dead times with fjo

Calibrations for S-Manager - Use all calibrations at your own risk (dyno tuning recommended)
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lwatkinson
Posts: 16
Joined: Fri Dec 21, 2012 6:34 am

dead times with fjo

Post by lwatkinson »

What should i set the dead times at?
Precision 1600cc with an fjo injector driver.
Better yet, should i tune them in with different battery voltage ?
lwatkinson
Posts: 16
Joined: Fri Dec 21, 2012 6:34 am

Re: dead times with fjo

Post by lwatkinson »

1.) GEt into your "dead time" or battery volt compensation map and zero all values, and make sure you're at "normaloperating temps" and zero out any air temp or coolant temp trims in thiese ranges while setting dead times (for me i disconnect then IAT and coolant temp sensors and set the values at teh extreme ends where the ECU will go to at zero compensation
2.) get the car up and running to where you have the best voltage you can normally get (for me that's between 13.6 warm and 14.4v cold at idle and above) the voltage drops as the engine and alt head up (this mens turn off all accessories/extra electronics you have, radio ncluded and especially a power inverter you might use for laptop, just use an extension cord fromthe house to power it)
3.) Get the engine timing locked to a value of somewhere between 10 and 20 degrees (what ever gives you the steadiest idle you can obtain) **disconnect the vac line from the AFPR and plug the leak/hose*** need to keep FP constant to do this
4.) set theAFR at this idle to somethng like 14.7 and adjust the pulse width for all the cells around the idle's current cell to the exact same value so if it changes cells for some reason you won't be thrown off and confused - at this idle, your volts should be at their best/highest average value, make sure the radio, lights and all electronics are OFF (or all thatyou can turn off that isn't needed in daily idle.driving situations)
5.)Set the dead time (volt comp) in this area at a nice low even number like say .200ms and take note of the AFR (you can tune the AFR for 14.7 or whatever you want, it's just a baseline for now to use as reference
6.)turn on enough accesories/lights to move the volt comp/dead time cell to it's next cell over (usally in a stand alone it will be a graph ov volts from 16 down to 6 or 8 volts in small increments) We are aiming for 13.6 or whatever your operating temp highest volts are - if 13.6 was our average peak, load the electrics enough to bring it to say 12.8/13.0 whatever is the next lowest volt cell
7.) Now, increase the dead time at this lower voltage untill you get the exact same stable AFR you had in step 5
8.) Load the electrics MORE to get to the NEXT lowest cell (say 12.0 - 11.8 volts, and repeat the process by raising dead times untill your AFR is again the same as step 5
9.) take note of the amount of pulsewidth/ms changed in the 2 cells you adjusted, average these out (say the first one took you fro .200 to .350 and the third took you to .486 (add them and divide by 2) .350+.486 = .836 ... Then .836 /2 = .418
10.) now make the new value .418 your initial full voltage dead time, and add the amoung of values you got from steps7 and 8 to fill in the next two cellsit would be like so...the initial .200 took .150ms to get AFR's back in check so now you'd add the .150 to the new value of .418 which is our actual base top voltage dead time example now you're table will read 14v = .418ms / 12.8v = .568 /11.8v ill now = .704 (the difference between the values you came up with in steps 7 and 8 added to the new dead time for the 12.8v range)So now the dead times table volt comp table will read .418 then .568 then .704Repeat this loading down the rest of the voltage cells/dead time cells with as much draw as you can put on via amps, lights, wipers, heater etc.. there's no need to reset the initial first value again after getting a baseline from the setting of the first two as the times will increase in a linear fashion, if your table is graphical just follow the shape of the rising curve, or if it's numeric based just figure out the average amount you're raising the dead time per volt dropped or each cell whatever it's range may be (some may be 1 volt per cell, some may be 1.3 v per cell) i'm sur eyou get iut by nowThen as you near the lowest end of the scale (say 8 volts) raise the values a bit more, say we were adding .150 per volt and did that from 12.8 volts down to 10 volts, well at anything below 10, make the value you add by increase by say 50% so .150 * .50 = .075... Then .150 + .075 = .225ms, and there you have it, no need to ask, post, use other's numbers to only have it still not be right etc..
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