Really, I have built more high power N/A cars then I can remember. The statement above was in response to an emailed question. Talking about things I have not done before, hmmm....

So lets see:
It does require grinding the rear plate to install the S5 intake on the S4 block.

You do loose the ability to actuate the 5th and 6th ports off exhaust pressure
unless you resort to a bunch of plumbing

The VDI cannot be actuated by the S4 ECU

The dyno chart that he has been referencing in multiplle threads for an engine that we build that is putting down 188rwhp is an S4 block with S4 intake with S5 rotating assembly on a stock ECU https://www.rx7club.com/time-slips-dyno-128/came-close-but-no-cigar-794037/

I would rather have 188rwhp then 135rwhp, but you guys can do whatever you like with your cars

 

I still stand by my statement, you can't even say two things the same.
Yes, this is true.


Thats two different statements, one sounds like its impossible and one sounds like its possible. On the link I posted its clear the person used back pressure to run his aux ports and if 'a bunch of plumbing' is stopping you from the swap then you aren't ready to make the intake swap anyway.

Using the S4 ECU, yes. While running the S4 ECU...no. Again, your statement may be technically correct you don't offer any solution around this problem. You just simply say 'its impossible'.

Really?...let me see here....
86-88 NA = 146 HP @ 6500 RPM w/ 138 Ft/lb @ 3500 RPM
89-91 NA = 160 HP @ 7000 RPM w/ 140 Ft/lb @ 4000 RPM

So thats a difference of 14 HP...and the intake is known to add 10-12 hp. (even check the dyno sheet I posted)
I dunno about you but I consider 71 - 85% of the power difference from s4 to s5 the real gains. The S4 doesn't even rev to 8k, so we don't know if the gap is closed even more. Plus S4 with the intake still uses the more restrictive S4 AFM.



Yeah, and I am skeptical that adding S5 rotors to a S4 block and it magically reached 188whp. And then I read it and saw...Motor rebuilt by Banzai Racing with an agressive street port, Pineapple inserts, HKS header with 2-1/2" HKS racing exhaust, Cone inlet filter.
And now I don't wonder where the power came from!!! A header, intake, streetport...

Go You!!!

I follow the theory of Defined Autoworks for my N/A motors. Last time I checked it was 216whp.

 

Just because something is brier rigged doesnt mean it is correct or will work reliably. Go to Banzai Racings website and then seriously think about what you said on Chris. Oh and I keep seeing that dyno chart and it looks like someone made that in paint application in about 5 minutes.

 

Sorry pal but when I get a one line question to a tech email address, I am not going to go into a 5 page explaination of how things can and cannot be worked around with multiple ECU options and servo motors. Especially considering this was just another question in a long line ranging from porting to TII conversions.

"You might have seen my post about S5 intake on S4. Have you ever done this conversion and did it have positive results?"

Dyno chart you posted shows 135rwhp +/- 1 , yippie

This really shows your level of intelligence, you are obviously one of those people that thinks they know everything, and tries to pick out the minute details of peoples posts to make youself feel smart.
Let's see the dyno sheet for your N/A car.

 

I made my ports actuate from vacuum, my air pump is out , also when you have open/free flow exhaust, the ports never actuate, if to use the exhaust pressure to actuate 'em !! I tested it on my car!!

 

In any case , you'd need to tune your ECU to have the best results.

I also think that when I had my 6 ports removed completely, it gave more power at high rpm, actually it was noticeable. Low rpm was also noticeable for having less torque, it was totally drivable but was eating slightly more gas with out the six ports.

 

No, you're just going to say its impossible instead of saying 'to retain aux ports and VDI you have to use rpm switches or reroute the plumbing'.

Instead of taking 5 seconds out of your time to give the person an idea about what is involved you wrote back that its impossible. This was subsequently posted on the board to add to the myriad of bad information out there. (Which I admit, even I have added to it from time to time)


I was going too, I even bought one and began preparations. Then I went a different route with my N/A and sold it.

I am one of those people that know I know jack ****. I am a software engineer. But I know enough to know that I don't know, and I do know enough to research the crap outta **** before I do anything. I also went to a good engineering school and have some very smart friends that I rely on for information. They also happen to be rotorheads. One in the 350whp+ class, one in the 400whp+ class. And one who custom built his own CNC Mill.

My car has all of 5 mins on it, and since I am not relying on solely myself to finish some fabrication on the car, I can tell you its going to be a very long time before my car is ready to be dynoed.


And this happens to show your level of intelligence because you fail to realize the significance of this graph. The actual power level is insignificant, nor is it even mine. The graph shows a large gain due to swapping the manifold over. This happens to be my evidence that the manifold is the reason for the power difference between an S5 and an S4. This graph is also backed up around the board in other places if you so choose to look.

I also used this to show people its not the S5 rotors that made the big difference, something mentioned in the email.


You also want to talk about me, yet you made some statement about how we can have fun with 135whp when you're the **** because you made 180whp. Well, I don't need to go over how you failed with the 135whp thing anyway, but don't be the pot that calls the kettle black.

 

I am not quite sure what you mean by brier rigged? What are you saying was rigged up? The S5 intake on S4 conversion? This has been used by many people over long periods of time. If you search around you will find plenty of people that run this mod and run it reliably.

I have been to Banzai's site and almost ordered from them once. But I was instructed that the allen bolts used in the omp delete kit was not the best solution. Don't remember 100% why, but it was something to do with the way allen bolts secure themselves. I also don't like that his rebuild replacement list does not list what manufacturer of seals are actually used to rebuild. It does say that 20Bs get RWS Super Seals, which I believe he is referring to Rotary Aviation Super Seals. I would assume then that his main seals are RA Regular seals which I am not a fan of.

I have also seen some of Chris's other threads that stick in my memory and I do not really like some of the things he has said or the way he acted. So I take what he says with a grain of salt.

Sure that dyno does look a bit bare, but its the easiest to find at any given moment. If you search around you can find other information to back it up.

 

Owell **** it. Even if it can be done I dont think its worth the hassle. I didnt mean to start a thread that questions peoples credibility. Every single person on this forum has their own idea of how things work and what works best. I sure as hell dont know much, but I think its safe to say that there are many routes to take when it comes to different mods and I dont think anyone can say which is best. An opinion is what it is.

 

Sorry I do not have time to argue with someone that does not take the time the read the basic info that is supplied. I read your posts and just laugh as I am sure many other people do as well. I have a busy week of building engines. You can continue to amuse me by talking about how you would set up cars if you had the skills but have really never done anything. Maybe you should actually do something instead of just regurgitating stuff you read on the internet, you do know it is not all true right? You counting on everyone else to tell you what is the right and wrong way to do things is going to get you into trouble.

 

The funniest thing so far is that you claim that I am " talking about things he has never done before" when it is really you that is going way overboard trying to convince people that you know what you are talking about when really,

"I was going too, I even bought one and began preparations. Then I went a different route with my N/A and sold it."

I can't control the laughter.........

 

You do not have to use an ecu to actuate the VDI or the aux ports. If you aren't willing to take the time to work it all out, don't do it. The S4 ecu doesn't have to be able to do crap. I made mine work without the help of an ecu. I do have an MS but it's not controlling VDI.

Claiming that an S5 makes only so much more power than an S4 for any one reason completely ignores how differently they are tuned. Both run rich. The S5 runs FAR richer. It's somewhere in the high 10 to low 11 afr's. While they may only appear to be 14 hp apart, when tuned perfectly it's not 14 hp. Both the S4 and S5 manifolds can make good power. The S5's will just do it over a wider range. Peak power is worthless without average power and it's average where the S5 is an improvement. Average power makes you faster, not peak.

 

Apparently some people failed to read my posts. The S4 ECU has jack to do with activating the VDI. A $50 RPM switch, a $5 emissions solenoid and the stock air pump will do it easily.

And while you're at it, you can buy a second rpm switch & solenoid (or use your existing ones) and get rid of the shitty backpressure activation method for the auxilliary ports.

Clearly the S5 intake manifold has far more engineering behind it than the S4 manifold, so doesn't it follow that with all the money Mazda dumped into developing it, the design might have some impact on performance? An evolved version of it made its way into the RX8 too, so you can be pretty sure Mazda felt they were moving in the right direction with the concept of dynamic runner length.

Here's an image straight from Mazda showing the way the system manipulates the pressure wave created by the intake "stroke".

 

The RX-8 manifold is the next evolution of the S5 manifold. Each one gets better than the previous one.

 

GO Turbo !!

 

I guess it comes down to the value that you put on an 8hp gain from 6k-7k rpm. With absolutely no HP increase in any of the normal rpm power band. This is according to the dyno sheet posted in this thread. I personally do not think it is worth the trouble. Yet, each owner has there own opinion and is entitled to it....

However, building the engine with S5 rotors with a decent streetport has yielded a 50+ rwhp gain over the peak HP shown in this thread for the S4 engine with S5 intake. That is a substantial gain and very noticeable at all rpm levels. https://www.rx7club.com/showthread.php?t=794037

The Rx8 has even higher compression rotors and even lighter parts with an even higher redline. You guys are missing the big picture, the intake tract is not the major contributor to the HP increase.

Here is a S5 we just finished building, no porting on the intake runners, TII exhaust sleeves, full exhaust, intake and engine is not broken-in yet (race track only car so street break-in is impossible) 173.7 rwhp. After our customer gets a few hours on it we will dial it in the rest of the way. This is 40 rwhp more then what you are posting for the S4 engine with S5 intake.

I just do not see the value for the money and amount of work for the 8hp...

 

s5 on s4 grounds out! !! be carefull!

 

I am very confused what you are arguing.

You are saying that a streetported S4 block with S5 rotating assembly makes more power then a s4 block with just a intake swap.

Duh.

I think its safe to say that 135whp with a s5 manifold is as close to a bone stock car as you can get. Build a complete S4 motor with only the s5 rotating assembly and then we actually have something to talk about as the porting and exhaust mods on the motor you made will be out of the equation.

Other then that, you are telling me that a S4 motor, ported, intake, exhaust, s5 rotating assembly and pinneaple inserts makes 182, and a S5 with no porting, exhaust, and intake makes 173. So the only difference between the motors is porting the manifold and the inserts. Well...last time I checked porting is a pretty big increase...so the fact that the S5 manifold almost made up for the lack of porting on this motor means....

And if you are going to bring up RX-8 Rotors, you should probably mention that they show no noticeable gain in a 13B motor, even though they are lighter, higher compression, and rev to a higher limit.

 

^^ Pfft, you again. I figured you would be confused , that is no surprise. Come back when you have something constructive to say and can prove that you can make power

Der, I don't understand....

Give me a break, I know better that to waste my customer's money installing an S5 UIM for 8hp at 7K rpm on a bone stock car. I would advise them to invest in an exhaust first, way more bang for the buck. I know you don't understand that either

 

The RX-8 rotors make less power than the high compression RX-7 rotors due to much looser seal tolerances. Compression is a non issue when it comes to making power when we are comparing anything between 9.0:1 and 11.0:1. There may be some benefit but it's minute. The higher redline most certainly helps the RX-8 make more power. Raising the redline with the ability to keep VE up will always do that. The manifold on that engine most certainly helps it keep the powerband as wide as it does and there isn't a single person that I can think of that can build another one that will do what it does. You may make more ultimate power but will sacrifice somewhere else. You could even make more low end power but top end will suffer. The manifold is a huge component in power and where you make it. Pineapple sleeves don't do crap for making additional usable power. They flow an average of 1 cfm better at 28" h2o test pressure.

Comparing one engine to another is a waste of time especially when one is built and ported and one isn't. There are too many things different to say any one thing gave the results it did. I've seen S5 motors with S5 manifolds break the 200 rwhp barrier but it's still a worthless comparison as it wouldn't be comparing like engines. As I said, each manifold is capable of good power. The S5's will be capable of a wider powerband in the process though.

I did see a gain on those before and after dynos. The difference started around 5200 rpm and continued all the way to redline. The S4 manifold falls off on the top end much sooner than the S5's. For daily driving I see no advantage or disadvantage either way as the minor differences can be attributed to dyno error. It just reaffirms that the S5 manifold makes more average power. Low to mid is no different but top end is extended and stronger. The nice thing about that comparison is that the only variable that has changed is the manifold. That's it. There's a power change so it's obvious what is causing it. No doubt more power could be had at the wheels with a lighter rotating assembly and porting. Perhaps each thing on it's own should be done before and after to see what does what. When doing multiple things at once, it's very possible that while everything gained as a whole, that something actually hurt power but it's negative effects were hidden by the strengths of the other changes. Change one thing and see what happens. This dyno shows the result of that.

I'm pretty sure those who defend the S4 manifold to the death are the ones that use it solely because they think it will flow better based on what it looks like. Air doesn't work that way. At the end of the day, it's not all about flow. Tuning is just as important and is what makes the S5 manifold better.

Keep in mind there are many people who constantly spend money on intakes that can't give 8 hp as cone filters do absolutely didly squat on these cars. Most people would love to see 8 hp as a gain. Yes the exhaust should come first. Lots of things should. That doesn't mean this is a waste of time though and by your own admission does give a power gain. Not all gains are justifiable to you though and that's OK. To others it is. I like the S5 manifold and will continue to make more power than an S4 manifold can give me because of it. Even if it's small.

 

I don't understand why this was even brought up in a conversation about manifolds.

I agree with you, that yes you are better off spending money on an exhaust vs a manifold swap...but I don't understand how it has anything to do with what we are arguing and why you felt inclined to bring it up.

 

farberio go away please

 

How about you come back when you actually have evidence that proves some point relevant to this conversation instead of saying how a sweet built motor has more power then a stock motor.

 

Duh...

The OP (millertime6009) is having his engine rebuilt and ported, so needless to say (for non-morons), everything I have posted has been completely relevant to the OP's build. Nice try

Thank you for your absolutely useless comments though

 

Too bad its nothing to do with the op's question.