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Offset Voltage data
Posted: 2021 Jul 20, 19:15
by efloth
Trying to get the injectors dialed in perfectly. Is this accurate? I am currently running 8% higher than this for 52PSI
http://www.usa.vdo.com/media/747302/fi1 ... ksheet.pdf
Should these numbers be different when using speed density/batch fire?
Re: Offset Voltage data
Posted: 2021 Jul 20, 19:41
by dleach1407
If you are running Siemens 80s, the best info is the ford info found below
https://performanceparts.ford.com/parts ... 3-lu80.pdf
They have data for 50, 55 and 60psi. If you go to 55psi you can calculate everything using the multiplier for 54.98 lbs.
Re: Offset Voltage data
Posted: 2021 Jul 21, 11:03
by efloth
You the man! Thanks
Re: Offset Voltage data
Posted: 2021 Jul 21, 13:10
by efloth
Diving into this today: How do we explain this discrepancy? First chart is Decipha's listed offsets for Speed Density @ 30PSI. .8722 is the multiplier for 30 PSI in the document you linked. @ 15v take .454/.8722 = .5205 != .721
Should I just take .5205 * 1.1883 to get speed density offset for 15v @ 55PSI? Hope this makes sense.
Code: Select all
FRPP 80 lb/hr @ 30psi
LU80
Siemens Deka 80 lb/hr @ 30psi BASE
K-Constant 30.00
High Slope 65.552
Breakpoint 0.00002119
Low Slope 65.400
VOLTAGE OFFSET
voltage ms
16.00 0.454
15.00 0.454
14.00 0.505
13.00 0.569
12.00 0.641
11.00 0.720
10.00 0.812
8.00 1.120
6.00 1.772
0.00 1.772
0.00 1.772
0.00 1.772
Code: Select all
FRPP 80 lb/hr @ 39.15psi
LU80
Siemens Deka 80 lb/hr
K-Constant 30.00
High Slope 75.157
Breakpoint 0.00002421
Low Slope 101.459
VOLTAGE OFFSET
voltage ms
16.00 0.721
15.00 0.721
14.00 0.801
13.00 0.903
12.00 1.017
11.00 1.142
10.00 1.288
8.00 1.777
6.00 2.811
0.00 2.811
0.00 2.811
0.00 2.811
Re: Offset Voltage data
Posted: 2021 Jul 21, 16:36
by dleach1407
You don't use your offsets in the ecu, you would use the data in the voltage offset column on the .pdf and then multiply it by .6303 which is the offset compensator for 30psi
You do the same thing for high slope, low slope, and breakpoint using the corresponding compensator for each. If the info is already on the home page i would just use that.
Re: Offset Voltage data
Posted: 2021 Jul 21, 18:32
by efloth
I don't think you understood. The offsets I posted for 30 psi (speed density) were from here:
http://efidynotuning.com/injdata.htm
if I take the high slope numbers in the pdf you linked * .8722 they don't match with decipha's. Trying to figure out what gives. Speed density is single slope so the other info is irrelevant in this case.
Re: Offset Voltage data
Posted: 2021 Jul 21, 19:42
by decipha
it matches perfectly
.8722 is for the high slope only
The offset gets multiplied by .6306
Re: Offset Voltage data
Posted: 2021 Jul 21, 19:45
by efloth
Ok so use low slope numbers for AHISL?
Re: Offset Voltage data
Posted: 2021 Jul 21, 20:04
by decipha
No, why would you do that?
Use the actual numbers they give you.
Re: Offset Voltage data
Posted: 2021 Jul 21, 20:06
by efloth
decipha wrote: ↑2021 Jul 21, 19:42
it matches perfectly
.8722 is for the high slope only
The offset gets multiplied by .6306
That's what you are telling me .6306 is low slope
EDIT: offcomp not low slope. I'm with you now. Thanks for the help guys.