Hey...if they could only get 250hp out of a new rotary, I'd be ok with that. In my mind, all they need to do right now is put out something better than the Toyobaru Twins since there is really no other competition, especially knowing that the Z is now likely on the way out.

I agree with you, but also think that since the RX-8 is already a superior car to the twins (outside of fuel economy, you get what you pay for.. smiles per gallon) they could really push for something better. I wouldn't be disappointed with a sub 300 HP NA engine, as long as the weight is kept down, but I do think Mazda is more than capable of hitting the 300 mark, and certainly so if they raise the displacement a bit. 300 NA hp on the nose would be fantastic, especially at anything below 3k lbs. A 1.6L 2 rotor may just be the ticket ;)

That's one thing that for-sure won't happen. The emissions and economy challenges come from the way the rotary works; namely intake/exhaust overlap and poor thermal efficiency. Those problems are compounded when you add more rotors. They are improved when you take away rotors or make the rotors bigger like in the 16x. In the unlikely event we see another rotary sports car I think it will still be a two rotor of the same or larger diameter as the 13B/RENESIS.

Yeah. I don't agree with the naysayers that insist it can't or won't happen, but I also don't agree with the people that get all excited and push for performance numbers that would push the car significantly outside of where Mazda has always been with road car performance, and/or into cost ranges that are approaching or surpassing double their current highest priced car. That just isn't reasonable at all.

a 200-220hp 2-rotor engine (detuned for longer lifespans, remember how the 100hp 13b has no problem topping 200,000 miles), and in a 2,500-2,600lb car would be roughly what I'd expect. Mazda won't want a sports car as heavy as the RX-8, their entire corporate direction is lighter lighter lighter, and in order to stay in the ~12-14lbs / hp range that they almost always have, that means the engine peak power drops correspondingly, which in turn drops the weight of things like drivetrain parts and brakes, and the engine power reduction also has significant financial gains in warranty/repair/lifespan/reliability/public-perception areas, plus a cheaper more affordable car for the public to buy. All good things for the company.

I'm positive that if anyone wants a higher power option, Mazda will be content to let them figure that out on their own dollar, footing their own repair costs, etc... It simply doesn't make sense for Mazda to produce a car with 300hp or more in a car with 2,700lbs or less, priced at a point where far less people can even buy it, with a greater headache, financial cost, and larger PR problem around warranty and repairs. Sure, it looks good in magazines, but again, pointing you back to the 2016 ND. They said they never once set performance benchmarks, never once tested a 0-60, never once put it on the skid pad for G numbers. Mazda just won't build a sports car to that level, or if they do, it will be a limited Mazdaspeed run, and not at all the base model.

Regarding port overlap:
I've often been curious about Mazda developing "Variable valve timing" for the rotary, to change the port characteristics dynamically. I'd expect there would be very noticeable gains in power, efficiency, and emissions if they could. It certainly would add more moving parts to the engine, reducing the simplicity for sure, but the gains could be worth that.

Dynamically variable ports are built into your 6-port RX-8. :)

There are dynamic intake valves, but not actual dynamic port valves. The ports in the irons stays the same shape regardless of RPM and flow. I'm referring to a changing port shape/position based on RPM and flow, which would function as variable valve lift, duration, etc... in an overhead valve piston engine.

Back in 2010 Mitsuo Hitomi, general manager of Mazda's powertrain division, said that the 16X was more fuel efficient than the non-Skyactiv 2 liter piston engine, even though there were problems meeting emission standards.
If one of the two main problems reported here (economy and emissions) had already been solved 5 years ago, then the other one could have been solved since then as well.

2012:
Mazda Design Breakthrough May Give Rotary New Life | Vehicles & Technology content from WardsAuto


(and incomplete burns cause further emissions problems, so they are hand in hand here)


The information nuggets about the development of the engine are out there if you look for them mixed in with all the rumor mill stuff.

If a port is closed it's effectively not there, if they are open it's effectively one big port. So it absolutely does dynamically change the "shape", "lift" and "duration" of the ports when the SSV and Aux valves open and close just like variable valve lift and duration etc. in a piston engine. Think about it.

Timing isn't changed as-is, true. But put an SSV-like valve on the primary ports and then timing becomes variable too. Albeit in one big step unless more ports and valves are added.

Yes, i'm fully aware of how the port's actual available open area does change as the rotor changes it's position across it. But that shape is still entirely fixed to one sequence. Making it variable would have gains. The simple fact that different porting work can move the torque peak around as the shape is changed proves that.

Blocking or introducing an entire port airflow as a means of making it "dynamic" is certainly something that they do, but that doesn't actually close up that gap to what would be optimal.

I really don't think the Mazda rotary needs yet another sliding interface to try and seal. Seals are at the root of most of the reliability, economy, and emissions problems we already have. You've seen what happens to the SSV when it gets caked with carbon. Can you imagine what would happen to a sliding port valve?

Multiple ports with control valves is the best approximation of variable ports the way-smarter-than-we-are engineers at Mazda could come up with. I'm sure they have thought about and maybe even tried a sliding port valve or some other method of changing the actual physical shape of the ports.

I can think of a couple of ways of doing it that have no need for any seals :) Or even wear surfaces.

Well then, get on the phone to Mazda's apparently-not-smarter-than-you engineers, stat! ;)

This is known as "motivated reasoning".
Taking a position and then finding the facts to back it up.

If the facts presented are true(proven), I guess the position was correct. :dunno:

there's no overlap in the Renesis. in fact a few race engine builders figured out ways to induce overlap to increase scavenging for more power

dynamic port shaping via some kind of sliding/rotating door? no thank you

But your points are more valid/proven, so these fallacies don't apply to you? All kidding aside, we'll all just have to wait see [EDIT] about whether or not Mazda will make another rotary powered vehicle.

IMO laser ignition is probably what will spur the rotary back into a production vehicle. The new laser plugs will last longer on higher compression. In addition, igniting the air fuel mixture from the center will increase how efficiently and evenly the mixture burns. Rotary engine emissions suffer because of the longer chamber being unable to ignite fully and properly. Ignition seems to be the one piece of the puzzle that hasn't been upgraded in most vehicles yet. The technology is being pursued, advances have been made, its simply a matter of time before it is figured out.

That is an interesting development to watch. It is promising for the rotary, not only for the reasons you list. I think Mazda mostly whipped the long chamber problem with dual plugs, but more-complete combustion never hurts. I think the biggest advantage would be elimination of the spark plug holes and cavities which allow lots of blow-by as the apex seal passes over them. Presumably with a laser there just needs to be a small optical window. If that window is flush with the housing surface it would eliminate blowby completely, improving emissions and economy. The apex seal would "wipe" the window with every pass (which wouldn't happen in a pissed-on engine, so presumably the window is self-cleaning just from the laser energy alone).

Looks like a laser manufacturer has demonstrated a prototype engine using laser ignition this year. More here.

Good on you GW!!...

I love your passion for Mazda's and anything RE.

YOU are the customers Mazda really does respect and will always do the right thing for you....always.

I certainly do not need to lecture you, but any owner who has a good relationship (long) with their car dealer will ensure they are looked after in the event of anything going physically wrong.
This is precisely how Mazda Australia and their private Retail Dealerships operate here and why the brand is the most successful one in the worlds largest and saturated market, no where else will you see over 65 different car makes for sale offering new cars.
Again why Mazda Australia has Dealers who have maintain their businesses for over 40 years and don't or wont sell any other make.

Mazda are not like 'other' car makers, they will not churn out cars which do not have a purpose, I can not think of any Mazda model which have been known as 'duds or lemons' from day one of production...perhaps a few Ford induced models (maybe).

Keep up your passion M8.................

Ash

All new Mazda EX-2
 

This is the rumour coming out for the Tokyo Motor show next month.

YES there will be an all new Mazda Rotary Concept.

Not certain on what platform this model will be off, my guess is the Mazda 3.
It will be essentially an electrically driven 4 seater vehicle, with a small Rotary Engine as a back up Generator supplier, similar to the Mazda Demio/ Mazda 2 EV.

It will be called a Mazda EX-2, E is for Electric, like R is for Rotary.
X is for experiment.

Anyway, while this is Interesting, it is not a RX- model.

It is not a Rotary Engine powered Sports Car.

Interesting times, we will see.

None are production ready at all.

Even the Koeru (whatever) thing was a mock up with NO opening doors or physically interior design,
this is/was rumoured to be a all new CUV, called a Mazda CX-4, as a 5 seater and off the CX-5 platform, a sportier CX-5.

If the window is even faintly narrower than the apex seal width, there would never be blowby, and that is possible. Also possible is a laser window in the iron, uncovered like the ports are. Also possible is a laser window in the rotor itself, though that would be more complicated. I could see a single laser able to shoot down the e-shaft and reflected at the right timing range for each of the 6 rotor faces into the combustion point, firing as the timing maps determine when. Too complicated to actually be used though, just possible. Port based in the irons is most likely i think. If they use lasers at all :)