Stevenbruzz Posted September 13, 2023 Share Posted September 13, 2023 So i've just purchased a injector tester and cleaner, i did a static test with and fg n/a injector and came very close to a high flow rate of a fg data, i was wondering if anyone knew how i could test for the low rate slope? Quote Link to comment Share on other sites More sharing options...
Puffwagon Posted September 13, 2023 Share Posted September 13, 2023 I ain't no expert but I would run them at lower and lower pulse widths until they deviated from the linear high slope line. This is where you will place your break point and underneath that will be the low slope. These all change with voltage, pressure and temperature. You might find that using a scope will be more accurate than a injector test bench or perhaps use them together. Again not an expert but that's what springs to mind. Have a read through this for the ford stuff http://injectordynamics.com/articles/ford-injector-characterization/ Here's another one http://injectordynamics.com/the-library/ And another one https://help.injectordynamics.com/support/solutions Finally if you want to find the low slope for your particular vehicle, you can generally adjust the low slope number while the car is idling to find what it is. I haven't personally scoped and flowed injectors to find the actual data, for the most part you can get it close enough with some tuning practice. Quote Link to comment Share on other sites More sharing options...
Stevenbruzz Posted September 13, 2023 Author Share Posted September 13, 2023 Cheers yeah il have a read through them, i didnt buy it to collect the data just thought might be handy to try it out if it can do it. I do have a cheap handheld ebay scope somewhere i bought for tuning amplifiers years ago when i was really into car audio so might try the scope too Quote Link to comment Share on other sites More sharing options...
hjtrbo Posted September 13, 2023 Share Posted September 13, 2023 (edited) I'll have a crack too... Find deadtime at 12V (since you're only interested in low slope) Then run it at a range of low pulse widths. e.g 0.8ms, 1ms, 1.2ms.... etc. for a decent amount of time, tracking PW count and fuel mass. Commanded PW - Dead Time = Injected fuel PW For each Commanded PW => Fuel g/s = Mass of Fuel in Container / (Injected Fuel PW * Count) Plot the points in excel and draw a best fit straight line. Where the points 'knee' into the linear range is the break point. Stick your high slope onto your plot at that point. Bada bing Edited September 13, 2023 by hjtrbo Quote Link to comment Share on other sites More sharing options...
Stevenbruzz Posted September 13, 2023 Author Share Posted September 13, 2023 3 minutes ago, hjtrbo said: I'll have a crack too... Find deadtime at 12V (since you're only interested in low slope) Then run it at a range of low pulse widths. e.g 0.8ms, 1ms, 1.2ms.... etc. for a decent amount of time, tracking PW count and fuel mass. Commanded PW - Dead Time = Injected fuel PW For each Commanded PW => Fuel g/s = Mass of Fuel in Container / (Injected Fuel PW * Count) Plot the points in excel and draw a best fit straight line. Where the points 'knee' into the linear range is the break point. Stick your high slope onto your lot at that point. Bada bing Yeah okay i might have a play when i've got some free time and sit down with it n plot them all. Im running metholated spirits in it at the moment, it was cheap and best thing at bunnings 😅 only thing that was open by time i got to post office to pick it up. Quote Link to comment Share on other sites More sharing options...
hjtrbo Posted September 13, 2023 Share Posted September 13, 2023 Dead time is when it just starts to dribble ever so slightly. Just sneak up on it. Quote Link to comment Share on other sites More sharing options...
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