87 RX-7

iTrader: (1)

Hello again,

I'm preparing to swap an S5 intake on my S4. I was wondering what modifications would be needed to swap the S5 UIM and LIM into my S4. I do not run emissions! Can I keep my current injectors?

I was also wondering if there a write-up out there for this? I looked and it seems that the links posted around the forums do not work anymore. While I'm in there, I was planning on doing the throttle body mod.

Thanks for your help!

MrGoodnight

iTrader: (1)

http://www.rotaryresurrection.com/ro...ries5swap.html

KompressorLOgic

iTrader: (6)

yes u can use your old injectors, you may need the s5 fuel rails however... I think they are different, buts it been years since ive messed with na stuff to that extent....

you prolly want to either reuse your throttle body and tps, or if u use the s5 tb, use the s5 tps but only wire the narrow band sensor up.
also you will need some method to control the 5-6 ports, and vdi, electronic actuators, electric airpump+ rpm switches, or something...
which need to be working to realize the benefits of the s5 manifolds

87 RX-7

iTrader: (1)

Thats a good start. Thank you!

Yeah I'm concerned on how to control the VDI and everything else associated with swapping the S5 manifold on. At least I'm getting an idea of what to keep and what to replace.

I thought I read somewhere that this swap may be less of a hassle if an S5 LIM was swapped in along with the S5 UIM. Is this true?

Molotovman

iTrader: (49)

There is a write up somewhere, it's old, but the last time. I checked all the pics still worked etc. have you checked the FAQ?

87 RX-7

iTrader: (1)

Yes I did but the link would not work for me. :/

Molotovman

iTrader: (49)

Here it is, but there are no pics.
https://web.archive.org/web/20120211...is/intake.html

MrGoodnight

iTrader: (1)

https://www.rx7club.com/showthread.p...824&styleid=17


Heres an excellent write up on how to use rpm switches for 5/6th ports and the VDI.

87 RX-7

iTrader: (1)

There is a lot of information there! Thank you! The descriptions are really good. I just hope that I can figure everything out without pictures.

One thing I noticed on the "tuning" section of that page is that they mention that the 5-6 ports and adjusting them with the ACV, which I no longer have. How would I go about tuning the 5-6 ports?

RXSpeed16

iTrader: (41)

Check out post #20 in this thread. I have some pics of what needs to be modified.

https://www.rx7club.com/2nd-generati.../#post11476722

1. Grind those ^.
2. Block off EGR.
3. You can use S4 injectors but need the S5 NA rails. S4 rails don't fit.
4. Deal with rear LIM stud. I removed it and used RTV. Worked fine.
5. RPM switch and solenoid to control 6-ports and another for VDI. Sources can be exhaust pressure, stock emissions air pump, lumbar air pump, nipple off ACV blockoff plate, etc.
6. S4 BAC connector hits the S5 fuel rails, so it doesn't quite fit. And the plug is on the wrong side of the engine.
7. Cobble together the coolant, BAC, OMP vac source lines.
8. Bend S4 omp rod into shape that works. It's trial and error.

misterstyx69

iTrader: (142)

/\/\..RxSpeed makes a good point.Many guys have found out that little glitch.
There is a bump in the center iron that will give you a NICE vacuum leak if you do not grind that part down.
It may "look like" the manifold sits nice and flush but you will find out that it Isn't when you try to get it to run steady.Result..Vacuum leak.