creating a basemap 2 liter sleeved gsr evo 560cc injectors

tandrew21 · Post by **tandrew21** » Tue Apr 28, 2009 12:26 pm

i thought you increase injector offset only until it idles right and use the fuel multiplier calculated by old and new injector size. If i mess wit the mulitiplier it will cause a lean or rich condition in the the idle? Please explain. more

ckretvix · Post by **ckretvix** » Tue Apr 28, 2009 12:31 pm

The injector multiplier is just taking away the fuel in the maps based on how big your injectors. If you set it at 560, it will be fine. The values in the maps represent the amount of time the injector is open. If it didnt decrease, the maps would be tellin the injectors to stay open for stock amounts of time, and with bigger injectors, that means alot more fuel. IE. I have 450cc injectors, and the map is based on 240cc, so it automatically reduces the maps .533. Dont worry about that #, just worry about the Offset and Final multiplier %.

tandrew21 · Post by **tandrew21** » Tue Apr 28, 2009 12:34 pm

ok so your saying start a fresh map, get the vehicle to idle with injector offset only with a stoich condition probably around 14.5 to 15.0 afr. After that the fuel multiplier is used to richen or lean out the entire map.

tandrew21 · Post by **tandrew21** » Tue Apr 28, 2009 12:37 pm

will the injector multiplier take and add from the entire map? for example lets say i get my car to idle with an injector offset of 30. AFRS look good at idle. Then i take it for a short vacuum drive and the wideband shows afrs of about 16.0 - 17.0 which is lean. I then go back and adjust my fuel multiplier to get those afrs down to say 13 to 14 afr. Once i make this change will my idle also be richened up to the point where i need to add more injector offset. hopefully that makes sense. Its kind of a give and take approach

ckretvix · Post by **ckretvix** » Tue Apr 28, 2009 12:38 pm

I wouldnt change the offset after doing that. The initial setting of the offset is to get the injector pulse delay right. You can test it by turning on all of the car accesories. The offset is to compensate for different voltages from the battery. If the AFR starts to change alot then the offset is wrong. If its to rich at idle after you tune the rest of the car for part throttle/afr just change the values in the map, because they're usually different after your done with everything else. Basically the offset is to keep the afr stable when the electrical system in the car is experiencing different loads. If it idles at say 16 AFR, and turning on the a/c doesnt change it, the offset is right and you should just mess with the final multiplier or the map directly.

tandrew21 · Post by **tandrew21** » Tue Apr 28, 2009 12:46 pm

i dont see a fuel multiplier box like you are talking about except in the upper right, what do lower values represent for the fuel multiplier and how does it affect the engine. I'm not understanding this fuel multiplier. I'm confused. Sorry but this is kinda tough for me. All i see is old injector size, i have set to 240 new injector size, i have set to 560 overall fuel trim, 20% injector battery offset, dsm 450s 95-99 and injector offset, 22 If i take out my overall fuel trim the motor will go lean im assuming, then i need to jack up my injector offset? correct? But by raising my injector offset will it richen the entire map but keep the same values?

Post by **Gaskleppie** » Tue Apr 28, 2009 12:47 pm

mmmm, Sorry but I have to advise you something else. The injector offset will be gone in the latest rom version. So using that to tune will give problems if you ever go to the latest rom version. This offset gave more problems then joy if you used too high values. Thats why I advised you to leave the injector correction and offset at 0 and just tune the maps by hand. Go for a ride and after a while you can see on the AF readings in the map were you have to adjust your maps. When you are pleased with the low load part of the map, go some further and take some boost.

tandrew21 · Post by **tandrew21** » Tue Apr 28, 2009 12:49 pm

that is a real good explanation! thank you. my idle with all accessories off is 14.8. but when i turn my headlights on it drops a whole point or more down to 13.2ish. Therefore my injector offset is wrong. So what i need to do is try different injector offsets till i can turn the lights on and off without seeing a change in the afr? correct

tandrew21 · Post by **tandrew21** » Tue Apr 28, 2009 12:52 pm

well thats not good for me if they are bein taken out. How am i suppossed to get the car to idle without the injector offset adjustment. That really worked well

ckretvix · Post by **ckretvix** » Tue Apr 28, 2009 12:52 pm

Gaskleppie wrote:mmmm, Sorry but I have to advise you something else. The injector offset will be gone in the latest rom version. So using that to tune will give problems if you ever go to the latest rom version. This offset gave more problems then joy if you used too high values. Thats why I advised you to leave the injector correction and offset at 0 and just tune the maps by hand. Go for a ride and after a while you can see on the AF readings in the map were you have to adjust your maps. When you are pleased with the low load part of the map, go some further and take some boost.

I dont understand. Even if he got the maps perfect, changing the electrical loading in the car is going to mess with things. Injector opening times are influenced by supply voltage. Injectors will operate faster at higher voltage than low, hence the variable. The battery offset adjusts the pulsewidth to achieve a linear injector response.

tandrew21 · Post by **tandrew21** » Tue Apr 28, 2009 12:57 pm

that makes sense, the more voltage being pulled from the injectors the slower they will open, so what is the reasoning behind removing this feature?

Post by **Gaskleppie** » Tue Apr 28, 2009 1:08 pm

but when i turn my headlights on it drops a whole point or more down to 13.2ish. Therefore my injector offset is wrong. So what i need to do is try different injector offsets till i can turn the lights on and off without seeing a change in the afr? correct

Its a good thing to adjust the battery offset table, but you have to use it only to compensate the voltage difference, not to adjust the overall AF of the maps. So first you let it idle and tune the maps to get it around 14,7:1 Then you look at the voltage level and as all works fine it would be around 13,8 volts. Then you have give load to the alternator by switching all the lights on to get the voltage as low as possible. Sometimes I disconnect the alternator plug and wait for the battery to fall down. When the voltage is dropping, you can see it in the battery table and correct the values so that the AF stays steady at 14,7:1 When you have tuned the battery table you can go on with the rest of the map.

tandrew21 · Post by **tandrew21** » Tue Apr 28, 2009 1:14 pm

i tried tweaking the battery table yesterday i left the lights on and radio on. I did see the rich condition upon doing this. I began to tweak the first column of the battery table because it was highlighted pink. But no matter what i put in the table. .20, .90, etc. it did not show any effect on the afr. maybe i was doing this wrong.

ckretvix · Post by **ckretvix** » Tue Apr 28, 2009 1:16 pm

Dont mess with that table. Just use the one box under Offset FV

tandrew21 · Post by **tandrew21** » Tue Apr 28, 2009 1:16 pm

i wasnt using the battery offset table to tweak the afr, i was using the injector offset + and -