Is it possible to put the 89-91 intake manifold on a 86-88 engine? Is there any advantages if it is possible?

Also Why cant I turn my timing CAS ???

-Daryl

 

Yes, yes.

Did you loosen the 10mm first?

 

yeah I sure did, every time I change something under the hood wether it be plugs, oil, air filter configuration etc...I always loosen the 10mm bolt and try and turn my CAS EVERY TIME!!! but it wont budge...Do I need a special tool to turn it with?

-Daryl

 

then change the airflow meter and ecu

 

go herehttp://homepage.mac.com/carldavis/intake/intro.html

 

Damn Along with the throttle body mod and a 89 intake you can give a 86-88 rx7 20 more HP! Alone the cleaning and polishing of everything your gonna notice this mod!

Sounds like fun to me.

-Daryl

 

I've heard that you actually lose HP after conversion to a Series V Intake swap but you gain It back at 7000 rpm. Again, this Is what I've heard.

 

The swap is useless unless you actuate the VDI as well.

Either get an RPM Switch and an electric airpump; or keep the S4 on it.

 

That would be because there's no way for the S4 ECU to activate the VDI. In the above example the VDI has been locked in the high-rpm position, which would cause some loss of low- to mid-range power.

 

Oops. I forgot to mention even If the VDI Is hooked up via RPM Switch and an old EGR Valve to Initiate the VDI actuator It still results In a lose of HP but gained back after 7000 rpm! In fact, a friend had said he was dissapointed with his dyno results as such a few other FC owners how did this conversion aswell.

I too was going to undertake this mod myself prior to hearing first hand of his experience. I went all out, getting the Upper/Lower Intake, Dynamic Chamber, 6 Port Actuators and all the freakin new gaskets from the dealership. I even bought an RPM Switch from Summit and cleaned up the Intake to pristine condition! Now, It sits In my garage collecting dust. I have been on this website: http://homepage.mac.com/carldavis/intake/intro.html
but don't know, for example, how well his setup Is working for him.

 

i have it on my rx-7 right now but i am thinking of taking it off because all of you say you lose hp and should i put my old intake manifold back on

 

It's amazing how many times my old S5 intake on an S4 engine writeup pops up in posts... memories...

FOR THE RECORD:
I was the one who wrote the information posted on http://homepage.mac.com/carldavis/intake/intro.html
I wrote that page immediately after I performed the swap on my old 86 block about 2 years ago. The writeup is hosted on that site because my website was taken down.

Since that page was posted so long ago, I've have had a lot more time to test and verrify the 10 HP gain on a S4 engine with the S5 intake. I'll tell you strait up: Its not worth the effort and the gain is not there.

Does the S5 intake give an S4 block more total HP? Yes. BUT the HP is only realized on the top end above 6000 RPM. The gain was about 8 HP at 7000 RPM

With this mod, you will lose low end? Yes. Down low, below 4000 RPM you will loose about 10 HP and 8 ft/lbs torque across the board.

TO DO THIS RIGHT? You really need the 89-91 NA block with the S5 rotors. The extra compression and lighter weight rotors make up for the 10 HP loss down low.

The only problem I have now with an entire S5 block in my 86 is that the stock ECU is running way to rich. My next step is the S-AFC to lean things out across the power band.

 

There you are wozoom! I knew you were going to come around to FINALLY PUT THIS TO REST!

I didn't want to bait up your name and have everyone Interested In this conversion to bombard your pm's.

I very much wanted to do this b'c I thought It would be cool to have better Intake runners and a VDI that Is setup on the dial.

Besides learning this Is not a practical mod, I learned that with the old EGR Solenoid that I have acquired and the new RPM Switch that I may be able to use It to dial In my 6 ports via electronically.

Anyways, I'm glad this mod has been put to rest...

 

if you get every thing working on the s5 intake will you gain any hp or should i put back my s4 intake

 

Well, it seems that my car is a freek car. The webpage referenced is mine, with the write up by Jeff Woznik (sorry if I butchered your last name). He says that he did not get the same results as I did. But I saw gains across the board.

My car is currently making 161 and if I remember correctly, 127ft/lbs of torque at the rear wheels with 70k on a Mazda reman engine. My only other mods are a K&N filter, RB headers, midpipe and a 50mm HKS Sport Exhaust.

So, it is working beautifully for me. I have had a few people say that the swap worked for them, but a few others say that it didn't work for them.

I just moved so I will have to find them, but I will post my dyno runs right before the swap and right after the swap so you guys can compare where you loose and where you gain power.

For those that can wait, I will be running the Mazda Drivers School at VIR at the end of Sept, you can see my setup.

Carl
88 GXL
99 Dakota

 

Oops, ment to post a picture of my current dyno chart. The VDI basically gave me a flat torque curve from 4200 on. It is really nice.



Carl
88 GXL
99 Dakota

 

Carl,
Your dyno sheets were the ones that convinced me to do this swap in the first place, so I don't doubt that your setup is working. What I haven't been able to figure out is why we have mixed results on different cars. So far I've only met 3 people that have seen gains across the powerband, while 6 people have seen mixed results with only gains on the top end.

As far as I know, our setups are very similar except that I still run a cat on my car.

What are you using for 6-port and VDI operation? RPM switches and the airpump?

 

what about using the intake mainfold from a third gen? Would you gain, or lose any more power?

 

If you can make them fit on an NA block, all the power to you! FYI: All turbos are 4 port engines...the only way it would fit would be to use 4-port engine housings.

 

The success rate is one of the things that I am wondering about also. I wonder if people just are not getting the activation of the VDI correct. I found that the pressure source to activate the VDI was really dependent on the pick up point off the airpump. Plus, there might not be enough pressure, the VDI uses something like 3psi, vs. the 6ports needing 1.5 or 2 psi. That may be a factor, or the RPM switch isn't connected right. I am not sure.

Well, I now have a cat back on my car, where I moved they are a little more strict on checking emissions requirements.

The 6 ports are removed and blocked off, the VDI runs off the air pump hose that sits between the exit of the air pump and the entrance to the air control valve, running through the factory vacumme spider to the EGR soleniod (contolled by an RPM switch) to the VDI actuator.

I have the actual Dyno run files and a viewer program, so I am going to overlay the before and after runs to see exactly what was gained and what was lost and where.

Carl
88 GXL
99 Dakota

 

I don't think it would be as efficient a manifold, since the 3rd gen manifold it set up for air flow due to the turbo. you might pick up some top end power, but most likely loose power down low.

Carl
88 GXL
99 Dakota

 

won't work at all, as a matter of fact (as has already been stated) -- 3rd gen engines are turbo motors, and they have 4 ports. 2nd gen NA engines have 6 ports, an the manifolds, etc. are waaay different. You'd end up running off (just a wild guess ) the intake port in the intermediate housing

 

Here is a link to the forum thread for the images

89 intake swap dyno results

Carl
88 GXL
99 Dakota