want to FI a 81 rx7 with a 87 13b
want to FI a 81 rx7 with a 87 13b
I have an 81 rx7, and I want to fuel inject it for fuel economy but I don't no much about that whole system.I already have the 13b with the whole intake, injection wiring setup. Has anybody done this or now a site I can go to.I was a carb guy,but have you seen the gas prices.
FB+FC=F-ME
Joined: Jul 2004
Posts: 3,353
Likes: 5
From: Rohnert Park CA
Realistically,economy shouldnt be the reason to go EFI.The bigger 13B is going to almost negate any advantage the EFI gives you.Youll gain only about 4-5 MPG over a carbed 12A,best case scenario.
What you will gain which is significant,is easy startup,no choke tickling,a means to diagnose engine problems(check engine codes) and easier driving in cold,humid or high altitude situations.
The S4 EFI swap isnt too hard,but it does require a moderate knowledge of EFI function and wiring.Youll need to adress fuel delivery,engine mounting and ECU electrical wiring.Do a search,theres lots of coverage.The non-turbo 2nd gen engine swap is almost identical to doing a turbo 2nd gen swap,so most changeover info is relevant to both.
If you dont understand EFI,start reading up.I recommend getting an FC factory service manual for the year of your engine.Its packed with info about the EFI components, plus there are lots of flow charts and wiring diagrams.Best 80 or so bucks youll ever spend,and I consider it a "must" before doing an FC engine swap.
What you will gain which is significant,is easy startup,no choke tickling,a means to diagnose engine problems(check engine codes) and easier driving in cold,humid or high altitude situations.
The S4 EFI swap isnt too hard,but it does require a moderate knowledge of EFI function and wiring.Youll need to adress fuel delivery,engine mounting and ECU electrical wiring.Do a search,theres lots of coverage.The non-turbo 2nd gen engine swap is almost identical to doing a turbo 2nd gen swap,so most changeover info is relevant to both.
If you dont understand EFI,start reading up.I recommend getting an FC factory service manual for the year of your engine.Its packed with info about the EFI components, plus there are lots of flow charts and wiring diagrams.Best 80 or so bucks youll ever spend,and I consider it a "must" before doing an FC engine swap.
hey well all that is great advice but my 12a blew and the housing are beyond repair.So about my 13b should I take the time and go fuel injection or carburator and if so do you know were I can find a six port intake for a reasonable price.
FB+FC=F-ME
Joined: Jul 2004
Posts: 3,353
Likes: 5
From: Rohnert Park CA
Nothing wrong with going 13B,Im just saying you wont see much increase in the way of fuel consumption.
That said,you will get a nice torquey engine with good lowend response and still having some topend punch.The stock EFI is the way to go if you want a bolt in setup that doesnt require tuning and Mazda knew how to max out the lowend power of the N/A 13B with their intake designs.
If you have all the parts already to install the EFI,I say go for it.The big right side harness is plug and play between the engine and ECU.There is no splicing or cutting required on it.The left side harness will have to be custom laid to power the ECU,CAS, fuel pump and coils.Its not that hard to do if you have an FSM and knowledge of EFI/wiring.An FC main relay and underhood fuse box will greatly simplify things and will also completely eliminate the need to cut/splice into the 1st gens electrical harness.
Im not sure of any sites or pages that just lay it all out,but believe me its not as hard as some people think.Once you study everything and know what your looking at,its quite simple.Thats where the FSM is a lifesaver.It has the easiest wiring charts Ive ever seen.Following the neccesary ECU pins is a breeze when you know exactly what components they go to and what color wires do what.
The hard part is getting all the extraneous stuff out of the way so you can see what your shooting for.
If you have no knowledge of EFI,this will prove more difficult,but anyone can learn if they become familiar enough with their work.I had ZERO experience with TII engines and I did it in 3 months of planning and a week of work.I did already have experience working with EFI,but it was the first full engine swap I did myself that involved going from carb to EFI.Been running strong for 4 years.....
Here is an example from the S5(89-91) FSM.Its mostly the same for a S4 swap since you are only wiring a few key components,not the whole engine.This single chart is the Holy Grail of doing an FC EFI swap and its really all you need to pull it off,page F1-8http://www.teamfc3s.org/main/factory..._non_turbo.pdf
That said,you will get a nice torquey engine with good lowend response and still having some topend punch.The stock EFI is the way to go if you want a bolt in setup that doesnt require tuning and Mazda knew how to max out the lowend power of the N/A 13B with their intake designs.
If you have all the parts already to install the EFI,I say go for it.The big right side harness is plug and play between the engine and ECU.There is no splicing or cutting required on it.The left side harness will have to be custom laid to power the ECU,CAS, fuel pump and coils.Its not that hard to do if you have an FSM and knowledge of EFI/wiring.An FC main relay and underhood fuse box will greatly simplify things and will also completely eliminate the need to cut/splice into the 1st gens electrical harness.
Im not sure of any sites or pages that just lay it all out,but believe me its not as hard as some people think.Once you study everything and know what your looking at,its quite simple.Thats where the FSM is a lifesaver.It has the easiest wiring charts Ive ever seen.Following the neccesary ECU pins is a breeze when you know exactly what components they go to and what color wires do what.
The hard part is getting all the extraneous stuff out of the way so you can see what your shooting for.
If you have no knowledge of EFI,this will prove more difficult,but anyone can learn if they become familiar enough with their work.I had ZERO experience with TII engines and I did it in 3 months of planning and a week of work.I did already have experience working with EFI,but it was the first full engine swap I did myself that involved going from carb to EFI.Been running strong for 4 years.....
Here is an example from the S5(89-91) FSM.Its mostly the same for a S4 swap since you are only wiring a few key components,not the whole engine.This single chart is the Holy Grail of doing an FC EFI swap and its really all you need to pull it off,page F1-8http://www.teamfc3s.org/main/factory..._non_turbo.pdf
Last edited by steve84GS TII; Aug 30, 2005 at 08:37 PM.
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Joined: Aug 2005
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From: PR/Maine/Ga/SC
you'll need a 13 b crossmember and maybe a driveshaft i've done two swaps 12 a's into se 's and swaped crossmembers and made new driveshafts another thing to think about if you use the secnd gen tranny you will need to modify the mount.good luck 
82, 83, 88, 82 RX-7again!
Joined: Mar 2006
Posts: 372
Likes: 1
From: Upstate New York
Originally Posted by steve84GS TII
Nothing wrong with going 13B,Im just saying you wont see much increase in the way of fuel consumption.
Scott
Originally Posted by aspirao
you'll need a 13 b crossmember and maybe a driveshaft i've done two swaps 12 a's into se 's and swaped crossmembers and made new driveshafts another thing to think about if you use the secnd gen tranny you will need to modify the mount.good luck
You do not need a 13B crossmember. You either modify the frount Mound or buy Mazda Trix's and use the Se front cover instead of the 2nd gen.
What do you need to modify the driveshaft for?
If you use the 2nd gen trans you swap out the tailshafts.
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