Thanks ROB. It’s the best of both worlds and will give you big reliable power over and over again. Love 4 rotor awd car. She’s going to be a beast once all the little kinks are worked out 💪🏽
Best video I've ever watched in my entire life about rotary engines porting. Thank you so much for the video, God bless you you sir. I'm on a J-port now making just around 700hp. But I wanted to know more about semi peripheralbport because I would like to have that in the future!
Hey,man. Just watched your video and I was wondering...what happens to the water jacket after sleeving it ? Does that car run hotter ? Does it over heat ?
I really enjoy this type of content. It's more than just opinions and hearsay, you gave us real examples of how and why they differ. I had never even considered your point of apex seal cooling before. Thanks for sharing
Awesome video! Thank you! I'm building a turbo II for my miata based Exocet. Planing to supercharged it too. Seriously thinking about your semi-p port. You give me plenty of reasons to go that route.
Thank you!! I am a huge fan of changing the closing edge so that the corner seal edge closes later but the oil seal edge is untouched. This aims the closing edge, where the air flows over, at the center of the chamber at the point of highest chamber expansion rate. It also softens the reversion pulse as the rotor closes the port, for less shock pushing the airflow back up the intake
5:00 cool track playing in the background - Cage the Elephant, No Rest For The Wicked. Super informative video, I was paying attention all the way through that's how I heard the track...
I totally agree with a Street port being better than a Bridge port..they last longer and if done right with a proper exhaust will still create a brapping idle..and semi is awesome..thanks for sharing
Solid video man. Really appreciate this kind of info. Looking to get a Series 4/5 RX7 soon and have been scouring the web for rotary knowledge, as it will be my first experience. Subbed!
The apex seal issue can also be caused by excess heat build up around the plug area, causing a high spot on the housing and wearing the centre of the seal (so I was told by one of the most reputable builders around)
Hi from Australia 🇦🇺 Absolutely brilliant video. I have been into Rotary Engines for decades and never knew a sharp closing street/extend port can brap like a bridge. Cheers for teaching me something new. Greatly appreciate it 👍
I'm building a semi PP 12a now, and had a couple questions. You mentioned you'd do a D port on the exhaust for a turbo semi. What about an NA build? I think my plans would be to do a mild street port and clean up on the side housing intake ports, but I'm not sure what to do for the exhaust. Rpm goal is the occasional blast to 9 with clearanced, unbalanced rotors, upgraded oil pump but no pressure increase, renesis stat gears and bearings. I would love to hear your input. Amazing video on porting.
I figure I have warped apex seals in my race fd engine right now for the exact reasons you mentioned. I’ll be pulling the motor in a week or so and once cleaned and prepped for inspection Ill know the full story. I’m with you on the Bridgeport thing too. I have built them and they sound great but my engineering brain never liked it. I run a much oversized street port and exhaust ports and my car on 7psi ( spring pressure only ) of boost made 404whp and the power curve was stunning.
My Rotary Life yes. The thing is. The bigger you port the farther you push the power band over. You will start to get that chugging sound and feel down low from the over lap. It all depends on what you goal is and what your doing with the car.
Thanks so much. Love the information share. I was wondering about P ports. Have an engine that needs major work. Actually so much work on the FD... My love and hate relationship.... had it since 2003.
11-12-2019.Do you know if amy cars with rotery run on NH3 and nitra?The second is the roter hollow form , back in 1966 my dad talked to some Big Mazda people regarding a longer hollow form have you incountered any?Thanck you.
So what would you recommend for an NA 12A? I’m thinking about buying an FB RX7 with the intent of pulling the motor and porting. It would end up being daily driven pretty frequently, but keep in mind that my standards for a daily aren’t exactly that high (I’ve been daily driving my 944 race car for about a year now. No a/c, stripped interior, bucket seats, harnesses, loud ass exhaust, etc). Looking for somewhere in the range of about 250hp while keeping the fuel consumption at above 10mpg. Is this possible or am I dreaming?
Hi thanx for the awesome information I'm from south africa when you are doing your semi pp do you weld the semi pp to the housing or do you just press fit them? I would just like your professional opinion if you don't mind sharing your information and expertise. Regards Shane
No I don’t weld them. We cnc the hole and block off plates. The tube stops about 5mm to the housing surface. Then I fill the housing with epoxy and place the plates in to the holes to block the water jackets.
What is the longevity of the sealant around the Semi P port/how many miles did you run that motor? I'd be concerned about differing expansion rates when it heat cycles.
Was thinking to only have a half bridge on the secondaries and extend port the primaries. Turbo 20B setup will be street driven. The exhaust leaking into the intake is what put me off a semi pp.
that bridge at 8:00 looked alright. you hit nail on the head. you didnt deburr, chamfer all that good stuff. I personally like that fact he kept a bit of distance from the water seal. will defo make it iastlonger
But in all cases the bridge width is thin? Why not leave the bridge width the diameter of the corner seal and allow a good section of meat behind it? Personally I think a bridge only disrupts air flow? Rather a decent extend port!
I'll be honest I love my bridges but I can't argue with anything you said. I do want your take on the semi pp reni hybrid motor with gslse housings with semi pps aswell as the exhaust. I do like that my bridges tend to make good power and for cheap cheap. But I can't say they last very long at best a year with as many reused parts as I can get away with. I do think since I'm getting low on housings if I'm gonna buy new I might aswell look into a better option. Still I can't say for cheap fun a bridge port is a bad idea as long as you can tune for it and make an intake cause all the OEM ones are too long. Thanks
Have you considered making a D shaped semi p? That way you could delay the timing. My thinking is that a D that's well chamfered to make the flow go out and up would reduce overlap and flow better. Your porting looks like mine, I like to get a smooth curve inside the port to help keep the flow attached to the surface. Some people don't get it that the air flow is upward not just straight into the chamber, so they put sharp edges on everything.
Red Bat Racing yes but it’s very hard to do it that small. Also it’s really not as bad as you would think because the semi p port is still between the side ports. Over lap is not as bad as a full p port
Good video, how does fuel consumption compare with bridge vs semi pp? My FD is stock, for me I was going to stick with stock ports or a mild street port but I'm wondering if there is a big fuel consumption difference between the 3 types? My guess is stick with stock ports for 300-400hp range?
Awesome video, I'm sold on the semi. I'm actually on a lookout for a rx8 to then later on have it semied, but one question, is it better just getting a13b rew and get it done then oh the renesis, I know they have different designs altogether, and I would think cause of emission laws they kinda lowered its performance somehow with this renesis. Also you have a new subscriber 👍
Hello, I’m in the same boat as you as I’ve just bought an rx8 and am also sticks between the renesis and the rew, did you ever end up deciding on which one to go with
@@ninjafang2 I haven't gotten the RX-8 yet, it's been difficult finding one around here in the condition I want it at. But I'm leaning towards the rew for sure in the build .
What would you recommend to be done to a 13B-REW to make 700whp & 9k redline? I know it has to be all clearanced and balanced correctly, would a semi pp port be capable of making that type of hp safely? What type of turbo can happily achieve that goal? I know some street ability will be taken away but I don't care, looking to get some advice for when I get my RX7 FD and start building it. The most obvious things I can think of I need are studs, side clearanced rotors & lightened, How big injectors? What seals do you recommend OEM or aftermarket? What does it take to safely run at that hp? Awesome video aswell I know so many guys appreciate your videos because of the information you provide, Cheers
77Knives yes. That’s what it’s for. Also with the clearancing and balancing it will go to 10k easy. All the drag cars you see running 6 seconds are semi p port engines.
Awesome Video. I’m building a unicorn 4 rotor. I’ve never worked on one. Sounds like the semi port might be a better idea than the Bridgeport. I’m really building a rotary for the sound. If you were building a 4 turboed 4 rotor what would be your dream build without getting into billet pieces?
Great video! I am looking to buy a RX-8 and have ‘the brap’. Semi P is a big change in the engine bay, so still thinking of a bridge port. Any recommendations? I’m aiming for 300BHP max(for the street and taking it to a race track, not a dragstrip). Want to get the power from balance and high RPM
Is it possible to do a semi p port on a Renesis engine if you swapped the rx8 rotor housings for rx7 FD rotor housings while still keeping the rx8 internals ? What would be HP numbers and daily driving capabilities for a naturally aspirated build like that?
Julian Guzman you can do that but you would have to delete the 6 port actuator. It’s in the same spot as the semi p port. It would loose a bit of low end. 275hp range
Thanks so much for this!! My coolant seal went and about to rebuild my motor and was pondering BP for longevity. So will skip it and go semi P.. Will semi P and my street port still be good for street? Running factory turbo s4 setup making 320hp (at wheels). I'm hoping for a solid over built 400hp on standard turbo (if possible). Thanks again man from Australia!
Joe GSPADE Galletta don’t do a semi p port on a stock turbo. The street port works fine with a semi p port.the semi p port will flow way to much for that stock turbo and egts through the Roof
@@Rotorguy479 thnx heaps man, my mate the previous owner, just said the same thing. Subscribed to your channel. Rotary community needs good advice from boys like you and it's greatly appreciated by novice guys like me :)
@@thokdesign if you haven't already, port the hell out of the wastegate of that stock S4 turbo, mine was boost spiking so bad it was barely drivable after I street ported + better exhaust (eg no cats) with the stock wastegate, ended up doing a hybrid turbo (bigger front end, stock rear end) but ported out the wastegate for some sort of boost control. 320atw with a stock S4 seems oddly high though, sure that wasn't crank/estimated crank? I thought they typically ran out of puff in the mid 200HP sorta range, not 300+
This might be a dumb question but can you run a semi pp on a naturally aspirated 12a? I have seen countless people talking about semi pp with the 13b and boost and all that.
What about 'streamlining' intersection of port and plate? Old work indicated a bend in intake duct improve performance, this could be from blocking mix going backwards, but at full throttle, experiments pointed to better performance and efficiency with peripheral ports. Besides in sport and aftermarket versions, Mazda always had side intake ports; in the Renesis, also side exhaust ports. What a mesh!
what about for NA application? looking to get more power from my gsl se when/if my stock motor ever gives, but would like to keep it na. Would you still suggest a semi p-port?
MazdaGuy well p port is nice but you have to understand it’s not going to be a daily driver. It’s very rough at idle and getting going but she will scream.
@@Rotorguy479 About n/a applications, is a semi pp worth in an rx8 if its daily driven without driver caring much about crazy horsepower numbers? I mean, I ve seen bridgies making 250-260 hp in n/a rx8's. Can a semi pp make that much power while being drivable and more reliable than the bridge? I mean something like a light semi pp that will not be used in a drag car but in a daily driven rx8 which means driveability and some reliablility as im not looking for high horsepower as I mentioned before(otherwise i'd go full pp) Sorry for my english and thanks in advance!
@@Rotorguy479 Thanks for your answer but may I ask another question? For an rx8, how to get some reliable n/a horsepower while maintaining some driveability for daily driving? Is a streetport the only solution? Or bridgeport is the other one but sacrifices reliability much?
I had to come back and comment again, I asked my engine builder about semi peripheral port engine. I was told is true semi can out perform bridge and only good for drag. Because you'll likely see boost being made from 6k rpm which too high for a street car.
Too high? Only time anything is ever too high when driving a street car is boost. Anyone i've met/talked to that has or does street drive a built car, they never ever mentioned anything about RPM ever. Lol! And 6k RPM is nothing.
@@TampaxVortex.666 What you on about? Boost coming in at 6k rpm is not too high, who have you been talking to, they like driving laggy drag car's/engine on the streets do they and thinks it's cool and normal? You don't get the point I'm making, semi PP is popular in drag racing because off the line you can launch from 6k rpm. In a street car which most of the time you need boost instant around 3k rpm minium!
@@MrChayl3 My bad, thought I saw you only mention RPM and not boost. Lol! That what i get for not double checking. But now that I know what was said, I agree. I had a car that would spool up around 4k, depending on weather, and I didn't like it. Felt hella lifeless until then, too.
I can tell you that’s not true there are plenty of street cars running semis with no lag issues on the road also there’s a guy in Cali all he does is build semi pp for street cars
What I don't understand is why hasn't anybody gone full P-port, and then drop in an asymmetrical reducer ring to tune the timing and overlap? If you used reducer rings, you could have something with a great huge hogged-out hole that flows like crazy but doesn't have any more overlap than a mild street port.
What about beveling or streamlining the intersections between ducts and working surface? Meaning the ports interface. You have a chart about this in 'Manual of Automobile technik', by BOSCH. An straight angle generates turbulence, losses, beveling improves a bit the situation, a parabolic section of duct when entering working chamber gives near 100 % Efficiency. It also mitigates the shock of seals every time it pass over port, the hammering as in 'chattered marks'. Blessings +
not much. I'm not no rotary guru but a 12a carbureted non turbo won't get much hp increase even with porting. Unless you go peripheral, expect 2-10 hp out of a street port, maybe 8+ on an extend port, not sure about the other porting
To be honest it really depends on what your goals are. The most power full PP. but if you want more bottom end. Semi p but you will loss some top end power.
i went to one of my countries best rotary builders and was told when i asked for a semi pp turbo it was to much for the road.. yet they suggested i do a bp turbo.. i walked away as i wasnt getting what i asked for.
draggeeks1 I do a drag semi different then a street semi. I do a medium street port and a Medium D port on exhaust. With a 3/4 semi p port. It works great on the street paired with the right turbo. It’s a beast on the street and not to choppy getting off the line. Some people go over board when porting and that is not good for the street.
