APD*98SS

I just found this information spec sheet on the Mototron 60# injectors:

Calibration Information:
Static Flow 10.8g/s @ 600KPa
Impedance 12 Ohms (High)
Gain= .110ms/mg
Offset= .055ms
Turn On Time= 1.14ms @ 14VDc
Turn Off Time= .85ms @ 600KPa

How is this information helpful on scaling the injectors and taking out some of the bite at idle???

Frost

iTrader: (45)

They can be kinda tough around 60psi; I use a boost referenced regulator that pulls fuel under vacuum and it made it pretty easy on my setup.

code4

iTrader: (30)

How do you tune this way? What do you set your base fuel pressure at?

WAHUSKER

iTrader: (4)

I set the min inj duty cycle to 2.0mS & made most of the timing & VE almost flat in the idle area & it seems to be pretty good. Still working on it tho.....haven't tried pulling fuel in vacuum, I only use the regulator to add fuel pressure in boost. And my scale runs from 62 to 69.

code4

iTrader: (30)

That is what I am planning, boost only no vacuum.

Country Boy

iTrader: (24)

Same here. I dont know what problems all these people are having as mine idle perfect with them...

pdanrichey

iTrader: (4)

I'm also having problems with the 60#. At idle and during decel, my AFR gets buried in the 10s...maybe lower...??? The gauge only goes down to 10 . I'm going to get it pro tuned here shortly though, so they should be able to address those issues. I've only driven it maybe 150 miles as is. The next drive it has will be down to the tuning shop. At PT and WOT, AFR is completely normal.

APD*98SS

First Question: Why would it be harder to tune at 60psi opposed to 58psi???

Second question: To WAHUSKER Originally Posted by WAHUSKER
I set the min inj duty cycle to 2.0mS & made most of the timing & VE almost flat in the idle area & it seems to be pretty good.

My stock minimum and default injector pulse width is 1.277 if you went to 2.0mS isn't the higher number a longer open pulse to the injector?

Finally, to those of you who plan to use a boost referenced fuel pressure regulator for boost only. How is that possible, as soon as you lift off the throttle the engine goes into vacuum. Boost and vacuum come from the same source so how do you plan to isolate the vacuum from the same signal or feed???

Can someone please post some scales and tables for reference on the 60#'ers please....

Frost

iTrader: (45)

I guess they could use a chack valve/one-way valve to keep it boost or nothing.... but.... WHY?

With the FPR referenced to the manifold, since it is 1:1, my IFR table is a flat line

MIGHTYMOUSE

iTrader: (59)

the only thing pulling fuel pressure with vaccum does is HELP your computer handle big injectors at idle.

set your base fp at 3 bar, scale your ifr flat (7.8 in edit terms) and adjust until you get a generally negative l-trim and then leave it alone.... sound easy??? it is.

WAHUSKER

iTrader: (4)

My min inj duty cycle was set at 3.997. Maybe that came from my Predator tune from years ago, but until I got the latest version of HPTuner & really started to play, I never touched paramters like that. ****, I never saw most of them.

I need to try the vacuum thing. As I said, all I tuned it for was to hold fuel pressure & maintain a/f under boost. Can I assume what MightyMouse said only works if you have a 3 Bar MAP? (which I need to install along with SD HPT)

MIGHTYMOUSE

iTrader: (59)

works fine, how an injector runs has nothing to do with volumetric efficiency

Country Boy

iTrader: (24)

My IFR is scalled normally as if you used smaller injectors on a N/A setup, but I also have the FPR taking out FP under vacuum.

Frost

iTrader: (45)

But that stock curve in the IFR is just to compensate for conditions... now the FPR is doing that if it's referenced properly.

code4

iTrader: (30)

Pull boost reference from the turbo, no vacuum there. I am totally lost on how to tune this with vacuum. How do you know what your base fuel pressure is to input the IFR, doesn't vacuum fluctuate all over the place? How do you do your initial startup?

This is my 1st boosted set up. I plan on turning key on without starting & setting FP at 58 psi. Scale injectors using the excel spreadsheet, start up and drive. Adjust VE using AFR error histogram.

Your way sounds great but I don't know how to start.

MIGHTYMOUSE

iTrader: (59)

as frost said.. the ifr table as is stock.. is on a slant to make up for the fact that the fuel pressure is not manifold referenced... once the pressure is manifold referenced.. then the ifr table should be flat

obviously you can get the right numbers out the tail pips lots of different ways.
you know your fuel pressure by what it says on the fp gauge you have.. right?

you can start where i said to start.. thats a good place in my opinion

RedHardSupra

iTrader: (1)

i did an experiment where instead of calculating the IFR based on what the fuel pressure SUPPOSED to be , i logged it, and then calculated the real IFR. to my huge suprise, FP was varying way more than i originally thought, and not just with manifold pressure like the traditional IFR table would have us believe. so here's an example (in grams/sec) of flows, across different MAP and RPM:


so my point here is: dont trust your fuel pump or the regulator on what it supposed to be doing, just map it out and see for yourself

Tiger2o69

iTrader: (16)

I didnt know you could do this.. My pressure drops from 60-62 down to 52 under WOT..

I have a racetronix fuel pump and FAST fuel rails.. 42# injectors... Which are maxing out.