Mk3 Focus RS DI max pulse width.

[Sub8]

Hi all - How can you determine injector pulse width on these? There doesnt appeart to be a injector pulse width PID to log? Have I missed it somewhere?

Thanks.

[Sub8]

No one logging RS pulse widths?

[Seishuku]

Most Ecoboost cals have a PID listed as injector pulse width, if it's not there, there isn't a lot you can do.
Maybe open a support ticket with HP and they can add it?
Or try the latest beta?

[Sub8]

Hi - There isn't and that was my next move, just wanted to see if I was being stoopid!

Does anyone know if Airflow limit (IDC) is calculated based on actual airflow Vs requested lambda using the injector charateristic (and pressure) or is based on a calibrated max angle or duration?????

[Rob@HPTuners]

Hi - There isn't and that was my next move, just wanted to see if I was being stoopid!

Does anyone know if Airflow limit (IDC) is calculated based on actual airflow Vs requested lambda using the injector charateristic (and pressure) or is based on a calibrated max angle or duration?????

Its a combination of both of these things. Injector duty cycle in the instance of DI engines is effectively the ratio between the current injection angle window and the maximum allowable. So 100% IDC basically means that your SOI and EOI are capped out to the current calibration limits.

The airflow limit source that youre probably seeing in the ETC or Fuel Sources is backwards calculated using the injector flow rate (which is affected by rail pressure) and the 100% IDC injection window to determine whether or not your driver requested airflow and torque can actually be delivered within the limitations of the fuel system. Target lambda is included in that for obvious reasons. So to answer your question, it's based on all of the things you listed.

If you're hitting this limit and want to overcome it, you need to either raise the fuel rail pressure target, or open up the DI injection angles. Injection window can have very drastic effects on your knock sensitivity so I would watch that closely. You should log your HPFP DC% as well. As you open the injection window, the pump needs to work harder to maintain the same pressure. If the pump regulator pegs at 100%, thats pretty much when you know its time for a fuel system upgrade. On the Focus ST (and I believe the RS as well), this is actually a convienent stopping point for a stock bottom end

[Sub8]

Rob - thanks for reply. I get what it is and how it's calculated. But unless we can see the actual pulse width or max angle vs actual it's still an infered flag based firstly on airflow. As we're not measuring airflow but estimating it based on aircharge model it may not be accurate. Does that make sense?

It's a built engine with xdi HPFP but std injectors still. Rail pressure is maxed and I've allready opened max inj timing to a (high) 285deg. Going from 275 to 285 made no difference to the airflow limit clip for InjDC.

With the aftermarket pump infered flow based on pump dc may also be questionable.

So any chance to get the pid added?

[Rob@HPTuners]

Rob - thanks for reply. I get what it is and how it's calculated. But unless we can see the actual pulse width or max angle vs actual it's still an infered flag based firstly on airflow. As we're not measuring airflow but estimating it based on aircharge model it may not be accurate. Does that make sense?

It's a built engine with xdi HPFP but std injectors still. Rail pressure is maxed and I've allready opened max inj timing to a (high) 285deg. Going from 275 to 285 made no difference to the airflow limit clip for InjDC.

With the aftermarket pump infered flow based on pump dc may also be questionable.

So any chance to get the pid added?

If you send a ticket we can get it added (it should already be there but we can investigate).

I'm not sure I understand what you mean about it being inferred and unreliable. Yes mass airflow is derived from the speed density model, which is technically inferred, but highly accurate when calibrated correctly. If you have extreme fuel trims due to this model being off, as well as the airflow limit source, then the solution is to properly tune the speed density. Otherwise I would assume it to be mostly trustworthy for this purpose.

The HPFP flow data is only needed for the feed-forward control of the regulator, it doesnt get used for any fuel flow calculation, that comes from the injector slopes.

My money would be on that youre out of injector. Unfortunately the upgraded HPFP doesn't allow you to sneak all that much more flow out of the injectors aside from maybe sustaining a higher pressure in lower rpm ranges.

[Sub8]

Hi Rob - ticket Re: Mk3 Focus RS - Missing logging PID - #488572

[Sub8]

To add, car also has cams and a bunch of other stuff. I've recut virtual VE model as you would expect. Trims are reasonable. BUT without an engine dyno and some good instrumentation it's all still a little on the 'estimated' side😉.

Does anyone have an idea of oem injector capability with uprated HPFP. Xdi blurb is 36% over std pump.

Thanks for support.

[HeavyChevy305]

The channels called (DI Injector Effective Pulse Width Int.)

Basically anything over 6.0/6.5ms. means you're out of injector if that helps. You said built motor, What size turbo and what fuel?

[Sub8]

Hi - I cant see that channel in scanner.