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Old 12-22-2014, 11:36 AM   #21
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Vlad, if you are referring to the other thread, it doesn't change anything about the question of stock injectors being too small to support the HP claimed.

Dann, as we don't know the fuel system, we are using the simplifying assumption of a 1:1 manifold referenced regulator.
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Old 12-22-2014, 11:40 AM   #22
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Quote:
Originally Posted by nitrodann View Post
Pulse width can go down while duty cycle goes up because the rate of pulses goes up over time( i.e. revolutions -per minute-).

I am sure you can get your head around the rest.

Jesus Adam don't conduse him!
He confirmed what I already said with math. There was really no need for that condescending "edit".
How about we don't start a pissing match in every thread and try to discuss the topic at hand? So far your only contribution is vague/arrogant posts.

Corky is obviously attempting to justify the "other" thread with this troll thread, and I don't think its working. But I'm open for being convinced otherwise.

Why would torque, or pulsewidths, drop fuel requirements up top, when you're still flowing more air and need more fuel? Pressure =/= flow.

Maybe I should re-read his post upside-down and I'll undestand everything ()
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Old 12-22-2014, 11:42 AM   #23
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Look at Mass Air Flow. Raw meter voltage is very non linear, so a small increase in voltage at the high end is more air than it seems. Add fuel as required to maintain the desired air/fuel ratio.

Due to the decrease in volumetric efficiency as rpm increases, you get less air per cylinder cycle but more cylinder cycles per segment of time. However, looking at the plots, the volumetric efficiency does not drop off fast enough to fulfill Corky's Xmas wishes.

I think, in Corky's case we are seeing the benefits of 60psi fuel pressure and a very conservatively flow rate specification specification for the OEM injector. I have no problem maintaining 11.5/1 on OEM injectors at 7psi and ~190whp.

Computer control of internal combustion engines is easy compared to world class petrochemical plants. Our cars just lack sufficient instrumentation and computer horsepower.
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Old 12-22-2014, 11:45 AM   #24
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Quote:
Originally Posted by exexx View Post
Look at Mass Air Flow. Raw meter voltage is very non linear, so a small increase in voltage at the high end is more air than it seems. Add fuel as required to maintain the desired air/fuel ratio.

Due to the decrease in volumetric efficiency as rpm increases, you get less air per cylinder cycle but more cylinder cycles per segment of time. However, looking at the plots, the volumetric efficiency does not drop off fast enough to fulfill Corky's Xmas wishes.
I think, in Corky's case we are seeing the benefits of 60psi fuel pressure and a very conservatively flow rate specification specification for the OEM injector. I have no problem maintaining 11.5/1 on OEM injectors at 7psi and ~190whp.

Computer control of internal combustion engines is easy compared to world class petrochemical plants. Our car just lack sufficient instrumentation and computer horsepower.
+100
Thank you.
This is, pretty much exactly where I was going.
Especially the bolded part.
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Old 12-22-2014, 11:50 AM   #25
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it's always shocking when i agree with dann.
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Old 12-22-2014, 11:50 AM   #26
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Quote:
Originally Posted by 18psi View Post

Why would torque, or pulsewidths, drop fuel requirements up top, when you're still flowing more air and need more fuel? Pressure =/= flow.
You are correct that fuel flow is proportional to IDC which is proportional to HP. It doesn't make sense in the OP to compare fuel flow to torque.
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Old 12-22-2014, 11:53 AM   #27
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Quote:
Originally Posted by Braineack View Post
how are you flowing more air?

the flowrate is constant.
ingesting the air faster?
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Old 12-22-2014, 11:58 AM   #28
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Quote:
Originally Posted by 18psi View Post
ingesting the air faster?
ignore me. i had a brain fart.

i was literally thinking displacement.

at 4000RPM the 1.8L @10psi is drawing in roughly 190CFM of air, at 7000RPM it's at roughly 333CFM. about 75% more VAF.
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Old 12-22-2014, 12:04 PM   #29
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I'm being as condescending to your stupid posts as you were to corkies.

And I answered exactly what was asked extremely succinctly in my first post in the thread.
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Old 12-22-2014, 12:08 PM   #30
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Quote:
Originally Posted by nitrodann View Post
I'm being as condescending to your stupid posts as you were to corkies.

And I answered exactly what was asked extremely succinctly in my first post in the thread.
My posts disagreeing with corky are stupid? Please explain oh great one, perhaps you and corky should get together and finally release the OMEGA-OMEGA kit that makes 350whp on stock 1.6 injectors with reverse boost creep and an upside-down fake dyno plot.
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Old 12-22-2014, 12:11 PM   #31
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You dont understand VE.

You don't understand how IDC does not correlate to pulse width.

You don't understand that pulse width at a given duty cycle changes with rpm.

And you feel justified in mocking corkys understanding in these topics..

This thread is literally me answering the OP in 4 words, and 2 pages of people explaining it to you.
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Old 12-22-2014, 12:13 PM   #32
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Quote:
Originally Posted by nitrodann View Post
You dont understand VE.

You don't understand how IDC does not correlate to pulse width.

You don't understand that pulse width at a given duty cycle changes with rpm.
And you feel justified in mocking corkys understanding in these topics..
wat?
go ahead, I'm dying to hear this one.

seems like I confused the two (idc/pw) and you jumped in with the quickness to **** all over me cause you're still bitter. you stated nothing but arrogant vague bs and attempted to sound smart.

So now for the final question: do you agree with Corky's logic or no? If yes, explain, if no then we have our confirmation that you're still a bitter little b and posted for no other reason than to point out my confusion at the begining.


... ta daaa?
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Old 12-22-2014, 12:16 PM   #33
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You are an idiot. Screenshotted.

I'm going to sit back and watch another 2 pages of people explaining my 4 word answer to you.
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Old 12-22-2014, 12:19 PM   #34
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Quote:
Originally Posted by nitrodann View Post
You are an idiot. Screenshotted.

I'm going to sit back and watch another 2 pages of people explaining my 4 word answer to you.
okay chief

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Old 12-22-2014, 12:31 PM   #35
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Exexx, we are not debating 190 HP, but 240 HP. Sure, there's headroom in the stock injectors, but 100%?

The higher fuel pressure gains sqrt(53/43) or 11% more fuel at 7psi over manifold referenced system.

My last post on this thread. Com'on guys, be civil.
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Old 12-22-2014, 12:33 PM   #36
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you know what's easier than all this bench racing?

taking a car with 265cc injectors to a dyno, pushing it to 240rwhp and see if you can still maintain >12:1AFR at redline.


oh wait... :P
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Old 12-22-2014, 12:40 PM   #37
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***** gettin too real
Attached Images
File Type: gif 5vukxw.gif (634.9 KB, 172 views)
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Old 12-22-2014, 12:42 PM   #38
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Quote:
Originally Posted by Braineack View Post
you know what's easier than all this bench racing?

taking a car with 265cc injectors to a dyno, pushing it to 240rwhp and see if you can still maintain >12:1AFR at redline.


oh wait... :P
You know, I was impressed by that.
I was also impressed that it was backed up on a different dyno.
I think the stock fuel system on our cars is underrated, perhaps the fuel pump is able to keep up even with the injectors never closing?
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Old 12-22-2014, 12:43 PM   #39
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No ****, 1L/ minute!?

Corkys post is a little cryptic, but in general, yeah, he's right.

My math says that at 12.5:1 Afr, on a 60psi non referenced system 240 crank is possible at 10psi.

Go to bed Vlad youre drunk.
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Old 12-22-2014, 12:51 PM   #40
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Good grief wft is going on in this thread. I've now realized that either the automotive world has hacked up normal engineering terms to where they make no sense, or that everyone is just generally confused...

So PWM: Classically PWM is a means to control average current to something with a purely digital system. In a valve you set a fixed frequency that is much higher than the valve can physically operate and control the duty cycle of that digital signal to control the average current to the valve. This average current control allows analog control of valve position with a digital system.

WTF is going on in the car world? I see people talking about PWM being a digital signal and that the injectors actually go binary and completely turn off/on with the PWM signal? I think the MS3 is set to 60us PMW freq? I don't see a $100 mechanical valve operating at 60us...

It's like I'm at work looking at a marketing hack job of my project.
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