HellRaiser

iTrader: (9)

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?

RedHardSupra

iTrader: (1)

use the calculator in stickies

HellRaiser

iTrader: (9)

ok I got the IFR set the car idles really nice but when you give it a little gas it bogs bad. What can I do to fix that?

Redline-Motorsports

iTrader: (3)

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....

HellRaiser

iTrader: (9)

Kinda figure it was somthing like that. I will have to just keep working at it and hope someone here came help me out.

WS6FirebirdTA00

iTrader: (33)

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.

Redline-Motorsports

iTrader: (3)

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!!

WS6FirebirdTA00

iTrader: (33)

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

Texas Terminator

not even close! it won't even run with that figure. my 57's are around 7.6 or so per the calculator.

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?

WS6FirebirdTA00

iTrader: (33)

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

02sierraz71_5.3

iTrader: (2)

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.

02sierraz71_5.3

iTrader: (2)

I just went through this seat of the pants tuning when installing my 8.1 injectors. I hate it.

Racetronix

iTrader: (2)

Delphi, Siemens and Bosch all consider much of the data you are asking about either proprietary or unnecessary for the product's intended application. Some data that is floating around the net is 3rd party and not necessarily accurate for LS1 applications. Even if we did gain access to this production information or ran tests using our flow bench at the end of the day it would be questionable as to whether or not it would really help. To get proper data we would have to set up a factory LS1 PCM and harness in conjunction with the flowbench. The driver circuits in the PCM and wiring harness are just as much a part of the picture as the injector itself. How quickly an injector opens and closes is directly affected by the type of driver and clamping circuit used in the PCM as well as the resistance found within its internal circuits and the wiring harness. What may work fine on a WRX motor may not on a LS1. Another thing to consider is that in many cases such as the LS1 the factory injector is custom built for the intended application based on criteria laid out by the GM powertrain engineers. Although the LS1 PCM is quite advanced in that it allows for injector offsets etc. it is limited by its programming and may not be able to extrapolate the injector control data exactly as required to drive an aftermarket injector. There will always be the 'fudge factor' in there. Not up until the past few years have aftermarket PCMs started to include user-programmable injector offset and coefficient tables and for the longest time people were able to tune cars quite well w/o them. This is not to say that it is not an improvement (assuming the injector data is available) but there is always a way around it. If people must adjust the PCM IFR tables as oppose to the injector tables to get everything to fall inline then so be it. As long as the A/F ratios are in check and the car drives well then there is nothing lost and everything gained. Never assume that the PCM's design, supporting firmware, components and sensors are perfect in respect to the data, math and control it provides. Sometimes one must implement what GM engineers may consider unorthodox methods to achieve the desired result. HP veterans have learned the hard way that this hobby is about adaptation and improvisation. Without these key factors the hobby would become limited and boring very quickly.

WS6FirebirdTA00

iTrader: (33)

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.