The ECU tracks HPFP to capture lobes timings knows when prop-valve control is in closed loop or open loop control. When this is too jittery, basic injection timings are used instead of rich powerful multi-shots.
What evidence do you have for this, and when it happens? If not enough fuel was injected, the engine would run lean. If the engine was lean, you'd see it on fuel trims. Or are you arguing this is a very transient effect?
Or... are these good to be used as pigtails to prevent oil in harnesses?
Yes. I have them in both my cars. There are two wire and three wire, so you need to match them to the CPS or solenoid. So, get the set of 8. The connectors fit and the wires are copper. What else is needed?
What evidence do you have for this, and when it happens?
If not enough fuel was injected, the engine would run lean.
If the engine was lean, you'd see it on fuel trims. Or are you arguing this is a very transient effect?
Kev,
We studied that clever design with Master Surya based on his in-depth research to understand.
TT features twin pumps.
I was going to say 3 or 4 cam lobes per pump.
On second thoughts, perhaps the lobe count matches cylinders count??
You're right about the trimmed mixture but with GDI Bosch added additional twists. It's a much finner granularity injection controlled by each individual cylinders to gain smooth uniform rotation speed.
Are you familiar with PLL: Phase Locked Loop regulation?
This is how I think the ECU synchronizes the proportioning valve PWM to the HPFP Cams rotation.
ECU does not have high resolution cam position ticks like our high resolution CKP teeth count. It has couple good reference ticks collected by CPS but has to extrapolate other lobs position vs. RPM.
Everytime ECU looses track, it must re-acquire the exact position. It's very kludgy. What could be better is a high resolution teeth count to track the camshaft position in degree and again that would be without counting on jittery unbalanced crank rotation that also screws camshaft rotation divided by half-speed.
Once you are familiar with that you can listen to engine idle and understand what ECU is up to. It pretty neat.
The big difference between closed-loop trimmed mixtures and GDI multi-shots is analog vs. digital.
-- With legacy timings ECU keeps adding/substracting fuel to make upstream lambda oscilate between rich/lean using maps. The exact number is centered between both.
-- With multi-shots the mixture is computed and fractioned differently to be injected during the compression stroke. The end result is more extremely powerful combustion + kick-*** acceleration I want you to enjoy.
My layman explanation is GDI really acts like a sort of turbo that pumps gas at 900.RPM instead of air at 2500.RPM - Now both combined, I really want to hear about that feedback!!!
With legacy timings this chassis you know is heavy, with GDI timings the gas pedal is pressure sensitive: it fly's off the line like a weight less hummingbird.
It's got awsome violent accelerations on tap, stable hot/cold performance.
It's freely built right in but disabled. No question you will need good cooling to meet engine load.
The next member who gets this is going to enjoy it beyond reason - This is a better focus than measuring elastic viscosity...
Again here it's 100% thanks to my dive master for enabling me to bump into this by chance. I am a rescue diver who knows search patterns.
Thanks to MS all day long!
++++ GETTING THERE ++++
Again in this topic, the best way to get there is to provide the engine conditions and let the ECU enable this power.
At first it's only a little then it gets bigger and better over a course of 2Mo as individual cylinder fuel maps get updated.
I am confident non-turbo ppl can waste their tires doing donuts with advanced multi-shots and with Turbo: I'd like to know... engine mounts survival rate shortened by hummingbird mode
Yes. I have them in both my cars. There are two wire and three wire, so you need to match them to the CPS or solenoid. So, get the set of 8. The connectors fit and the wires are copper. What else is needed?
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