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Discussion Starter · #1 ·
Anyone know the size of our stock injectors. Thinking about attempting a fuel system upgrade.
 

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The injectors are unique to the MZR engine. They shoot a stream line directly at the spark plug at ~1800psi IIRC. There are currently no aftermarket replacements that I am aware of. So far the fuel system hasn't been maxed out, so upgrading it wouldn't do too much yet. In fact, it would probably do more harm than good considering how rich this car runs stock. We won't need that until we have A) the turbo upgrade available, and B) a tuning solution.
 

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Discussion Starter · #3 ·
Anyone have a cc per minute rate?

Rich is safer then lean. There are plenty of hacks and piggybacks out there that should work for this car.
 

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Anyone have a cc per minute rate?

Rich is safer then lean. There are plenty of hacks and piggybacks out there that should work for this car.
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They are direct injectors and work on direct injection principles of operation. You cannot make them work like port injectors. As the injectors are timed with the engine rotation.
 

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Discussion Starter · #5 ·
An afc hack for example keeps the injector open longer or shorter. There has to be something controlling the duration the injector is open or the amount of fuel supplied to the injector, so that there fore can be hacked.
 

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An afc hack for example keeps the injector open longer or shorter. There has to be something controlling the duration the injector is open or the amount of fuel supplied to the injector, so that there fore can be hacked.
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You cant keep injectors open longer or shorter in a direct injection engine the injectors must fire in phase with engine RPM and cycle. Prolonging the phase of a direct injection cycle will introduce fuel into the combustion chamber at inappropriate times since the intake valves play no role in fuel control.

They are not like port injectors where you can run them to 100 percent IDC regardless of engine phase. In port injection the timing of fuel entering the cylnders is soley regulated by the intake valves.
 

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Discussion Starter · #7 ·
The injector is told by the ecu how much fuel to deliver at 1600 psi. Since the ecu is electrical it can be hacked or piggybacked to modify the signal. The injector is being told some value of fuel to deliver electrically. The injector does not deliver the same cc's all the time, if it did the engine would be so rich at start up and low rpms it would never start or run.

Anyway the original question was what size are the injectors in cc.
 

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Not trying to bash, but uping the fuel in this car is not the way to go. It already dips below 10:1 afr. It has too much fuel / not enough air as it is.
 

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true that. everyone who looks at the black eyes on the back of my bumper always say the same thing. "man is that thing running rich?" haha
 

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Now if someone were to pick up that GT35R kit and a good tuner (when it's available), we might need to start moving in that direction. But no-one will know until it's attempted and someone reaches the limits of the stock fuel system. For all we know, the stock fuel system might not have any limits. Not even upgraded turbos are hiting the limit as of yet. Only time will tell.
 

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we would also be wise to see how the B7 or B8 (can't remember)audi platform tuners are working. they have the same or similar hurdles to us. Maybe we can start cross referencing their DI injectors and high pressure pumps as well to see if there is one company making the parts.

Case in point, Bosch tuning gods GIAC's solution to the DI A4 2.0T

http://www.awe-tuning.com/pages/shared/par...s&IL=b7chip
 

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Discussion Starter · #13 ·
84 cc's, there's 4 of them in the engine and 1 in the transmission.
(hey, maybe it'll make him quiet down)
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Anyone know the actual flow rate per injector???
 

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Anyone know the actual flow rate per injector???
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Probably not. Try asking a dealer or someone there. They may even be rated differently (don't know why they would though) Considering the type of injector, I think Diesel people would know more about them since diesels use direct injection (little different and at way higher pressures)

But as some have said before, since the fuel is injected into the cylinder as opposed to the head or intake manifold as in port injection, there is only a short period of time when fuel can be injected. Normal injectors can run all the time and the fuel wll just sit on the intake valve until it opens (which actually a lot of cars do to heat up the fuel before it burned)

anyway, your best bet would be to try a dealer. I dont think anyone has even tried to do much with the injectors yet as no one is to the point of needing them yet.
 
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Anyone know the actual flow rate per injector???
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It does not matter what number we tell you because it cannot be compared to the industry standard injector due to the massively different fuel pressures. Lets take a 750cc injector for example. It will flow 750cc at 43psi, but the DISI injectors are flowing at 1600 psi.

For a direct injected engine, fuel is injected at different times based on several engine parameters, so modifying the injector size could have a very negative effect on part throttle operation. During part throttle, the fuel is injected as the piston approaches TDC of the compression stroke instead of the normal injection of fuel during the intake stroke.

This engine operates on a completely different level than the standard port injection engines that everyone is now used to.
 

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Discussion Starter · #16 ·
Psi is the pressure being ejected by the injector. There has to be a volume rate.

Lets take a 750cc injector for example. It will flow 750cc at 43psi, but the DISI injectors are flowing at 1600 psi.
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I am just saying that there has to be a volume rate for 1600psi??

If nobody knows just make this a dead thread.
 

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I think the best way to up the fuel past the current fuel system capabilities, would be to tap an injector into the intake manifold and run it as a port injection is run (a direct injection / port injection hybrid if you will). It could potentially damage the intake manifold though because it was not designed to deliver fuel. There could be dead zones where fuel would pool up and could potentially ignite, thus causing massive engine failier. Solution: custom manifold that IS designed to deliver fuel with no dead zones. Another thing that would have to be looked at is the valves that are also not designed for fuel delivery.

For the time being though, all we need is more air and some tuning.
 

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Discussion Starter · #18 ·
How is everybody tuning if all I keep hereing about that there are no tuning options yet?
 

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How is everybody tuning if all I keep hereing about that there are no tuning options yet?
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Nobody is tuning. All we really have is a turboback exhaust, cai, and soon a fmic. There is the turboxs dtec but you cant tune with it. Couple places are working on upgraded turbos. Some places are working on tuning software etc but there is nothing available yet. The market is still fairly new for this car.
 
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