Who has the highest horsepower NA 6-port?
 

Im curious, i haven't found any definitive numbers but im curious who makes the most? Im guessing its around 200-205 but im not sure. So what have u guys done?

i believe it is about 285whp from the renesis with extensive mods...

joking aside, from the early 13B engine probably about 205whp with stock intake manifolds. carbed likely around 250whp with a short runner manifold. semi/PP motors upwards of 350whp(different category but for comparison sake).

4 port blocks seem to respond better to making more power over the 6 ports.

finding dyno sheets of 6 port numbers isn't easy, because the 200whp rule still seems to apply without ditching at least the 6 port restrictive factory intake manifold. even bridged 6 port engines aren't breaking the rules, they seem to fall far short, mainly because you simply can't pull enough air through the factory intake to make much more.

since you mentioned that you think you could get that kind of hp out of an FC engine, here's an idea.

since the difference between the Renesis and the Fc is partly that the Renesis intake ports are bigger and open earlier, why not just port the FC like an Rx8?

and get a casting for larger/shorter runners, larger throttle body and retain the 6 port actuator system? ;)

the whole renesis intake system has larger total volume yet about 6" or more shorter than the FC engine. don't quote me, i'm just picturing differences in my head. the 5/6th port actuators are much more well designed than even these "inserts" you find while the auxiliary ports are approximately 30% larger. the difference being a less dramatic ramp and a corkscrew design.

compare versus the 4 port renesis, which made about 35 horsepower less at the crank(FC engine revisited?). overall the exhaust being the next restriction, the side port exhaust allowing for more total volume over the PP early exhausts and less sharp evacuation cycles giving it better scavenging effects.

the Rx8 has different runner lengths for each port, they did their homework!

there is a shop in Japan that is using an Rx8 intake on a bp REW engine..

Hmm.. Ok guys, my question really is street ported 6 ports, all other mods are fair game, like RotaryEvolution said its hard to find any dyno sheets of 6 ports, but I'm so curious because I need to know where to shoot (;

likely because most if not all have never broken 200whp on the 6 port block with stock manifolds. bridged 6 port? nope. street port? nope. EMS? nope. full intake and exhaust? nope. the porting is already rather extreme so porting aside from exhaust has marginal benefit.

easiest way to break that number is actually by removing the exhaust diffusers and running a carb or TBI, but you have the side effects of that crude fuel delivery.

removed diffusers, EMS, full intake and exhaust will net you about that 200whp figure but breaking it requires a more sledge hammer approach.

i keep going back and forth on the exhaust diffuser issue as to just how big a deal they are. so this seems like as good a place as any to throw it out there. in your experiences and/or research, just how much flow (and, of course, translated power) are we talking about - ballpark?

~10-15% overall power restriction.

RotaryEvolution is spot on. My old setup was just shy of 200HP. Full street port, exhaust sleeves removed, full intake and exhaust setup, etc... TBH, it was all a waste of money. For the cost of everything, I could have almost done a T2 swap at the time, but you live and learn.

For me, 6 port is daily driver that will drag on for 100~200k miles if taken care of. If you want performance, swap to the 4 port.

here is mine (Built by Rotary Evolution)
Attachment 680074
This is in my ’90 GTUs and terrorizing local tracks (and myself) from time to time.
Let’s see if I can remember everything:

Apexi’ intake and cold air box
6-port streetport by K. Landers
Atkins aux ports inserts
3rd gen housings
Atkins 2mm seals
Stock balance (assembly not balanced)
Removed ac, ps, mech fan
Stock air pump actuating aux ports
Removed exhaust diffusers
Port matched, ceramic coated RB uncollected header to uncollected RB exhaust: individual pre-silencer and muffler for each rotor.
Stock intake manifolds including both sets of throttle plates
Stock injectors
Stock ECU
T2 fuel pump
SAFC for fuel control
10W30 dino oil (supposedly this is worth 1-2 HP over 20W50)
Stock spark plugs
CDI ignition (Mallory HyFire)

Conservatively tuned by Chris Ott @ Rotary Performance to about 12.5:1 AFR under WOT, 185whp. It made 190whp before the tune running about 13.5:1.

Other ‘low hanging fruit’ which may be able to break the 200hp number:
Extrude-hone intake
Remove 2nd throttle plates
Port match gaskets etc
Rtek or other ECU for tighter fuel and spark curve control; though Chris thinks this will not yield much.

This is a stout n/a: more power than a stock T2, very decent torque, traction-limited in 1st, very spunky car especially with the 4.3 rear end. Mileage is still decent: mid 20’s on road trips, high teens around town on 87 octane.

It is faster in a straight line and all around more capable than a new BRZ. This was my goal.

Good luck

ouch! so that basically neutralizes the gains you'd expect from the average streetport? that's pretty significant ... and it also explains a lot about some of the ported 6-port results that i've seen reported.

needless to say, i'm off the fence now.

thanks, RE.

porting the 6 port motor yields basically almost nothing without removing the diffuser wings in the exhaust. even with them removed the difference is probably a max of about 3% peak power(closer to the 15% figure at the top end i mentioned earlier), the ports don't flow well and are already enlarged about as much as you should go. clean up work is about the best thing you can do, smoothing out the airflow.

4 port n/a blocks generally respond better to street and bridge porting.

Customer's ITS Car, Banzai Racing S5 engine, no porting, stock intake manifold, full exhaust, Power FC, 199whp. Multiple time Regional Champion with numerous course records

http://www.banzai-racing.com/dyno_ch...o_10-01-10.jpg

I am envious of the graph Banzai Racing posted. Definitely highlights the benefit of a professionally built motor.

Here is mine for a stock S5 with VDI and 5th & 6th ports wired open, cone intake, Racing Beat race header collected to a single muffler and exit out back, and Haltech E8. Motor is a garage build in 2005. Tracked ~12 per year, some race some track day.


jason

out of curiosity, is the exhaust a mass-produced aftermarket system or something that was custom-built?

It is custom.

all the off the shelf exhausts are hardly a step up from stock. like RB for example i have seen many custom basic setups outperform it without any effort, they are basically untuned aftermarket replacements.

^didnt SDJ?? Have the highest hp header on the market for some time? But the price was absolutely crazy! You are right though about off the shelf exhaust systems.

i'd like to see what numbers defined autoworks managed on their tuned manifolds. another that worked ok but not available any longer were the mindtrain headers.

are these dyno numbers at the wheels or at the flywheel? because that can make a huge difference! you lose a lot of power through the drive train.

Mine's RWHP.

199whp = 199 Wheel Horse Power

sorry, i didn't see the whp behind it. i just notice some big differences in some of the hp numbers thats why i asked. very impressive though! and i must say i'm kinda jealous.

u should check out the headers from rotaryshack, proven hp, over the others by far

Who has the highest horsepower NA 6-port?
 

No thanks those are Chinese cheap imitation stuff.:icon_tdow

defiantly not china crap! you are misinformed as usual.. they are made locally to order per customers specs.. took 2 weeks to get mine made and i picked up almost 22 rwhp! awesome product

Their website is broken.

Who has the highest horsepower NA 6-port
 

I'm not misinformed perhaps you are one his followers side kicks friends and he gave you a good deal so you come here to post a good referral about his junk product,Perhaps you are not aware Rotary Shack is banned from this forum for scamming members of this forum. :icon_tdow. I'm well Informed If not take a look its name under the Bad and Fugly Business Section.

Well Still need to dyno mine, but I have a 6-port 87 NA with about 106,000 miles right now... When It was stock it was OK in acceleration and little to no low rpm throttle response or torque... With Headers, FULLY open straight pipes with no cats or resonators or mufflers just pipes from the header back and some tips, K&N Filter and just your normal oil changes and taking care of the car like a baby, it is a BEAST now!!! I have driven many cars and this car is NOT slow by any means.... The exhaust is not some exhaust from a website or some chrome stuff, it was designed by me and a exhaust shop and the headers were created from a header flange. I also removed the 02 sensor (SAME gas mileage so it probably has not worked in a while). But yea BIG BIG BIG difference in every way.. I have GREAT throttle response in the low end now... 2000 rpms and up it responds well! 4000 rpms it takes off like a rocket!! My Buddy has a S5 rx7 with paperwork stating a rebuild and We were neck and neck with his exhaust open almost like mine, he literally didnt pass me an inch and I swear by the end of 3rd gear I was pulling a little.. Maybe because My K&N filter idk..... This was before the headers that I have now.... My other buddy has a S5 Turbo II (Either S4 or S5 I dont remember) and well we went for a ride in his car and he was only getting 4 psi boost (yes it needs work), But yea it was SLOW!!! I was like omg this is what a turbo II does..... did not feel much faster than my NA if any faster..... Maybe severe issues i dont know.... That was my first ride in a turbo II with full exhaust and intake and boost controllers and bla bla and it was TOTALLY disappointing.....

But yea thats my 2 cents... K&N Filter, remove the ENTIRE stock exhaust, remove the exhaust manifold, remove 02 sensor, add custom headers from a flange, add 2.5 inch exhaust from the header back (I kept my dual exhaust), Put some nice tips like $35 for both tips (I said nice not expensive!! :p) change your oil OFTEN, 87 Octane.. Makes a fun rx7! Total Cost around $285.....

I did MULTIPLE exhaust designs trying to get it right and spent over $400 trying different designs... so I spent like about $700, but what I wrote above works WELL for me!

NOW, I WARN you now!!! It will be STUPID loud, like a drag car or something... I mean literally it will get you pulled over....EASY.. I did lol.... :lol: You can get a ECV (Exhaust Control Valve) to limit the noise substantially, OR you can get aluminum screen mesh $13, Steel Wool (Yes initial fire..) or something similar $10, and some plumbing clamps that you use a flat head screw driver to tighten and stuff your exhaust with the steel wool.... $3 Use about 8-15 small steel wool pads per pipe.... Yes sounds stupid and it would be IF you didnt have exhaust coming out, But My Exhaust has port holes for it near the end letting most the noise go down instead of straight back. This setup makes the headers with straight pipes drivable on the street!! I drive it daily with this setup and as long as you dont floor it, its not that bad at all!!!... You might lose some power if any depending on your setup.... I dont feel ANY power loss... but no dyno so idk,,,,.

So yea.... any questions or insults??

Attachment 671487

Attachment 671488

Attachment 671489

Attachment 671490

Attachment 671491

Hm, well thanks everyone for the advice, i should be getting to work soon.. now im very determined, but have heard enough to know that no matter what the car will be fun and fast (not that i ever doubted that haha)

201rwhp 6 port secondary bridgeport, megasquirt ecu, more to come out of it yet the ignition map is pretty ordinary,


https://www.rx7club.com/attachments/...dyno-chart-jpg

^That dyno graph looks all sorts of wrong... why is the crossover at 3k RPM? Also shouldn't you have more than 60 hp at 3k rpm?

The crossover is irrelevant as its the way the graph has been scaled with the hp on one side and torque on the other, And I think 60hp is around about right for a bridgeport its not much above idle as it idles at around 1800rpm

Ah my bad I didn't notice the different scaling.

why only 6k+ on the RPM's? why aren't you reving that thing?

When the owner went for a tune he didnt have enough gas in the tank to spend the time on it and I tink they ran out of gas before they had time to tune it in the higher revs, I don't think the tuner was very interested either, I have looked at the ignition map and it hasnt had alot of time spent on it, the owner was going to get it retuned this time properly but he is in Australia working and the car is here at his parents house in New Zealand so he may do it on a trip home

It varies a bit, our headers perform best when the porting style is aggressive or best yet when using our porting templates. For example on stock ports the gain is pretty small vs. a racing beat system.

The 6-port is limited to about 200rwhp unless the stock intake is switched out. Its simply way too long. Designed for torque in the 4-5k range, and we all know top end torque is needed to net 200+.

Rotary evolution you already know, but are totally correct on the intake. This is why properly setup, Banzai made 200rwhp with stock ports. The ports are already too big vs. the long intake. Chain is only as strong as the weakest link...

The 6-port with aftermarket intake is still at a disadvantage, it closes too late and has a bad reversion wave going up the wrong direction. The stock intake uses a loop system to try and "charge" the opposite rotor. Once a short aftermarket intake is fitted the loop system is not in place. Just bad reversion at that point.

The 4-port is king in my opinion, much better, broader, more powerful powerband. This is our 230rwhp street port 4-port engine for comparison, daily driven, very quiet. Note 130rwtq at 3500 and 153rwtq peak.


Attachment 666388

wow... the power curve of rotaries still amazes me.

That's very impressive, almost unheard of power no? Logan, any pictures of the engine bay?

not unheard of for a 4 port n/a no, the 6 port engines simply have too many things going against them for larger numbers which Logan went on to explain.

to make close on a 6 port block would require a custom intake manifold/throttle body, or fill in the crappy ports and peripheral port it.

the MSP managed about as much as a refined 6 port engine could do with the exception being that the auxiliary ports are twice as big as the early engines and have tuned sleeves for improved airflow.

Thanks for the clarification. Since I am new to trying to understand the difference between a 2nd gen 4 port motor and a 6 port motor (I understand the obvious in ports on the irons), is there a link/thread you could point me in the direction of that would better explain it? For an N/A motor. Thanks!

somewhere in one of these threads i mentioned that i did that, and didn't get alot of attention, but yeah... i did the primary ports only leaving the outside irons factory. the seals clear it, but the housings/apexseals i had were no good, that motor wouldn't even start on it's own, or rev over 5k.... gonna reuse the middle plate with my next build,a semi pp with all side ports working.. pretty much gonna copy define's 428hp 20b.... sorry guys. i'm a theif.

Trying to do some learning, so don't mind this thread necro.

The four port engines are the SA13B, correct? For these >200Hp numbers, are people using carbs? FI? ITB's? Could I consider using my stock S5 intake manifolds with a standalone fuel injection system?

On this note, why wouldn't someone just bridge the aux to the main ports on a 6 port iron, could this be done? Would it be beneficial? Since I'd be planning to run without the AUX valves anyways.

I have been searching this crap for weeks, and I give up, so now I'm asking.

4 ports are more commonly TURBO 4 port engines..

been done. you can find other that did them and observe their results and maybe find the mistakes or issues that resulted in the less then desired performance. the port isnt the problem it's the intake.
and you want to make them bigger? no, just get some 4 port housings if you're going to make your own intake manifold... if you plan on using the factory N/a intake.. why even bother.

as far as carb vs EFI everyone setup is different. but EFI is the way to go.. unless you're asking a first gen guy. or a 12a guy.

So assume I go fuel injected. Would I need a standalone EMS to push out around 200 HP? I had been looking into running a Power FC, but I don't see where anyone makes a harness for an NA setup, only the Turbo engines.

Our adapters work on both N/A and turbo, the same. The 200rwhp car referenced in this thread is running the PFC and our S5 adapter. We have tuned N/A base maps that are set up for vacuum only APEXi Power FC Adapter Kit (89-91 RX-7)

That is good to know. Thank you very much!!

Alright guys. Finally, I've got my stock 6 port itb set up tuned. Ended up with 169.6 max hp. Let me know if you think there is room for improvement without cracking the engine open and what can be done.

https://cimg1.ibsrv.net/gimg/www.rx7...a8ebd64af4.jpg


NOTE: I had to trace the lines with a pencil because the lines didn't print well. I'm not hiding anything, nor did I modify the graph in anyway. I'm waiting for an electronic file from the tuner to prove this.