Injector dead times and opening times

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aleksanderk
Posts: 68
Joined: Fri Feb 01, 2019 4:36 pm
ECU Model: S80 Pro
Firmware Version: 6500

Injector dead times and opening times

Post by aleksanderk »

Hello everyone!
I've got a set of Siemens Deka 630cc that I need to put in the dead time values for.

On siemensdeka.com, I see that they specify a Turn on time @ 14VDC: 1.14ms and Turn off time: 0.85ms @ 600KPa

But on the website I bought the injectors from they specify a dead time with battery compensation which is as follows:
3 BAR dead time/latency offset Table:
8 volts 1.538 ms; 9v 1.231ms; 10v 0.923; 11v 0.708; 12v 0.523; 13v 0.400ms; 14v 0.308; 15v 0.215; 16v 0.092; 17v 0.000

On my S80 Pro I entered the values from where I bought the injectors from into Battery compensation. But do I need to add the opening and closing time also?
My battery compensation ranges from 8-17,5 volts, and I have interpolated for all the "half" voltages.
stevieturbo
Posts: 3577
Joined: Tue Aug 02, 2011 12:08 pm
ECU Model: No ECU
Location: Norn Iron

Re: Injector dead times and opening times

Post by stevieturbo »

The Siemens site is a little unclear as to what pressure they're stating those figures at.

Their closing time is stated at 6 bar. There is no value indicated for the opening time stated. Gain and offset ? who knows.

Different ecu's can use data in different forms for these matters.

Enter the values from the table where yo bought your injectors, and then perform the test as noted in the manual to determine injector dead time. Then you can find a happy medium, and scale any other values and different voltages etc in a sensible manner

Or you could try running your system at different voltages and pressures for a more complete test. Not an easy task.

But really....if you have massive voltage swings in your system, you need to fix that. You should have very stable voltage within small margins.
Rob Stevens
Posts: 1247
Joined: Thu Jul 28, 2011 4:10 am
ECU Model: S100 Pro
Distributor: None-Coil On Plug :)

Re: Injector dead times and opening times

Post by Rob Stevens »

If you have a wideband fitted, why don't you use the dead time measuring tool that is built into the software? Won't cover all the voltages but gives you a great head start.
aleksanderk
Posts: 68
Joined: Fri Feb 01, 2019 4:36 pm
ECU Model: S80 Pro
Firmware Version: 6500

Re: Injector dead times and opening times

Post by aleksanderk »

I did use that function in the end. Ended up on 0.66ms@13v which is where the car idles at. Thanks for reminding me :)
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