Those Good With IFR
08-16-2006, 10:04 PM
#1
Those Good With IFR So here is the scoop... I got my car max tuned with 42#injectors, they were at 116% duty cycle so I went to siemens 57#. I used the IFR table off of this webpage and the car wont run. The LTFT's are sitting on +25 and if I stay in open loop my wideband reads 18.00 all the time. I set the IFR to 53 up to 59 and it seems to run good. A tuner from this forum tells me the tune is garbage because my IFR is wrong. But even my LTFT's are 0 to -1. So I dont understand. It is a bit lean on the PE but I am working on that! The car ran 11.56 at 125 on this tune. And its all still together. Am I just totally missing something? Any ideas?
08-17-2006, 10:39 AM
#4
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If you only adjust the IFR for a straight injector swap, the remainder of the fueling calculations will be based on the car being stock...only with bigger injectors.
There's a couple of ways people tune. The accepted way on here is to set your IFR based on your fuel pressure and injector size. Then, tune the VE, PE and MAF accordingly.
If you tune with the IFR table, then your numbers won't match the spreadsheet because you'll be telling the computer the injectors are smaller than what they really are so that they stay open longer and dump more fuel in. This is the "old school" way of doing things.
Personally, I like a little bit of both. I'll get the car close with the IFR and then dial it in with the MAF/VE. It may not be socially acceptable in the forum here. But, it doesn't take me 2 months to dial in a tune either.
There's a couple of ways people tune. The accepted way on here is to set your IFR based on your fuel pressure and injector size. Then, tune the VE, PE and MAF accordingly.
If you tune with the IFR table, then your numbers won't match the spreadsheet because you'll be telling the computer the injectors are smaller than what they really are so that they stay open longer and dump more fuel in. This is the "old school" way of doing things.
Personally, I like a little bit of both. I'll get the car close with the IFR and then dial it in with the MAF/VE. It may not be socially acceptable in the forum here. But, it doesn't take me 2 months to dial in a tune either.
08-17-2006, 11:56 AM
#5
I understand the concept but cant understand why my car is so lean with that IFR table. I mean I cant get it to not be lean. No matter how high I take the VE table. I scaled it way up and still lean as could be. Even in open loop with the fuel trims reset.
