Tip-In

[DanStraffa]

G’day

 

Just wondering if anyone has fiddled with Tip-In’s to add more fuel when you punch the throttle.

 

I’ve changed my air intake manifold on my BF NA 6 to the plastic FG manifold, I’ve also put the V8 throttle body on it for when I boost it and when I punch the throttle it has a big lean pop and cough then comes good.

 

I’ve also got the FG injectors and have changed the data to FG injectors.

[Roland@pcmtec]

You can modify the tip in pump shot multiplier auF0205 however it should never go so lean it misfires. 

Did this happen before you changed the manifold? You can also try changing the manifold volume auF0204

After changing the throttle body did you copy all the throttle maps over from the V8 as well?

EDIT: You must also set the tip-in and tip-out gains to a non zero value.

Eg setting auF1156 to 0.05 would result in the following extra fuel at a coolant temp of 156°F.

0.05 * 0.986 = 0.0493

4.93% extra fuel will be injected.

A tip in/tip out event is defined when there is a change in airmass > 0.00002lb per event. An event is considered a PIP eg a cylinder cylinder fill event.

[apoc]

I've got a full plastic FG inlet on my BA motor, didn't need any tip in adjustment to make it run well, just a bit of slope and fuelling adjustment.

Does the XR8 throttle fit straight on?

 

[Roland@pcmtec]

Eg it sounds like an underlying issue with injector data made worse by this change. 

[apoc]

42 minutes ago, apoc said:

I've got a full plastic FG inlet on my BA motor, didn't need any tip in adjustment to make it run well, just a bit of slope and fuelling adjustment.

Does the XR8 throttle fit straight on?

 

Note I changed the injector data to FG as well, to suit the new injectors in a BF PCM (HACCKBC)

[DanStraffa]

Didn’t happen before I changed the manifold Roland.

Haven’t changed the V8 throttle maps yet.

Going to do a bit of data logging of the AFR’s to see what the go is first Roland.

 

The V8 throttle body fitted on by re drilling the mounting holes Apoc.

[Roland@pcmtec]

46 minutes ago, DanStraffa said:

Didn’t happen before I changed the manifold Roland.

Haven’t changed the V8 throttle maps yet.

Going to do a bit of data logging of the AFR’s to see what the go is first Roland.

 

The V8 throttle body fitted on by re drilling the mounting holes Apoc.

Well that's good. At least you know the cause now.

I would do a compare to the vehicle you took the throttle body from and work through the differences copying anything throttle airflow model related. Be careful though, if you get this wrong the throttle may operate dangerously. We recommend not touching the ETC stuff unless your vehicle is strapped to a dyno, that way any uncontrolled acceleration won't be dangerous.

For example if you modify the cruise control torque control you can have the car go WOT via cruise control on you. It is very important to do this stuff in a safe environment.

[DanStraffa]

1 hour ago, Roland@pcmtec said:

Well that's good. At least you know the cause now.

I would do a compare to the vehicle you took the throttle body from and work through the differences copying anything throttle airflow model related. Be careful though, if you get this wrong the throttle may operate dangerously. We recommend not touching the ETC stuff unless your vehicle is strapped to a dyno, that way any uncontrolled acceleration won't be dangerous.

For example if you modify the cruise control torque control you can have the car go WOT via cruise control on you. It is very important to do this stuff in a safe environment.

Yeah, my mate Carl thinks it’s Tip-In for sure he’s heard it and knows a bit about cars and tuning.

I took it off my 2008 BF GT MK2.

[DanStraffa]

Hey Roland

With my Ute the FG manifold and bigger throttle body etc.

I increased the Idle RPM to 750 from 550 in Drive and 700 in Park/Neutral from 575.

I also changed the Min to 700 from 400 and Max idle speed to 800 from 850.

In first gear I’ll tap the throttle and it’ll hold revs no matter what speed. It’ll hold a bit in other gears then start decelling but not as bad.

How can I fix this?

 

[Roland@pcmtec]

What do you mean start decelling? 

[DanStraffa]

Idling down, engine braking?

[Roland@pcmtec]

Not really sure what the scenario is. 

[DanStraffa]

I’ll take a video.

Edited November 2, 2018 by DanStraffa

[DanStraffa]

Stock idle parameters.

[DanStraffa]

Idle up.

[Roland@pcmtec]

This is commonly referred to as throttle hang. Did you change the throttle maps over? The airflow map is most likely ass about now and it is pegging at minimum airflow however minimum airflow is obviously way too much.

You could probably hack up dashpot to fix it but to fix it properly you'll need all the ETC and throttle related stuff fixed.

Basically the engine is emulating an idle air valve using the throttle body itself, however the minimum airflow figure is now a lot higher due to the larger throttle blade.

[DanStraffa]

This was all happening before I changed to FG intake manifold and V8 throttle body.

I’ve narrowed it down to just the idle in gear, I’ve been upping it in 25rpm increments from the stock 550 rpm.

I’m at 650 now and it is starting to hold a bit then drop a bit then hold again and so on.

[Roland@pcmtec]

You possibly have an air leak. Does it idle at the set point? 

Pull the intake off and see what the throttle is doing. It could be sticking.

[DanStraffa]

Yeah idles perfect, where ever I set it.

Okay will do.

Edited November 5, 2018 by DanStraffa

[Roland@pcmtec]

I would check all your dash pot settings against the v8 model then 

[DanStraffa]

Okay I will.

[finnigan001]

Old post but relevant.

Has anyone played with the Accelerator pump values?  In particular auF1156 - Tip-in gain for digital pump shot.  Its 0 by default which makes guessing a scale of 'appropriate' values to try hard.  Is it a multiplier or and adder etc?

 

[Roland@pcmtec]

16 hours ago, finnigan001 said:

Old post but relevant.

Has anyone played with the Accelerator pump values?  In particular auF1156 - Tip-in gain for digital pump shot.  Its 0 by default which makes guessing a scale of 'appropriate' values to try hard.  Is it a multiplier or and adder etc?

Good question finnigan. I actually had no idea this was 0 in most calibrations. This means there is no tip in / tip out fueling at all in most cars. Probably explains why I personally had such poor result many years ago (eg zero change) when playing with the pump shot table!

The tip logic is as follows

air_lb = Air mass scaled against ECT in (auF0205) and also put through a low pass filter.

If (air_lb > auF1540 (tip in threshold))

     transient_extra_air = auF1156 (tip in gain) * air_lb

If (air_lb < auF2501 (tip out threshold))

     transient_extra_air = auF1303 (tip out gain) * air_lb

transient_extra_air is then added to the final airmass value which is fed into the injector slope model to determine fuel mass.

So if you set auF1156 to 0.1 and your coolant is 156°F you would get the following extra air mass added to the calc:

auF0205 (0.986) * 0.1 = 0.0846

so you would see an extra 8.46% fuel injected during a tip in event.

[finnigan001]

WELL! That explains a lot .

I have had marginal luck playing with the pump shot affecting tip-in so was hunting through other values.

Thank you so much once again

[Roland@pcmtec]

I've been thinking about this some more and it seems if Ford put 0 as the standard gain value it implies the TMAP speed density system should be able to correctly fuel in all transient conditions. This suggests if you get a rich/lean tip in/out there are issues with the closed loop O2 system or injector slopes. That said, i would be a very easy way to fudge much better drivability where you cannot improve it otherwise (eg using dekka injectors etc). It seems ford themselves do a lot of "fudge" tuning which can be seeing with the "Tuning Correction" tables etc which effectively are Alpha - N style correction maps.

[Milanski]

I have enabled the accelerator pump action "tipin" as outline above 0.1s, 0.1 gain.  Will see how the car drives.  I have lots of issues with transient at the tipin point between vac and boost from the supercharger.  Will keep you all posted.

[Roland@pcmtec]

On 6/22/2019 at 10:51 PM, Milanski said:

I have enabled the accelerator pump action "tipin" as outline above 0.1s, 0.1 gain.  Will see how the car drives.  I have lots of issues with transient at the tipin point between vac and boost from the supercharger.  Will keep you all posted.

How good have you gotten the fuel trims? Also even if you are getting transient lean/rich readings on the wideband, how does it drive?

I found I was trying to perfect these conditions too much and providing they were within 10% on transient conditions the car actually drove as good as factory, so that is something to keep in mind as well.

I've never actually had the oppurtunity to log a completely stock Ford vehicle, I would be curious to see how good they are from factory on transient conditions, I know at a steady state their trims will be within 2-3% which is why this is what I recommend people aim for to achieve stock drivability.

[Milanski]

Hi Roland, I did two days of scanning on the car.  (PS. had to use VCM Scanner, PCMTEC logger needs a bit of work - for another subject)

I removed the downstream (after cat) O2 sensor and installed a AFR gauge.  Disabled the logic in the PCM.   I then started looking at the injector data and plotted some stuff in excel.  Roland was correct in saying the High Slope and Low Slope are linked and any change to the low slope will impact fueling when using high slope.  Here was my starting LTFT.

At idle, cruise way too much fuel being pulled out.  

I started by increasing the low slope curve - which makes the system leaner.  And found immediate results.  However, around the mid section 1800-2200 rpm the car ran very lean.  This made good sense from looking at the excel charts.  So I pulled back the high Slop to correct - with some good success.  However I am not too concerned with high load just yet.

What I have found was under light acceleration the pinging actually got worse,  than I had originally.  AFR lean about 15.5.  No matter what I did with the low and high slope this region was a bit of problem.  Then I noticed the commanded injection pulsewidth was very close to the breakpoint.  Hence this region needed to be richer.  The only option I had was to move the offset as the higher RPM in closed loop cruise was perfect.  In the end my settings went from:

 

to

 

The voltage offset was adjusted by 105% to get:

So after about 1/2 hour of driving i have ended up with a LTFT histogram like this:

STFT (ignoring the reds as it went to open loop at a few fangs.  There is not enough counts but its a good start.   It shows I have gone from super rich to mild lean at idles.  This also shows my pressure regulator is doing its job with a walbro 460 up behind it (including an oversized return orifice at the pump - a must do).  I am happy with the mid cruise areas for now.  

I have plotted some graphs in excel to tune in these settings.

The car feels very snappy at the slightest touch of acceleration.  I am working on the lean mixtures around 1800-2200 and boost pressure about zero (101kPA) just as the supercharger gets load on, seems to get lean for a couple of seconds until the ECU catches up.  This i guess is where the accelerator pumps come in!

 

As for the accelerator pump shots:

Went from gain 0.1 to 0.05 as it slugged down at throttle impulse.  Again - minor improvement to my lean issue around mid section vac-to-boost area.  

The transient seems to work but for a very short time.  It still takes 2-3 seconds for the ecu to play catch up and richen the injectors.

I got some data from a 5.4L Cobra S/C file from HP Tuners and had a look at their base fuel lambda table - interesting they run lower lambda much further down .

My lambda table is:

 

The Mustang GT500 (same engine but different compression ratios) is like this

At 30-40% throttle and 1500-2000 rpm they target 0.95 lambda.  So I will be trialling this after work today.