S5 intake swap complete.
 

Thanks to many of you here on the forum, I finally completed my project. About a year ago, I put an S5 intake on my SE. The swap was a snap, but I couldn't get the car running good for quite some time. Prior to the project, the car sat for 15 years in my garage, so I had a lot of issues. The last dilemma I had was that the car ran way too rich and stumbled at idle and hiccupped through the RPM range. It ran so rich that I would have to drian the oil because there was so much fuel in it. A special thanks to Kent (GSL-SE ADDICT) and Mark Stauber for helping me in much troubleshooting. The main culprit ended up being a loose/corroded ECU fusible link----I always seem to learn the hard way :-)

I'm still not totally out of the water yet, as I think I have a bad air/intake temp sensor and Oxy sensor. But I drove the car yesterday, and I was so happy to finally have my SE back---- stronger than ever. The reponse was smooth and snappy, and she pulled real hard all the way to 8K. Conclusion: the swap was worth it. The aux ports seem to be working well off of exhaust backpressure, and I can feel the VDI open up at 5,200. The biggest difference I notice most of all is how she pulls from 5K to 8K. I guess I'll have to contribute this to the VDI.

Once again, I want to thank everyone who contributed to my learning, especially Kent. As busy as he was, he always took the time to help me. We have some really special moderators on this forum (Yes, I mean you too RX-7 doctor) :-)

Mike

Good deal, Mike. Happy to help. Glad that you got it pretty well sorted out.

You should post some pics and maybe some details on how you did the VDI, aux ports, what fuel rail used, etc. I think that it may help people who what to try this in the future.

Kent

Nice to see some one is having an easy time with that swap…:scratch:

I did that swap a few months ago and I am having nothing but issues. I got rid of all of the vacuum leaks; while I was there I took out the rats nest and cleaned up the engine bay a lot. Now it will idle fine at 1500 rpm (also revs very slowly) but anything lower then that and it will barely stay running. It also has a huge hesitation when I gun the gas from a stop and it feels like it has no power at all.

Any advice on this and I will greatly appreciate it. I am about to give up and just go carbed :lol:

I am willing to help, but it wil require more info. What exactly did you remove from the rats nest? Because you removed some of the rats nest at the same time you did the swap, it is more difficult to trace the source of the problem. How did your car run before the swap? If it ran fine before the swap, then your issue has to do with whatever you did in the process of the swap. Just by simply swapping the intakes (with everything else the same) the car should start, idle, and accelerate like before.

Are you sure you have no vac leaks? You might want to get a propane torch/bottle and go around the engine to check for leaks. A common leak is on the top of the LIM.

If that checks well, go back to the basics:

Make sure you got good spark at all 4 plugs
Make sure vac lines are correct and not missing/leaking
Check all electrical connectors


Let me know what you find,

Mike

hey congrats on the swap i did the S4 swap to mine b4 i put a 88 na in my SE and then i put the s5 swap pulled super hard all the time faster than some of the S5's around here.

horrorbeaver did you trim the bolt hole on the its kinda like a nipple for the inspection plate for the tranny. i ll get a pic in a minute. if you didnt trim it then the upper wont mate properly with the lower.

Quick noob question, why would you do this? Power increase? If so, how much and is it worth the time and trouble?

pretty big power increase, worth it? probably better just to do a whole s5 swap. i think doing an S5 swap would take less time than using the S5 intake on the SE. I have most of the parts, but have decided not to do it.

I think I'd rather just do a racing beat 48 IDA intake...

Curious because NASA only charges two points for an intake swap on a RX-7, but an engine swap, you have to dyno your car and will probably getted bumped up to the next class.

A detailed write up and all of the parts needed is much appreciated.

PM me.

I did this swap mostly out of curiosity and also because I wanted to get every bit of extra HP that I could without spending a lot of money. There were a few guys on the forum that did the S4 swap and were pleased with it. I figured if I was going to do an intake swap, it definitely was going to be an S5 (1989-91). I wanted to take advantage of the VDI. I know that my SE motor probably has a different torque curve than the S5, so I knew that swapping intakes was not going to give me the full horsepower advantage like an S5 engine. But it still is a noticeable difference, especially after 5,000 RPM. As far as gains, let's do the math (I know I'm going to open up a can of worms here):

Stock SE motor = 136 HP
Racing Beat Racing Exhaust = at least 20% hp which = approximately 25 hp. But let's go with 20 to be safe.
Electric fan = frees up approx 10 hp (do a search, it's been documented). But to be a bit conservative, let's go with 5 HP.
S5 Intake----Although the S5 motor has 25 more HP than the SE, I don't expect that I have gained 25 more HP by doing the swap. But let's say that there was a 15 hp gain, which I believe is reasonable.
2GCDFIS = I'm not sure on this. It's definitely is a stronger spark. I would think that it would have to add a few ponies, but I won't count it.
Aux Ports with Pineapple Racing Sleeves = 6-8 hp (that's what they claim, I believe). Let's go with 5 HP.

Now lets add all this up to see how much HP a NA S3 13B can achieve:

136 + 20 + 5 + 15 + 5 = 181 HP.

Now subtract about 45 HP for an engine that has 121,000 miles on it, and guess what? I know have 136 HP again like when it was new--Yippie!

PM'd you.

Some interesting math and can of worms opened...

Yeah I don't know about those pineapple sleeves adding 5hp...

Ok, if it makes you happy, subtract 5 = 176 hp. But like I said, my engine has mileage on it, so I don't think my RWHP is anywhere near that.

Srry to revive the old thread but I need to know how you did this I'm about to do it to my car and would like to know what I'm in for before I tear it apart. I plan on swapping the port actuators over what my main concern is all the fuel injector holes

I am willing to help any way I can. It's been a while since I did the swap, so I'm going off memory. I regret not documenting what I did and for not taking pics. But as far as the fuel injector holes, (I'm guessing you're talking about the secondary injectors), I plugged mine. I am still only using the two stock SE injectors in the primary rail. There is no need whatsoever to use 4 injectors on these engines with no porting and staying N/A. Let me know what other questions you have.

Mike

Sweet so I can leave my fuel system alone and just plug any extras also do you think that there's enough pressure from the aux ports to open the vdi? Thanks I'm goin to get this done sooner than I thought

Trust me, you do not want the VDI opening at 3,500-3,800 rpm's like the Aux ports. What I did was I bought a small pump and an rpm switch from summit racing that opens the VDI at 5,200 RPM's. Not the best set-up, but it works.

I am looking for information on doing an S4 intake swap onto my GSL-SE engine. I have been running the SE 13B in my race car but at the last race we experienced overheating so it is time to get another engine ready for the 24hr coming up in August. I have a complete 86 S4 engine and I had planned on building that engine but once I got it apart it needs more time and money invested than I want to do before the next race so it looks like new seals in the SE engine is the best route. Since I will have everything apart and I already have the pieces I am thinking about installing the S4 intake and throttle body on the SE engine before I put it back in the car, it fits but any experience with this swap would be helpful. It helps that it is a race car and almost everything has already been removed so I won’t have to worry about vacuum hoses and rats nests, I would really like to get some more HP at the top end, the back straight at VIR is really long…

Ideally I would really like to have the 4 injector and coil pack electronics of the S4 engine, and especially the larger air flow meter. But for the ease and cost if I can get some noticeable gain just be swapping the intake I think I will take it.


Attachment 623196

Attachment 623197

The S4 water pump housing will also fit. It does require a plug in one of the holes. Use the S4 water pump and pulley. I put an S4 water pump housing on my 12A. I really like the weight savings.

s4 is a direct fit onto a s3 block. Only thing to complicate things is you will have to wad up some aluminum foil and stuff it into the EGR slot on the intermediate iron and fill it full of RTV as it wont line up and creates an exhaust leak. You will have to make new coolant and vacuum lines. I used the s3 rats nest. Although I eliminated all unwanted rats nest components. I just have the ignition advance solenoid and a few vac lines. I plugged the secondary injectors with NPT threaded plugs found in the coolant section at the parts store. I swapped the s3 TPS, IAT, and BAC onto the s4 intake. The Dynamic chamber takes a bit of grinding to get the s3 BAC to bolt up. Youll see what I mean when you test fit. Otherwise you use the same gasket and it bolts up just like factory. You have to swap TPS brackets or modify the s3 to fit the s4 TB or it wont have proper plunger clearance.

I have pictures in my build thread. Search something along the lines of "Back in the 1st gen game again" and my thread should pop up.

Wow, this thread just gave me flashbacks.

Looks like everything will work out for me, since it is a race car I don’t have the BAC so that is not an issue. Since I have the engine apart I will be doing some porting and I will probably put the center iron in the mill and cut the primary ports to match the much larger S4 intake, while I am in there I will block off the EGR port.

How about air flow meters? The S4 meter is a good bit larger than the S3, but everything I have been able to find says that it is not really possible to swap the air flow meters.

I really hate to necro this thread from so long ago, but do you happen to have a parts list for an S5 intake onto a GSL-SE engine? I am looking to do this as I have access to an S5 engine but don't know what is all involved.

Hey Spetz,
For starters, you will need the 3 manifolds: upper, middle, (plenum), and lower. You will also need the S4 TB. If I remember correctly I went with the S4 TB, because it used a single throttle position sensor, (With the S4 TB, you can also still use the mechanical oil injection). The S5 is set up with a dual TPS and does not use the mechanical oil injection from the linkage rod from the throttle body. I now have the S5 TB only because I have an aftermarket haltech and I'm utilizing both TPS's. I also premix the gas with 2 cycle oil, so I no longer need the oil metering system.

I can't remember which fuel rail I used. I believe I used the stock S3. To get the VDI to actually work, I used a small air pump activated by an RPM switch. I believe I used a power seat air pump from a Ford Thunderbird.....can't remember. If you read up on some of the threads where this has been done before, someone mentions using seat lumbar pumps and says what car they were taken from.

Aside from this, you will use the stock AFM and stock injectors. You will plug the secondary injector ports. You will need the S4 or S5 TB intake adapter and hose assembly. You can figure out how to adapt the S5 intake hose assembly into your S3 air filter air flow meter housing, or go from the S5 air funnel intake to a cone filter with the AFM inline somewhere. I currently do not have the air flow meter or distributor or any of that stuff as I am running full after market engine management. So I can't even take pictures for you.

Good luck,
Mike

Since this thread has already been revived, can I ask for more details on how you drove S5 aux ports using exhaust backpressure? My understanding is that unlike S3 and S4 aux ports, S5 ports need the air pump to pull the ports open. I have a full S5 swap on my FB but would love to remove the air pump since it's otherwise worthless

I am currently using the stock air pump to feed both the VDI and aux ports. My Haltech controls the triggered rpm for the VDI. My rpm switch controls the trigger for the aux ports. I strongly recommend using your factory air pump. There's no better way to work the vdi and aux ports The S3 aux ports will bolt up to the S5 LIM no problem. There's little modifucatiom. Then you can use exhaust BP for the aux, if you want to go that route..But you still need a pump for the VDI, and the stock air pump is best IMO.

In the future, I am going to start pumping fresh air into the exhaust from the air pump to dilute the strong exhaust fumes. I currently have no emissions components.

BTW..... The drag of an air pump is probably immeasureable.

The drag of a properly working air pump is probably immeasurable.

The drag of a seized air pump is unmeasurable .. as in it will not budge no matter how hard I try.

https://cimg8.ibsrv.net/gimg/www.rx7...360d9697ac.jpg


I would gladly trade off the extra weight and parasitic drag of an air pump in exchange for properly working VDI and auxiliary ports.

You can disassemble the Air Pump and you'll find there are 3 metal vanes and one of yours has become dislodged and jammed somewhere in the scroll mechanism. The basic operation is that an offset shaft rotates around a fixed plenum which results in compression of air against these 3 fin vanes inside. They're remarkably similar in size and shape to Apex Seals, and you may find that the one which became dislodged is located in the rubber tube leading to the Air Control Valve. Imagine my disbelief when I found what appeared to be an Apex Seal in there,...

I removed the one bad vane, and rebuilt and regreased the remaining mechanism, and it's passed emissions testing on multiple occasions! Apparently, you don't need a lot of airflow to work properly, as it's only operating at 66% efficiency for air movement. Regardless - don't throw away your Air Pump!