HOWTO: Injector Scaling Basics

[Whiteford]

Edit : highly recommended to check this tool out 

 

Hi Guys,

I am far from a tuner however would like to know if a car has had 1000CC injectors installed, no other mods and a stock tune, what parameters would need to be changed for the car to be able to drive to a tuner?

Any input welcome.

Thank you

[Roland@pcmtec]

Edit: This will give you a rough guide on what items need to be changed to scale injectors.

I have ID1000 in my BF which should be similar to yours, they are matched sets but they can vary up to 5% so remember this.

Here is the official ID1000 data

http://injectordynamics.com/wp-content/uploads/2014/08/ID1000-Ford-Characterization-Tables-8-6-14.xls

Correct their spread sheet for a 4 bar reg and 0% ethanol

This gives you a high slope of 0.031774 lbm/s and a low slope of 0.035023 lbm/s

Now I used this data and the fuel trims were way off. After lots of logging and cruising I now get 1.00 0.98 trims at cruise and worst case 0.9% under some deaccel conditions. Generally around 0.95 most of the time.

Here is the data I ended up with. Make sure to use the +/- symbols to ensure all the decimal places show when working with these small numbers.

High slope = 0.0296729 lbm/s

Low slope = 0.031059 lbm/s

Pulse width minimum = 0.00019 seconds

Injector breakpoint = 0.000027 lbm

breakpoint_ms = breakpoint / lowslope * 1000 + offset(volts)

To scale these figures I datalogged long term trims (after first giving the car 80kms to zero the trims in, don't datalog immediately after making changes as you will forever chase your tail). I then datalogged airmass to determine what needed changing, low slope, highslope or the breakpoint. Pulsewidth minimum you only decrease if you are getting anything other than an 18:1 lean condition on deaccel fuel cut. If you get a pop pop pop when holding revs at 2k in neutral this can also mean your pulse width min needs increasing or your low slope needs increasing.

Slopes were about 7% -12% less than the ID1000 data.

Zero this out (I don't think its used)

Deadtime I had very similar to the ID1000 data

Leave this stock

Zero this out (once again I don't believe it is used)

I included the .tec file so you can do a compare and copy. This should get the car idling and cruise good enough to get it to a tuner. Stay off load until you get it on a dyno with a wideband. If you want to be safe change the fuel base (rpm, tps) auF0172 to be 0.73 in the upper tps range, this will be extremely rich but you should be pretty safe this way.

I then played with the lost fuel tables and injector pump to fix a transient leanout when very cold. Eg change gears on very low load/rpm when cold and it would go quite lean for 2-3 seconds. Winding out the cold start, accelerator pump and cold start tables fixed this.

note if you want to log when you are on the low or high slope log injector ms and you can tell which slope you are on. Use the following calculation to determine the breakpoint in ms

breakpoint_ms = breakpoint / lowslope * 1000 + offset(volts)

edit: Here is a visual representation of the injector slopes

Offset - affects low load and wot

low slope - affects low load and wot

breakpoint - affects low->medium load and wot

high slope - only affects high load.

If you change the low slope it will change the offset of the high slope. Check out this image I've drawn. You can see that if you adjust the low slope and leave the high slope unchanged, you will have offset your high slope and hence affected WOT fueling. Same story with modifying the breakpoint.

For this reason if you change the low slope and want to keep the same wot fueling, you can see you must also massage your high slope as well. For this reason you should tune in the following order

first deadtime(offset)

then low slope

then breakpoint and high slope

 

hackkga BF manual ID1000 PW Stage2 Intercooler 4inch dump 100CPI cat Walbro 460.tec

 

[Carl]

Hi i have a set of bosch 160lb injectors and am having problems scaling them. i can get them to ldle but as soon as you touch the throttle it pops and bangs and goes lean i have tried to move the breakpoint and pw around with no luck am I missing somthing. Ps I have attached the data sheet of the injectors.

[Roland@pcmtec]

Can you post up your high slope, low slope, breakpoint, dead time, what fuel pump and what regulator you at using?

Bonus if you can measure your base fuel pressure as well. 

Also are your injectors brand new and a matched set? Eg that data is definitely for the set you have? 

First things are your base fuel pressure may not be the same as that data sheet. Your dead time may be completely wrong as well. 

Loud pops suggests it is very lean. 

Edit: base fuel pressure for an xr6t is 400kpa / 58psi so you need to get data for that pressure. 

[Carl]

Iam not a 100% sure if the data sheet is correct for the injectors thay are bosch 160lb white tops p/n 02080150846 thay are matched. Its running 2 bosch 044 fuel pumps a trubo smart fpr1200 reg set to 40psi. 

[Roland@pcmtec]

I would start by checking your fuel pressure, otherwise you will be chasing your tail.

You need to confirm the data is correct as well otherwise you will just be guessing.

You can probably get it running OK by guessing but I wouldn't recommend anyone do that.

What does your wide band say when idling in open loop? Make sure you disable closed loop otherwise it will mask the fact the injector data is off. There is a thread on here showing you how to do that. 

[Carl]

At idle its afr is 11.0 with the 02 disconnected as soon as you hit the throttle it pops and farts and afrs got to like 20.7. Like a big lean spot 

[BeerTurbo]

On 6/3/2018 at 10:40 AM, Roland@pcmtec said:

To scale these figures I datalogged long term trims (after first giving the car 80kms to zero the trims in, don't datalog immediately after making changes as you will forever chase your tail).

Hi Roland, is it possible to reset all trim data using the software, so you can them preform your data log straight away?

Edited August 28, 2018 by BeerTurbo
cant spell

[Roland@pcmtec]

Zero was the wrong word to use. The trims are already zero'd after a flash.

I mean dialled in, as in the trims will approach their final value after 80kms as you will have hit all the load cells multiple times.

[Carl]

Is it normal for the stft to go to + 40% AT WOT even with cloced loop disabled or am I doing somthing. 

[Roland@pcmtec]

At WOT they will be ignored.

[shadowgun]

im a little confused about adjusting the trims?

when adjusting slopes is there a way to determine the difference between the low/high slopes? (for e.g would low slope be off boost, high slope for boosted fuel areas?)

im trying to understand it in a way where if i come across injectors that dont have data provided like ID give then i know how to go about dialing them in

cheers

[Roland@pcmtec]

The slopes are to attempt to model the injector curve. 

Eg for a given ms open how much does the injector flow. Due to friction the injector is non linear at low pulse widths. Eg first you have a deadtime, eg a certain time until any fuel at all is released (eg how long the coil takes to physically open the injector) the you have a very small zone (low slope) where the injector will quickly ramp up in flow. Eventually the injector flow stabilises and you get the high slope where the injector remains linear. The point at which the injector flow becomes linear is at the breakpoint. 

Without data you have to determine this yourself. Usually you can get ballpark (+-25%) by picking another injector or simililar design and size. 

At idle on 98 and 1000cc or smaller you will be operating on the low slope. You can trial and error this until your trims are ok at idle and light cruise. Light cruise/decel being rich but idle being ok suggest your deadtime is too low. This is because your pulse width is higher at idle than cruise/decel. Cruise being ok but idle being too rich suggests your low slope is off. Next turn on closed loop and use your LTFT to further improve this until you are close 0 to 2% in all idle, cruise and decel scenarios. It takes a few minutes for the LTFT to stop changing. 

Next force open loop again and make up a breakpoint and high slope and check your mixtures on load, once they are ballpark turn closed loop back on and further adjust the breakpoint and slope to hone it in. 

Remember that fuel  injected above the breakpoint (on boost) is offset + low slope + breakpoint + high slope. Eg all these constants affect fueling. 

Below the breakpoint only offset and the low slope affect fueling. Eg cruise, decel and idle 

In decel and extremely low load the offset almost entirely dictates your fueling error. 

There are some good graphs by paul yaw at ID that I will post up. 

[Roland@pcmtec]

Have a read of this 

http://injectordynamics.com/articles/drillbits-and-dipshits/

and these if you get time

http://injectordynamics.com/the-library/

You can see the non linearities of the injector flow. The low slope is the steep slope up until about 1.25msec, the highslope is after this and is approximated by the white line. You can see that if you shift the offset it shifts the entire curve left or right, if you shift the breakpoint it shifts the entire high slope left or right.

[shadowgun]

Very informative information, ill check out the ID articles 

 

Thank you roland, appreciated.

[Milanski]

Roland: from previous two posts: "Cruise being ok but idle being too rich suggests your low slope is off." 

Makes sense to increase low slope to lean out the mixture? Can you confirm.  My reasoning would be that for a given lb/s say its 1 lb/s and the requested charge is 1lb, then the pcm would request 1 sec.  If the mixture is too rich, then the pulse was too long.  Hence the slope needs to increase so the effective pulse time is shortened.

Will try this in the morn.  

[Roland@pcmtec]

Beware that changing your low slope  will also offset your WOT fueling.

[Milanski]

8 hours ago, Roland@pcmtec said:

Beware that changing your low slope  will also offset your WOT fueling.

Thank you for confirmation. 

[Puffwagon]

9 hours ago, Roland@pcmtec said:

Beware that changing your low slope  will also offset your WOT fueling.

1 hour ago, Milanski said:

Thank you for confirmation. 

 

The low slope doesn't affect the WOT fuelling and in the most cases won't be in use, other than idle, decel and very low speed cruise. 

As per the ID diagram, the low slope only pertains to the non linear part of the injector slope that is below the break point.

It is the high slope that affects WOT.

[Milanski]

26 minutes ago, Puffwagon said:

 

The low slope doesn't affect the WOT fuelling and in the most cases won't be in use, other than idle, decel and very low speed cruise. 

As per the ID diagram, the low slope only pertains to the non linear part of the injector slope that is below the break point.

It is the high slope that affects WOT.

Thank you Puffwagon, now I am a little stumped.  Roland has identified in the PCM program that the system uses the HIGH SLOPE + LOW SLOPE + VoltageOFFSET to determine pulsewidth requirements.  This being the case any change to low slope will affect the high slope.  Im now a little confused.  Puffwagon - are you 100% sure about your comment.  I am OK with either as I will find out very shortly when I do some experiments.  

[Puffwagon]

23 minutes ago, Milanski said:

Roland has identified in the PCM program that the system uses the HIGH SLOPE + LOW SLOPE + VoltageOFFSET to determine pulsewidth requirements. 

This does not contradict my comment,  and yes I'm 100% sure my comment is correct about how the injector slopes and breakpoint works.

Head over to the injector dynamics website and read up for yourself.

[Puffwagon]

If it's a bit tricky to understand I can explain it differently so you can understand it.

[Milanski]

Thanks Puffwagon, appreciate the info thus far.  I have plotted both curves and breakpoint into excel to see the outcome.

[Puffwagon]

Excel is a good starting point, I did a similar thing when I worked out my injector data a few years back.

I found that there is some real world difference from excel to when you put the numbers into the tune, and you will more than likely have to move the slopes around slightly to get them spot on for your vehicles setup.

There's plenty of info available and people willing to help, so good luck with it!

[Roland@pcmtec]

2 hours ago, Puffwagon said:

This does not contradict my comment,  and yes I'm 100% sure my comment is correct about how the injector slopes and breakpoint works.

Head over to the injector dynamics website and read up for yourself.

Offset - affects low load and high load

low slope - affects low load and high load

high slope - only affects high load.

If you change the low slope it will change the offset of the high slope and hence affect WOT fueling. Check out this image I've drawn. You can see that if you adjust the low slope and leave the high slope unchanged, you will have offset your high slope and hence affected WOT fueling. Same goes for breakpoint and deadtime, all of these will affect WOT fueling as well and can affect it quite a bit. A small change to the low slope could cause a 10-20% change in WOT fueling depending on the breakpoint you use. 

In an extreme example if you made the breakpoint very high you could technically cause a 90% change in fueling from a 5% change in the low slope. Just draw it in paint and you'll be able to visualise it.

For this reason if you change the low slope and want to keep the same wot fueling, you can see you must also massage your high slope as well. For this reason you should tune in the following order

first deadtime(offset)

then low slope

then breakpoint and high slope

[Roland@pcmtec]

Here is the actual equation if you want to build a slope calculator in excel. I worked this out drawing the straight lines and some year 9 algebra (yes there was a point to learning all that maths!)

IF (fuelmass >= breakpoint) y (fuelmass_lbs) = highslope_lb_sec * (x (injector_sec) - (breakpoint * (1/lowslope_lb_s - 1/highslope_lb_s) + offset_sec))
IF (fuelmass < breakpoint) y (fuelmass_lbs) = lowslope_lb_sec * (x (injector_sec) - offset_sec)

fuelmass_lbs = airmass_lbs/ commanded_AFR

 

The equation for the lines would then be

Above breakpoint

y = h * (x - (b * (l-1/h)+o))

below breakpoint

y = l * (x-o)

Where:

y = fuel_mass

x = injector_pulse_width (seconds)

l = low_slope (lb/s)

h = high_slope (lb/s)

b = breakpoint (lb)

o = offset (seconds)

 

You can then invert the equation if you want to solve for injector pulse width as well.

above breakpoint

x = (b*(h*l-1)+h*o+y) / h

below breakpoint

x = (y/l) + o

[Milanski]

Wow Roland, Never cease to amaze.  I had very similar charts in excel plotted.

 

I started with this fine tuning because ive had 4 tuning shops have a go.  Some quite reputable.  They run the car on the dyno up a few times for WOT and make a few tweaks on the closed loop VE corrections and tables.  Pay the 1000$ and off you go.  Then when you drive it WOT is great, but cruise is at -20% fuel trim. Tipin (transient) pings to death. The days of spending time looking at RPM/load/map histograms seem to be gone and its get in and make a quick buck by coping from one car to another.  Then I look at the injector data provided by ID for a 1050x and its worlds apart with what is in the car.  I'm not saying its wrong, but to be 70% different rings alarm bells. 

So I'm getting into the tuning myself to see what I can (or cannot do).  Shortly I will have a scope for injector timing using a picoscope, an AFR Wideband (by PLX) reading back into HP Tuners Scanner, and will do some road testing/tuning to hone in the speed density properly.   

 

I like you're addendum to your previous post.  Certainly clears it up.  

[Roland@pcmtec]

A lot of shops will just hack up the speed density tables to get the trims better, but if you have a stock intake manifold and turbo there should be minimal need to do that. You can figure out if your speed density if off by following a similar process to what I did years ago on the hptuners forum

https://forum.hptuners.com/showthread.php?58174-Custom-graphing-software-for-logging-fuel-trims-and-recalculating-speed-density-maps

If you isolate all data from a single histogram plot and then plot that against a 4th variable (eg map pressure) you can figure out if the speed density map slope/offset needs changing. If its a perfectly linear error then your injector slopes will most likely be the culprit.

Doing this properly honestly takes a week. Unless every customer uses the same injectors and parts a workshop can't just reuse injector data, as you are only paying them for a few hours labour its not possible for them to do this from first principles and still make a profit..

The reality is Ford would budget close to a million dollars to do a tune from scratch, if you are paying $1k and don't have a team of calibrators and a controlled engine dyno room you just cannot get the same results in any reasonable time, this is why you see a lot of cars going around with fairly average fuel trims.

Personally if you have ~5 hours to tune a car from scratch and have some base injector data you should be able to get the trims under 10%, but if you have zero data at all, you may not get there in the time the customer has paid for.

Your best bet is to ask the workshop what injectors they use on the majority of their cars and make sure you use those, that way you know they have some known base data they are working off. If every customer turns up with something different in the car then the results you get shouldn't surprise you.

It sounds like you have the knowledge required and more importantly the time required, so you should be able to get within +-3% fuel trims if you spend 2-3 full days logging all possible cells with a reasonable cell hit count (look for at least 1000 hits per cell).

edit: Something that's extremely important to check is fuel pressure, if this is not constant you will chase your tail and never get there. Big fuel pump and stock regulator will mean high pressure at idle, this will result in weird injector slopes required to get things working.

[Puffwagon]

Good write up rolls.

To play devils advocate, ive seen plenty of people get too caught up with tuning their computer and forget they are tuning an engine and the results show.

As i said earlier use the high slope for wot and the low slope for idle and start up. This is all anyone needs to know to in regard to slopes to effectively tune their car, as long as they know what an engine needs and they have a good set of matrix goggles.

[Milanski]

1 hour ago, Puffwagon said:

Good write up rolls.

To play devils advocate, ive seen plenty of people get too caught up with tuning their computer and forget they are tuning an engine and the results show.

As i said earlier use the high slope for wot and the low slope for idle and start up. This is all anyone needs to know to in regard to slopes to effectively tune their car, as long as they know what an engine needs and they have a good set of matrix goggles.

Hi Puffwagon,  top stuff.  Need time to digest.

[Milanski]

On 6/20/2019 at 1:13 PM, Roland@pcmtec said:

y = h * (x - (b * (l-1/h)+o))

correction y = h * (x - (b * (1/l-1/h)+o)) or my equation which yields the same result  y = h(x- b/l - o) + b

 

[Roland@pcmtec]

20 hours ago, Milanski said:

correction y = h * (x - (b * (1/l-1/h)+o)) or my equation which yields the same result  y = h(x- b/l - o) + b

 

Just depends how you simplify the equation. I just used wolfram alpha to do it as I'm lazy.

https://www.wolframalpha.com/widgets/view.jsp?id=4be4308d0f9d17d1da68eea39de9b2ce

[Milanski]

5 hours ago, Roland@pcmtec said:

Just depends how you simplify the equation. I just used wolfram alpha to do it as I'm lazy.

https://www.wolframalpha.com/widgets/view.jsp?id=4be4308d0f9d17d1da68eea39de9b2ce

very funny.  I went back to first principles.  like you was testing my year 9/10 math.  You are spot on with the curves.  Im tyding up the template in excel and will post up shortly.  I have also used to check injector Dynamics data against their won curves - some interesting findings.

[Roland@pcmtec]

On 6/22/2019 at 10:45 PM, Milanski said:

very funny.  I went back to first principles.  like you was testing my year 9/10 math.  You are spot on with the curves.  Im tyding up the template in excel and will post up shortly.  I have also used to check injector Dynamics data against their won curves - some interesting findings.

Great. I did a spreadsheet a long time ago that allowed me to enter in a +-% adjustment to the breakpoint and preserve the WOT fueling. Basically it would shift the low slope by the amount needed then adjust the high slope to ensure it intercepted at the same fuel mass point as it did previously for a given load. I will see if I can dig it up.

[Roland@pcmtec]

tuning slopes.xlsx

Here you go, have a look at this and it might be of use. I did this back in 2016 so I honestly can't tell you if its completely correct however I did get my trims within 3% across the board at that time using this and lots of datalogging (several weeks of it).

There is a description in the spreadsheet of how to use it. The max duty cycle (ms) is where you want fueling to be preserved, eg make this your peak torque value and it will ensure that you don't affect WOT fueling when adjusting the low slope. This is useful if you've got your WOT dyno run done but your cruise is off and you don't want to re-do the WOT fueling.

edit: The main use of this calculator was to hone in on the dogleg of the injector slope, eg the breakpoint. This is if your trims are great on decel, great on medium load but off on light load (eg holding in neutral or light cruise). You probably already know this but idle is actually higher load (more duty cycle) than cruise due the fact the rpm are lower. So if you see a kink in your fuel trims when going from cruise to decel to idle the breakpoint being incorrect is usually the problem, this calc can help you shift the breakpoint in 2 dimensions to hone it in.

[Milanski]

Ha, I think we are on the same page.  Here is my sheet I've been using.  Still a awork in progress to get the y-axis to cc/s

Injector Slopes2.xlsx

[Roland@pcmtec]

For anyone doing this from scratch I recommend logging the following values and loading it into mega log viewer. In this case the vehicle simple has the wrong slopes. I believe they have put slopes for a KPM 1100 injector which have a less steep low slope (reverse of say an ID1000).

	Engine speed
	load used for spark table
	desired lambda
	long term fuel trim
	Fuel mass requested
	Pulse width
	open loop
	TPS
	vehicle speed
	Intake cam position
	Exhaust cam position
	Current speed density offset
	Current speed density slope

 

I then loaded this into a scatterplot, red is 1.0, rest of the scale is on the right. I also filtered this data against transient by taking the derivative of rpm and adding a data filter (these are included in megalog HD). Here is the filter I used

(abs([ENGINE_SPEED] - [ENGINE_SPEED-4]) > ([ENGINE_SPEED] * 0.05)) 

I also made a histogram

Here are the injector figures (ID1000s)

As you can see the low slope is completely wrong and far too rich (I believe KPM injectors have a weird slope like this). For ID1000s the low slope should be steeper than the high slope.

From the scatter plot you can see the high slope appears perfect. This means we need to adjust both slopes to accomodate for the new low slow (will pull 12% off fueling out first go)

REST TO COME SOON

[itcy]

iv got a customer with an FG MK1 XR6T and has supplied his own injectors, now the injectors are from MTQ/sonic and are "1250cc"

http://www.sonicperformance.com.au/BSS1250/Modified-Bosch-Fuel-Injector-1250cc-EV14-3_or_4-Length/pd.php

now the problem iv got is they can not supply me with any data on them other then the dead time.......... not sure where to go from here........ has anyone got any ideas? anything help would be amazing ! 

cheers peeps!  

[Roland@pcmtec]

Spend a day scaling them in using the methods above. The deadtime is the hardest part to calculate so you have that to start with. With completely unknown data I'd estimate you'd need a few hours to get them acceptable, a day to get to 1% and perfect. Use the ID1000 data above as a base, it should have you within 20-30% trims so the motor will at least crank.

OR

Sell them and put in injectors that you've already scaled.

Personally if I ran a workshop I would spend a week scaling 1000,1500 and 2000cc injectors until I could get them within 1% on stock fuel pressure. Then every customer that came in with something else, I'd replace their injectors with one of those 3 depending on the application. If the customer says no, tell them to go down the road.

The amount of times I've seen people burn days on blocked, mismatched or unknown injectors is absolutely crazy. Just get something known and stick with it. You'll save a lot of time and money. Re-scaling injectors from scratch every time is a great way to go broke or send a lot of cars out with terrible fuel trims (and hence stall etc).

[itcy]

i agree, we quoted injector dynamics but he didnt want to go that way, thank you for your quick reply !  

[Superb]

@Roland@pcmtec Im trying to recreate your graphs in megalogviewer with the DMR's I have available in the enthusiast version.

Any tips you can provide?

 

[Superb]

[Roland@pcmtec]

Change your axis scaling so you can see the actual values.

[Superb]

9 hours ago, Roland@pcmtec said:

Change your axis scaling so you can see the actual values.

Thanks, I have tried that before. From what I can see the range for injector pulse width goes up to 6000 in your graphs, but I can not replicate that.

I using your filter (abs([ENGINE_SPEED] - [ENGINE_SPEED-4]) > ([ENGINE_SPEED] * 0.05)) 

Not sure what I'm doing wrong

 

[Roland@pcmtec]

Your FUEL_PW uses different units that are seconds. Either change your log to ms, or change the scaling to suit.

edit: Just looking at that scatter plot its immediately obvious that your injector offset and high slope need major changes of ~15%

[Superb]

On 4/8/2020 at 10:21 AM, Roland@pcmtec said:

Your FUEL_PW uses different units that are seconds. Either change your log to ms, or change the scaling to suit.

edit: Just looking at that scatter plot its immediately obvious that your injector offset and high slope need major changes of ~15%

Thanks I was aware I need to make some changes. A/F under WOT is ok but I'm learning as I go.

[Superb]

Hi back again with a bit of an update.

Spent about 3 weeks logging and think I got trims as good as I can.

Running live LTFT through android auto I'm seeing +/- 2%

Thoughts?

[Roland@pcmtec]

5 hours ago, Superb said:

Thoughts?

Nailed it. That's as good as you will get. 

[DanStraffa]

Hey @Roland@pcmtec here is my histograms of cam angle vs rpm vs LTFT and Fuel pulse width vs LBMF/event vs LTFT.

Also my injectors are Bosch 980cc.

 

Edited November 9, 2020 by DanStraffa

[Roland@pcmtec]

Those are atrocious fuel trims. You are maxing out at the 25% limit. You need to be within 3% to have factory driveability. Follow this thread and rescale them to an acceptable level otherwise you are going to have hunting/stalling and all sorts of dramas.

[DanStraffa]

Yeah I honestly don’t know what happened they weren’t that bad few months ago.

I’m going to start from scratch, least I can only go up from here @Roland@pcmtec

 

I’m not sure but I think one of my dramas could be is I changed my alternator pulley to a larger one from Dynomite Performance and my battery isn’t seeing 14 bolts it’s only seeing 12.6-12.8 volts.

 

Could that be a contributing factor? 

Edited November 10, 2020 by DanStraffa

[Roland@pcmtec]

Depends if your deadtime offset has been calculated correctly for those voltages. When you scaled your deadtimes did you rescale the whole table every time, or just the 14v row?

[DanStraffa]

Nah we rescaled the whole lot, not just 14v.

[DanStraffa]

Thoughts now? After a few changes of deadtime and low slope.

[Roland@pcmtec]

Looks pretty close. Drive it for at least 80kms to dial in then see if it persists. 

[DanStraffa]

Okay will do thank you 👌

[Milanski]

On 6/20/2019 at 1:13 PM, Roland@pcmtec said:

Here is the actual equation if you want to build a slope calculator in excel. I worked this out drawing the straight lines and some year 9 algebra (yes there was a point to learning all that maths!)

IF (fuelmass >= breakpoint) y (fuelmass_lbs) = highslope_lb_sec * (x (injector_sec) - (breakpoint * (1/lowslope_lb_s - 1/highslope_lb_s) + offset_sec))
IF (fuelmass < breakpoint) y (fuelmass_lbs) = lowslope_lb_sec * (x (injector_sec) - offset_sec)

fuelmass_lbs = airmass_lbs/ commanded_AFR

 

The equation for the lines would then be

Above breakpoint

y = h * (x - (b * (l-1/h)+o))

below breakpoint

y = l * (x-o)

Where:

y = fuel_mass

x = injector_pulse_width (seconds)

l = low_slope (lb/s)

h = high_slope (lb/s)

b = breakpoint (lb)

o = offset (seconds)

 

You can then invert the equation if you want to solve for injector pulse width as well.

above breakpoint

x = (b*(h*l-1)+h*o+y) / h

below breakpoint

x = (y/l) + o

Hi Roland, just to pick this up.  Does Min Pulse Width = offset in these equations?  I think you mentioned it early on.  How does the battery offset come into equation then?

[Roland@pcmtec]

Min pulsewidth should be above the dead time. Min pulsewidth is basically saying between deadtime and now the injector will be dribbling or otherwise unreliable in its fuel delivery (misfires etc) so clip it at this pulsewidth to ensure combustion is complete (but it will be rich as a result).

Properly designed and sized injectors should never hit the min pulse width clip to ensure good fuel economy. 

Dekas are a great example of a crap injector needing a high min pulsewidth to operate without misfiring and hence have poor fuel economy and run below lambda at cruise/decel as they are hitting the min pulse width clip. 

[Milanski]

Thanks understood, maybe I will ask the questions another way,  the offset_sec  in the equations comes from the battery offset table?  

[Roland@pcmtec]

15 hours ago, Milanski said:

Thanks understood, maybe I will ask the questions another way,  the offset_sec  in the equations comes from the battery offset table?  

Yes the offset is the deadtime. They are the same thing. Minimum pulse width is simply a minimum clip value.

[john.z]

Ive just fitted 1000cc injectors, the only info ive received is a dead time of 1.59ms @ 12V and 3 Bar. running 4 bar, how should i be scaling this? what ive currently done is entered in 1.49ms @ 12V and moved the whole voltage curve the same difference. Is that the wrong approach? It's a cammed boss 290. Got it running alright, there is a slight hesitation while cranking after the first fire, but never struggles

[john.z]

@Roland@pcmteci should be able to log for individual banks yes? not sure why but this is how it came out. It's fuel flow bank 1 doing it

[JVK]

Did you try swapping the injectors from right bank to left just to rule out an injector issue ?

[john.z]

32 minutes ago, JVK said:

Did you try swapping the injectors from right bank to left just to rule out an injector issue ?

Happening with the stock and the new  injectors. 

[john.z]

noticed throughout my logs that there was no difference between the pulsewidths on either bank, it seems to be just recording bank 2 and reporting that as both. which expains the weird plot. LTFT and fuel flow show up right though. Is this just an oversight in PCMTEC datalogging?

 

[Roland@pcmtec]

2 hours ago, john.z said:

noticed throughout my logs that there was no difference between the pulsewidths on either bank, it seems to be just recording bank 2 and reporting that as both. which expains the weird plot. LTFT and fuel flow show up right though. Is this just an oversight in PCMTEC datalogging?

 

They are the real internal values. They may be pre fuel trim scaling though. Can you set them both to high priority and attach the log file here? I will have a look at the asm tomorrow and see if there is anything added after that value that you can log seperately. 

Can you also include the OSID of your vehicle. I will double check the addresses are different as a sanity check.

[john.z]

okay ill get that through tomorrow

 

[john.z]

aren't the first 15 already set as high priority? if so here is my first log after adding the 1000cc injectors

 

 

1000cc log1.teclog

[john.z]

also i cant log STFT for both sides?

 

[Roland@pcmtec]

5 minutes ago, john.z said:

also i cant log STFT for both sides?

Try logging F_A_RATIO[0] F_A_RATIO[1] instead as this is effectively the STFT per bank, we have never had a v8 test car so this stuff has all been developed for the 6 cylinder. The Pulsewidth calc is copied and always identical for the two banks as its actually done on a per cylinder basis and the bank reading is not really used for anything useful internally that I can see.

There are actually 8 pulsewidths you can log, one for each cylinder. This is what is really going to the injector. These are logged as FPW[0], FPW[1]...FPW[8]

[john.z]

2 hours ago, Roland@pcmtec said:

Try logging F_A_RATIO[0] F_A_RATIO[1] instead as this is effectively the STFT per bank, we have never had a v8 test car so this stuff has all been developed for the 6 cylinder. The Pulsewidth calc is copied and always identical for the two banks as its actually done on a per cylinder basis and the bank reading is not really used for anything useful internally that I can see.

There are actually 8 pulsewidths you can log, one for each cylinder. This is what is really going to the injector. These are logged as FPW[0], FPW[1]...FPW[8]

None of those show up. I’m using professional, they only on workshop?

Edited July 20, 2021 by john.z

[Roland@pcmtec]

Yes, they are not in pro afaik. 

[jpknobel]

Hi Roland,

I'm not sure if this is the right place to ask but it's relevant and may assist others in future. Please let me know if this isn't the right place.

Im using PCMtec Pro and also have HPtuners. (i usually tune diesels and have only done a small number of petrol tunes (not for paying customers).

Have a FG XR6 that has just been turbo'd (is an NA motor) and has the following relevant mods:

- Custom Alloy Welding billet centre feed intake manifold 

- Raceworks INJ-213 Injectors (1100cc at 58PSI)

- 4" turbo back exhaust

- Walbro 460 pump with a Turbosmart FPR800 reg set to 58PSI

- Innovate wideband

 

I have setup (taken a preliminary guess) some blending between tables of the NA calibration and a factory turbo calibration in terms of timing and fuelling. I've copied over most speed density, cam control and whatever else may be partially related to the current tune from a factory turbo tune.

 

The issue i am having is unstable AFRs. I believe this is due to my injector data being off (raceworks supplied) however am unsure. If i disable closed loop O2 control my idle and light cruise at 100kmhr AFRs maintain target AFRs close enough at this point (assuming some SD stuff will need tweaking due to intake manifold).

The main issue i am seeing is when closed loop boost control is enabled my AFR gauge swings between 13.5:1 and 15/16:1 and will do a full swing once every second or two.

I have attempted to log relevant data as you have previously described but it doesn't look that far out (i may be interpreting this completely wrong).

Do you have any pointers for me please?

[Roland@pcmtec]

The main issue i am seeing is when closed loop boost control is enabled my AFR gauge swings between 13.5:1 and 15/16:1 and will do a full swing once every second or two.

You mean closed loop O2 control right?

The O2 circuit purposely oscillates rich/lean to keep the cat converter working correctly. If you can show a datalog of the narrowband voltages and wideband overlaid on top this would be interesting to see.

Your plot looks pretty good to me, if you don't look at the datalog and the car drives smooth with no stalling I would call it a day. If you ever get a stock car do the same logging and you may be surprised how good yours is.

I suspect there are hardly any cell counts at the 0.95 region?

 

[jpknobel]

Sorry, yes, closed loop O2 control is what i was meant to say.

I don't currently have a way to datalog wideband against any of the pcmtec data unfortunately.

The car drives okay while its sweeping i just wasn't sure how wide of a sweep was normal. I verified the in car wideband against my portable wideband (LM2) and my dyno and they all seem to correlate (close enough anyway as dump pipe sensor vs tail pipe).

I might continue tuning with closed loop O2 off so i remove that factor and when i'm done ill just re-enable.

The only other question I had which is probably off topic is to do with the aftermarket intake manifold. What data would you expect that i need to change to account for it?

 

Thankyou for your help mate, its appreciated.

[Roland@pcmtec]

On 10/9/2021 at 7:48 AM, jpknobel said:

The only other question I had which is probably off topic is to do with the aftermarket intake manifold. What data would you expect that i need to change to account for it?

It likely affects the VE in a small way which would likely be linear to rpm/load if you plotted it.

You could most likely fudge this error in a variety of ways, tuning correction, injector slopes etc. The correct way would be to rescale the speed density offset/slope tables to suit, but that is an extremely time consuming process which requires you lock the cams at each position and datalog each cam/rpm cell in steady state on a dyno. Realistically no one would do this.

What is more likely a problem is unbalanced flow across the cylinders, the stock manifold is the best and if you've used a front facing plenum you likely will need individual cylinder air mass trims, the only way to determine this is with individual EGT and lambda probes.

edit: Do you mean the new plenum the intake is in the centre? If so its likely its reasonably balanced, but you never know.

[jpknobel]

Thanks Roland, appreciate it.

Yeah its a billet centre feed intake. I chose centre feed over front feed as i figured its inherently more likely to have a more even flow due to the centre feed design than a forward facing design.

Photo of manifold attached if you were interested.

 

[DanStraffa]

G'day men, just put some 2200cc injectors in, I got some ID2000's data off their website it seems pretty good so far I've driven for the 80ks but I'm unsure of what to change first. I'm not the smartest cookie in the jar, I've read this whole forum but yeah don't know what to change first I don't want to be stepping backwards.





@Roland@pcmtec the 2.10 beta with the DMR's can you post an updated list of them like STFT - LAM FINAL?, LTFT, is Fuel pulse width INJ PW NORM? etc
Don't know if there is another thread for this or not.

[dat111]

hey lads. currently tuning my NA+T BF MKII 

have restored 99% of stuff back to stock that had been changed for no reason at all on the tune. 
using the stock turbo injectors. an the turbo data 

Breakpoint 0.00000939999972615624
High Slope   0.00929140020161867
Low Slope   0.0135736996307969
4bar bosch fuel reg. 

LTFT's are sitting at between -15 an -16
**waiting on my tactrix, its in the mail havent flashed new tune in it yet. **
attached are both tunes. 

HACCKA5 old one V1.tec HACCKA5 - updated2.0.tec

Edited December 10, 2021 by dat111

[Puffwagon]

After looking at the old tune the other day, you can see it doesn't have stock injector data in it.

I didn't look further to see what else will be causing the trims to be out as you didn't mention it then.

[dat111]

11 hours ago, Puffwagon said:

After looking at the old tune the other day, you can see it doesn't have stock injector data in it.

I didn't look further to see what else will be causing the trims to be out as you didn't mention it then.

probs something i should have mentioned to you,
im going to wait until i flash the new tune in, an then go from there. as the tune was very average to say the least. 

[SKD]

Hi Everyone,

Just installed some Bosch 1000cc injectors and am trying to get it to run well enough to get it on the trailer to the tuner. It currently has a bad miss and afr is out (0.85 at idle), I'm praying it isn't any of the new hardware... I was hoping someone would throw some input my way as the first time I have scaled injectors! I have based changes on the information I could find within the forum but given everything is different I could be miles off. I have included my tec file if anyone wanted to have a look??

Thanks!

HAANFH4-BAE101-1000cc-Importdata.tec

[Puffwagon]

5 minutes ago, SKD said:

Bosch 1000cc injectors

 

On 4/10/2019 at 5:59 PM, Puffwagon said:

I'll just leave it here for anyone to use. Bear in mind that all cars are slightly different and you need to double check the tune with a wideband. I left the low slope slightly rich as it starts much better like that when it's freezing cold. Feel free to raise the low slope to 120 (less fuel) if you feel like it.

 

 

Bosch 980cc injector parameters.param 19.61 kB · 218 downloads

This will get you driving

[SKD]

10 minutes ago, Puffwagon said:

 

This will get you driving

I actually tried the parameters you had... Its why I'm leaning to a possible issue elsewhere. It would idle though again afr was quite a bit out? I guess I could be expecting too much from the changes too and need to wait my tune?? 

[Puffwagon]

Hardware changes can throw out a tune to the point of it being not drivable.

If you only want to get it on the trailer, just add 10 to each of the slopes and try again.

[Roland@pcmtec]

If you haven't seen it already check this out

 

[Andre34]

Hey I’m not sure if this is a wrong question but I’ve just got some new injectors in the car and I want to have a go at getting the idle stft right. At the moment I see it go as high as 23%. 
 

My question: 

if the stft is negative, does that indicate it is pulling fuel which means the minimum slope is too high? and if it is reading positive, does that mean it is adding fuel meaning the minimum pulsewidth is too low?

[Puffwagon]

25 minutes ago, Andre34 said:

new injectors

What injectors are they? Someone might have used them and can get you in the ballpark.

[Andre34]

25 minutes ago, Puffwagon said:

What injectors are they? Someone might have used them and can get you in the ballpark.

They are Bosch 627cc/min EV14 Injectors 0 280 158 123

ive used some dekka 650cc injector data to help me get started because I couldn’t find anything online at all for mine. 
 

they’re on an na bf xr6. If someone has data for them that would be awesome.

 

I’ve got screenshots of the data I used for them attached here

Edited October 13, 2023 by Andre34

[Puffwagon]

Don't touch the minimum PW or breakpoint at this stage. They will work for now.

It looks like your previous Deka data was based on a 4 bar fuel reg. At least the high slope is anyway. An na car runs a 2.7 bar fuel pressure iirc.

Try 0.0125625 for the high slope and 0.020925 for the low slope.

I based the high slope number on the injector flow at 2.7 bar and I based the low slope from your data extrapolated from 4 bar down to 2.7 bar. Long story short I multiplied them by 0.675.

It's gonna add a bunch of fuel and should see the trims swing to -10 or so. Better to start rich and lean it out gradually, rather than have it lean af under load. The trims only work at idle, cruise and mild acceleration, full load does what you tell it to do which in this case is probably very lean. Doesn't matter on an na car, it won't hurt the engine but not ideal and loses power.

Haha see what I mean about needing a wideband now?! Heh mebbe we can get an admin to make a new thread ay?

[Andre34]

9 minutes ago, Puffwagon said:

Don't touch the minimum PW or breakpoint at this stage. They will work for now.

It looks like your previous Deka data was based on a 4 bar fuel reg. At least the high slope is anyway. An na car runs a 2.7 bar fuel pressure iirc.

Try 0.0125625 for the high slope and 0.020925 for the low slope.

I based the high slope number on the injector flow at 2.7 bar and I based the low slope from your data extrapolated from 4 bar down to 2.7 bar. Long story short I multiplied them by 0.675.

It's gonna add a bunch of fuel and should see the trims swing to -10 or so. Better to start rich and lean it out gradually, rather than have it lean af under load. The trims only work at idle, cruise and mild acceleration, full load does what you tell it to do which in this case is probably very lean. Doesn't matter on an na car, it won't hurt the engine but not ideal and loses power.

Haha see what I mean about needing a wideband now?! Heh mebbe we can get an admin to make a new thread ay?

Hahah yes life would be much easier with a wideband!! 
 

im doing my best to get fuel trims as close as possible for my own knowledge and to also save on hours once I take it to the dyno. Once I get the injectors at a good spot, I’ll put a 255lph pump and take it for a proper tune with the dyno. 
 

I’ll try those numbers tomorrow and check out the fuel trims. Once they’re at ~-11, do I just slightly increase the low slope until it’s closer to 0 (around -5)?

i don’t think I’ll do anything to the high slope since I don’t have afr readings. I’ll have it rich until the dyno.

once I get to the dyno, should I adjust the high slope until it gets a decent afr reading and then fine tune using the fuel tables, or should I keep my high slope as is and just adjust using the fuel table?

 

 

also, should I leave the dead times how they are? 
 

this is the only info I was given about these injectors and I couldn’t see anything from my understanding that would help

 

Edited October 13, 2023 by Andre34

[Puffwagon]

You can adjust the low slope to get the idle trim closer to 0. Leave it at a negative number rather than a positive number, otherwise you'll probably have poor cold starts and possible stalling at intersections.

There is a method for dialling in both slopes in the driveway but I ain't about to type it out on my phone. I'll see if I've posted it and copy paste it for you. You need a wideband to do it tho so get onto it.

On the dyno the wideband should read the same as the base table. You use injector data and speed density tables to make this work. Start with high slope adjustments, this is likely all you'll have to do with a fairly stock na car.

It's past my bedtime now so I'll get back to you later.

[Andre34]

2 hours ago, Puffwagon said:

You can adjust the low slope to get the idle trim closer to 0. Leave it at a negative number rather than a positive number, otherwise you'll probably have poor cold starts and possible stalling at intersections.

There is a method for dialling in both slopes in the driveway but I ain't about to type it out on my phone. I'll see if I've posted it and copy paste it for you. You need a wideband to do it tho so get onto it.

On the dyno the wideband should read the same as the base table. You use injector data and speed density tables to make this work. Start with high slope adjustments, this is likely all you'll have to do with a fairly stock na car.

It's past my bedtime now so I'll get back to you later.

I ended up increasing my low slope to 0.020925. Here is the data log.

 

I noticed that the stft goes very rich on decel. Does this mean i need to increase my deadpoint? Also, i noticed alot of fluctiuation in my rpms and stft on idle. Is that normal and if not, does that mean my minimum pw is too low? 

 

I also noticed that my stft was reading lower before i took the car around the block a few times. It looks like the car didnt go into open loop at all. Im not sure if that's normal or not.

 

Cheers

14-10-2023 02-29-40 AM Log new injector data.teclog

[Puffwagon]

7 hours ago, Andre34 said:

I noticed that the stft goes very rich on decel.

No it doesn't, rather the opposite is true. Minor decel events are lean and the major decel event is also lean. Likely this is caused by the high slope being lean.

You are asking questions that could be answered if you understood how a few things work. As I mentioned, you need to read up on the difference between a wide band and a narrow band O2 sensor. Specifically read up on how a narrow band sensor operates and what output you should expect from it when you read the log.

You need to go back into the log and check it a lot more carefully, the car did go into open loop when it was supposed to. Read up on the difference between open and closed loop O2 control. After you understand this and how a nbO2 sensor works you will have answered your questions.

Also don't floor the car until you have a wide band installed. If it was a turbo car you would have likely kicked a rod out by now. As I said you won't blow up an na car but it's not worth trying to find out.

The trims look pretty good overall, I wouldn't bother touching the low slope any more, it's more or less where it needs to be. Change the high slope to where I said because I know you're gonna floor it again. When you install a wideband and dlp8 you can check it.

Do the reading and if you need specific things answered about them I will help. Nothing you've asked so far can't be answered by doing your own research.

Honestly, get that high slope to where it needs to be and it will be good enough to drive.

[LRiordon]

When logging STFT is it normal to read for 30seconds then go back to 1.0? 
Reading matches the afr gauge when it’s reading however when it goes to 1.0 it’s super rich.

[BeerTurbo]

On 10/13/2023 at 7:33 PM, Andre34 said:

They are Bosch 627cc/min EV14 Injectors 0 280 158 123

ive used some dekka 650cc injector data to help me get started because I couldn’t find anything online at all for mine. 
 

they’re on an na bf xr6. If someone has data for them that would be awesome.

Bosch 627cc/min EV14 Injectors 0 280 158 123*

i used these on my bf/turbo r31. i found they were near impossible to dial in with the 2.7bar factory regulator. i found some flow information whitch indicated they dident like opening at 2.5bar and i figured at idle maybe that's why i was having issues.

so with a  4 bar regulator, this is what i was last using.

[Andre34]

2 hours ago, BeerTurbo said:

Bosch 627cc/min EV14 Injectors 0 280 158 123*

i used these on my bf/turbo r31. i found they were near impossible to dial in with the 2.7bar factory regulator. i found some flow information whitch indicated they dident like opening at 2.5bar and i figured at idle maybe that's why i was having issues.

so with a  4 bar regulator, this is what i was last using.

Awesome! Thanks for this. I’ll go get myself a 4bar as well in that case

[Andre34]

2 hours ago, BeerTurbo said:

Bosch 627cc/min EV14 Injectors 0 280 158 123*

i used these on my bf/turbo r31. i found they were near impossible to dial in with the 2.7bar factory regulator. i found some flow information whitch indicated they dident like opening at 2.5bar and i figured at idle maybe that's why i was having issues.

so with a  4 bar regulator, this is what i was last using.

Just ordered one. Hopefully the na likes the same scaling as the turbo. I’m assuming it should work with the same scaling

[Roland@pcmtec]

The scaling should be identical however if you've gone from NA to turbo you'll need to tweak the speed density due to increased back pressure.

[GreG]

What would be the equivalent to LBMF_INJ on the Falcon 5.0?