i hurd of a couple people doing it, i was just messing around with it and found out how, but i dont understand why you would need to. and if you would get anything out of it. and i still dont know what would go into the boxes

 

Well you would put in very rich values for when boost hits in high load areas. I ordered my cable and i await for it!

 

well what about the timing map, would you have to adjust that as well?what would u put in there?

 

To answer a few questions ...

You can't "add" new load columns, but you can re-scale the existing columns. You basically combine some of the columns in the lower load areas and move the existing columns to the left, then add the higher load columns on the right side. Search in the ECUFlash forum and you'll see what I'm talking about.

The reason to scale for injectors ...

You scale for new injectors for stock-like closed loop operation. If you don't scale the ECU for the new injectors, the fuel trims will likely max out and the trim values can throw off your open loop tune, as well as make you idle rich. Your fuel trim logs will tell you how far off your current scaling is.

As far as the fuel map with injector scaling ... the values in the fuel map are based on the injector scaling (along with other factors). So, if you've tuned those tables then setting the scaling correctly for the new injectors will put you very close to your previous tuned AFR. Basically, you should not find yourself adding super rich or lean areas to the fuel map to correct for injectors.

Now, if you add a turbo and injectors on a NA tune, you will have to modify the fuel map regardless, but you should still not have to add any odd values to over compensate for injectors.

For the timing with boost ... easy. You will run less timing than NA. Period. So, for the initial tune, set the timing map even lower to keep it safe before you start to dial in the fuel.

 

speaking in general, when you add injectors using a vortech 12:1 fmu, you will be very rich correct? so would it be neccessary to remove fuel from the top area? or would i just take the fmu off???

 

I don't think the FMU would be needed using ECUFlash and larger injectors. The 2 work in different ways. The FMU changes fuel pressure to modify the AFR and the ECU changes pulse width.

At WOT you are operating in open loop, so the ECU will apply the pulse width determined in the fuel map, no matter what the FMU is doing with the pressure. The only way to know what the mix is would be to log your AFR. That would tell you if you needed to add or pull fuel.

With my understanding of the operation of the FMU, I think it would be likely that you would be a rich on the stock fuel map and larger injectors. What AFR are you running? Any logs?

Either way, FMU or not, your closed loop fuel is going to be way off if you don't scale the injectors.

 

what i have hurd was that fmu and mod'en the ecu is pretty much the same. but i found this out after i bought my fmu. so i installed mine anyways and tuned with it on with ecuflash. but i never scaled my injectors due to the fact that i didnt want to blow anything or take chances. its easier to pull out fuel, and run rich when your tuning then it is to start up the car and do a pull and find out that you dont have enough gas, and your knock sum has a 40 count.
but if you do scale them make sure its less then the original cc of the injecotrs, like i said before so they dont run on %100 duty cycle and max out

 

100% duty is 100% duty, no matter what the scaling is. I'm not sure what you mean there.

Any time you tune from scratch you want to start with something you know is safe. So, if you scale your injectors and add boost you wouldn't want to use the stock fuel map since it's set up for NA operation. You would richen the entire map and do some real-time logging to start so you could watch the AFR and knock and back off if needed.

Let me just re-state this so it is clear ...

You scale the injectors for better closed loop operation. If you scale your larger injectors properly, you will not need to make dramatic changes to your fuel map if it is already tuned for your setup.

If you add larger injectors and do not re-scale for them in the ECU, your fuel trims will likely be maxed out making you idle and cruise rich, you will have lower gas mileage and you will definitely have to re-tune your fuel map ... likely with outrageous values.

 

ok, i never rescaled mine, idles fine without a probelm, and when im crusing around town ive logged and i get awesome afrs(14.7). last time i checked my millage i was getting 31.5 miles to the gallon. when i step on it i get around 11 afrs.(gas millage of corse goes down) but thats just what has happened to me. if you feel the need to rescale then by all means do it, but i saying it dosnt have to be done.

 

How do your fuel trims look? Oh, and what type of values do you have in your fuel map? Not trying to prove anything, I'm just interested in the differences between the approaches.

For instance, ideally your fuel trims should be within 10% of perfect (100 in EvoScan or 0 in Mitsulogger) and your fuel map should match closely to your actual AFR (it won't be perfect). For instance, a 10.8 should be around 11.2:1 or so AFR.

 

alright so i found out what i was looking for. here you go

Injector Scaling - Stock is set @ 513 for USDM cars. End user must re-scale injectors when using bigger aftermarket injectors. Rule of thumb is: the number in the table should be 10-15% smaller than the actual injector size. End user must log fuel trims to make sure that the number in the table is accurate. Fuel trims must be kept between +/-5.
(i know thats for the evo but i think it would still mean the same thing for our cars.)
https://www.evolutionm.net/forums/sh...ling+injectors

 

what psi are we running here guys?

 

how do you look at them?


im running 7-10

 

Log your car with EvoScan or Mitsulogger. The LTFT Low and Mid will tell you how much correction the ECU is applying to reach stoich in closed loop.

 

what should it be?