LNF GDI Fuel System Duty Cycle

[405HP_Z06]

I suspect At some point I will be adding an additional fuel rail in the runner for high rpm/boost. The nice thing they did for us is give us a load vs rpm MAf trim function. Makes it easier to trim fuel out up top to maintain AFR when using such a setup.
Perhaps some nice methanol alcohol....

I would be interested in how your going to add additional injectors.

[Baldturbofreak.com]

Piggyback pcm ( I like Megasquirts,microsquirts), 2ndary tank&pump , 2ndary rail mounted in a factory manifold.

[405HP_Z06]

Piggyback pcm ( I like Megasquirts,microsquirts), 2ndary tank&pump , 2ndary rail mounted in a factory manifold.

So you will integrate standard PFI injectors into injector bungs welded into the factory intake manifold? I assume the piggyback PCM would only be active during homogeneous engine modes. Is there a piggyback PCM that can sense GDI engine mode so fuel is metered properly? How would you integrate this with the charge motion valve?

[Baldturbofreak.com]

There isnt any charge motion valve. I have an intake in front of me right now and it's as hollow as a balloon.
Unless it's in the head?? But I dont think there's anything in there either.

I plan on activation being a function of Boost pressure and RPM. Only activating under high rpm/boost pressure should ensure that it only occurs in Homogenous mode.

[405HP_Z06]

Your correct, I was mis-reading Bosch material There are two ways of achieving charge motion in a GDI engine:

1. Charge motion valve - Like the Ford/Mazda GDI
2. Piston design - This is what GM chose to do for the LNF.

Here's a picture of the piston. The crown design is specifically to achieve charge motion for the different engine modes.

[Baldturbofreak.com]

Is there anything in there about what the bosch systems compute the cam timing with respect to?

[Baldturbofreak.com]

It's going to be time for bigger injectors soon, unless the secondary fuel system is successfull.

We are going to need access to the flow rate constant in the PCM. Also beginning of injection even would be handy.

Is the camshaft duration a known constant in the PCM?

[405HP_Z06]

It's going to be time for bigger injectors soon, unless the secondary fuel system is successfull.

We are going to need access to the flow rate constant in the PCM. Also beginning of injection even would be handy.

Is the camshaft duration a known constant in the PCM?

These would be great. I'm still waiting for fuel system pressure and duty cycle PIDS!!!!!

[justmike]

These would be great. I'm still waiting for fuel system pressure and duty cycle PIDS!!!!!

+1

[2000Firehawk]

Maybe the injectors from these 2 new engines will work if they will fit & flow more fuel...

2.4L DI details
The new 2.4L DI engine delivers an estimated 180 horsepower (134 kW) @ 6700 rpm and 172 lb.-ft. of torque (232 Nm) @4900 rpm. It uses technology based on GM's other four-cylinder direct injection applications, but with unique features designed for its specific application. This includes an 11.4:1 compression ratio that helps build power, slightly dished pistons that increase combustion efficiency and injectors with an application-specific flow rate.

GM benchmarked the best fuel system and noise attenuation products to provide customers with quiet operation.

3.0L DI details
The new 3.0L DI engine is a variant of GM's family of high-feature DOHC V-6 engines that also includes GM's 3.6L DI engine in the Cadillac CTS – an engine named to Ward's AutoWorld's 2009 "Ten Best Engines" list for North America, for the second consecutive year.

The 3.0L is rated at an estimated 255 horsepower (187 kW) and 214 lb.-ft. of torque (290 Nm), for an impressive power-to-displacement ratio of 85 hp per liter. (Output will vary by model.) The 3.0L DI features an isolated fuel injector system that reduces the direct injection high-pressure fuel system pulses for quieter operation. Rubber isolators are used with the fuel rail to eliminate metal-to-metal contact that would otherwise transmit noise and vibration from the high-pressure fuel system.

Along with direct injection technology, both the 3.0L DI and 2.4L DI engines use variable valve timing to optimize power and fuel efficiency across the rpm band, as well as reduce emissions.

How DI works
In a conventionally port fuel injected engine, air and fuel are mixed before they enter the combustion chamber. With GM's DI engines, fuel is sprayed directly into the cylinder where it is mixed with air. As the piston approaches top-dead center, the mixture is ignited by the spark plug; and when the fuel vaporizes in the cylinder, the air and fuel mixture is cooled. This enables the use of a higher compression ratio in the combustion chamber, which improves the engine's power and efficiency.

On cold starts, direct injection can be controlled to create a richer air/fuel mixture around the spark plug, making it easier to ignite in a cold engine. This results in a smoother operation of the engine and lower emissions during the cold start and warm-up, when most harmful tailpipe emissions are typically created. GM's direct injected engines reduce cold-start vehicle emissions by 25 percent.

Because the fuel is injected directly into the combustion chamber, direct injection uses higher fuel pressure than conventional fuel injected engines. This is enabled by a special high pressure pump driven by one of the engine's camshafts.

[fr0stb1t3]

Maybe the injectors from these 2 new engines will work if they will fit & flow more fuel...

2.4L DI details
The new 2.4L DI engine delivers an estimated 180 horsepower (134 kW) @ 6700 rpm and 172 lb.-ft. of torque (232 Nm) @4900 rpm. It uses technology based on GM's other four-cylinder direct injection applications, but with unique features designed for its specific application. This includes an 11.4:1 compression ratio that helps build power, slightly dished pistons that increase combustion efficiency and injectors with an application-specific flow rate.

GM benchmarked the best fuel system and noise attenuation products to provide customers with quiet operation.

3.0L DI details
The new 3.0L DI engine is a variant of GM's family of high-feature DOHC V-6 engines that also includes GM's 3.6L DI engine in the Cadillac CTS – an engine named to Ward's AutoWorld's 2009 "Ten Best Engines" list for North America, for the second consecutive year.

The 3.0L is rated at an estimated 255 horsepower (187 kW) and 214 lb.-ft. of torque (290 Nm), for an impressive power-to-displacement ratio of 85 hp per liter. (Output will vary by model.) The 3.0L DI features an isolated fuel injector system that reduces the direct injection high-pressure fuel system pulses for quieter operation. Rubber isolators are used with the fuel rail to eliminate metal-to-metal contact that would otherwise transmit noise and vibration from the high-pressure fuel system.

Along with direct injection technology, both the 3.0L DI and 2.4L DI engines use variable valve timing to optimize power and fuel efficiency across the rpm band, as well as reduce emissions.

How DI works
In a conventionally port fuel injected engine, air and fuel are mixed before they enter the combustion chamber. With GM's DI engines, fuel is sprayed directly into the cylinder where it is mixed with air. As the piston approaches top-dead center, the mixture is ignited by the spark plug; and when the fuel vaporizes in the cylinder, the air and fuel mixture is cooled. This enables the use of a higher compression ratio in the combustion chamber, which improves the engine's power and efficiency.

On cold starts, direct injection can be controlled to create a richer air/fuel mixture around the spark plug, making it easier to ignite in a cold engine. This results in a smoother operation of the engine and lower emissions during the cold start and warm-up, when most harmful tailpipe emissions are typically created. GM's direct injected engines reduce cold-start vehicle emissions by 25 percent.

Because the fuel is injected directly into the combustion chamber, direct injection uses higher fuel pressure than conventional fuel injected engines. This is enabled by a special high pressure pump driven by one of the engine's camshafts.

Both of those engines produce less power than ours, not sure why they'd have bigger injectors.

May provide more incentive for the aftermarket though