When does the ecu change from low slop to high slop.
I have been told low slop is for idle only.
and high slop is all the throttle movement.
When does the ecu change from low slop to high slop.
I have been told low slop is for idle only.
and high slop is all the throttle movement.
The fuel mass as indicated by the breakpoint. Have a look at some of the calibrated success articles or Injector Dynamics. It's very easy to see the breakpoint for the transition. I've done a few exercises with different injectors via spreadsheets so I know when I'm running off the low or high slope. Remember the battery offset value (deadtime), which is an adder, has a large percentage of the calculated pulsewidth at low rpm /and it load....and will diminish as the overall calculated pulsewidth increases (ie rpm/load increases).
I have just completed an exercise in drilling my standard injectors out on an FG, I used a home made flow bench to flow match them.
Then calculated the Hi & Low slope and applied it. I then loged it with a wideband and moved the hi slope until the wideband matched the commanded AFR.
Then with the low slope again applied a calculated slope and trimed it so the stft and ltft was as closed to zero as possible at idle which was also reflected in the closed loop cruise fuel trims.
The break point and offset settings have been left standard probably not optimal, however the vehicle shows no drivability issues at all and without a drivability issue I do not see a reason why they should be moved unless it effects my fuel consumption and that has not been confirmed yet. The flow rate was only marginaly increased to approximately 45lb all matched this is probably why using these standard settings caused no issues.
Last edited by Yortt; 08-01-2014 at 05:39 AM.
This gives some insight
http://eectuning.org/forums/viewtopic.php?p=91289
drilling the injectors will have more fuel puddling and data may vary accordingly from test to test
Is this the same as with an equivalent size non drilled injector?Originally Posted by Huddo
drilling them destroys the spray pattern, rather than spraying out at the correct angle to eliminate the wall divider in the port, it comes out as a straightish squirt which hits this divider, this also applies to any narrow spray pattern injector. Many people have used them though with no apparent issues to power
The theory is logical, that is why I decided not to use ID1000 injectors being large pintle type injectors which I purchased with the intention of installing. Instead I decided to drill the standard injector as an exercise to try and maintain a reasonable spray pattern/atomisation for economy and meet the engines current fuel needs.
Logging indicates fuel control at idle and cruise had the same variation as the standard injectors and the wideband indicated a smooth even fuel delivery at WOT under boost. We will see what the economy is like.
I also fitted another set of ID1000 to another FG XR6T using the supplied injector setting, they idled and performed better than I expected for a very large injector, the logged idle fuel delivery was not as tight as the smaller drilled injectors as indicated by the STFT. Fuel consumption was checked on a trip from Sydney to Canberra with feedback of fuel consumption of 8.7 litres per 100k.
From the preliminary results/feedback it would appear in practice the adverse effects of a poor spray pattern appear not to be as bad as the theory would dictate.
Last edited by Yortt; 08-02-2014 at 06:38 AM.
Use and highly recommend ID injectors
Dont use and do not recommend drilled injectors .....
FG F6 400+RWKW .....10.9 @ 132mph.... FIRST 10sec F6 in SA ( sold )
DYNO DYNAMICS 1200hp ...... Tuning weapon..... ( sold )
OFFICIAL JONNY TIG INDUSTRIES SUPPLIER ..... Biggest and lightest intercoolers for B and F falcons
SUBARU BRZ ......AVO TURBO KIT coming......soon
VF R8 CLUBSPORT SV...... 340FWKW.....ASE BIG SINGLE KIT .....one day
How did you drill the injector?
What drills did you use?
Micro Carbide PCB CNC Route Drill Bits
A bench drill press.
And a lot of practice on old injectors first!
The ID spray pattern is a lot better than the drilled injectors
Stav, when you go from a dual spray disc type injector to a large pintle type injector on a multivalve engine it is hard to believe there will not be any shortfalls. However with ID 1000 injectors it is difficult to tell the difference in idle quality when compared to standard injectors, and they give all the fuel you require for a modified street car even with E85. Fuel consumption also appears to be comparable with standard injectors; I guess this is why they are the first choice by tuners. An example of greatly improved injector technology.
I suspect where the difference will be, is with emissions.
I believe there are dual spray injectors at 1000cc or bigger out there, however I have had no experience with them.
Remember id's still have a rotational " best " and is often referred to as the "angle of the dangle" or maybe thats what some glue eating homo said once lol
Some tune shops have fine tuned the way they are installed to suit the desired effect better than others, splitting hairs ? Maybe, maybe not all i know is i follow suit and have had zero issues
Just a hint places like nizpro install them very unique vs anyone else ive seen, have a look peoples
FG F6 400+RWKW .....10.9 @ 132mph.... FIRST 10sec F6 in SA ( sold )
DYNO DYNAMICS 1200hp ...... Tuning weapon..... ( sold )
OFFICIAL JONNY TIG INDUSTRIES SUPPLIER ..... Biggest and lightest intercoolers for B and F falcons
SUBARU BRZ ......AVO TURBO KIT coming......soon
VF R8 CLUBSPORT SV...... 340FWKW.....ASE BIG SINGLE KIT .....one day
The stock injector has some bent angle to get the fuel down the port and in the back of the valves, but in the case of ID's with a narrow 5 degrees cone angle I reckon you're totally splitting hairs and will see absolutely fuckall difference as to whether you split the cone angle at the top or bottom of the port. There are other things in the calibration...and mechanically (plug gap for eg)...that will have a much larger influence on the operation of the motor.
Talking of Nizpro who certainly have the runs on the board, don't they or didn't they specialise in "Drilled Injectors" !
Last edited by Yortt; 08-04-2014 at 11:43 PM.
I had a set of Nizpro drilled 72lb injectors in mine on pump fuel. When i went to E85 I bought ID1000's they are great!
fpv09,
You certainly a got a lot of responses but no one actually laid it out for you. Anyway here is what I used for calculating the change over time:
Need BreakPoint and Low Slope. Breakpoint is the amount of fuel at which the ecu changes from the low slope to the high slope. So to calculate the time you need to divide the breakpoint by the low slope. So for example with my injectors (Bosch 0280 158 117) and at 4bar rail pressure I have the following parameters:
Low Slope: 62.06 (lb/hr)
High Slope: 57.46 (lb/hr)
Breakpoint: 0.0000157 (lb)
so in order to get 0.0000157lb of fuel on the low slope I did
break point fuel time = 0.0000157 / (62.06/3600) = 0.910 ms
Now or the actual pulse width you will need to add the injector offset at the voltage. For 13V I had a figure of 1.088ms so as Toads said it is a big portion of the time (0.910+1.088 = 1.998ms).
Note if you log the injector pw with SCT or Torque OBD II app the values reported do not include the offset.
For pw calculations after the breakpoint simply subtract the breakpoint value from the required fuel and divide by the high slope and then add the the breakpoint time.
If anyone thinks this is not correct please fell free to correct it.
hi mate
it makes a bit of sense know.
but were did the 3600 come from.
I have a palmer scanner that logs injector pw
iam very new and iam learning as I go.iam knot a a grade student and iam more the hands on
learning then the reading to under stand.
I really under stand where your at
thanks
Last edited by fpv09; 08-06-2014 at 03:42 AM.
fpv09,
3600 is the number of seconds in an hour and is used to convert lb/hr to lb/sec.
I also did a quick conversion by multiplying the break point fuel time by 1000 to get milliseconds.
Be interested to know if the palmer scanner reports times without the offset like Torque and SCT.
Darryl.
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