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Adjustments for bigger injectors

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I have upgraded from id1000 to Bosch 1250 injectors, so a 25% increase. 
I have decreased the master fuel number by 25% and have been able to drive the car. (7ms - 5.25ms) But as soon as I use a bit of throttle it’s lean. So I have been road tuning but am finding the numbers to be going well over 50 at 100kpa and I’m going to max out the table.

what I’d like to know is, is there another or better way to adjust to get very close to original tune? Am I better off leaving the old master fuel number and decreasing the fuel table by 25%?



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Ah ok. I just went 7ms - 25% on the cal and got 5.25. But if I go 5.6 + 25% I’m back at 7.  Care to help me out with a bit of simple math? Can’t think right now. Must be working it out wrong. 

But yeah it makes sense with going lean. I have put my new dead times in though.


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If your dead times are right before and after the change, you injected quantity is like injector flow * actual injector opening time. 

When you go for bigger injectors you want still the same quantity to be injected. So if you *1.25 injector flow you divide the time by 1.25 too and not multiplying by 0.75

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