Scotracer wrote:Erm, the Italia has
no boost
If you think there's a comparable development cycle to go from a 3.0 NA V10 to a 2.4 NA V8 and from a 2.4 NA V8 to a completely new formula with many new technologies then you are dreaming. Especially given the far reduced workforce that the teams have now (most of the teams have almost completely disbanded their engine departments!).
Correct, about the boosting, but do you think that Ferrari is short of experience on turbo engines? The Italia has all the bells and whistles on the important stuff like the latest direct injection and variable valve technology. Ferrari are going to have a massive overflow in the engine department when the gestione sportiva is reduced from 900 to 350 people in December this year.
dav115 wrote:Just to throw a spanner in the works, Marmorini also said that it wouldn't be possible to use the I4 as a load bearing member in the same way as the current V8s without having a "huge engine casing".
The quote (translated from Italian) was
Besides this, Marmorini notes that to install an inline 4 cylinder engine would require a complete redesign of the chassis. "Like this it won't have a structural role", explains the Ferrari engineer, "It needs a reinforcement structure around it, if you are to do without a huge engine casing."
Source
here.
That is a valid point but nothing that can't be fixed by a good flange design on the chassis side of the engine. V-engines are more rigid but you can make L-engines sufficiently rigid by good design. The current gear boxes have smaller cross sections than L-engines and they are stressed as well. The BMW M12 engine that ringo showed in his pic has an iron engine block designed in 1961. That was massively pre CAD and the material was also well below current standards of material selection.
747heavy wrote:What would be the power advantage of DI with all bells and whistles compared to port injection?
What would be the potential fuel saving in full power mode? and why?
1. Power and fuel savings mainly come from the same source, better and leaner combustion. What you get depends of your injection technology and how much boost you apply. If you keep the boost the same you end up with fuel saving mainly. But you also get a bit more power because the direct injected fuel cools the air fuel mixture inside the cylinder by evaporation. With port injection the cooling effect happens to the uncompressed mixture. So with DI the evaporation works a bit like inter cooling which also boosts power. I reckon this effect is small like 1 % only.
2. Using the best spray guided outward opening 200 bar piezo injectors you get about 5 - 15% less fuel depending of the rpm range you use. At high power settings which are relevant for F1 the fuel saving would be at the lower limit. You do get a near homogenous non stratified mixture that is still a lot leaner than the port injected mixture. The lambda is about stoichiometric and higher. The fuel is injected in the compression stroke between 20 and 10° shortly before the piston is in the upper dead point and not in the intake stroke as in port injected. Spray guided means that the fuel spray is forming a hollow cone with very high pressure and speed. The process depends of a particular nozzle geometry and uses the fastest (piezo driven) actuators in the business. Due to the high speed of the spray the cone geometry is fairly stable at different internal pressures. The arrangement of the injector is at the top while the ignition source is on the outer diameter of the combustion chamber. Due to the spray geometry the fuel cloud is centered in the combustion chamber within a wrapper of air. This essentially causes the much leaner combustion. Older, less efficient direct injection methods are wall guided and air guided injection. They achieve much lower efficiencies. Air guided injection also causes pumping losses due to the need to initiate a revolving air movement inside the cylinder. Spray guided injection can be conveniently combined with throttle less engine management by means of variable valve timing and lift. I hope this helps with the understanding of the matter.
