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Hey guys.
So I'm pretty new to RX7, it always my dream to own one.
It has been pretty hard to find a decent Turbo 2 S5.
But one of my friend actually has a GTU that he bought, he is rebuilding that car and he told me he can make that car into a Turbo ii if I'm interested.
he actually has a brand new crate motor from Mazda, the 13B-REW motor.
I understand is a FD motor, and its a bit better and reliable.
But I'm just not sure if this is a good idea.
Please let me know what you think?
Is putting a FD motor into the FC comment??
Anyone tried and ran into any problems??
ive been thinking about an FD 13B-REW into an FC for a while, the trouble is that the way costs are it usually does not make much sense to do it. the only time it might make sense is to do a turbo swap.
so the easy way would be to sell off the REW stuff and buy T2 stuff, seems like a lot of work, but the T2 is stock, so it bolts in. FD is not.
getting the engine in the car isn't too bad. you need a set of mount brackets, like these https://motivefab.com/product/13b-re...ne-swap-mounts
the FC clutch will bolt on the FD flywheel, and that is it, engine is in the car, this is where the trouble starts
Exhaust: the exhaust bolt pattern on the engine is the same, so you have a lot of flexibility here, which is nice. the FC has more space for a turbo, and the FD engine does too, so you really have room for anything.
the FD turbos will fit, but they are longer than anything else, and this causes problems elsewhere. also the FD down pipe does not fit off the shelf, its close, but it hits the floor, any muffler shop can fix this.
Intake: the intake ports move between the FC and FD, so if you run an FD engine you need the FD intake manifolds. they fit really well, however every throttle elbow kind of points the wrong way, and thus you can't run power steering without fabricating something (you can either move the PS pump, or make a new elbow). you also need to run some kind of front mount intercooler, as the FC one will not fit.
Water Pump: this is one of the most annoying parts of the whole swap. the FD water pump obviously fits the engine, and you can run the serpentine belts and such, its also lighter. however you need to run an electric fan. also due to the FD turbos being really long Mazda moved the lower radiator hose more toward the center of the car. to use an FC radiator you can either modify the FD pump, like i did, or find some hose that makes crazy bends in a really small space. the FD turbos are also really close to the radiator, they are long! also possible to use a different radiator with the hose barb either in the FD spot, or the other side would fit too. if you keep the FD pump unmodified, the FD heater hose fits.
the FC water pump imo would be ideal, because then you can just run all the stock hoses and such, but the FC pump hits the FD fuel rail, which is weird. also the metering lines might need to go with the water pump, the FD lines do not fit the FC pump.
ECU, one of the upgrades of the FD is that it has a better Crank Angle Sensor (CAS) setup, the bad news is that the impedance is different, so the FC ecu will not work. lots of options here, if you keep the FD turbos the Apexi Power FC is probably the best choice. its also a good choice if you want to keep the stock harness and emissions. easy button here is the Banzai kit APEXi Power FC Adapter Kit (89-91 RX-7) it seems expensive, but i made my own and it was half the money and took way longer.... mine is single turbo, with emissions, so i used the S5 engine harness with adaptors to mate it to the FD ecu and sensors. you could use the stock FD ecu as well, but to keep the check engine light off you need to either hook everything up or use resistors, the PFC doesn't care about that stuff. the other thing about the PFC is that it is setup for a JDM FD, which has a pinout that is closer to the FC. obviously if you use something that isn't stock Mazda based you can make the harness and do whatever you need.
lets see, the FD oil cooler hoses are different, they went to 18mm on the front cover, instead of 16mm, and then the rear goes to the oil filter pedestal. no off the shelf kit for this. it is probably easiest to weld an AN fitting on the pipe that goes to the oil filter pedestal, and then buy an FC oil hose kit and cut/modify it. you could also run the FD style coolers, but that is a big custom job. the JDM tuners do this on high powered cars
the FD ignition and fuel rails and such obviously fit. the vacuum rack is pretty scary, but its actually modular, so you can remove the stuff you're not using really easily. the fuel lines plug right in, which is nice. you can use either the FD or FC ignitions (depending on the ECU) the FD setup is lighter and more powerful so its the best choice (also the weight is more centered).
PS/AC if you use the FD water pump and serpentine belt, the FC AC and PS pumps do not line up. the PS is close enough where you can put the FC pulley on the FD pulley and make it work, but the AC is not. plan B would be to run the FD stuff, which the belts would work, also the IC pipes become really easy, as the PS is out of the way. the downside is that you would need to make hoses for everything. its not impossible to run PS in an FC-REW, but it is tricky to run PS and AC
Turbo oil lines: if you're running the FD turbos this is a bolt on, no problems. if you run an FD turbo kit, its a bolt on no problems. if you are running some random junk, like me the FD uses T2 sized oil drains and the FC is T3/T4, so its 16mm vs 19mm? its been kind of a PITA to find something that works, or maybe its more fair to say that nothing bolts up easily.
Emissions: basically the FD air pump is bigger than the FC, so an FC turbo kit usually puts the turbo too far forward for the FD air pump. you also need to add the relay for the FD air pump clutch, which is easy. FD fuel pump drops right into the FC, although plenty of options here.
pics to come later! and feel free to ask questions
[QUOTE=j9fd3s;12543749
the FC water pump imo would be ideal, because then you can just run all the stock hoses and such, but the FC pump hits the FD fuel rail, which is weird. also the metering lines might need to go with the water pump, the FD lines do not fit the FC pump.
[/QUOTE]
Which fuel rail does it hit primary or secondary? Any chance that one could run the 13B-RE fuel rails with the FD manifolds and if so would it solve the issue of the FC water pump hitting the fuel rail? Since IIRC it used an FC style pump. Also would aftermarket fuel rails that let you run more modern injectors also hit the water pump?
Which fuel rail does it hit primary or secondary? Any chance that one could run the 13B-RE fuel rails with the FD manifolds and if so would it solve the issue of the FC water pump hitting the fuel rail? Since IIRC it used an FC style pump. Also would aftermarket fuel rails that let you run more modern injectors also hit the water pump?
its the primary rail. its weird, the FD water pump moves forward compared to the FC pump. its actually the hose barb on the FC pump hitting the hose between the fuel rails.
ive messed with it a couple of times, its fixable. you can remove the hose barb, and it'll go on, but then you have other problems like there is no water for the thermowax.
its the primary rail. its weird, the FD water pump moves forward compared to the FC pump. its actually the hose barb on the FC pump hitting the hose between the fuel rails.
ive messed with it a couple of times, its fixable. you can remove the hose barb, and it'll go on, but then you have other problems like there is no water for the thermowax.
Depending on how the fuel lines are routed maybe an aftermarket fuel rail for top feed injectors is the solution if one wants to run an FC water pump.
Depending on how the fuel lines are routed maybe an aftermarket fuel rail for top feed injectors is the solution if one wants to run an FC water pump.
i'm sure there are a ton of aftermarket rails that would work, but the gotcha, maybe is that since the ACV lives above the injectors most rails require you to remove the ACV. so if you need to smog the car, it doesn't work.
i've kind of wondered if the S5 rail would fit.
the FD is nice because all the stuff you don't want to look at is under the intake
This is really great info here!I just recently picked up an brand new FD crate motor and was looking to see how complex it would be to get it to work in my FC. I do have a question about the intake manifolds though. Is there anyway to get the upper and lower manifolds to be interchangeable with modifications to the runner ports or would flipping a FD upper intake plenum adapter upside-down to run an Fd lower intake manifold to a FC upper intake manifold work? I know the FD unit flows more but I would like to keep the parts I have acquired for the FC.
This is really great info here!I just recently picked up an brand new FD crate motor and was looking to see how complex it would be to get it to work in my FC. I do have a question about the intake manifolds though. Is there anyway to get the upper and lower manifolds to be interchangeable with modifications to the runner ports or would flipping a FD upper intake plenum adapter upside-down to run an Fd lower intake manifold to a FC upper intake manifold work? I know the FD unit flows more but I would like to keep the parts I have acquired for the FC.
while i think you could physically put the adaptor upside down or something, something is different enough that the throttle body is in a different place.
i'll have pics shortly, or better ones, actually its a weird thing to have a pic of maybe not at all, lol
if you have an FD engine, with FD intakes, the primary throttle is basically centered on the center iron, when you have an FC lower and FD upper the throttle body is further toward the rear. it may matter, and it may not
its kind of a how this swap goes, you spend a lot of time getting odd things to fit.
This is really great info here!I just recently picked up an brand new FD crate motor
plan B might be just to buy the FC irons and an o ring set, and just make a crate FC engine. sell FD irons and you'd be in the ballpark of revenue neutral
just for fun, here are some pics of FC-REW swaps, the tip off is usually that if its an FC engine with the FD stuff on it, it will still have the FC fuel rail
notice things like the radiator hoses, not sure what radiator this is using, its too narrow to be an FD
this one has the FD AC/PS bracket, and its interesting where the battery ends up
and just for comparison here is an FC with an FD upper and FC power steering. i think the PS pump is not quite in the stock location though
couple more pics of REW swapped cars. the FD thermostat neck fits, but its really tall, and depending on engine mounts is probably hitting the hood. the more mods you do, bigger turbo, Front mount, ecu, the easier the swap gets
This one looks like it was less easy. i'm not sure what the wiring is for, maybe the fans?
If we look at it system by system, or maybe part by part it helps. instead of one big job, maybe its better to look at it as a lot of little ones.
ECU: the FC ecu will not work with the FD CAS's, so the computer needs to either be upgraded to the FD computer, Power FC or something else (Haltech, Motec, or the Link)
the FD ecu is looking for all of the stock emissions and turbo control stuff (and the OMP, fuel pump resistor, etc) and so you either need to run all of this stuff or use some resistors to keep the CEL off.
the Power FC is nice here because it can run all of the stock stuff, but doesn't care if its there or not. the FD ecu is faster than the FC and the PFC is faster than that, these are both noticeable.
the JDM tuners tend to keep the FC wiring harness and then add whatever they need as like an expansion harness. one of the weight savings between the FC and the FD is that the FD harness is like a foot shorter than the FC, so you can't take the two and put them together.
Sensors, etc
Crank Angle Sensor: One of the reasons for doing the FD swap. the FD uses a crank trigger, its more accurate and since the pulley and CAS plate are pinned it can only be assembled one way. the connector changes to these, https://lms-efi-llc.myshopify.com/co...-cas-connector if one has an S5, its easy to make a little pigtail. if one has an S4 with the CAS wire in the charging harness, it might be better/easier to just make something new.
Coolant Temp Sensor; the FD sensor is physically different, but electrically the same. the FD is one of the best packaged engine bays, the FC sensor uses a square connector, and the FD is oval. the FC sensor hits the alternator.. it is very easy to file just a big off the alternator and use the FC sensor, or the FD one works too. it just depends on which connector on the harness is easier to get.
Air Temp sensor: the FC and FC have different sensors, the connectors are different, and the outputs are basically opposite as well. the PFC needs the FD style sensor.
TPS: one of the benefits of the FD swap is the FD style rotary TPS, its much better. electrically its the same as the S5 setup, narrow and full range sensors. if one is using an FC wiring harness the connector is different, but easy to make an adaptor https://lms-efi-llc.myshopify.com/co...-tps-connector
Oil Pressure Sensor: the FD has a different part, but the threads in the engine are the same, and the LHD cars have the wire on the chassis, so you can run either sensor. the FD has a Male Spade connector instead of the thing the 81-91 cars have
AFM: a third upgrade reason, the FD doesn't have one. its almost worth upgrading to the FD style ecu just to get rid of the AFM.
Map/Pressure/Boost Sensor: The FD uses this instead of the AFM. of course the FD also uses a weird sensor, most would go to 15psi, aka 2 bar, but the FD goes a little higher, 17. if you want to use the FD ecu, you need the FD map sensor. any non stock ecu will let you use something else. connector goes from an unsealed 4 pin to a 3 pin Amp Econo seal, very easy to make a little adaptor if one is using FC wiring
Fan Switch: the S5 and FD use the same connector, which is nice. S4 if equipped needs the connector, if one wants to run the FD multi speed setup.
Fans: since the FC used a mechanical fan, and the FD uses a 3 speed electrical setup, the wiring just needs to be added. the FD setup uses two 2 speed motors, and 4 relays. there is the fan switch, the AC switch, which most FC's have and then the ECU has an output as well. imho it seems easier in the US to run the Taurus (or Quest) 2 speed fan. the Taurus is F4DZ 8C607-CA. mine is using the ECU to just run the low speed and its been fine, but if i had AC i'd want the high speed
Clutch Switch: the S5 and FD use the same one, which is nice. not sure about the S4, but i think it is electrically the same. stock ecu or PFC wants it to figure out if its idling or just running at low speed.
Air Pump: the FD air pump is basically the same as the FC, but it uses a clutch like an AC Compressor (everyone thinks it IS the ac compressor). if one wants to run the air pump, the relay and wiring need to be added, very simple
Air Control Valve, ACV: the FD valve is a little simpler than the FC valve, but uses the same two solenoids, with the same two connectors.
Fuel Pressure Solenoid: literally the same, same connector, same function
Fuel Temp Sensor: the FD adds one in the fuel rail. it uses the same sensor and connector https://lms-efi-llc.myshopify.com/co...temp-connector as the coolant temp sensor. since its an addition, it needs the wire added. obviously if one isn't running a stock FD or PFC ecu you don't need this.
Purge Valve: The plumbing for this is the same, i think, however the FD uses a solenoid instead of the vacuum thing. Wire needs to be added to run it
Oil Level Sensor, i think the FD has a different connector, but that is it, so you can swap the FC unit right in, the O Ring is N326-10-T11
Coolant Temp sensor for the Gauge, the S5 and FD use the same one, so its super easy. if you have an S4 its different, and you need G607-18-51X. its the sensor for an S4 with a replacement housing, so its S5 or FD threads with the S4 connector and resistance range.
Holy Moly, Thank you for the info! I have most of the those items that I could make work. Its just a few changes to make this work with the AP Engineering apexi power FC i have.
Holy Moly, Thank you for the info! I have most of the those items that I could make work. Its just a few changes to make this work with the AP Engineering apexi power FC i have.
yes, its sort of simpler and harder with that. you can't run the fuel temp sensor, so you don't need to worry about it. i think also you can't run the e fans, but i am maybe not correct about that
Here is a pic of what you're dealing with with the lower hose.
it seems to be that if you run an aftermarket radiator things get better, this one is the old K2RD/AFCO radiator, hose barb is straight instead of angled up
over the years i've noticed that the FD upper radiator hose is really good if you're fabricating stuff, it just works well
12-12-22, 08:53 PM
13B-REW crate motor into a GTU?
