Proton Holdings today held a at the Ricardo works in the UK. So, what is GDI and TGDI, and what does it mean in terms of engine design?GDI stands for Gasoline Direct Injection, and the T denotes Turbo. In terms of Proton’s engine development, this means a move away from multi-point injection (MPI) where the injectors shoot fuel into the inlet tract to the more efficient GDI, with injectors firing directly into combustion chamber.It differs from other forms of fuel injection in that fuel is delivered at a much higher pressure directly into the combustion chamber.
The advantage of this is fuel is able to be more accurately controlled in terms of volume and timing, resulting in more hp from a given engine capacity.The development of GDI is not new, having made its first appearance in aircraft engines over 120 years ago. The 1990s saw a rebirth of GDI, with Mitsubishi including it into its 4G93 engine.
“The CryoPower split-cycle engine concept aims to significantly exceed the thermal efficiency of current state-of-the-art heavy-duty diesel engines used in trucks, distributed power systems, and other applications,” said Simon Brewster, CEO Dolphin N2 Ltd, the CryoPower spinoff from Ricardo. “It is based on the use of a separate induction. Ricardo is a small company and the guys who developed the software don't have credentials just like the case of software Star-CD. Wave is a software for small people (low level engineers) or the beginners in compressible flow.
Other automakers followed suit through the 2000s, with BMW even trying out a low-pressure GDI in its V12.According to Proton, its GDI engine will give a fuel savings of 25% over the previous VVT engine in the Iriz. Typically, a GDI engine will work in one of three modes. In normal running, the ECU will set the GDI to as close to the stoichiometric ratio as possible, which in theoretical terms is 14.7:1 of air to petrol by mass.While perfect combustion is never achievable in the real-world, the engineering push towards this goal will result in better fuel efficiency and controlled emissions. For Proton’s new engines, this means working towards the forthcoming Euro 6C standard.At low engine speeds, where the engine is turning at or near idle, the ECU sets the engine up for an ultra lean burn. While Proton didn’t say anything about how far they were going to push the limit, some engines from other manufacturers go as far as 65% lean, right on the verge of detonation.For wide-open throttle, GDI goes the other way, enriching the mixture to ensure that power is available, and a little left over for cooling.
In TGDI applications, the fuel-air mixture can be optimised to suit boost pressure, and any changes in barometric pressure – which turbos can be sensitive to – that might affect the engine’s performance.The GDI path has the benefit of putting the fuel mixture in optimum position for the spark to propagate the flame front in the most efficient manner. This means the maximum amount of fuel is burnt during the combustion cycle for the maximum amount of power for piston speed. While MPI can do this, it is to a much lesser degree, and efficiency is subject to the porting of the inlet.So, if that’s the way it works, and the benefits, what are the drawbacks? One is complexity.
Instead of having injectors in the manifold or inlet tract, the injectors are shooting fuel directly into the combustion chamber.This means one injector per cylinder, sometimes two, depending on design. The cylinder head has to be redesigned to accommodate this. The other is that fuel delivery is under much higher pressure. The fuel delivery system has to be upgraded to suit, and this also means high pressure hoses and fittings.Also, GDI injectors are also more sensitive to contaminated fuel, or fuel containing too high a percentage of after-market additives in the wrong ratio. Sludging of the injectors and carbon build-up is a real possibility, since the injector orifices are much finer than in MPI.Because fuel is no longer sprayed on the back of intake valves, it is possible for build-up to occur on the intake ports. Stratification of the fuel mixture could also lead to carbon build-up on the chamber walls, with carbon contaminants blocking injectors and lodging in catalytic convertors, causing local hot spots and leading to the failure of the convertor.Some engine designers get around the problem of stratification and carbon build-up by using both GDI and port injection. The ECU in such engines, such as in the Toyota D-4S and VW’s EA888, is programmed to use either, or both, injectors, depending on load and engine state.All this costs money, and Proton says it spent RM600 million to develop the new range of engines.
This complexity is somewhat off-set by the inclusion of diagnostic software to troubleshoot errors in the GDI.For Proton, the numbers it is looking for in the, already much higher than MPI 1.6 CFE, 138 hp, 205 Nm and 25% more efficient. In the short-term, GDI engines promise better fuel efficiency and more power per litre of fuel, while in the long-term, the reduced emissions will benefit the environment. TurboManonatMat Salleh’s culture is usually more direct. So they respect those who tells it to their face what you are thinking. If they messed up, tell it to their face & they will respect you for it.
Those that are based in Asia for a couple of years learnt our culture. But if you work there, or one that just came in, expect this.
Generally the first few months would be the adjustment phase, both for you and them.I know cause i worked abroad for way too long in environments that ain’t too friendly ( Think oil rigs in Alaska, North Sea, Russian Caspian ). Recently came back and got a mini culture shock everyday in the office.Whether they care about us or not, do you care about GM in US, whether it fails or succeed? Do you care about oldsmobile? I know I don’t, at least until they sell their Camaros and Corvette here in Malaysia and priced it the way it should be, a working man’s sports car. Syer1nonatnow the weight is on me? Your total clueless world never fail to fascinate me.
I’ll make this engine timeline in kindergarten style for you.Step 1) Petronas co-operate with Ricardo to develop an engine.Step 2) Proton bought the engine along with the technological pattern from Petronas.Step 3) Proton return to Ricardo with the original engine and pattern to further develop the engine to suit road use instead of racing.Step 4) You argue to ask Lotus to develop Petronas engine which clearly out of their knowledge so they will take time to reverse-engineer it. Time is money. TurboManonatDoesn’t matter if they tebuk one lubang. I won’t care one bit.The key is knowing where to tebuk and what to do once the lubang is there. Fitting the right injectors running it at the right pressures, modelling the fuel flow/position in the cylinder to give the largest bang per drop of fuel. Doing it in such a way that it doesn’t cause carbon buildup.
That is the art.Engineering doesn’t have to be complicated. It needs to work. The best engineering solutions are usually the simplest.There is a story about a factory that has to shut down and nobody knows how to fix it. An engineer was brought in, spent a day walking around the factory, finally took a hammer and hit a pipe hard. Within 5 sec, the factory springs back to life.He charged RM10000 for that service. The factory manager said, just one bang for RM10000?
Please provide me with an itemised bill.So the bill goes like this, RM1 for banging. RM9999 for knowing exactly where and how hard to bang. Bugbear1986onatCarbon buildup at inlet port isnt caused by the injection in the combustion chamber of GDI engines, it’s due to engineer trying to increase the volumetric efficiency of the particular cylinder by retarding the inlet valve closing time (therefore fuel particle being suck back into inlet valve, sooner or later. Carbon deposit build up there and causing reliability issues)Therefore such problem is widely to be seen and happened at many GDI engines such as BMW Prince Engine (Peugeot/Citroen/Mini Cooper’s) and also Mazda’s Skyactiv (as early as 50k km at some local models, Mazda3)Downside of the GDI engine, is emission. The carbon particles. Sudonano (Member)onatGDI is great, if done right.You see, one of the things with GDI engines is carbon build up.
If not properly addressed (read early Prince THP 1.6 engines, as per 308 Turbo, 408 Turbo), the carbon buildup saps off performance and fuel economy. However it’s not all bad news. Many of the large manufacturers, like BMW’s High Pressure Injection, Mercedes’ BlueDIRECT, VAG’s FSI engine technology all have become very mature, that now, stories of carbon build up is almost non existent.If at all, I personally think it’s not the best move to dump the money into building engines only, instead, they should consider the entire powertrain. I was genuinely shocked to hear they were actually sticking to the CVT transmission.
Like really, we all know how badly the CVT performs when driven somewhat enthusiastically. If Proton really wants to put those engines to good use, dump the CVT, give us a real automatic instead. No amount of flappy paddles and fancy ProTronic branding is gonna make that CVT any better.
OllieonatFirstly, excellent technical writeup. But to put it simply, a car company that is losing market share by day, and is facing cash flow crunch is not in the position to spend RM600mil on engine development, not even RM 6 mil!Secondly. Lovely labels by blind supporters.If you read properly, all negative comments about Proton are constructive. Re: modular design, lower procurement complexity, rely on ready-made modular parts just as all developed car makers to lower development costs (i.e. Even Ferrari, Porsche, Bentley use modular parts from their parent companies!), cut losses (i.e. Not spend RM 600 mil on new engines when you are losing market share), reduce design complexity, create a rational model line-up (i.e. Inspira and Accordana are basically competitors in the same market, as Waja/Gen2/Persona), make rational business decisions as in focus on further developing models that sell (as in focus on the Saga, its the best-selling model, but no, no glamour in Saga, must develop GDI 2.0 T only baru glamour, no sell nevermind, janji glamour), develop business rationalisation plans as the business is losing money every month!The last point is most critical.
I want to see the faces of the so-called die-hard Proton supporters when thousands lose their jobs due to VSS and retrenchment when Proton faces bankruptcy.Proton is to face bankruptcy by Oct 2017. That’s in around 18 months time based on current free cash flow and net assets.
Be ready to cry for all the workers, dealers, distributors who are going to lose livelihoods.That’s the truth, stop supporting blindly, and listen to the so-called Proton bashers instead of just talking nonsense. LansiliewonatProton will be respected if they manage to produce the GDI engine that not suffered like those vw/audi, GM’s Hyundai and others that had tons of problems mainly carbon build up that need the valves to be manually clean and worse in hyundai case the fuel leak into the engine and cause the engine to seize which pose a safety risks. Action class law suit have been taken on hyundai in the US, VW/Audi and ford ecoboast owners are emptying their pocket like money is out of fashion. Will Proton manage? Testing an engine on a test bed is not the same as everday life with stop and go and uncontrol enviroment.
How Does A Turbojet Work?Turbojets work by passing air through 5 primary sections of the engine:Step 1: Air IntakeThe air intake is essentially a tube in front of the engine. The air intake may look simple, but it's incredibly important. The intake's job is to smoothly direct air into the compressor blades. At low speeds, it needs to minimize the loss of airflow into the engine, and at supersonic speeds, it needs to slow the airflow below Mach 1 (the air flowing into a turbojet needs to be subsonic, regardless of how ).Step 2: CompressorThe compressor is driven by the turbine in the rear of the engine, and its job is to compress the incoming air, significantly increasing the air's pressure. The compressor is a series of 'fans', each with smaller and smaller blades. As air passes through each compressor stage, it gets more compressed.Step 3: Combustion ChamberNext up is the combustion chamber, where the magic really starts happening.
The high pressure air is combined with fuel, and the mixture is ignited. As the fuel/air mixture burns, it continues through the engine toward the turbine. Turbojets run very lean, with approximately 50 parts air to every 1 part of fuel (most reciprocating engines run anywhere from 6-to-1 to 18-to-1). One of the main reasons turbines run this lean is that extra airflow is needed to keep a turbojet cool.Step 4: TurbineThe turbine is another series of 'fans', which work like a windmill, absorbing energy from the high speed air passing through it. The turbine blades are connected to and turn a shaft, which is also connected to the compressor blades at the front of the engine. The turbjet's 'circle of life' is almost complete.Step 5: Exhaust (aka 'I'm outta here!'
)The high speed burned fuel/air mixture exits the engine through an exhaust nozzle. As the high speed air exits the rear of the engine, it produces thrust, and pushes the airplane (or whatever it's attached to) forward.Turbojet takeaway:. Pros:.
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Relatively simple design. Capable of very high speeds. Takes up little space. Cons:. High fuel consumption.
Loud. Poor performance at slow speeds2) Turboprop Engine. How Does A Turboprop Work?Step 1: The turbojet spins a shaft, which is connected to a gearboxStep 2: A gears box slows down the spinning, and the slowest moving gear connects to the propellerStep 3: The propeller rotates through the air, producing thrust just like your Cessna 172Turboprop takeaway:. Pros:. Very fuel efficient. Most efficient at mid-range speed between 250-400 knots.
Most efficient at mid-range altitudes of 18,000-30,000 feet. Cons:.
Limited forward airspeed. Gearing systems are heavy and can break down3) Turbofan Engine. How Does A Turbofan Work?Turbofans work by attaching a ducted fan to the front of a turbojet engine. The fan creates additional thrust, helps cool the engine, and lowers the noise output of the engine.Step 1: Inlet air is divided into two separate streams. One stream flows around the engine (bypass air), while the other passes through the engine core. Step 2: Bypass air passes around the engine and is accelerated by a duct fan, producing additional thrust.Step 3: Air flows through the turbojet engine, continuing the production of thrust.Turbofan takeaway:.
Pros:. Fuel efficient. Quieter than turbojets.
They look awesome. Cons:. Heavier than turbojets.
Larger frontal area than turbojets. Inefficient at very high altitudes. How Does A Turboshaft Work?Turboshafts are essentially a turbojet engine with a large shaft connect to the back of it. And since most of these engines are used on helicopters, that shaft is connected to the rotor blade transmission.Step 1: The engine operates like a turbojet, for the most part.Step 2: The power shaft attached to the turbine powers the transmission.Step 3: The transmission transfers rotation from the shaft to the rotor blade. Step 4: The helicopter, through mostly unknown and magical means, is able to fly through the sky.Turboshaft takeaway:. Pros:. Much higher power-to-weight ratio than piston engines.
Typically smaller than piston engines. Cons:. Loud. Gear systems connected to the shaft can be complex and break down4 Types Of Engines, Based On The Same Basic ConceptGas turbine engines have come a long way in the past 100 years. And while turbojets, turboprops, turbofans and turboshafts all have their differences, they way they produce power is essentially the same: intake, compression, power, and exhaust.