direct injection 5.0 in the future?

[SFC]

I'm wondering when they're going to give in and just convert everything to diesel. Direct injection? Turbo chargers? Why not just jump to the logical conclusion and get it over with...

[sport the war]

Direct injection can handle plenty of power.

tell that to the poor bastards with mazdaspeed 3's

[iamtheshaner]

I'm wondering when they're going to give in and just convert everything to diesel. Direct injection? Turbo chargers? Why not just jump to the logical conclusion and get it over with...

Too bad gasoline doesn't freeze though. Plus, the manufacturing costs associated with a diesel engine compared to a DI/FI gas motor make it an easy choice. You have to beef up the bottom end to handle the forces of combustion and the high pressure pumps are more expensive to manufacture as well.

DI gas is the way to go. It isn't difficult to control HC or CO emissions in either gas or diesel but it is difficult to control NOx emissions in a diesel. This is why aftertreatment systems and power-robbing water cooled EGR systems make diesels a pain the arse. DI gas doesn't even make much NOx because the combustion is cooled so well the temps don't reach the 2500*F+ needed for NOx to form. External EGR systems are a thing of the past with DI. We can literally get enough EGR to control NOx with valve overlap nowdays with many DI gas motors.

In my opinion the BTU content of diesel vs gas and the ease of refining fuel oil vs distillates are the only advantages of a diesel vs gas in these applications.

[Fosters]

One of the biggest banes to direct injection is carbon buildup in the intake manifold. Ive found this out not with my mazdaspeed6 which is direct injection and if these motors have any boost in them then you get huge carbon buildup and have to either seafoam your engine after every oil change or install a OCC (which im planning on doing fairly soon to mine).

But direct injection seems to be where things are heading trying to save on fuel economy and not sacrifice power.

How the hell do you get carbon buildup in the intake manifold if the fuel is sprayed straight into the combustion chamber and never sees the manifold?

[sport the war]

How the hell do you get carbon buildup in the intake manifold if the fuel is sprayed straight into the combustion chamber and never sees the manifold?

[iamtheshaner]

How the hell do you get carbon buildup in the intake manifold if the fuel is sprayed straight into the combustion chamber and never sees the manifold?

Glad you asked

Although there is no longer an issue with fuel deposits being left behind on the intake valves....there ARE still crankcase fuel and oil vapors introduced via PCV. With DI, there is no longer a little wash of solvent (gasoline) being sprayed on the valves to clean those deposits off.

Carbon buildup IS a disadvantage of DI but it is somewhat counter-intuitive at first glance...


I don't see it as a big deal though. Forced induction reduces these deposits due to airflow dynamics and the presence of the necessary "catch-can" seperators but an occasional decarb is a necessary service even with port fed EFI. Old school water decarbs FTMFW

[konastang5.0]

How the hell do you get carbon buildup in the intake manifold if the fuel is sprayed straight into the combustion chamber and never sees the manifold?

From the PCV system and EGR.

[Stormwalker]

Direct injection into the combustion chamber? Hogwash. I'm going to make an even MORE efficient system, by going even further downstream. Exhaust injection will be the new wave of the future.

[Notch]

Direct injection into the combustion chamber? Hogwash. I'm going to make an even MORE efficient system, by going even further downstream. Exhaust injection will be the new wave of the future.

Ima mount the injector in the piston and have it spray right into the spark plug

[Slow35th]

Ima mount the injector in the piston and have it spray right into the spark plug

[Fosters]

From the PCV system and EGR.

Valve cover breathers and EGR delete kits. Next!



Fuck, I have to think of everything...

[iamtheshaner]

Draft tubes and EGR delete kits. Next!



Fuck, I have to think of everything...

fix.t

[MisterCMK]

Too bad gasoline doesn't freeze though. Plus, the manufacturing costs associated with a diesel engine compared to a DI/FI gas motor make it an easy choice. You have to beef up the bottom end to handle the forces of combustion and the high pressure pumps are more expensive to manufacture as well.

DI gas is the way to go. It isn't difficult to control HC or CO emissions in either gas or diesel but it is difficult to control NOx emissions in a diesel. This is why aftertreatment systems and power-robbing water cooled EGR systems make diesels a pain the arse. DI gas doesn't even make much NOx because the combustion is cooled so well the temps don't reach the 2500*F+ needed for NOx to form. External EGR systems are a thing of the past with DI. We can literally get enough EGR to control NOx with valve overlap nowdays with many DI gas motors.

In my opinion the BTU content of diesel vs gas and the ease of refining fuel oil vs distillates are the only advantages of a diesel vs gas in these applications.

Wait, diesels have emissions controls? Oh, that must be what the big hunk of crap was that I pulled off the downpipe and what the tuner turned off is.

[budderigs]

fix.t

I think im in love with your sig pic.

[merkerguitars]

One of the biggest banes to direct injection is carbon buildup in the intake manifold. Ive found this out not with my mazdaspeed6 which is direct injection and if these motors have any boost in them then you get huge carbon buildup and have to either seafoam your engine after every oil change or install a OCC (which im planning on doing fairly soon to mine).

But direct injection seems to be where things are heading trying to save on fuel economy and not sacrifice power.

VW/Audi cars have been seeing these problems now, problem too is you just can't get the car hot and yank out the fuel rail and spray the runners with throttle body clean to decarbon the valves.

Our BG rep said they bought a new Taurus SHO and have been seeing MPG constantly drop due to carbon buildup. The only major drawback of DFI.

BTW You can make huge power with direct injected engines...