Ok I have read Shifted's FAQ on doing this. I want to make sure I'm 100% clear on this. I'm going to be putting in 36lb injectors. Stock is 24lb. so:
Inj Const = .20250 * (24 / 36) = .1349999 Does this look correct? I also have a question about something I read that shifted wrote.
Quote:
Obviously these numbers will change if your fuel pressure changes. My injector constant is actually a little higher than that because I run my fuel pressure at 40 PSI.
The above formula did not bring pressure into it, so how does the pressure affect the injector constant? I understand that the higher the pressure the more the injector puts out. I'm going to be running factory pressure regulator, so factory pressure. I should be able to use the above constant number and it run fine correct? Thanks for any info and help.
FU Tuning
Pressure affects injector flow, makes injector size appear larger or smaller. Change in flow, or new flow, equal to squar root of (new pressure / old pressure) * old flow. Once the new flow is calculated for the new injector, you can adjust the constant the same as before.
-->Slow
slowolej wrote:Pressure affects injector flow, makes injector size appear larger or smaller. Change in flow, or new flow, equal to squar root of (new pressure / old pressure) * old flow. Once the new flow is calculated for the new injector, you can adjust the constant the same as before.
-->Slow
Sorry reading what you wrote sort of confused me. My pressure is not changing from what it was (is still, stock). I'm changing just the injectors. Since I'm not changing pressure then I would just worry about the injector constant. Correct?
FU Tuning
Right.
Basically changing the fuel pressure changes how much fuel your injectors flow. If you change your injectors AND your fuel pressure, then you will need to take that into account when you change your constant. Since you are only changing the injectors, then the formula in the first post should work just fine. There still may be a little tweaking involved, but it will get you close.
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Shifted wrote:Right.
Basically changing the fuel pressure changes how much fuel your injectors flow. If you change your injectors AND your fuel pressure, then you will need to take that into account when you change your constant. Since you are only changing the injectors, then the formula in the first post should work just fine. There still may be a little tweaking involved, but it will get you close.
Ok thanks. I do understand what you mean about changing the pressure will change what the constant needs to be.
Thanks guys.
FU Tuning
