Renesis_8

Probably just above it, they'll find a way to avoid the injectors, or leave enough room for them, since it is the only way to route the intake track.
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Buy bubblers

Renesis_8

I like the idea that we get both DI and port injection. Since we only need the fuel economy at low rpm, who cares about it at high rpm! thats when the port injectors kick in.

Perhaps putting the DI injector above the spark plugs is harder than we thought, with a moving combustion chamber, they definitely need a lot more time to play with this idea. Tuning is gonna be a nightmare if we do end up with a DI injector above the plugs.
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Yenniffer cam

chetrickerman

Personnally i dont think they will have a third spark plug, cause if you look at it, when that fires, its gonna push the apex the opposite way than you want it to go, so i think it would hold the engine back. If anything, the 3rd plug would be underneath the first two. But thats just my two cents

rotarygod

It would only do that if it fired first. When the 3rd plug does fire, it's only getting residual fuel and the flame front has already been established in the correct direction. It wouldn't push backwards at all.

chetrickerman

oh, good to know. I agree with renesis 8 in that the DI should come on until WOT or near there, then the PI should come into action.

Renesis_8

Just as what RG said, this idea is also tried and tested in the 1991 LeMans winning 787B. So it works great!

I am trying to find the Technical paper for the 787B again, to look up the benefits of the 3rd spark plug in the 4-rotor engine.
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Headshop

rotarygod

It was decreased fuel consumption and greater torque. Keep in mind it was only about a 3-4% improvement but that's still an improvement.

Renesis_8

The 3rd spark plug will also give you some torque. The graph is a comparison to a 2 spark plug engine.


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Avandia Settlement

chetrickerman

wow, very nice mazda, keep it up! im stoked.

Floyd

I could be wrong but wouldn't the cooling effect be negated if the DI injectors weren't fired along with the intake? If the intake cycle is closed before DI then the charge density would be fixed. Wouldn't it? If this is the case perhaps that is a reason that the DI injectors are where they are, to maximize the cooling effect and increase charge density.

Lasse wankel

Ok you're absolutely right!

/Lasse

Mazmart

iTrader: (12)

Direct injection in a Wankel is definitely not the same as it's piston powered cousins. There are all sorts of obstacles.

Paul.

rotarygod

Of course you know nothing about all of that!

Mazmart

iTrader: (12)

Nothing, nothing at all!

Paul.

ASH8

Yea, Well this old fart is still VERY concerned about the price of gas...
$100.00 US a barrel soon...

I recall when Mr.Forbes (your $billion icon) was in Australia a few years back oil was at $62, he said, "OH oil will be back to $30 soon"!!. Yeah right.

The way the US dollar is going, you guys will be paying a lot more for gas and cars.
I am really concerned about the 16X future as a gas only rotary.

The dearer gas becomes the more marginal V8 and Rotary sales are, who are going to buy them.

It was back in 1973 when Mazda were working on the 15A a 2 x 737cc Experimental Rotary, and do you know what stopped it, the oil crisis.

I hope the bean counters at Ford do not do the same again, History repeating itself here.

I want this to succeed..

Spin9k

The world has turned...several times in fact since then. Then it was a shock. Now..we're pretty used to the ups and down. Not a deal killer anymore. You see plenty of mega pickups and mega SUVs, etc. transportation has become a lifestyle, sports cars will always be a minority, but its a pastime created witrh disposable income. too. Anyone who wants that has to pay.

ASH8

^^^ I beg to differ, SUV and large gas guzzlers are down in sales by 35% or more.

Fuel cost has an effect on the hip pocket and what people buy.

I agree sports cars are very much the sales minority, but, they also have to be a
profitable venture for the manufacturer.

neit_jnf

so if the thickness of the coolant pasages (engine OD-ID) is smaller, wouldn't this reduce the engine's potential for boost? thinner rotor housings = structurally weaker??

Rootski

iTrader: (1)

So I assume running negative split on the far trailing would be a big no-no?

Sigma

Overall. Sure. But many models are actually up year-over-year. Large and Luxury SUVs in particular. Sales of the Expedition are up 20% from last year, largely on the success of the uber-large stretch version available now. Sales of the Navigator are up 10%. Land Rover as a whole is up almost 10%. September sales of the Escalade were up 20%, the Suburban up 35%, Tahoe up 60%.

The models that are down the most are those that are easily replaced with more crossover-type vehicles. That segment was more fuel-price-sensitive than others.

There'a always going to be a market for V8s, large vehicles, and other gas-guzzling vehicles. And it's a VERY substantial one. There's a whole lot of people in this country with a lot of disposable income. That doesn't mean that the segment isn't going to, as a whole, shed off a lot of fuel-price-sensitive buyers. It of course will, particularly on the low-end of the market (cheaper trucks and/or smaller SUVs). But when you're talking about large/luxury SUVs you're talking about vehicles that are $40-60,000+ -- those people are potentially paying $1000/month for a car payment and certainly making a decent chunk of change. An extra $100 for fuel isn't a significant deterrent to much of that market.

The key is to offer a vehicle that doesn't have a suitable, perhaps more eco-friendly, alternative on the market. Make a vehicle that gets 30mpg and is as big and luxurious as a Lincoln Navigator, and perhaps you'll see some sales move.

The sports car market is much the same. Fuel economy is definitely not a prime consideration for most of that market. The buyers generally aren't going to go "I came here to get a 350Z, but man, that Sentra gets 40mpg, I'll take one of those instead". But, all else being equal, if they are having a hard time deciding between two sports cars and one gets 16mpg and the other 24mpg, that could certainly help them make their decision.

fmzambon

Especially if, like it's now here in Italy, the price for unleaded reaches 1.32 €/l (roughly 9.2 $ per gallon using 1 gal = 3.78 l and 1 € = 1.42 $)
Then it's easy to understand why here diesel sports car are becoming common...

Well, at least I drive a diesel car that manages 52 mpg

Mazmart

iTrader: (12)

And back to technical observations about 16X please.

Paul.

chetrickerman

i would doubt it. rotaries have really high temps inside them, and i assume the developers took that into consideration, so im guessing they used a different type of aluminum, or added some structual reinforcement without sacrificing the cooling flow. There are many different grades and types of aluminum which have different strenghts and weaknesses. 6061-T6 aluminum is a rather high grade but cheap too, 7075-T6 is more expensive, but almost 40% stronger than 6061. But we will see what they have in store for us.

zoom44

Mark Rechtin of AutomotiveNews had an Interview with R&D chief Kanai about the 16x during the show. Article will be in this monday's edition of AutomotiveNews.

chetrickerman

where/what is that? never heard of it.