission . So the wire at this pin can really be ignored in most cases.

Lastly, if you're using low impedence injectors on a high impedence NA harness (87.5-88), you will need to buy resistors to wire in (www.mouserelectronics.com, I bought some 6 Ohm, 10W ones here) & you will need to modify the injector clips or buy low imp. clips and splice them in. High impedence injectors have a tab that is centered, while low impedence have an offset tab (mine did at least, chime in if some don't have this). I solved this problem by carving some of plastic out of the clips with an exacto knife.

Also, although some sources will say otherwise, you should not use the S4 convertible ECU N338 in place of N332 or N333. The guys at Pocketlogger say it won't work any better than an NA (N326/327) ECU would: https://www.rx7club.com/rtek-forum-1.../#post10530365

Rx7_boss

iTrader: (-1)

wiring ???? i am swapping my 91 is the harness on the passenger side firewall the only one i dont need and when i put the s5 t2 harness in is there any modding necicary for that too work with my car??

RotaryRocket88

iTrader: (7)

The details in the first post of the thread are for S4 swaps. And don't swap in the TII harness. You'll just be wasting your time not adapting the NA harness. Like S4 swaps, the S5 NA harness easily adapts to the S5 TII engine.

********************* FOR S5 SWAPS ONLY ***********************

When using the S5 NA EM harness:

1) Plug 6PI connector into turbo duty solenoid (ECU pin 3R)
2) Cut VDI plug off and connect ECU-side wire (Y/B) to knock sensor (ECU pin 2M)

Other than that, it's basically the exact same procedure (with the S5 electronics) as is outlined in the first post of this thread. The only real exception is that the N370 US-spec ECU should be used, or a chipped N374 J-spec ECU. The stock N374s have a history of not firing the injectors properly when mated to US-spec wiring.

kneel_to_the_rotary69

what would you guys do, im using the same setup here also, but when my n/a was in i had spark and fuel now i have nothing at all. i may get one pop when i yank the cas out and spin it by hand but other then that i get nothing after words. now you talk about wiring in 6 ohm resisters, what for if the tii harness never came with resisters on them? if you have some idea of why it might not fire let me know im all ideas looks like you have done this swap before and you might have an idea of why i get one pop from my coils and then nothing. ps... im getting fuel to the injectors but nothing after that.

barnett87rx7

iTrader: (1)

is it not easier to use the TII harness over adapting the NA harness

HAILERS

What harness did you use on the engine? It's called the EM harness. Did you use the non turbo EM harness or the TURBO harness on the engine?

If you used the non turbo harness i.e. same harness you had when you were non turbo, then I'd go to the small plug on the ECU and see if you have batt voltage on the fuel injector wires in that plug. Pull the plug off, key to ON, then check the light green, light green/red, light green/black and light green/white for batt voltgage. It HAS to be there on the small plug. NOT the ECU side, the PLUG side.

Got it there? Should. Then pull the elect plugs off the AFM, TPS, BOOST SENSOR and spin the CAS again to see if you have spark or not. Should. You do this because if one of those sensors is wired wrong it can KILL the ref voltage internal to the ECU. That ref voltage is used for the making of spark and fuel injector pulses. Its death may be just a temp thing once the wiring is straightened out.

Spinning the CAS by hand should cause the primary injectors to click. Listen for that.

Non USA built turbo engines have the fuel lines opposite the USA version. If you hear the fuel injectors clicking when spinning the CAS by hand, then try swapping the fuel lines at the engine connections. Do that only after you also have spark.

If you used the Turbo EM harness on the engine. ....that is probably your problem. Didn't take care of business by rewiring the turbo EM harness plug(s).

Also, if you remove the lead sparkplugs from the engine, and have EVERYTHING else connected up, and spin the engine with the starter, does the tach make small bounces as you crank the engine over?

RotaryRocket88

iTrader: (7)

Take Hailer's advice and break out the multimeter. Check over any re-wiring you may have done, and compare it with the NA & TII wiring diagrams.

Also, the resistors are only needed if you are using low impedence injectors (before 87.5'), and do not have a stock resistor pack on the EM harness (after 87.5'). A lack of resistors won't keep the injectors from firing, but it will allow too much current, which can damage the ECU and the injectors themselves. Note that high impedence injectors won't need any resistors in the circuit.

No. The TII EM harness must be adapted to work with the NA front harness & changes must also be made to the alternator wiring since the NA and TII have them run differently. It is far more work than adapting the NA EM harness.

HAILERS

The attached jpgs show the two ORANGE IN COLOR plugs on the EM harness.

The differences b/t TURBO and non turbo are delineated with the ( ) around the given wire.

Those wires with ( ) do not have the same function as the wires without the ( ) around them.

Nowhere above did I say you can't use a Turbo EM harness with/on a non turbo car, but you have to take corrective action to make it work right. You do that by comparing the wires in the wiring diagrams that are free and online. IMHO it's easier to reconfigure a non turbo EM harness to fit a Turbo engine in a non turbo car.

barnett87rx7

iTrader: (1)

In regards to the first poster you also need a knock control box if you don't want all of the idiot lights on.

One thing i have always wondered about is will a japan import engine work with a left hand drive wiring harness? and are there any major changes you have to make?

will a japanese RHD wiring harness work on a LHD car?

RotaryRocket88

iTrader: (7)

No. That is wrong. The knock box has absolutely nothing to do with the warning lights.

JDM and USDM turbo engines are 99% the same. It doesn't matter.

Too short. Wires have to be extended. Go back and read the information above. Using any turbo harness in a turbo swap is a waste of time that usually leads to electrical problems.

raksj04

iTrader: (1)

i am glad i kept my N/A harness. i have the JDM N340 ecu. so i should still just use the N/A harness.

do u have any good pics of the emissions removal?

i am also going to print this. hopefully my motor will go in on may 9.



if you don't have a stock bov what would you recommend that will fit easy and cheaply on my corksport charge pipe.

arghx

iTrader: (3)

Do yourself a favor. if you have a spare CAS, just unplug the one that is installed (leave it in front cover) and hook up the spare one and spin that. Then you don't have to go and reinstall the CAS again.

FC_fan

iTrader: (2)

whoever said to use the S5 turbo and manifold, +1 to them. it eliminates the need to use that twin scroll system AND it just plain is a better system IMO. its not that hard to change that either, only a few other sensors need changing to S5 ones.

FC_fan

iTrader: (2)

hey, I do have one question. my car doesn't have power steering to begin with (10/85). even though I do not have pwr steering, I would still have to do that 1R plug right? its still technically in my harness I would think.

RotaryRocket88

iTrader: (7)

No, you don't have to do anything to 1R if you don't have P/S. The only reason to cut it is to prevent the P/S from sending a signal to the ECU, which could retard timing (the ECU would see the signal as knock).

TeAm-FaTaL

Ok so what If I'm taking out my Jspec swapped S5 t2 out of my S5 to swap Into my S4? Does It just drop right In? Asking cause my S4 Is wayyy cleaner and not crashed like my S5.. Bumpppppppppp

RotaryRocket88

iTrader: (7)

http://www.rotaryresurrection.com/2n...o_s4_swap.html

13B_Conceptz

iTrader: (4)

samething happened to me... it was the egi comp fuse that blew out check that. its a 30amp 32v fuse in the engine bay.

dvs71990

i now have an 86 made in 09/85, do i have to use resistors for my after market 720's

RotaryRocket88

iTrader: (7)

Probably not. Most aftermarket injectors are low impedance, and 86-87.5 cars use low impedance injectors already. No resistors needed.

NYC7

iTrader: (3)

After swaping the TII engine and tranny, and using the NA rear ends. How long do they normaly last? I know the TII engine have a lot of torque. I'm just curious how long can the NA rear last untill it breaks.

Thanks guys.

need RX7

iTrader: (4)

Depends on how the car is used. If it's just driven on the street, with a few pulls here and there, it'll last a while, but if you do hard launches all the time, it's life will be shortened considerably.

RotaryRocket88

iTrader: (7)

I've been using my NA LSD for almost a year, and it's just fine. Others have been using them for longer, with even more power, and still not broken them. It will mainly come down to how hard you are on it. If you'll be doing nothing but launching the car, you might want to use a TII rear end. Even a torqueless NA engine can break the rear end if you get lots of wheel hop.

2_3D_SC

While I can,.'t say how long the diff will last in your case, I have a friend running a full T2 drive train with the exception of the NA Diff. It puts down 462 on a mustang dyno and the car is used for NASA TT and is not subjected to hard launches and has lasted for quite a few track sessions. The weakest link in an NA to t2 swap is the NA clutch and trans. I will have to agree on using the NA harness, the only changes I had to make was to add the wire for the temp gauge directly to the gauge, extend the TPS and BAC wires.

In my case I used astock S4 NA engine, stock T2 AFM, MAP, FMIC and ECU with 700cc Secondary injectors, ported S4 turbo LIM and stock UIM with S4 TB and TPS, S5 hybrid turbo @ 8 psi, full T2 drive train. The car puts out 250 RWHP and runs and drives great.

I would suggest that you use a WB to verify your AF's.