Mazda Switching to Direct Injection

[Antoine]

Mazda Switching to Direct Injection
Source: Car Connection


While green machines didn't dominate the floor at Makuhari Messe the way they have in years past, automakers from <?XML:NAMESPACE PREFIX = ST1 /><ST1LACE w:st="on"><ST1:COUNTRY-REGION w:st="on">Japan</ST1:COUNTRY-REGION> </ST1LACE>and abroad certainly didn't ignore the issues of mileage and emissions. Mazda CEO Hisakuzu Imaki opened his company's press conference by promising to "pursue" direct injection gasoline technology, which could soon dominate the Japanese maker's powertrain lineup. DI systems inject fuel directly into the cylinder to improve the combustion process, boosting both performance and mileage, while lowering emissions.

Mazda, added Imaki, is developing a "smart" engine stop/start system that will go into mass production "in three years." It's also set to begin testing of a new hybrid powertrain system developed by its <ST1LACE w:st="on"><ST1:COUNTRY-REGION w:st="on">U.S.</ST1:COUNTRY-REGION> </ST1LACE>affiliate, Ford Motor Co. A prototype, hydrogen-powered version of the RX-8 sports car will go into limited leasing next year, while a hydrogen-fueled version of the Premacy is under development, as well, according to Imaki.

 

[vindication]

yeah, doesn't the MS6 and regular 6 come with this. lots of other companies have been using this. bout time mazda does

 

[Iggy]

the regular 6 does not, but companies are making a move torwards it. would it be possible on the renisis? or is a rotary automatically direct injection

 

[Rainman]

IIRC, the MS6 is the first direct injection production vehicle in North America. The other NA Mazda 6 vehicles do not do this yet, and the other manufacturers do not offer direct injection on any of their NA models.

R

 

[SciFiMan]

Who the hell is going to lease a hydrogen RX-8? There's only a couple places in the country to fill it. I suppose it may help with real-world testing and refinement though, so that in a dozen or more years regular people may get them.

 

[evilmonkeyMSP]

The new MS6 is Direct injection...its on Mazda USA's site...

 

[eting_pro5]

Audi had it first I'm pretty sure.

Does any one know the technical reasons that make direct injection more efficient than current methods. I understand that it allows more accurate fuel delivery to each cylinder, but isn't there less atomization of the fuel if its mixing with the air for such a short time?

IIRC, the MS6 is the first direct injection production vehicle in North America. The other NA Mazda 6 vehicles do not do this yet, and the other manufacturers do not offer direct injection on any of their NA models.

R

 

[evilmonkeyMSP]

actually didnt Isuzu have it first in the Axiom?

 

[BradC]

Audi had it first I'm pretty sure.

Does any one know the technical reasons that make direct injection more efficient than current methods. I understand that it allows more accurate fuel delivery to each cylinder, but isn't there less atomization of the fuel if its mixing with the air for such a short time?

From "http://en.wikipedia.org/wiki/Fuel_injection#Direct_injection "
"Some hi-tech petrol engines utilize this system as well. This can improve the engine's volumetric efficiency by permitting more design freedom for the air induction system. The injector also features distinct spray modes to better manage combustion characteristics."

Also check out http://www.siemensvdo.com/products_...irect-injection/gasoline-direct-injection.htm

 

[ZoomZoomH]

this is just the next step in ICE evolution, much like when carburators were replaced by fuel injection 20 years ago

 

[Kooldino]

I understand that it allows more accurate fuel delivery to each cylinder, but isn't there less atomization of the fuel if its mixing with the air for such a short time?

No, because it runs higher pressure and has a more optimal spray pattern.

 

[ZoomZoomH]

^which means more power AND better efficiency

 

[ZoomZoomH]

the regular 6 does not, but companies are making a move torwards it. would it be possible on the renisis? or is a rotary automatically direct injection

i think the hydrogen/gasoline hybrid rotary engine they're testing/leasing right now is direct injection... or they just have 2 full sets of injectors for switching between hydrogen and gasoline...

the current production RENESIS is regular fuel injection, where air/fuel is mixed in the intake manifold before entering the combustion chamber

 

[Spooled]

There are a lot of direct injection engines out/coming out all at once. It's definitely the way to go. I've driven 3 cars with the VW 2.0L FSI turbo (GLI, A3 and A4) and it's amazing. You can have a higher static compression ratio matched with a turbo for an awesome powerband. One of the best parts is that you are injecting the fuel in during the combustion stroke (like a diesel), so the chances of predetonation are reduced immensely.

 

[TheMAN]

nissan has been selling direction injection engines in japan since about 99 on certain cars... such as the sunny and primera.... with "NeoDI"

 

[Mallard]

Actually Mitsubishi was the first company to produce a DI engine. GM did a lot of research on it in the 1980-90's until the project was put on hold. Mitsu stepped in where GM left off and was able to bring it to production.

The injectors shoot a very fine mist of fuel, which requires very high fuel pressures. (20-60,000 psi is not unheard of) Direct injection allows the engine to run leaner when not under load by injecting the fuel later in the cycle. Since the fuel is injected in the cylinder and not in the intake port you don't have to worry about pre-detonation. Because of this you can run higher compression ratios that boost power and volumetric efficiency. Plus some of the fuel injected will vaporize and cool the intake charge/cylinder walls.<!-- / message -->

 

[eting_pro5]

No, because it runs higher pressure and has a more optimal spray pattern.

EDIT: NEVERMIND. Didn't see we were to page 2 yet. Thanks Mallard.

Are you saying higher fuel pressure, or just higer compression ratio?


I understand that you can run a higher compression ratio with the DI systems, but do they also run on higer fuel pressure?

 

[TampaSport20]

Who the hell is going to lease a hydrogen RX-8? There's only a couple places in the country to fill it. I suppose it may help with real-world testing and refinement though, so that in a dozen or more years regular people may get them.

Actually there are multiple fill up places in California, which is most likely where they will sell it...also it is stated they are commercial leases....certain companies will have their own fill up stations

 

[ZoomZoomH]

actually, those leased Hydrogen RX-8s are for Japan only.......

 

[Mallard]

EDIT: NEVERMIND. Didn't see we were to page 2 yet. Thanks Mallard.

Are you saying higher fuel pressure, or just higer compression ratio?


I understand that you can run a higher compression ratio with the DI systems, but do they also run on higer fuel pressure?

Higher fuel pressure in order to get better fuel atomization and higher compression ratios are also used.