Gasoline Direct Injection

[Irvingthien]

I heard some one in the Mercedes FO110Q forum that the Mp4-18 engine used gasoline direct injection.does the engine in the MP4 -19 has GDi too?
can anybody explain to me how it differs from traditional fuel injection and does it produce the same amount of hp using GDI.

[NickT]

Just read a big article in Race Engine Technology. GDI isn't quite ready for the dissy speeds of an F! engine just yet, but all the manufactures are looking at it for the future.

However that is not to say that some of the technology is not being incorporated currently. Fuel pressure at the injector has risen massively in recent years and the injector technology is also bing used, all be it still by indirect injection into the intake manifold. Basically this enables better atomisation, mixture control and charge cooling all adding up to a much fatter torque curve and some extra Gee Gees to

[Guest]

If I'm well informed Audi has been using it in the 24 hrs of Lemans to good effect for the past 3/4 yrs? Should I be right, then GDI could as well be feasible in F1 engines given that the Audi Lemans cars produced around 600bhp. However F1 engines rev so high that I'm not too optimistic about it...but I might be wrong though. If we find out that the mclarens can pitstop much later than the oppositions in races, this would add weight to the rumour that Mercedes has got GDI technology in its latest engines...

[Strax]

They won't be pitting later than the other teams necessarily since one of the major changes in the MP4-19 were the smaller fuel tanks. They said that it was because of the new regulations, but who really knows...

[Guest]

They won't be pitting later than the other teams necessarily since one of the major changes in the MP4-19 were the smaller fuel tanks. They said that it was because of the new regulations, but who really knows...

But still, smaller fuel tank (like other teams) & much lower fuel consumption means you could pit later!

[Reca]

Until now I’ve read many opinions by engineers and none was convinced that GDI is currently feasible at F1 revs, furthermore most of them have many doubts about it being a real advantage.
Amongst the different gains, the main benefit of the system in production cars is that it allows to use a stratified charge at part load, meaning a non-homogeneous distribution of fuel in the combustion chamber, lean mixture in most of it and the right fuel/air ratio just close to the sparkplug, reducing fuel consumption. At full load an homogeneous distribution is required anyway and since a race engine is almost ever at full load, the advantage is definitively reduced. According to Audi, on production cars, the fuel save because of the FSI (Audi DI) is up to 15%. In the 3 times Le Mans winner R8 they managed a reduction of 7-8%. That’s enough for a 2 stops save (180 liters of fuel and lot of time) in 24 hours, but, also assuming, very optimistically, a similar % gain for a F1 engine, it would be less than 15 kg in the whole race. FIA new rules makes each year more profitable an increment of number of stints, so this amount has to be divided by the number of stints, probably the advantage is just 3-4 kg, possibly 1 more lap per stint, not the huge difference you expect and not automatically a decisive factor because with 2+ stops the best strategy isn’t necessarily to stay out a further lap, things are more complicated than that.
Apparently GDI works at his best in low revving engines with limited overboost for endurance races were also a minimal gain in fuel consumption is helpful, exactly the description of the R8 3.6 V8 turbo engine and revving at less than 8000 rpm designed for LeMans.
An F1 engine has different requirements, anyway, as NickT wrote, almost all manufacturers are experimenting in conjunction with fuel suppliers so if it’s possible to adopt the system and it’s helpful we’ll surely see it in the future.

[mx_tifoso]

Good idea to search for this topic before starting a new one...

Does anyone know of advancements or any news at all regarding the use of direct injection in Formula One?

I've been researching this technology for the past hour or so, and have read some very good articles on it, which led me to wonder if it is possibly used in Formula One at the moment. Although from what 'Reca' said I doubt it is, given that engine speeds remain at about 19K.

Well, I just looked up the engine regs, albeit for 2006, and came up to this section;

5.7.2 Only one fuel injector per cylinder is permitted which must inject directly into the side or the top of the inlet
port.

This means that 'Direct Injection' is not allowed right? Since fuel must be injected into the inlet port, which leads to the combustion chamber, thus negating DI...

Although what about the quantity of fuel pumps permitted for [edit>] the engines? Is it only one or multiple?

Thanks in advance.

[DaveKillens]

As you pointed out mx_tifosi, the positioning of the fuel injectors is very restricted. As well, the fuel pressure cannot exceed 100 bar. I did not see any reference to the number of fuel pumps allowed.

5.7 Fuel systems
5.7.1 The pressure of the fuel supplied to the injectors may not exceed 100 bar. Sensors must be fitted which directly measure the pressure of the fuel supplied to the injectors, these signals must be supplied to the FIA data logger.
5.7.2 Only one fuel injector per cylinder is permitted which must inject directly into the side or the top of the inlet port.

It's a shame that Formula One engines have such restrictions.

[Belatti]

5.7.2 Only one fuel injector per cylinder is permitted which must inject directly into the side or the top of the inlet
port.

This means that 'Direct Injection' is not allowed right? Since fuel must be injected into the inlet port, which leads to the combustion chamber, thus negating DI...

Although what about the quantity of fuel pumps permitted for each cylinder? Is it only one each?

Thanks in advance.

Right, it is not allowed.

But your q about pumps its a very good one. I think F1 engines have only 1 fuel pump, maybe pump-injector arrengement is not necessary in indirect injection engines.

I got plenty of info about GDI for passanger cars, Including Porsche, GM, Audi, Bosch, Siemens and Renault papers. I will re-read them to see what can I find.

From the top of my head, it is prefectly achievable to inject up to 6 times at 7000 rpm and that would let us inject 2 times at 21000 rpm and 3 times at 14000 rpm.

EDIT: oops, Dave has overtaken

[mx_tifoso]

Here are some links to Porsches LMP2 RS Spyder, which happens to use DFI in a high revving naturally-aspirated engine. They were provided by a good old friend... thank you.

Gordon Kirby: The Way It Is/ Searching for efficiency au Petit Le Mans

Porsche RS Spyder: Technology & Concept

Mulsanne's Corner: News July/August 08

Jalopnik: New Porsche RS Spyder Race Engine Gets Direct Injection

[donskar]

5.7.2 Only one fuel injector per cylinder is permitted which must inject directly into the side or the top of the inlet
port.

Just ANOTHER example of the FIA forcing F1 to be trailing edge technology.

[alexbarwell]

Yes, Audi lemans have been using DI on the V10 diesel for the past few years. Production car electronic injection, simple versions were little more than a solenoid valve off the pressurised fuel line serving as an electronically regulated jet high up in the throttle body, everything else was traditional, a lot of fuel dropped out as droplets in the manifold making for misfueling and iffy emissions. More recently, multipoints took the injectors to either a late point on the inlet manifold or early on the head. I think mitsubishi were early adopters of GDI once they developed an injector that could handle the heat and dynamic pressures of the combustion chamber.

[mx_tifoso]

RCE mentioned in their article about the Porsche LMP2 DFI V8 (say that five times fast) that in road car engine DFI can contribute up to double digit fuel economy figures.

And with the direction this fuel system is moving, I don't see why it can't be used in Formula One in a few years, given that engine speeds might decrease a bit. Porsche's is the fastest revving DFI engine at the moment, at about 10k.

[Belatti]

I got plenty of info about GDI for passanger cars, Including Porsche, GM, Audi, Bosch, Siemens and Renault papers. I will re-read them to see what can I find.

From the top of my head, it is prefectly achievable to inject up to 6 times at 7000 rpm and that would let us inject 2 times at 21000 rpm and 3 times at 14000 rpm.

Still with no time to sit and read, I was wondering, if the limitation of current Injectors for a revy engine is the frecuency, what about using... charaaaaannnn 2 Injectors?

[riff_raff]

Belatti,

The injection duration required (generally referred to as PW or pulse width) is much shorter for a DI diesel engine than for a GDI engine, operating at a similar speed. In addition, the modern common-rail DI diesel injection system operates at rail pressures approaching 2000 bar, while a GDI system will only need about 200 bar.

The DI diesel injection duration may be as short as 0.1 millisecond while the GDI injection event may be 10 times as long. But even at 0.1 msec/injection, the modern piezo-electrically actuated injection nozzle is up to the task. Modern production diesel engine injection systems use up to 5 sequential injections per cycle, from a single injector, if you can believe it! A GDI F1 engine at 19,000 rpm would only need to achieve a 0.3 msec injection event at minimum. So it's achievable, even with production injector technology.

Take a look here: http://www.conti-online.com/generator/w ... gi_en.html