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-   -   S5 intake on S4? (https://www.rx7club.com/2nd-generation-specific-1986-1992-17/s5-intake-s4-813390/)

millertime6009 01-15-09 08:00 PM

S5 intake on S4?
 
Found a S5 intakemanifold for 85 bucks.

Power gains?

francogt1 01-15-09 08:04 PM

none

FelixIsGod29X 01-15-09 08:04 PM

Power gains are minimal. Save for something more worthy.

farberio 01-15-09 08:16 PM


Originally Posted by millertime6009 (Post 8882839)
Found a S5 intakemanifold for 85 bucks.

Power gains?

edit:
Bah...Rotarygods post is far superior...read one post down

rotarygod 01-15-09 08:16 PM

Why do people keep saying none or minimal gains? That's not true. You can pick up roughly 15 hp on the top end and extend your powerband across a wider range. It's definitely beneficial but you have to keep VDI and the aux ports working.

I have no doubt someone is going to try to compare the power of an S4 to an S5 and point out that there is only a 14 hp difference between them even though there is a better afm, different intake manifold, and higher compression. However this would be completely ignoring the fact that at full throttle the stock S5 runs in the high 10 to low 11 afr's and hence is being severly held back in power as a result. While the S4's do run rich, they aren't that rich. Tune each engine for it's optimal output and you'll see far more than a 16 hp difference. The S5 intake is superior to the S4 any day of the week. Sorry to burst some people's bubble. Don't base flow or potential on what each looks like. Air doesn't always do what you think it will and if you think it's better and more beneficial through an S4 intake, you just proved my point! Keep in mind different porting style like different things but for street use the S5 is king.

Now saying all of this, it's not quite a simple swap. There's alot to do to make it work properly so don't think you'll be done in half an hour with a perfectly running car with more power. It's the people that do it this way that typically regret the mod and proclaim it a failure.

BTW: I currently have an S5 intake on my streetported GSL-SE first gen. It works great! I used to have an S4 intake.

millertime6009 01-15-09 08:38 PM

Well Id just have it installed when i have my engine rebuilt. So worth 85 bucks? Also would I need an S5 throttle body? Found one of them for $50. I am also getting a streetport done.

Blaen99 01-15-09 08:46 PM


Originally Posted by rotarygod (Post 8882899)
Why do people keep saying none or minimal gains? That's not true. You can pick up roughly 15 hp on the top end and extend your powerband across a wider range. It's definitely beneficial but you have to keep VDI and the aux ports working.

I have no doubt someone is going to try to compare the power of an S4 to an S5 and point out that there is only a 14 hp difference between them even though there is a better afm, different intake manifold, and higher compression. However this would be completely ignoring the fact that at full throttle the stock S5 runs in the high 10 to low 11 afr's and hence is being severly held back in power as a result. While the S4's do run rich, they aren't that rich. Tune each engine for it's optimal output and you'll see far more than a 16 hp difference. The S5 intake is superior to the S4 any day of the week. Sorry to burst some people's bubble. Don't base flow or potential on what each looks like. Air doesn't always do what you think it will and if you think it's better and more beneficial through an S4 intake, you just proved my point! Keep in mind different porting style like different things but for street use the S5 is king.

Now saying all of this, it's not quite a simple swap. There's alot to do to make it work properly so don't think you'll be done in half an hour with a perfectly running car with more power. It's the people that do it this way that typically regret the mod and proclaim it a failure.

BTW: I currently have an S5 intake on my streetported GSL-SE first gen. It works great! I used to have an S4 intake.

Did you use just the S5 UIM, or the S5 UIM+LIM?

RotaryRocket88 01-15-09 08:53 PM

4 Attachment(s)
The power band from 4k to 7k becomes almost completely linear with the S5 manifold and working VDI. I converted to the S5 manifold on my S4 NA motor (before going turbo), and easily felt the extra pull up to redline. And as mentioned already, it was not a simple mod. I spent the weekend mostly trying to get the block ground down the right amount to get the UIM to seal against the LIM. My advice is grind it a lot more than you think you need. Bending the OMP rod correctly is also a pain in the ass since it just barely clears the UIM and alternator nut (I cut this nut down to fit better).

I attached Silver88GXL's dyno of the results, as well as some pictures of my manifold setup and my S4/S5 hybrid vacuum diagram that keeps all emissions (except EGR) intact.

Writeups: http://homepage.mac.com/carldavis/intake.html
http://howto.globalvicinity.com/gv_w...i=63&co=1&vi=1

Edit: I used the S4 LIM & TB, S5 UIM, S5 primary and secondary fuel rails, 2 rpm switches (6PI & VDI), 2 egr solenoids & a modified stock airpump.

millertime6009 01-15-09 09:06 PM

so is the s5 throttle body not required then?

RotaryRocket88 01-15-09 09:16 PM


Originally Posted by millertime6009 (Post 8883045)
so is the s5 throttle body not required then?

No, the S5 TB has no place for the S4 TPS or the OMP rod (not needed if premixing). You use the S4 TB and TB spacer for this.

need RX7 01-15-09 09:24 PM

I've contemplated doing this swap before, I'd imagine it's much easier if you have no emissions and premix (no OMP)? If that's the case, all you'd need to do is all the physical modifications to make it fit and find a way to make the 6pi and VDI systems work, right? I'm reading through the guide right now, but figured I'd ask anyway.

RotaryRocket88 01-15-09 10:34 PM

2 Attachment(s)

Originally Posted by need RX7 (Post 8883081)
I've contemplated doing this swap before, I'd imagine it's much easier if you have no emissions and premix (no OMP)? If that's the case, all you'd need to do is all the physical modifications to make it fit and find a way to make the 6pi and VDI systems work, right? I'm reading through the guide right now, but figured I'd ask anyway.

It's easier w/out emissions or the OMP, but the metal work is the main reason for it being a "difficult mod". Grinding the block is harder than it sounds since all sorts of things stick up in the way and make it hard to get the right angle w/ a die grinder. A cone shaped grinding stone seems to work the best for this part, but it still takes forever (even w/ an air powered grinder). Then there's the slotting of the S5 UIM if you keep the S4 LIM. A lot of metal has to come out of the rear intake runner to allow you to redrill the hole for the stud and allow a nut to fit in there too. If throwing out emissions however, you can use the S5 LIM and avoid this part.

Attached are pictures of the modified UIM and the ground rear iron.

need RX7 01-15-09 10:41 PM

Thanks :icon_tup:. I'm planning on rebuilding and street porting my motor in the spring/summer and I think the VDI will really complement the port.

rotarygod 01-15-09 11:11 PM


Originally Posted by Blaen99 (Post 8882989)
Did you use just the S5 UIM, or the S5 UIM+LIM?

The whole thing upper, mid, and lower but I used an S4 throttlebody. My car had no emissions. It was going on a 1st gen anyways. Making the VDI work was a bit of a pain. As was mentioned, rebending the omp rod really sucks. I retrofitted a Mustang tps (which is no simple task!) since I use a Megasquirt. I too had to grind the top of the rear housing but the bit for my die grinder will get rid of it in less than a minute!

I love the powerband width. The car just keeps on pulling up top. I've got my rev limit set at 9000 and it's still strong up past 8K with no problems. When I had the S4 manifold there was no point in shifting much after 7K and it was a big improvement over my GSL-SE manifold which was pointless above 6.5K. I honestly don't really see much of a difference below that level. It's the top end improvement and extension that I love about the S5 manifold. I drove around for a while with VDI wired open and the aux ports open and I hated it. Talk about gutless on the low to mid range! I think alot of people are too lazy to make it all work properly and as I did with the same incomplete setup end up hating it.

The S4 manifold is definitely simple. I've even seen someone mention wanting to retrofit it to an S5 car. That made me laugh but sadly was based on people here bashing the S5 setup. There is a way to modify the hell out of an S4 manifold and make is powerful as hell compared to stock but the powerband will shift upwards. It also involves cutting it in half, doing a bunch of work, and then welding it all back together again. Low end and drivability suffer alot though. For a race engine it would be fun but for street not so much.

If you do the S5 swap, take your time, be thorough, and complete it. Make everything works including the VDI and aux ports. Again I have no idea why people like to disable them. Been there, done that. Make them work!

millertime6009 01-17-09 05:32 PM

Ok I think Im gonna go for it. After I install the manifold, get it rebuilt, ported and tuned, ill definitely be able to tell it by the seat of my pants. 148whp can say goodbye and hello to about 190 :)

-CON- 01-17-09 06:35 PM

I tested the intake manifolds, I don't know if there is much difference, I think I had better results with S4 intake, the power bend was much smoother. Also I did it on S5 ECU, the whole car was S5 except engine, engine was S4, red line on S5 is higher, on S4 car S5 manifold for me , would be worthless.

But for you, how else would you learn with out trying it !?!

millertime6009 01-17-09 06:54 PM

I wouldnt know with the mixed reviews im getting haha

-CON- 01-18-09 04:07 AM

You got to note that S5 rev higher than S4, that is why the S5 manifold would be better for S5.

For me I wouldn't bother with S5 manifold on S4 everything else, instead I would just do some work to S4 manifold.

farberio 01-18-09 07:42 AM


Originally Posted by -CON- (Post 8888967)
You got to note that S5 rev higher than S4, that is why the S5 manifold would be better for S5.

For me I wouldn't bother with S5 manifold on S4 everything else, instead I would just do some work to S4 manifold.

No No No. The S5 Manifold adds power over the S4. Its better on both applications. Unless you are going for an all out motor, in which case you have no business using either of the stock manifolds.

importtuner137 01-18-09 10:43 AM

This is straight from Icemark when I asked him about the debateable part of the power gains in a PM.

"On the intake manifold it depends on what you are doing with the motor and what the motor is (S4 vs S5 and non turbo vs turbo).

I am assuming you have a S4 non turbo and are thinking about using a S5 non turbo intake runner system... if so, the discussions and testing over the last 10 years have come down to the following:

If you have a non turbo S4 motor the gains that can be found are at the top end (6000+ RPM). Typically breathing for the S4 intake runs out in the high 5800-6000 range, while using a VDI you can get pretty stable breathing up to the redline of 7000 RPM. So your gains are really only at peak RPM. But there is a downside... because the S5 lower intake runners are slightly smaller (to help keep up intake velocity) it compromises mid-end torque (3000-4000 range)... to fix this really a combo manifold using the S4 lower intake , while using the S5 middle/VDI and top sections (port matched to the S4 LIM) gives the best power potential.

Then you can get a pretty stable across the board stock powerband until you hit the 5000-5500+ RPM where you will see moderate peak increases (anywhere between 2 and 14HP peak power increase based on dyno tests).

But sticking with the all S5 intake runner system on the S4 motor showed a typically loss of around 10 HP and 5 FT/LBS until 4000 RPM. At 4000 RPM the power line leveled off and as the engine approached higher RPMs power increased slightly.

So you are probably wondering what this means to you?

Well if you have already made exhaust and intake filter changes that have shown positive HP increases on the dyno, then using the S5 VDI and upper section will net you some more power back (again anywhere between 2 and 12 HP peak). But if you have not made any changes that have increased power, just bolting in the intake, will not net you much at all.

The other thing to consider is that the stock Mazda ECU can not keep much control over the coils much past 6500 RPM. So even if you bolt in the intake to make it capable of producing power all the way up to 7000 RPM the stock ignition may run out before you can take full advantage the better breathing at high RPM. This means that you will probably need to look at a CDI ignition system or coil amp to get better control back... of course then you are spending more money.

So it comes down to, do you need to make max power to 7000 RPM? or is the normal 6500 RPM fine?"

-CON- 01-18-09 12:52 PM

Also note that, S4 lower intake manifold one bolt pattern ( by the firewall ) will not match with S5 upper manifold.

joeylyrech 01-18-09 02:50 PM

i want a NA FC so i can play with this stuff 2,im bored with my turbo.

need RX7 01-18-09 02:54 PM

That's alot of good info from Icemark. :icon_tup: :icon_tup:

Also, I think my rev limiter is broken, because I've had my S4 to 8k before. heh.

millertime6009 01-18-09 03:47 PM

This is what Chris Sanders at Banzai shared with me.

"It requires grinding of the rear plate to fit and you loose the ability to have 5&6th ports actuate. It is also impossible to actuate the VDI with the S4 ECU. The dyno chart that you reference is an S4 block with S4 intake. The real gains come from the higher compression lightweight S5 rotors, not the intake."

farberio 01-18-09 03:51 PM

Then Chris Sanders is a complete and utter nincompoop and is talking about things he has never done before.

Read these

Also
http://howto.globalvicinity.com/gv_w...i=63&co=1&vi=1

and

http://www.globalvicinity.com/images....9577_2807.jpg

Banzai-Racing 01-18-09 06:08 PM


Originally Posted by farberio (Post 8889892)
Then Chris Sanders is a complete and utter nincompoop and is talking about things he has never done before.
[/IMG]


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

farberio 01-18-09 07:14 PM

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

Originally Posted by millertime6009 (Post 8889889)
"It requires grinding of the rear plate to fit

Yes, this is true.



Originally Posted by millertime6009 (Post 8889889)
and you loose the ability to have 5&6th ports actuate.


Originally Posted by Banzai-Racing (Post 8890229)
You do loose the ability to actuate the 5th and 6th ports off exhaust pressure
unless you resort to a bunch of plumbing

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.


Originally Posted by millertime6009 (Post 889889)
It is also impossible to actuate the VDI with the S4 ECU.

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'.


Originally Posted by millertime6009 (Post 889889)
The real gains come from the higher compression lightweight S5 rotors, not the intake."

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.




Originally Posted by Banzai-Racing (Post 8890229)

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/showthread.php?t=794037

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...


Originally Posted by Banzai-Racing (Post 8890229)
I would rather have 188rwhp then 135rwhp, but you guys can do whatever you like with your cars

Go You!!! :gayboy:

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

millertime6009 01-18-09 07:21 PM

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.

Banzai-Racing 01-18-09 07:38 PM


Originally Posted by farberio (Post 8890356)

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'.

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


Originally Posted by farberio (Post 8890356)

Go You!!! :gayboy:
.

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.

-CON- 01-18-09 08:20 PM

I made my ports actuate from vacuum, my air pump is out :icon_tup: , 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!!

-CON- 01-18-09 09:31 PM

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.

farberio 01-18-09 10:14 PM


Originally Posted by Banzai-Racing (Post 8890397)
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.

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)



Originally Posted by Banzai-Racing (Post 8890397)
"You might have seen my post about S5 intake on S4. Have you ever done this conversion and did it have positive results?"

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


Originally Posted by Banzai-Racing (Post 8890397)
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 am one of those people that know I know jack shit. 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 shit 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.



Originally Posted by Banzai-Racing (Post 8890397)

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

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 shit 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.

farberio 01-18-09 10:39 PM


Originally Posted by millertime6009 (Post 8890374)
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.

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.

millertime6009 01-18-09 11:55 PM

Owell fuck 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.

Banzai-Racing 01-19-09 05:54 AM

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.

Banzai-Racing 01-19-09 06:55 AM

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.........

rotarygod 01-19-09 11:29 AM

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.

RotaryRocket88 01-19-09 02:22 PM

1 Attachment(s)

Originally Posted by RotaryRocket88 (Post 8883008)
...I used the S4 LIM & TB, S5 UIM, S5 primary and secondary fuel rails, 2 rpm switches (6PI & VDI), 2 egr solenoids & a modified stock airpump.

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".

rotarygod 01-19-09 03:15 PM

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

-CON- 01-19-09 03:17 PM

GO Turbo !!

Banzai-Racing 01-19-09 03:41 PM

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...

http://www.banzai-racing.com/2008_cu...t_01-06-09.jpg

RXzeben 01-19-09 03:51 PM

s5 on s4 grounds out! !! be carefull!

farberio 01-19-09 04:44 PM


Originally Posted by Banzai-Racing (Post 8892527)
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...

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.

Banzai-Racing 01-19-09 05:04 PM

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

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 :scratch:

:lol: :lol: :lol: :lol:

rotarygod 01-19-09 05:20 PM

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.

farberio 01-19-09 05:54 PM


Originally Posted by Banzai-Racing (Post 8892752)
I would advise them to invest in an exhaust first, way more bang for the buck. I know you don't understand that either :scratch:

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.

millertime6009 01-19-09 05:57 PM

farberio go away please

farberio 01-19-09 05:59 PM


Originally Posted by Banzai-Racing (Post 8892752)
Come back when you have something constructive to say


Originally Posted by rotarygod (Post 8892787)
Comparing one engine to another is a waste of time especially when one is built and ported and one isn't.

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.

Banzai-Racing 01-19-09 06:28 PM

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 :lol: :lol: :lol:

Thank you for your absolutely useless comments though:icon_tup:

farberio 01-19-09 06:35 PM


Originally Posted by Banzai-Racing (Post 8892996)
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.

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


Originally Posted by millertime6009 (Post 8882839)
Found a S5 intakemanifold for 85 bucks.

Power gains?



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