What will come after the 2.4 V8?

[WhiteBlue]

The pocket in the piston makes it air based combustion. This is the type of system that Porsche uses with lower pressures and higher pumping losses due to the gas exchange requirements of such a geometry. The possible efficiency improvements of that strategy are more limited than the spray guided process.

[ringo]

Yes

[WhiteBlue]

That is a very good graphic explanation. We probably agree that F1 engines will only use the best available equipment and processes?

[ringo]

Yes the stratified injection is better. Well, we know Mercedes has no problem implementing this, since it is already being used on their cars.
BMW may return to F1 as an engine supplier, since they have mastered direct injection turbo charged engines with their 335i.

Whether the lean burn will be used or if the FIA even allows direct injection, we'll have to wait and see. The main issue is the NOx production, this is only remedied with catalytic converters. The cars will be releasing more NOx into the air than the current engines, though there will be less carbon.
Can we expect cars with catalysts in 2013 as well?
I sure hope not. The sound is very crucial. The cars are very slow as they are already. It wont help if they sound sluggish.

[riff_raff]

For the most part, a race engine would not benefit from stratified (lean) charge combustion, since they're primarily concerned with best power. And that will occur with a homogeneous charge at near stoichiometric mixtures.

Production car engines are more concerned with SFC and emissions, and they tend to mostly operate at part throttle, so stratified charge operation is very beneficial. For these engines, wall guided GDI is probably best. For part throttle, stratified charge (lean) combustion, wall guided GDI uses late injection timing (after IVC) and "tumble" intake swirl to create a rich, easily ignitable mixture near the center sparkplug, and a leaner, stratified mixture further away in the chamber. For full throttle operation, the injection timing is much advanced so that a richer, homogeneous charge is produced.

Spray guided GDI is usually less effective, and also requires "helical" intake swirl for proper mixing. Helical swirl intake flow usually ends up being less efficient, and the centrally located injector means the sparkplug must be located in an undesirable position.

[WhiteBlue]

Spray guided GDI is usually less effective, and also requires "helical" intake swirl for proper mixing. Helical swirl intake flow usually ends up being less efficient, and the centrally located injector means the sparkplug must be located in an undesirable position.

I believe your knowledge is super ceded by the development of outward opening nozzles with high pressure and piezo drivers. The literature I quoted above says that they are much superior to twisting and multi hole injectors. They also overcome the need for helical intake flow by delivering a much finer spray that is more stable regarding penetration and is typically injected much later in the compression stroke.

Whether the lean burn will be used or if the FIA even allows direct injection, we'll have to wait and see. The main issue is the NOx production, this is only remedied with catalytic converters. The cars will be releasing more NOx into the air than the current engines, though there will be less carbon.

I remember that Gilles Simon (Jean Todt's new "Director of power trains and electronics" from Ferrari and Peugeot) has set a policy pro efficiency in his first FiA publication and that means pro direct injection and variable valves as well. He specifically mentioned downsizing and turbos which are obviously in the process of being decided by FOTA.

Jean has the conviction that we need to have sustainability in motor sport and that we must push forward the idea. The primary area where this can be achieved is in the design of powertrains. We believe that we need to work closely with all of the manufacturers to have a sustainable economy, with the right level of investment and return, and a technical direction that is right for their general strategy.

The trend towards smaller turbocharged engines in passenger cars is going to make them less noisy. But I am an engineer and I love the noise as it’s a main part of the show.

We have to try to push forward with fuel efficiency. If, as an engine engineer, I am given a maximum fuel load, I will try to give the driver the maximum horsepower possible, building the most efficient engine I can. It is a technical competition, and as efficiency is obviously good for road cars, that could be good for them as well. So we want to try to adapt the rules we have in the run-up to the new engine formula.

It would be strange if Simon would turn away from the path he used to follow at Ferrari and which have now brought Ferrari one of the best direct injected V8 engines on the market.

Regarding NOx I think that they will use EGR to fight this in partial load conditions which should be possible with the variable valve concepts.

[ringo]

Partial throttle is few and far between in F1.

This is for the Honda ra168E engine at the san marino GP.
Engine is relevant to the discussion because it's a 1.5lt turbo engine. It revs fairly high at 13,500rpm.
http://www.zzw30.com/HondaRA168EEngine.pdf



84% of the time the engine is at full load condition or off throttle. More focus will be made on fuel efficiency at these times. The DI policy may be completely different than what we see in production cars, where partial load and constant speed is the focus of stratified injection. F1 DI may be more targeted at anti knock and cylinder pressures.

The second graph is brake specific fuel consumption vs engine speed. As Xpensive said, engine speed increases friction power, from the relationship with oil film shear force, we all agreed to this. Increasing boost side tracks the need to build power with purely engine speed, however there is a balance, since boost can only be made with increased engine speed. The other diagram displays this perfectly.
Consumption reduces steadily, though there is an increase as it goes beyond 13.
I guess with improved cylinder materials and tolerances we may be revving beyond 10 and 13000 rpm.

Another thing that can be gleaned from the article, is the air to fuel ratios.

regarding air to fuel ratio, peak power is reached at an equivalence ratio of 1.15, and power gradually reduces as the ratio falls bellow this number.
The leaner the mixture becomes, the better the B.S.F.C., as shown in Fig12.
However with a ratio lower than 1.02, unsatisfactory transient response may appear, thus making the engine insufficient for racing performance.

I don't know what transient response it is referring to. An equivalence ratio of 1 is stoichiometric (fuel:air/ stoic fuel:air), but DI wasn't used then; maybe this transient response would be eliminated with piezo direct injection.

[alexisgreene]

I am new here and kinda jumping into the middle of this discussion. I only read the last 2 pages so I apologize if this has already been addressed.

Lean mixtures result in higher cylinder temperatures. I can understand the use of ultra lean mixtures with DI for fuel efficiency, but how are the extreme temperatures being kept in check?

[WhiteBlue]

Partial throttle is few and far between in F1.

This is for the Honda ra168E engine at the san marino GP.
Engine is relevant to the discussion because it's a 1.5lt turbo engine. It revs fairly high at 13,500rpm.
http://www.zzw30.com/HondaRA168EEngine.pdf

I believe that your example is not representative for today's technology. The old turbo engines had no variable vanes and massive turbo lag. They were practically driven with a binary throttle. Gerhardt Berger has told that story many times.

I would prefer to look at recent throttle statistics of V8 driven cars because they would give us a better representation of the partial load conditions that apply.

Lean mixtures result in higher cylinder temperatures. I can understand the use of ultra lean mixtures with DI for fuel efficiency, but how are the extreme temperatures being kept in check?

By using stratified injection combustion the fuel air mixture is wrapped in air. They are also using EGR to keep the oxygen content and the temps lower.

[ringo]

The engine formula of the eighties is the closest thing you will get to what we might see. The technology is fundamentally the same, just less refined.

The new V8s are in a different classification all together, you have almost twice the displacement and no forced induction. The torque curve will be very different along the rev range, and this affects how the driver manipulates the throttle as he makes his way around the track. Secondly i wanted something that is related to the rev range that you might prescribe to, 11,000~13,000 rpm.
Partial throttle is something that's seen only on turn exit, especially in the rain, where a driver wants to prevent slip and keep the rear under control. The car is also accelerating during these times so stratified lean burn injection wont be significant at these fleeting instances, especially when you want to build back the boost as fast as possible.

an example:
[youtube]http://www.youtube.com/watch?v=03VUI6jFknY[/youtube]
vs
[youtube]http://www.youtube.com/watch?v=bE13zilzvXE[/youtube]

partail throttle is something that is very rare in F1.

[WhiteBlue]

I don't agree with your view ringo. The throttle position is not relevant as the new engines will be throttle less. It is more relevant how partial loads are required for todays cars.

I also think that the fuel capped new formula will generate even more partial load conditions than we see today.

[ringo]

So F1 will no longer be racing then?

It will be a 2 hour waltz. I don't want to see that, I'm sure others paying big bucks to watch at the venues don't want that either.

Throtless means the intake valve will be doing the throttling. This will be wired to the gas pedal. Throttle plate or intake valves, full or off throttle will be the order of the day.


Your taking this green thing too far. To what end?
If production car racing or Lemans, which is more road relevant, is not doing what you prescribe, why should F1 cripple itself by taking up the burden of miserly fuel use?

If i had my way, it would be 1.5 lt turbo charged v6, mid bank twin sequential turbo, direct injection. KERS offcourse and maybe hydrogen fuel.

Rev how you like, boost how you like, just limited fuel. 6 engines per season.

If you want 1500hp, at 17,000rpm so be it. Just do it cleanly.

[WhiteBlue]

Throtless means the intake valve will be doing the throttling. This will be wired to the gas pedal. Throttle plate or intake valves, full or off throttle will be the order of the day.

That is not what I have learned about throttle less engine management. The valves will be having a role in regulating the engine power but also the fuel injected and the ignition timing. For every throttle pedal position, load and ambient condition there will be different sets of valve, injection and ignition parameters. Very complex management programs indeed.

Your taking this green thing too far. To what end? If production car racing or Lemans, which is more road relevant, is not doing what you prescribe, why should F1 cripple itself by taking up the burden of miserly fuel use?

The reason LeMans is not doing it is the use of air restricted diesels. If they would let the diesels run free they would be even more dominant than they are today. Essentially due to the different LMP and GT formulae LeMans cannot afford to really run fuel restricted.

But I'm convinced that F1 is going to go fuel capped. They have only one type of engine and that is going to happen in 2013 again - probably with the 1.6L V4s. There is no reason why a fuel capped formula cannot be as exciting as the present racing. In fact we already see self fuel restriction because with lower fuel weight the teams can reach higher performance. This will simply be enhanced to make the more fuel efficient cars go significantly faster. At the same time there will be different ways to improve efficiency.

Combustion
KERS
Aerodynamics

Teams will be using different strategies to get the shortest time to the finish line. I expect that to be exciting and very technical indeed.

[alelanza]

The ignition is actually some degree after TDC and the 12-15° ignition after injection is required to evaporate the fuel and help it cool the compressed air.

I think you have the bolded words all mixed up

[WhiteBlue]

The ignition is actually some degree after TDC and the 12-15° ignition after injection is required to evaporate the fuel and help it cool the compressed air.

I think you have the bolded words all mixed up

Injection starts 20° before TDC
Injection ends 10° before TDC
Ignition happens appr. between 2-5° after TDC

-> ignition 12-15° after end of injection to allow for proper evaporation and ignition in the downstroke.