s4 to s5/A conversion
#1
Litreacola
![](https://www.rx7club.com/images/misc/05_year_icon.png)
Thread Starter
Join Date: Jul 2004
Location: Corpus Christi, Texas
Posts: 173
Likes: 0
Received 0 Likes
on
0 Posts
s4 to s5/A conversion
i asked a local mechanic and he said itll bolt right up but ive also heard that the sensors and such are in different places and s4 to s5 wont work unless you have all the s5 sensors and all that other stuff. I know theres athread on this but i couldnt find it. can somone help me?
#3
Litreacola
![](https://www.rx7club.com/images/misc/05_year_icon.png)
Thread Starter
Join Date: Jul 2004
Location: Corpus Christi, Texas
Posts: 173
Likes: 0
Received 0 Likes
on
0 Posts
so
theres a longblock for an s5 i know somone is selling, and the na in my 87 doesnt run. should i buy the longblock and use it or how would it work?
#4
coolant leak that kills
![](https://www.rx7club.com/images/misc/05_year_icon.png)
iTrader: (1)
Join Date: Sep 2004
Location: colorado
Posts: 411
Likes: 0
Received 0 Likes
on
0 Posts
it really depends on what you plan on using from which series. if you want to retain the s5 manifolds (and the VDI), then the s5 ecu has to go in, as well. search for swap (kinda generic, i know, but it'll help) and wade through threads until you find your info. "s4" and "s5" are too short to be search terms, so that's kind of a problem. it takes time. there was a recent one in which i posted a bunch of links that i'd found in various places about it.
#7
Passing life by
![](https://www.rx7club.com/images/misc/05_year_icon.png)
The easy way to make that work is to take the short block of it. Meaning strip the motor apart to just the housings and irons. Now do the same on your S4. Swap all of the long block parts IE the parts you pulled off the S4 and bolt them up to the S5. That should get it up and running without having to worry about all the electronics. This still leaves the OMP a big issue. You can swap the front cover plates and the OMP from your S4. Or you can premix the car. Swap the front cover plate and the OMP from your S4.
Parts I am referring to swapping over- Fuel injectors, LIM, UIM, dynamic chamber, TB, TPS, front cover plate, OMP, I suggest a rats nest removal at this point.
That’s all I can think of off the top of my head.
Parts I am referring to swapping over- Fuel injectors, LIM, UIM, dynamic chamber, TB, TPS, front cover plate, OMP, I suggest a rats nest removal at this point.
That’s all I can think of off the top of my head.
Last edited by iceblue; 07-14-05 at 11:46 PM.
Trending Topics
#9
Ahh.. If it were only this simple.
Take it from someone that has already done this.. If you use the S4 UIM on that S5 Block, you are going to run into trouble because even though the Intake gaskets (LIM to Block) are the same, the intermediate housings are different (S4 to S5). What ends up happenening is there is about a 1/4 inch hole that extends down past the center intake manifold, where exhaust gets out. What I did, (and I got this from Kevin Landers) was JB weld the gap shut. Not perfect, but it did the job.
So having said that, here is how I did my swap:
Used all the S4 uppers, including the existing vac rack and wiring harness, upper intake Manifold (UIM), Lower Intake Manifold (LIM), Removed the front cover and replaced with the S4 cover (then promptly forgot the oil control ring..DOH!), and retained the S4 ECU.
Reason I did this? Emissions, pure and simple... But it works, and the car passes beautifully.
If you have no emissions, may I suggest you take another route.
Take it from someone that has already done this.. If you use the S4 UIM on that S5 Block, you are going to run into trouble because even though the Intake gaskets (LIM to Block) are the same, the intermediate housings are different (S4 to S5). What ends up happenening is there is about a 1/4 inch hole that extends down past the center intake manifold, where exhaust gets out. What I did, (and I got this from Kevin Landers) was JB weld the gap shut. Not perfect, but it did the job.
So having said that, here is how I did my swap:
Used all the S4 uppers, including the existing vac rack and wiring harness, upper intake Manifold (UIM), Lower Intake Manifold (LIM), Removed the front cover and replaced with the S4 cover (then promptly forgot the oil control ring..DOH!), and retained the S4 ECU.
Reason I did this? Emissions, pure and simple... But it works, and the car passes beautifully.
If you have no emissions, may I suggest you take another route.
#10
Litreacola
![](https://www.rx7club.com/images/misc/05_year_icon.png)
Thread Starter
Join Date: Jul 2004
Location: Corpus Christi, Texas
Posts: 173
Likes: 0
Received 0 Likes
on
0 Posts
yea, there no emissions here yet
and i dont htink my city really cares and by the time it does get here if they decide to start testing is wait a couple of yrs and it will be 20 yrs old and the law of 20 yrs old or older will make it exempt
#11
Passing life by
![](https://www.rx7club.com/images/misc/05_year_icon.png)
Originally Posted by J-Rat
Ahh.. If it were only this simple.
Take it from someone that has already done this.. If you use the S4 UIM on that S5 Block, you are going to run into trouble because even though the Intake gaskets (LIM to Block) are the same, the intermediate housings are different (S4 to S5). What ends up happenening is there is about a 1/4 inch hole that extends down past the center intake manifold, where exhaust gets out. What I did, (and I got this from Kevin Landers) was JB weld the gap shut. Not perfect, but it did the job.
So having said that, here is how I did my swap:
Used all the S4 uppers, including the existing vac rack and wiring harness, upper intake Manifold (UIM), Lower Intake Manifold (LIM), Removed the front cover and replaced with the S4 cover (then promptly forgot the oil control ring..DOH!), and retained the S4 ECU.
Reason I did this? Emissions, pure and simple... But it works, and the car passes beautifully.
If you have no emissions, may I suggest you take another route.
Take it from someone that has already done this.. If you use the S4 UIM on that S5 Block, you are going to run into trouble because even though the Intake gaskets (LIM to Block) are the same, the intermediate housings are different (S4 to S5). What ends up happenening is there is about a 1/4 inch hole that extends down past the center intake manifold, where exhaust gets out. What I did, (and I got this from Kevin Landers) was JB weld the gap shut. Not perfect, but it did the job.
So having said that, here is how I did my swap:
Used all the S4 uppers, including the existing vac rack and wiring harness, upper intake Manifold (UIM), Lower Intake Manifold (LIM), Removed the front cover and replaced with the S4 cover (then promptly forgot the oil control ring..DOH!), and retained the S4 ECU.
Reason I did this? Emissions, pure and simple... But it works, and the car passes beautifully.
If you have no emissions, may I suggest you take another route.
#12
Well, then you can bare block it, but you still need the ECU. And if you decide on the S5 uppers, you will have to devise a way to control the 6-ports/VDI. So my suggestion would be to bare block it, but retain the S4 uppers. OR, you can use the S5 LIM and UIM, but use the S4 Throttle body (and dynamic chamber), thats been done before.
*edit* Putting an S4 TB on the S5 UIM will require some grinding.. Thought I would put that out there now. And I havent done it that way, so I am not ENTIRELY sure what you have to grind. O
*edit* Putting an S4 TB on the S5 UIM will require some grinding.. Thought I would put that out there now. And I havent done it that way, so I am not ENTIRELY sure what you have to grind. O
Last edited by J-Rat; 07-15-05 at 12:03 AM.
#13
with some effort and studying both S4 and S5 FSM's and wiring diagrams, u can use complete S5 longblock with S5 engine (emission) harness and ECU and splice it into your in-car S4 harness
its acutally not that hard as S5 ECU does have lots of additional stuff build into ECU compared to S4
if u will get 3 specific connectors (probably from junkyard S5), you can splice them into your S4 incar harness (keeping your S4 connectors uncut) and still have chance to convert it all back to S4 stuff anytime later if you will need to
its acutally not that hard as S5 ECU does have lots of additional stuff build into ECU compared to S4
if u will get 3 specific connectors (probably from junkyard S5), you can splice them into your S4 incar harness (keeping your S4 connectors uncut) and still have chance to convert it all back to S4 stuff anytime later if you will need to