Flow rate of the factory gen 3 DI injectors

[illtal]

maybe someone like @engineermike can answer the question.
What is the nominal flow rate of the factory gen 3 DI injectors?
Is it worthwhile to upgrade them?

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[engineermike]

You asked the wrong guy….how much do you want to know?

I can get the flow rating from the stock calibration. They are smaller than just about every Ford gdi injector out there, and can barely maintain the stock commanded di/pi 90% blend on a stock engine. But the issue is that as you attempt to get more flow using very specific tuning (not offered by most tuners) you’ll find you run out of gdi pump before injector. If you upgrade the pump, then you find that even after extending the injection window and raising pressure, you can get 100% duty cycle from the big pump on stock injectors. Only lowering gdi pressure will get more from the big pump, but lowering the pressure requires more window so you have to balance the two. Upgrading injectors would allow me to lower the pressure without extending the window so I could get more gdi flow.

The stock pump can flow about 330 lb/min if tuned right. The xdi pump is limited to about 360 on the stock injectors. With big gdi injectors, I could get 400+ out of it.

 

[illtal]

You asked the wrong guy….how much do you want to know?

I can get the flow rating from the stock calibration. They are smaller than just about every Ford gdi injector out there, and can barely maintain the stock commanded di/pi 90% blend on a stock engine. But the issue is that as you attempt to get more flow using very specific tuning (not offered by most tuners) you’ll find you run out of gdi pump before injector. If you upgrade the pump, then you find that even after extending the injection window and raising pressure, you can get 100% duty cycle from the big pump on stock injectors. Only lowering gdi pressure will get more from the big pump, but lowering the pressure requires more window so you have to balance the two. Upgrading injectors would allow me to lower the pressure without extending the window so I could get more gdi flow.

The stock pump can flow about 330 lb/min if tuned right. The xdi pump is limited to about 360 on the stock injectors. With big gdi injectors, I could get 400+ out of it.

Most of what you said is most what I wanted to know....
Since I'm already at 90% of full stupid on my current project, I'm weighing options...
Anyways here's what I'm looking at, see attached:

Let me know what you see in this tuning/characterization table.

Edit*
Do you mean 330lb/hr? not lb/min

 

[engineermike]

Sorry, you're correct it's 360-370 lb/hr.

The mustang injector rate is 138 lb/hr at 3000 psi or 200 bar. For comparison, the 3.5 gen 2 eb is about 163 at 200 bar. A Mustang 2.3 eb is about 180 lb/hr at the same 200 bar. I did a bunch of research and finally found stock Ford GDI injectors that included all the right data in an accessible calibration and were bigger than stock Mustang GT, so I bought one and it's the wrong connector. I gave up at that point because I am able to reach 100% DC on my XDI pump on the stock injectors at 3500 psi and the benefit of larger injectors starts looking to not be worth it. I checked briefly into XDI injectors and was told they are over $2000.

It really irritates me that most aftermarket tuners don't bother trying to optimize the stock GDI system. We were able to make big gains on the stock pump and injectors vs some pretty maintream aftermarket tunes.

 

[illtal]

Sorry, you're correct it's 360-370 lb/hr.

The mustang injector rate is 138 lb/hr at 3000 psi or 200 bar. For comparison, the 3.5 gen 2 eb is about 163 at 200 bar. A Mustang 2.3 eb is about 180 lb/hr at the same 200 bar. I did a bunch of research and finally found stock Ford GDI injectors that included all the right data in an accessible calibration and were bigger than stock Mustang GT, so I bought one and it's the wrong connector. I gave up at that point because I am able to reach 100% DC on my XDI pump on the stock injectors at 3500 psi and the benefit of larger injectors starts looking to not be worth it. I checked briefly into XDI injectors and was told they are over $2000.

It really irritates me that most aftermarket tuners don't bother trying to optimize the stock GDI system. We were able to make big gains on the stock pump and injectors vs some pretty maintream aftermarket tunes.

They are 1349 USD and the stock DI are something like ~85 USD per injector.

Not a huge difference in price. The pump seems to be the way to go then. I remember you saying with that pump and some calibration you were able to run more boost on 93. I also saw something where hellion put out that they made 1000 WHP with that pump on 93 which isn't completely out of the realm of thought.

Finding a tuner willing to optimize this will be challenging. Will ask around.

 

[engineermike]

What’s your setup and who’s tuning it now?

On true 93, I can run the Whipple 3.375 pulley and about 17 deg timing in low humidity and 18-19 in high humidity. I’ve been able to run up to 22 deg timing on the 3.875 pulley. I’m actually working on something now that will adjust timing as a function of humidity, but that’s a different subject.

 

[illtal]

What’s your setup and who’s tuning it now?

On true 93, I can run the Whipple 3.375 pulley and about 17 deg timing in low humidity and 18-19 in high humidity. I’ve been able to run up to 22 deg timing on the 3.875 pulley. I’m actually working on something now that will adjust timing as a function of humidity, but that’s a different subject.

Lund tuned the EB setup. Ran great.

 

[illtal]

What’s your setup and who’s tuning it now?

On true 93, I can run the Whipple 3.375 pulley and about 17 deg timing in low humidity and 18-19 in high humidity. I’ve been able to run up to 22 deg timing on the 3.875 pulley. I’m actually working on something now that will adjust timing as a function of humidity, but that’s a different subject.

So as far as a tuning window is concerned, how much more leeway are you afforded over the stock pump. 19 degrees seem like a lot on 93. What is normally achievable before the pump on the same pulley combination?

 

[engineermike]

I once established it was 2 deg or 2 psi, but since then found more. Now, maybe 3 deg or 3 psi.

 

[illtal]

I once established it was 2 deg or 2 psi, but since then found more. Now, maybe 3 deg or 3 psi.

I that sir seems like quite a bit: isn't the airflow > extra timing?

 

[engineermike]

I that sir seems like quite a bit: isn't the airflow > extra timing?

Yes, given the option if you add boost it will be worth more power, at the expensive of additional fuel and heat. Now that I’ve proven on the dyno that the 3.5” pulley is a fair bit more powerful than the 3.875, I switched to 3.375 and might go even smaller.

 

[illtal]

Yes, given the option if you add boost it will be worth more power, at the expensive of additional fuel and heat. Now that I’ve proven on the dyno that the 3.5” pulley is a fair bit more powerful than the 3.875, I switched to 3.375 and might go even smaller.

all in all it looks like I'll have to find an "alternate" tuner to tune the XDI pump and or injectors

 

[engineermike]

You seem like a smart guy. Tune it yourself. This is a pump gas build?

 

[illtal]

You seem like a smart guy. Tune it yourself. This is a pump gas build?

I am relative smart however I don't have the car with me to tinker with it.
When I am permanently back stateside I do plan on tuning my own cars.
I used to tune Hondas back in the day; they were easy to tune.
The car will be on Pump when traveling (when there is not a lot of E85 available).
I have to learn DI windows and all but I think I got the jist of it.

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