T2 engine swap question

[Justin51982]

So as I toy around with ideas of what to do with my RX7, I can get a pretty good deal on a JDM stock T2 engine, transmission, ecu and wiring harnesses.

I wanted to find out if any of you guys have had experience with this kind of swap?

Also, one of the things that might concern me is that since JDM cars are RHD and ours are LHD, will the harness hook up and have enough link, and has anyone had any experience with these JDM engines?

Thanks!

[Five*Star*]

I haven't actually done one of these swaps, but I read up on it years ago. You probably can run your ecu on the opposite side of the car if need be. What year is your car. S4 and S5 FC chassis use diffent computers and sensors and I think it needs the cluster and underdash rewiring. I may be totally off here, but it's easiest to get the same series as your car is when doing the swap.

Check RX7club.com FAQ in the 2nd gen section

[Justin51982]

I haven't actually done one of these swaps, but I read up on it years ago. You probably can run your ecu on the opposite side of the car if need be. What year is your car. S4 and S5 FC chassis use diffent computers and sensors and I think it needs the cluster and underdash rewiring. I may be totally off here, but it's easiest to get the same series as your car is when doing the swap.

Check RX7club.com FAQ in the 2nd gen section

I'll check that out. My car is a 1990 S5

[sc0rp7]

get a S5 Jspec with harness and ecu... The ecu is mounted in the same place on JDM and US spec cars. the transmission and engine will bolt in with little problem. Remember you are gonna need a TII hood or to move the intercooler as they have a stock top mount. The fuel pump should be upgraded as the stock NA fuel pump does not flow as much as a TII unit and with simple bolt ons you would reach the limit of it (stock NA fuel pump). The only other obstacle I can see you having to handle is whether to get a TII rear end or a custom/modified driveshaft to go from the TII transmission to the NA rear end. Also, remember you dont know how the motor was treated before you got it. It could last years, or merely a single month, just some food for thought. Ask me if you have any more questions and ill do my best to answer them.

- Chris

[Justin51982]

get a S5 Jspec with harness and ecu... The ecu is mounted in the same place on JDM and US spec cars. the transmission and engine will bolt in with little problem. Remember you are gonna need a TII hood or to move the intercooler as they have a stock top mount. The fuel pump should be upgraded as the stock NA fuel pump does not flow as much as a TII unit and with simple bolt ons you would reach the limit of it (stock NA fuel pump). The only other obstacle I can see you having to handle is whether to get a TII rear end or a custom/modified driveshaft to go from the TII transmission to the NA rear end. Also, remember you dont know how the motor was treated before you got it. It could last years, or merely a single month, just some food for thought. Ask me if you have any more questions and ill do my best to answer them.

- Chris

Do you know anyone who would be able to modify the driveshaft?

[Boosted FC]

Mazdatrix sells the D/shafts for the swaps

[Justin51982]

Is the rear able to handle the turbo?

[Justin51982]

I just checked out mazdatrix, good prices, i got the answer to my question, thanks.

[Boosted FC]

Get with Rob over at R@D Automotive if you are serious about doing the swap. He has done a few.

[Justin51982]

I'll probably do the work myself, I have most the tools I would need and what I don't my good friends do. Plus I did the engine in my MG, so this should probably be as simple.

[eraser4g63]

Get with Rob over at R@D Automotive if you are serious about doing the swap. He has done a few.

Rob is the only person around I would and do take my rotary to, my wife calls him the rotary whisperer and he truly is that good.

[sc0rp7]

Thanks for answering the driveshaft question sheldon, I have been pretty busy at work.

The rear can hold some power, I forget where the limit is reached off hand, but if you plan on modifying the car beyond stock turbo (230-250 whp) I would probably do the diff swap to be on the safe/reliable side. Good luck on your swap and if you have any questions I'm sure someone on here or rx7club can answer them as this has been done numerous times before.

- Chris

[YoshiFD3S]

Just as a side note..

IIRC, your N/A S5 is still 4-lug, where-as TII's are all 5-lug, and as previously mentioned...the LSD is different too.

[Boosted FC]

Just as a side note..

IIRC, your N/A S5 is still 4-lug, where-as TII's are all 5-lug, and as previously mentioned...the LSD is different too.

You are so wrong. No S5s came 4lug.

[David88vert]

You are so wrong. No S5s came 4lug.

x2


To the OP, generally you end up cheaper in the long run to just buy a T2, then sell your NA.

[thegovanator]

All S5's are 5 lug disrespectful motherfucker...

[Boosted FC]

All S5's are 5 lug disrespectful motherfucker...

I wouldn't call him a disrespectful motherfucker, just an uneducated one when it comes to FCs. Hope he knows more about his FD than what he knows about FCs........

[gottraction?]

yea easier to sell and just buy a t2! what model s5 do you have?

[Justin51982]

I think I decided to do the swap. Probably will do it myself when I get to it though.

[Boosted FC]

Good luck. Keep us updated on the swap.

[Justin51982]

Good luck. Keep us updated on the swap.

You know I will, I will probably come on here and solict yall for help

I am working on the Datsun now, I am hoping/planning to get to the RX by late spring early summer.

[kain]

the type of engine really doesnt matter as far as what series goes. most of the sensors will swap over.

however, it is a pain in the DICK to get an engine from japan because you know zero about its current condition.

anyways. an s5t2 engine by itseld, will need an s5 t2 afm, s5t2 pressure sensor, s5t2 intake manifolds. the injectors need to be cleaned. the fuel pump will need an upgrade. the s5 turbo is ok, but needs to be upgraded as far as the waste gate goes so you dont get boost creep. the ecu is shit. the omp is shit. the harness is shit. ditch those. get a stand alone ecu, some bigger injectors, and then your ok.

oh, and dont forget to get a throttle cable. those are different as well as the hood.

at this point go ahead and get a new clutch slave, and new ss clutch line. youll be glad that you did.

if the engine comes with a series 5 t2 tranny, get the mazdatrix driveshaft as you well know by now, and then it will bolt right up.

the exhaust is all pretty good and well and the stock catbacks are almost identical between a na and t2. just size and flow.

[Justin51982]

Thanks man!

[kain]

Thanks man!

yah no problem. i go to school near kennesaw, and if you need help with anything, lemme know.

[Boosted FC]

Nice post Pete.

[yomomspimp06]

the S5 turbo is much better than the S4 turbo as far as the wastegate goes. I had mine ported tho once I get my injectors in I'll be able to see how well it works. I heard the Rtek is a decent upgrade if you can't afford full stand alone. it allows timing and fuel control. The AFM is what limits the system so before you go full standalone decide what your goals are. < 300whp mark the Rtek. should be fine. Read of it running cars with much more power but everyone complains AFM...wouldn't know much about it yet. I'm still trying to find one and My car is still under construction.

have you bought a motor yet? I'm on my second T2 motor the first I bought was blown. if you are about to order one I would suggest going to rx7club.com and looking up "Japan2La" the guy sells the best motors 100psi+ compression guarantee. he has one for $1295 plus shipping now. Shipping was $200 I think.

When you get ready to swap call me I wanna help haven't played on an S5 yet

[kain]

the S5 turbo is much better than the S4 turbo as far as the wastegate goes. I had mine ported tho once I get my injectors in I'll be able to see how well it works. I heard the Rtek is a decent upgrade if you can't afford full stand alone. it allows timing and fuel control. The AFM is what limits the system so before you go full standalone decide what your goals are. < 300whp mark the Rtek. should be fine. Read of it running cars with much more power but everyone complains AFM...wouldn't know much about it yet. I'm still trying to find one and My car is still under construction.

no matter how much someone will say something, i will always disslike the rtek.

heres why.

you are using the old stock mazda electronis that are notoriously bad in the rx7. do you want to still keep those? i bet you dont. the connectors are bad, the sensors are getting hold and worn out, and you dont wanna have to try and get used or new mazda sensors. trust me.

the airflow meter on the s5 isnt bad at all. its actually a proper shape. since its before the turbo, its not too much of a restriction.

like i said... dont waste time and money on slapping band aids on the stock electronics that drive the engine. go full stand alone, and you will never look back.

i highly recommend the haltech platinum sport 1000

[thegovanator]

^ That last sentence sounds scary

I can vouch for Japan2La he sells a lot of good shit on rx7club and 99% of his customers are more than satisfied. He also has all the JDM goodies and rarities

[yomomspimp06]

I guess I see where you are coming from with the Rtek...won't stop me from getting one though. do you have a thread for your car KAIN?

[kain]

I guess I see where you are coming from with the Rtek...won't stop me from getting one though. do you have a thread for your car KAIN?

well that sucks. i like i said.... save 500 more much and you'll have a haltech ( e6x atleast ) and you'll be better off, but its your car. i wont try and voice a better option if you dont want it.


no. i dont have a thread on my car. i dont need one nor care to have one.

[Boosted FC]

well that sucks. i like i said.... save 500 more much and you'll have a haltech ( e6x atleast ) and you'll be better off, but its your car. i wont try and voice a better option if you dont want it.


no. i dont have a thread on my car. i dont need one nor care to have one.

Ain't that the damn truth......

[kain]

Ain't that the damn truth......

it is sadly enough.

its scary when people dont even know what condition their stock harness is in. but 20 years of heat and oil and gasoline vapors wreak havoc on those coatings on the wires and often the wires break right at the sensor or connector.

also those connectors. i dare anyone with a 20 year old stock or non modified rx7 and start disconnecting things. youll find out the injector clips will glady break before disconnecting. whoops.

[sc0rp7]

Nice and very informative posts Kain, I agree with most of your logic and whilst I think you are intelligent, I think you should try to be a little less condescending in your posts.

Also:

1.The series of motor is more important for the wiring and electronics that come with it than for the actual keg itself. The S5 TII harness will plug up, whilst if he got an S4 harness he would need to modify the 20 year old brittle harness you referred to.

2.The S5 turbo has an upgraded waste gate when compared to the S4 turbo and normally will not creep with the stock cat-back exhaust.

3.The Rtek is handy in certain low modification situations because it allows you to retain the stock driveability of the car without having to have it precision tuned every single time you change anything.

4. The S5 AFM has a very similar air flow capacity to the S4 AFM, and they both do cause a considerable restriction on modified cars, especially TII's

- Chris

[kain]

Nice and very informative posts Kain, I agree with most of your logic and whilst I think you are intelligent, I think you should try to be a little less condescending in your posts.

Also:

1.The series of motor is more important for the wiring and electronics that come with it than for the actual keg itself. The S5 TII harness will plug up, whilst if he got an S4 harness he would need to modify the 20 year old brittle harness you referred to.

2.The S5 turbo has an upgraded waste gate when compared to the S4 turbo and normally will not creep with the stock cat-back exhaust.

3.The Rtek is handy in certain low modification situations because it allows you to retain the stock driveability of the car without having to have it precision tuned every single time you change anything.

4. The S5 AFM has a very similar air flow capacity to the S4 AFM, and they both do cause a considerable restriction on modified cars, especially TII's

- Chris

i appreciate the comment. i just think its foolhardy when someone says something to not at least step back and look at the scenario a little bit.

the s5 turbo does indeed have a better waste gate system, and a true twin scroll system. however the fact remains that the ports are generally too small to prevent boost creep on any exhaust with no restrictions. not to mention the stock cat backs are restrictive so that will in fact produce negative lifespan results of the engine.

while you are indeed correct about having to generally re tune the car when a part is modified, it plays a not so significant role in how things turn out when you have spent the time and energy is a fully programmable system. anything changed with also affect the rtec. when the ecu does not know whats going on, it wont compensate.

airflow meters can vary in complexity and how they operate. however, a flap type vs plunger type although quite similar in operation where a pathway is kept restricted by a sprung restriction, the design of the restriction makes a huge difference. that being said, i still think the s5 is superior in design to the s4.

im a little confused about the whole s4 vs s5 thing you mentioned. running an s5 engine in an s4 car and visa versa is quite simple. the fact remains that these plastic pieces are brittle after age, and corrosion on the contacts is ugly.

also the fact remains that you are paying 500 dollars for a tiny improvement. depending on what rtek and what series rtek you choose makes a big difference in the tune ability of your engine.

wanna run e85? sorry. rtek wont handle that. wanna use high imp injectors with low imp injectors? sorry. cant do that. want to run twin fuel pumps? nope. sorry. want to run zero split or positive split timing? whoops. nope.

just like with anything you have to think about the future. will the rtek work will a stock engine and a little bit of boost? yah. works well to re tune. however, anyone who modifies cars probably will want something a little bit more. more power, and later on down the road will indeed achieve it. you should anticipate this and prepare for it as something that will be inevitable in the future. you will want more power and most notably will need more fuel and more finite timing control. assume this. its always better to start big and use little than to start small and overuse what you have.

for example, my setup is way overkill. hell... when i went meth injection at 250 whp was making a lot of people scratch their heads. however, the fact remains that i will have this at my disposal in the future. same with fuel. i have huge injectors and a huge fuel pump. are they overkill? yes. will they support me currently at 250 wheel hp? yes. will they support me till about 350 400 or so wheel hp with meth? yep.

all im saying is think about it. your gonna spend 500 bucks anyways, so whats another 500 or 700 more on all new harness and connectors and ecu?

[sc0rp7]

All very well stated, and I think we agree in most aspects here..

I agree if you think that in the end you plan on building an eventual monster of some sort, you should consider going with the best upgrade for future mods as well. This may be a full top of the line stand alone EMS, especially with a new wiring harness and more capabilities, or it may be a simple RTEK 1.7 with 720cc secondaries and no control over AF ratios or timing whatsoever... Do the research and decide on what you believe your goals are, then buy whatever best suits your situation.

to reply to the key points mentioned kain:

1. You are completely correct about the S5 turbo's waste gate. I agree with everything you said whilst clarifying that it will normally start to creep on an exhaust with no restriction i.e. no catalytic converter, etc. and somewhere over 2 1/4" piping...

2. I was also referring to the lesser RTEK's that dont allow adjustments and will compensate because of the AFM reading a different amount of air taken in.

3. I agree with your logic and reasoning on the S5 AFM being a superior design (shape), but the fact remains that on the RX-7, S4 AFM is larger and therefore has very similar air flow characteristics. All I was saying here is that the S4 AFM isnt really worse than the S5, but that a restriction in air flow is a restriction in air flow, regardless of shape and they both cause very similar restriction.

4. Interchanging the S4 and S5 engines can be done, but if you have the correct series harness for your vehicle, aka: the correct series engine, then the ecu harness plugs directly into the factory dash harness of your vehicle rather than having to modify it as S4 and S5 dash harnesses are not the same and this is the connection where you connect to the ignition coils and get your factory power and ground from, etc. You get the idea, I was merely stating it was easier with the same series engine.

5. The 500 dollar thing, that goes back to my original statement of depending on application as well as depending on the budget you are working with.

6. I agree with everything you stated a RTEK cant do except for the twin fuel pump thing, you can run as many as you want. Wire a relay, wire a hobbs switch if you want the second one boost activated, whatever you require. Everything else goes back to choosing whats right for your application.

Your statement about people normally wanting more and more from a vehicle is very true. What most people in that situation lack is the ability to know when they have enough, before they start having to drop multiple thousands on that motor thats pinned, because they blew it apart, or that late S5 rear housing thats got a stronger casting, etc. Going bigger and getting more is not always better, because of cost most notibly.

I like your example, as you have a goal of where you are headed... Good luck and if it fits your overall goal and you know what you are doing then other peoples opinions dont really matter.

- Chris

[yomomspimp06]

good info here...usually when I don't know much about what I'm talking about I shut up.
Kain, your set-up isn't overkill. It leaves room for improvement . I'm not searching for big numbers. I just want a car I can have fun with. 300whp is where I want to top out with this car and it won't happen till probably jan 2011. If I can do it without spending a lot of money then that is a plus in my book.
Notice I didn't say "cheap". I've learned that cheap gets you headaches and lots of debt in the long run. I ported my s4 turbo so I won't have to worry much about creep. My harness is actually in great condition for it's age the only problem being my wire from my O2 sensor. Once I get my Rtek thought I'll be able to see how everything goes and if there is a problem I'll say "damnit, Kain warned me about this" Can't cry over spilled milk though. Thanks for the info guys

[kain]

good info here...usually when I don't know much about what I'm talking about I shut up.
Kain, your set-up isn't overkill. It leaves room for improvement . I'm not searching for big numbers. I just want a car I can have fun with. 300whp is where I want to top out with this car and it won't happen till probably jan 2011. If I can do it without spending a lot of money then that is a plus in my book.
Notice I didn't say "cheap". I've learned that cheap gets you headaches and lots of debt in the long run. I ported my s4 turbo so I won't have to worry much about creep. My harness is actually in great condition for it's age the only problem being my wire from my O2 sensor. Once I get my Rtek thought I'll be able to see how everything goes and if there is a problem I'll say "damnit, Kain warned me about this" Can't cry over spilled milk though. Thanks for the info guys

ha ha ha. i totally know what you mean man. i totally know

All very well stated, and I think we agree in most aspects here..

I agree if you think that in the end you plan on building an eventual monster of some sort, you should consider going with the best upgrade for future mods as well. This may be a full top of the line stand alone EMS, especially with a new wiring harness and more capabilities, or it may be a simple RTEK 1.7 with 720cc secondaries and no control over AF ratios or timing whatsoever... Do the research and decide on what you believe your goals are, then buy whatever best suits your situation.

to reply to the key points mentioned kain:

1. You are completely correct about the S5 turbo's waste gate. I agree with everything you said whilst clarifying that it will normally start to creep on an exhaust with no restriction i.e. no catalytic converter, etc. and somewhere over 2 1/4" piping...

2. I was also referring to the lesser RTEK's that dont allow adjustments and will compensate because of the AFM reading a different amount of air taken in.

3. I agree with your logic and reasoning on the S5 AFM being a superior design (shape), but the fact remains that on the RX-7, S4 AFM is larger and therefore has very similar air flow characteristics. All I was saying here is that the S4 AFM isnt really worse than the S5, but that a restriction in air flow is a restriction in air flow, regardless of shape and they both cause very similar restriction.

4. Interchanging the S4 and S5 engines can be done, but if you have the correct series harness for your vehicle, aka: the correct series engine, then the ecu harness plugs directly into the factory dash harness of your vehicle rather than having to modify it as S4 and S5 dash harnesses are not the same and this is the connection where you connect to the ignition coils and get your factory power and ground from, etc. You get the idea, I was merely stating it was easier with the same series engine.

5. The 500 dollar thing, that goes back to my original statement of depending on application as well as depending on the budget you are working with.

6. I agree with everything you stated a RTEK cant do except for the twin fuel pump thing, you can run as many as you want. Wire a relay, wire a hobbs switch if you want the second one boost activated, whatever you require. Everything else goes back to choosing whats right for your application.

Your statement about people normally wanting more and more from a vehicle is very true. What most people in that situation lack is the ability to know when they have enough, before they start having to drop multiple thousands on that motor thats pinned, because they blew it apart, or that late S5 rear housing thats got a stronger casting, etc. Going bigger and getting more is not always better, because of cost most notibly.

I like your example, as you have a goal of where you are headed... Good luck and if it fits your overall goal and you know what you are doing then other peoples opinions dont really matter.

- Chris

eh. i guess so. lol.

ITS CHRISMAS!! i wonder how my engine will like a lil eggnog in the gas tank.

[sc0rp7]

hahaha... that'll work... happy holidays to everyone

[Boosted FC]

Hmmm....

[kain]

Hmmm....

sheldon... what are you hmmming about?