setting IFR
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From: Bucks County, PA
setting IFR I have to put in my new injectors and was wondering what I have to do. I came up with 67.47 for the 60# mototron's. Do I have to fill up that whole bar in the ifr vs. kpa vac? Increasing it as I go up?
There is more to change in the PCM when swapping injectors other then the injector scaling table. Every different set of injectors has specific "on-time" rates that need to be considered. There are also a couple other items that need to be addressed with setting up the larger injectors. Hopefully someone will chime in that has the required specs for these injectors. That's the problem though....
with bigger injectors you will need to modify the proportional fueling table. you should lower these numbers. as high as they are they give too much of a fuel shot for a big injector. from everything i have done this seems to be the only stuff that actually makes a difference that is good.
I would like to know more about the setup required for an injector change. The scaling seems to be the easiest to understand and the first thing to do. This topic needs it's own thread!!
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unless the vendor supplies you with detailed information or a flow rating curve it will never be perect. ive had so many problems with my racetronix ones cutting out at low pulse width i have tried all the tables and the ifr and proportional fuel make the biggest difference and seem to make the only difference
9d9ls, are you crazy? send some money this way for me please! you have a lot of bad *** cars lol, damn and i thought one 440 rwhp car would be nice
9d9ls, are you crazy? send some money this way for me please! you have a lot of bad *** cars lol, damn and i thought one 440 rwhp car would be nice
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Joined: Jul 2002
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From: Beaver Falls, PA
Originally Posted by HellRaiser
I have to put in my new injectors and was wondering what I have to do. I came up with 67.47 for the 60# mototron's. Do I have to fill up that whole bar in the ifr vs. kpa vac? Increasing it as I go up?
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Joined: Jul 2002
Posts: 1,426
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From: Beaver Falls, PA
Originally Posted by WS6FirebirdTA00
with bigger injectors you will need to modify the proportional fueling table. you should lower these numbers. as high as they are they give too much of a fuel shot for a big injector. from everything i have done this seems to be the only stuff that actually makes a difference that is good.
that is my point i have been trying to make as well as others, to some of these suppliers. you can only get the injectors how they should be by a guessing game. the proportional fueling i did by starting with a base that ken at hp tuners uses for large injected cars andwent from there. from what i can tell, monitoring your o2s for proper oscillation will help get this table dialed in better
not to change to subject but what is considered a proper amount of 02 oscillation, with narrowbands and running SD I get values that range +-300 afr with the maf on I get values +-150 afr so I run the maf it makes everything seem so much smoother.
Originally Posted by 9D9LS
I would like to know more about the setup required for an injector change. The scaling seems to be the easiest to understand and the first thing to do. This topic needs it's own thread!!
I just went through this seat of the pants tuning when installing my 8.1 injectors. I hate it. 
Joined: Mar 2002
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From: A Racetronix dealer near you...
Originally Posted by Texas Terminator
if you are talking about the injector pulse width, i was told by mototron that that figure is computer specific. i don't buy it, but without knowing more about the charactics of the injector (that they nor racetronics provide) how are you going to know how to modify it?
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there are some key numbers that we can get from vendors that would help us tuning. right now we tune blindly for some of these injecotrs compensating for inaccurate ifr tables by the ve table. i feel the injectors should come with some kind of data besides what it flows at 3 and 4 bar. what woudl be nice is a plotted curve with different points marked through out to show how the new injectors change with increasing or decreasing flow. also knowing the injecotrs pulse width limits would be helpful, as well as response time. if there was info on all injecotrs about this stuff we can compair and start making proper changes before having to guess and can get the car dialed in even better. what makes it hard on most of us is that these are our own cars we tune, we wanna get it right, if its wrong we know it. a tuner can tune someones car and not think twice about it to have something work. it make work, and just as well at that as if it was done correctly, but in my mind and many others on this board we want it right, which is why this info would give us some sort of insight on what to do.
