Injector technology for GDI racing engines

[WhiteBlue]

I have recently searched online for specific information on injector technologies that can be used for direct injection for F1 engines. Here are some sources which I thought I share:

http://en.wikipedia.org/wiki/Gasoline_direct_injection
Some basic concepts of GDI

http://www.sae.org/mags/aei/ENRG/7142
Covers a new solenoid driven outward opening injector generation made by Delphi for spray guided stratified combustion which will become available in the next year.

http://books.google.de/books?id=GXUS1qa ... &q&f=false
This is the public section of a German language report estimating the fuel saving potential of various injection technologies. The book gives an excellent introduction into the state of the art three years ago and helps very much with understanding the concepts of wall guided, air guided or spray guided direct injection combustion.

http://books.google.de/books?id=ldkTecM ... &q&f=false
This public section of an English language book looks also into HCCI.

I hope that other engineers who are interested in direct injection will add more interesting references and perhaps also their own insights into the challenge of direct injection for F1 engines.

[alexisgreene]

Something I found interesting going through these links was the brief mention of laser ignition. The laser can even remove carbon deposits from its lens. The use of a remotely mounted laser diode and some type of fiber-optic cable leading to the combustion chamber would take up less space in and around the combustion chamber than a spark plug. No more ignition coils, no more dwell cycles, no more spark plugs or plug related problems (fouling, wetting, etc.), not to mention that a laser should consume less energy than a spark plug does. This is just me thinking...

Here is a link to some articles I found while searching for more information on this subject:
http://publik.tuwien.ac.at/files/pub-mb_2880.pdf
http://www.liv.ac.uk/researchintelligen ... nition.htm

EDIT: I read the 2nd article after posting this. Fiber optics seem to have been tested and do not work well.

[WhiteBlue]

Yep, I saw that but wasn't sure it was relevant. Results in a nut shell.



Looks like it could solve the location problem for the ignition better than a spark plug as the laser cuts a relatively long line through the combustion chamber.

[seenathkumar]

Fuel is a serious point the really show the difference.

[Just_a_fan]

I assume this thread is in the same vein as the others talking about rule changes for the near future. If not, I think direct injection is currently not allowed by the rules which require fuel to be injected above or to the side of the inlet port.

Presumably direct injection would be something the engine guys would like to play with if they were allowed to develop engines in a meaningful way

[Edis]

I assume this thread is in the same vein as the others talking about rule changes for the near future. If not, I think direct injection is currently not allowed by the rules which require fuel to be injected above or to the side of the inlet port.

Presumably direct injection would be something the engine guys would like to play with if they were allowed to develop engines in a meaningful way

Mercedes-Ilmor ran tests with direct injection in the past. Using 150 bar they could run to 16,500-17,000 rpm without losing power but after that it did cost some power. The fuel efficiency was about 5% better.

Back then it was however difficult to find suitable injectors, these days high pressure motorsport injectors are availible from for instance Bosch Motorsport.

http://www.bosch-motorsport.de/pdf/comp ... HDEV_5.pdf

[WhiteBlue]

The Bosch injector is at least one generation behind. It uses 100 bar injection pressure and it is inward opening. It is unsuitable for spray guided direct injection. But it is good to learn that less efficient technologies already give 5% fuel use reduction compared to port injection in motorsport. Hopefully higher developed injectors will significantly improve on this.

[Edis]

The Bosch injector is at least one generation behind. It uses 100 bar injection pressure and it is inward opening. It is unsuitable for spray guided direct injection. But it is good to learn that less efficient technologies already give 5% fuel use reduction compared to port injection in motorsport. Hopefully higher developed injectors will significantly improve on this.

HDEV5 can be used with up to 200 bar fuel pressure. HDEV4 is the piezo version (not listed on their website). They are considered second generation direct injection systems introduced a few years ago. The solenoid version use inward opening and the piezo version use outward opening. Outward operation require a piezo actuator or two solenoids and HDEV5 only got one solenoid.

Motorsport requirement will differ somewhat from production engines as racing engines operate with a homogenous mixture during high load and speed where mixture preparation is important. Passenger car engines are focused on part load and here the use of stratified injection can lead to significant fuel savings.

[ChrisTipper]

With the G.D.I keeping cost down because of the ECW, will Formula One use this say in 2013 as part of the new engines and KERS?

[WhiteBlue]

HDEV5 can be used with up to 200 bar fuel pressure. HDEV4 is the piezo version (not listed on their website). They are considered second generation direct injection systems introduced a few years ago. The solenoid version use inward opening and the piezo version use outward opening. Outward operation require a piezo actuator or two solenoids and HDEV5 only got one solenoid.

Motorsport requirement will differ somewhat from production engines as racing engines operate with a homogenous mixture during high load and speed where mixture preparation is important. Passenger car engines are focused on part load and here the use of stratified injection can lead to significant fuel savings.

As Ferrari are using 200 bar piezo injectors (probably outward opening) for the 458 Italia V8 I would expect F1 to use no inferior product. I hope they will be able to even improve on the data they got now. F1 cars are also in partial load mode for appr. 40% of the race which could lead to significant fuel savings in a fuel capped formula.

The following book is the best I have found so far on the Bosch injection technology. It has a bunch of drawings of the HDEV4 and HDEV5 injectors and the high pressure pumps by Bosch and Siemens.

Richard van Basshuysen - Gasoline Engine with Direct Injection

One should keep in mind that the this second generation gasoline direct injection technology is now almost 6 years old. The first commercial application was the Mercedes CLS 350 CGI which appeared in 2006. One has to assume that new developments are afoot to make injection faster and expand the stratification range from what was possible in 2005.

[Edis]

HDEV5 can be used with up to 200 bar fuel pressure. HDEV4 is the piezo version (not listed on their website). They are considered second generation direct injection systems introduced a few years ago. The solenoid version use inward opening and the piezo version use outward opening. Outward operation require a piezo actuator or two solenoids and HDEV5 only got one solenoid.

Motorsport requirement will differ somewhat from production engines as racing engines operate with a homogenous mixture during high load and speed where mixture preparation is important. Passenger car engines are focused on part load and here the use of stratified injection can lead to significant fuel savings.

As Ferrari are using 200 bar piezo injectors (probably outward opening) for the 458 Italia V8 I would expect F1 to use no inferior product. I hope they will be able to even improve on the data they got now. F1 cars are also in partial load mode for appr. 40% of the race which could lead to significant fuel savings in a fuel capped formula.

The following book is the best I have found so far on the Bosch injection technology. It has a bunch of drawings of the HDEV4 and HDEV5 injectors and the high pressure pumps by Bosch and Siemens.

Richard van Basshuysen - Gasoline Engine with Direct Injection

One should keep in mind that the this second generation gasoline direct injection technology is now almost 6 years old. The first commercial application was the Mercedes CLS 350 CGI which appeared in 2006. One has to assume that new developments are afoot to make injection faster and expand the stratification range from what was possible in 2005.

Part throttle is more like less than 20% of the time. Most of the time is spent on full throttle, approx 60%, which is followed by off throttle conditions for about 20% of the time. So the focus will be on full throttle power and fuel consumption while with roadcars the focus is on part throttle fuel consumption and emissions.

Ferrari California is also using the HDEV5 with 200 bar fuel pressure. It's possible they use HDEV4 on 458 instead, also with 200 bar fuel pressure.

[tok-tokkie]

Is not the advantage of direct injection for road cars (with mostly part throttle operation) that it can run on a stratified charge WITHOUT a throttle. Power determined, just as in a diesel engine, by fuel quantity injected - the stratified charge ensuring that the gasoline mixture is combustible & the unused part of the induced air is without any fuel at all. The thermodynamic losses associated with a throttled air intake are thus not present. An inherently more efficient design.

For racing part throttle operation is insignificant. So the focus for direct injection for racing is not focusing on the requirements for road cars. Unfortunate.

[WhiteBlue]

Throttle less operation is only possible with variable valve timing and lift. As Edis said high revving F1 racing engines will be mainly used in homogenous charge and not in stratified charge. Nevertheless the best injection, ignition and variable valve technologies will provide significant fuel savings. Optimum direct injection with laser ignition will give much reduced lambdas even at full load compared to today's technology. Ten percent fuel saving will be almost certain even on full power if all the technology is used. This would not include variable compression which is too heavy for racing engines I reckon.

[tok-tokkie]

My Toyota diesel pick up has no throttle and it has fixed valve timing & lift. I appreciate that diesel ignition is entirely different to petrol ignition. I don't understand why a throttle is required if you have direct gasoline injection creating a stratified charge. Is it not possible (desireable) to inject the fuel so that it creates a combustible stratified charge around the spark plug and unfueld air beyond that? Why is a variable valve timing or a throttle necessary?

[WhiteBlue]

Diesel always compress the total air charge and regulate power by injection. They are self igniting.

Petrol engines throttle the air to regulate power unless they have variable valves to control the air intake or even variable compression as the DiesOtto experimental engines do.

Stratified or homogeneous charge is purely a matter of the speed of the injection technology vs the rpms of the engine. Current injection technology isn't fast enough to create layered charges by multiple injection events and the spray geometry isn't very suitable for stratification with high loads.

Laser ignition saves about 3% fuel compared to spark plug ignition but is very expensive.