$lacker

iTrader: (9)

if you think marriage is expensive, try divorce

Siraniko

iTrader: (13)

And it is cheaper to keep her lol

Bwarrrrrp

12's are being replaced by turbo 8's. 8's are being replaced by turbo 6's and 6's by turbo 4's. I would be surprised if we ever see a new v12 devloped.

It is still possible to keep piston engines within emissions targets because they aren't really that bad to start with, and it's easy enough to lean out the specific rev range tested. With every company on earth developing them, there is collaboration and competition driving the progress.

Emissions laws are based on total weight, not a ppm basis. That means that two rotors have twice the emissions of one rotor despite the same exhaust gas proportions. 3 rotors is worse. Only one company is trying to get the rotary anywhere (and truly we don't even know if they are even working it) so there is no competition to push progress. Pushing **** uphill is the proverbial. I'd love to see a new rotary engine, but I believe it's a false hope.

arghx

iTrader: (3)

You're very right about that. Smaller engines have less frictional and cooling losses. It's more efficient to run a smaller engine at higher loads than a bigger engine at lower loads in terms of CO2 emissions/fuel economy.

However, when an engine is being developed it all starts with a single combustion chamber, usually with a clear quartz window so that high speed photography can visualize what's going on in the combustion chamber. Mazda uses these with rotary engines, and of course it's common on piston engines.

It depends what you mean by emissions laws. If you are talking about CO2/fuel economy, it's based on what the vehicle produces and it depends on what laws and test cycles the market has adopted. It's super complicated.

When it comes to actual air quality emissions, like hydrocarbons and particulates, it's based on grams per mile (if USA) or grams per kilometer if Japan or European test cycles. The US is epecially complicated because there are a bunch of test cycles involved. The exact emission standard the vehicle has to meet depends on how it's classified and what the model year is. Basically a new Rx-7 would have to make the same HC/NMOG and particulate emissions as say a Volkswagen GTi or even a Corvette.

2017 would probably require California LEV III-ULEV70 emissions (Cali and Federal emissions will be basically the same for 2917) and then Euro 6C in markets that adopt it. I don't remember what the Japanese standards are for 2017.

Bwarrrrrp

Yes, I've played with them.



UHC, CO, NOx. The rotary in general is god awful at these.

When it comes to actual air quality emissions, like hydrocarbons and particulates, it's based on grams per mile (if USA) or grams per kilometer if Japan or European test cycles.

Which is what I meant by total weight. You may have a considerable low ppm reading in a griffon engine but at 37L there is going to be issues.

00SPEC

iTrader: (9)

"having a lend"

An Australian term meaning to be lying to a person for one's own amusement


says urban dict

fmzambon

True, but you missed some:

• 40th anniversary of the Rx-7 in 2018
• 60th anniversary of the Wankel rotary engine in 2017 (february the 1st 2017, if I remember correctly)
• 100th anniversary of Mazda in 2020

Is that enough of a motivation for Mazda ?

Piston engines are not that bad to start with if the engine is a fairly recent design. Try taking a piston engine designed in the '60s and make it meet modern emission standards.
That's more or less what Mazda has been doing with the rotary up to the Renesis.

Until we know for sure how much of an emission improvement can be had with the switch to a completely new geometry, I don't think we can call the rotary dead.

EDIT: 100 posts

Andrea.

t-von

iTrader: (8)

^Right! We may be to a point were we can thrown ALL conventional rotary combustion knowledge out the window with the new geometry. I have a strong gut feeling Mazda's got things sorted out for once.

j9fd3s

iTrader: (3)

they've been playing with it for almost a decade!

moritsune

iTrader: (3)

I only trust one strong gut feeling

Bwarrrrrp

Yes, never mind that "playing with it" included being removed from the european market for failing to meet emissions standards. Lets hope strong gut feelings can pull us through.

BryanDowns

iTrader: (2)

Thats actually why you are LESS likely to get a new Rx7 and instead an equivalent Mx7 or even nothing. Unlike those other competitors that parts bin from all kinds of other cars, the single largest expense of the entire new rx7 cant be shared with anything, making it nearly not a viable business plan.

j9fd3s

iTrader: (3)

they showed us the 16x in 2007. it is now 2014. this is 7 years. which is nearly a decade.

i'm not the gut feeling guy, there is a new SAE paper out on the rotary engine. Mazda outsourced the research.

the two questions that spring to mind are, why have a new paper if the engine is dead? and why outsource it if they have a rotary engine research lab in house?

BLUE TII

iTrader: (9)

the single largest expense of the entire new rx7 cant be shared with anything, making it nearly not a viable business plan.
__________________

That is about what Mazda said and everyone gave up hope on a new RX.

But then they showed their plan for the rotary generator which could be sold in high volume.

Soooo, Mazda could theoretically make a 1.32L 4 rotor based off the p-port intake, side port exhaust and direct injection generator motor with a couple special pieces (intermediate plate, e-shaft, oil sump, etc).

It can run off gas, diesel, e-whatever- brings new meaning to the word flex-fuel.

1,320cc and 1320ft in 1/4 mile... Yeah, this pretty much has to happen now

BryanDowns

iTrader: (2)

Would you really want a 4 rotor 1.3l rotary? Its basically whats already available but with twice the complexity and length.

As for research papers, remember it doesnt take but a team of one or two under a managers pet project to keep a few million dollar budget going. Doesnt mean it has any reasonable chance of making it to light

BLUE TII

iTrader: (9)

I will take what I can get, plus it would sound really good.

If the parts are cheap from millions of units in service instead of thousands that would be a bonus.

Bwarrrrrp

SAE paper number?

In complete seriousness, how will it run on diesel? spark ignition diesels run like **** and any compression ignition event risks destroying seals all over the shop.

Bwarrrrrp

edit.

fmzambon

If Mazda was really serious about using the rotary engine, there could be several ways to sell more of them. Mainly by offering the rotary as an option on more vehicles.
Obviously a mandatory requirement is that such a new engine must be comparable to a piston engine with similar output as far as reliability and fuel consumption are concerned.

A rotary Miata option would be the most obvious. Mazda, if I'm not mistaken, stated that the rotary is too powerful for the Miata, but a detuned 200 to 220hp rotary shouldn't be a problem. Plus it'd make the Miata even lighter. From a financial point of view, it wouldn't cost Mazda that much to drop a rotary in a miata after the engine has been developed for the Rx-7.

A more expensive proposition would be the idea of making a second gen Rx-8 on a further lengthened Miata chassis and using the same engine (or engines, if multiple configurations are offered) as the 7. Same engine, same chassis, only further stretched out compared to the 7. More expensive than a rotary Miata, but still able to generate sales to quickly recoup whatever must be spent on in in R&D and get a net profit.

One could also dream of using a rotary in the speed 3, but that's just a dream i fear .
By the way, the rumors of a 300hp speed 3 point even more toward a 350+ hp Rx-7, as they can't have an Rx-7 that's less powerful than a speed 3.

I feel that these rotary cars, if offered, could pass the 100000 units per year figure hinted at months ago. In the first couple of years, the Rx-8 alone was selling around 60000 units per year worldwide. Add a 7 alongside it and make both with a 2 and 3 rotor option and you'd be damn close to that 100000 figure. Then add the rotary Miata and you're done. And I didn't even mention the RE plug-in hybrid or the rotary generator.

A business case for the rotary can be found, if one really wants to. The problem is wanting to...

Andrea.

BLUE TII

iTrader: (9)

In complete seriousness, how will it run on diesel? spark ignition diesels run like **** and any compression ignition event risks destroying seals all over the shop.

Direct injection spark ignition Wankels have been running off diesel, JP jetfuel and gas since at least the Curtis-Wright RC2-60 U10 just fine since at least 1964.

I believe the most common comercial/military application of the Wankel has been Auxiliary Power Units (APU) due to its high power density, though now it is used for drones as well.

j9fd3s

iTrader: (3)

2014-01-1664 and 2014-01-1665

rx7 SE

iTrader: (5)

Definitely learned something new. That gives me more hope for this proclaimed new rx7.

KevinK2

Yes, based on hp/lb or hp/cubic-foot (engine volume), right?

.

thegemini

Can Mazda release a sketch or a rendering of something that may resemble a freaking RX7?

You know to keep me going for the next 3 years!

fmzambon

Mazda hasn't released anything as far as the body of the Mx-5 is concerned, and that car will be unveiled in a few months. No way they are going to release an Rx-7 rendering now .

I don't expect to see anything solid at least until the 2015 Tokyo Motor Show, and even then I'd expect an engine (or parts of one), not a complete car.

Andrea.