Equation for tuning fuel maps. Please help before I try to tune.
#1
Equation for tuning fuel maps. Please help before I try to tune.
Sorry for the new thread about the formula but I was doing some math and something doesn't work out for me correctly and I figured people could throw their 2 cents in to give me a hand.
Shoot me if I'm wrong but if you use the formula of: % to change=[(known/calculated)/known]*100 then it works sometimes. Example: [(10/11.5)/10]*100=8.6% then you want to pull 8.6% of your fuel. True, this was already discussed in a previous topic. My problem is like this if you are at 10 and you want to hit 14.7 then according to the formula you only pull 6.8% of your fuel which wont even get you to the previously mentioned 11.5. Am I doing something wrong here or is the forumla flawed?
Shoot me if I'm wrong but if you use the formula of: % to change=[(known/calculated)/known]*100 then it works sometimes. Example: [(10/11.5)/10]*100=8.6% then you want to pull 8.6% of your fuel. True, this was already discussed in a previous topic. My problem is like this if you are at 10 and you want to hit 14.7 then according to the formula you only pull 6.8% of your fuel which wont even get you to the previously mentioned 11.5. Am I doing something wrong here or is the forumla flawed?
#3
Re: Equation for tuning fuel maps. Please help before I try to tune.
I see, so in theory if i want to get from 10.5 to 14.7 I should pull about 35%, IN THEORY-I'm not going to pull that much fuel at once because of how much it could truely affect, but that is how it works, right?
#4
Re: Equation for tuning fuel maps. Please help before I try to tune.
Originally Posted by Darkelvis
I see, so in theory if i want to get from 10.5 to 14.7 I should pull about 35%, IN THEORY-I'm not going to pull that much fuel at once because of how much it could truely affect, but that is how it works, right?
what part of your rpm range are you trying to lean out that much?
#5
Re: Equation for tuning fuel maps. Please help before I try to tune.
That seems really way too rich for a scaled basemap.
I would lean out 5 or 10% at a time in problem areas until you get closer to your target and then start using that formula. 35% is a pretty big jump.
I would lean out 5 or 10% at a time in problem areas until you get closer to your target and then start using that formula. 35% is a pretty big jump.
#6
Re: Equation for tuning fuel maps. Please help before I try to tune.
No... the forumula is perfect, very simple math.
If you're at 10.5, and you want to be at 14.7.. Do this:
10.5 / 14.7 = 0.71428571428571428571428571428571
(0.71428571428571428571428571428571 - 1) = -0.28571428571428571428571428571429
-0.28571428571428571428571428571429 * 100 = -28.571428571428571428571428571429
...then you take, -29% ...very simple.
I use that formula in an autotune routine in my datalogger... I get almost perfectly flat AFRs in 3-4 pulls on the dyno... ..so, do whatever you feel like you need to do.
If you're at 10.5, and you want to be at 14.7.. Do this:
10.5 / 14.7 = 0.71428571428571428571428571428571
(0.71428571428571428571428571428571 - 1) = -0.28571428571428571428571428571429
-0.28571428571428571428571428571429 * 100 = -28.571428571428571428571428571429
...then you take, -29% ...very simple.
I use that formula in an autotune routine in my datalogger... I get almost perfectly flat AFRs in 3-4 pulls on the dyno... ..so, do whatever you feel like you need to do.
#7
Re: Equation for tuning fuel maps. Please help before I try to tune.
I see, I just had my formula wrong, thank you very much. **** and 95redex 10.5 was just an example my map from xenocron is in the 11-13's range in vac.
#8
Re: Equation for tuning fuel maps. Please help before I try to tune.
Originally Posted by Darkelvis
I see, I just had my formula wrong, thank you very much. **** and 95redex 10.5 was just an example my map from xenocron is in the 11-13's range in vac.
#10
Re: Equation for tuning fuel maps. Please help before I try to tune.
[(where you are at/where you want to be) - 1] * 100
Example. your wideband reads 11.9 and you want to be at 14.7
11.9/14.7 = 0.809523809523
0.809523809523 - 1 = -0.190476190477
-0.190476190477 * 100 = -19.0476190477
So you highlight the area that you are at 11.9 and then pull 19% of your fuel from that area.
Example. your wideband reads 11.9 and you want to be at 14.7
11.9/14.7 = 0.809523809523
0.809523809523 - 1 = -0.190476190477
-0.190476190477 * 100 = -19.0476190477
So you highlight the area that you are at 11.9 and then pull 19% of your fuel from that area.