stage injection
 

alright guys lets talk about stage injection. what should be the stage scaling factor if you have difference size injector,delay times.are there any calculation to follow in this process. im going to tune a car that have 850 primary and 1600 secondary what the scaling factor should be and delay time for this set up.also where do you found a better transaction on boost or in vac areas what technic do you found better.thanks

Copied and pasted from my Megasquirt tutorial:

The scaling factor you enter here will be dependant on the size difference between the primary and secondary injectors. "255" is the number to be used when both injectors are the same size as is OEM in all stock 2nd gens. If you have a larger secondary injector, you must calculate a new scaling factor. To do this, use the following equation:

Scale factor = Primary Injector Size/(Primary Injector Size + Secondary Size)* 512

So if we have 550CC primaries and 1680CC secondaries, it would look like this:

Scale Factor = 550/(550 + 1680)* 512
Scale Factor = (550/2230) * 512
Scale Factor = 0.246 * 512
Scale Factor = 126 (actually 125.9 but I rounded)

You must perform this calculation otherwise the car will be very hard to tune as the secondaries come online and the map will end up with a massive difference in values around the stage point.

I always set my staging to 3500 RPM and 90KpA, which is roughly similar to the stock 3800RPM and 2". Your staging delay is over how many engine cycles the stage takes place. A larger value will give a smoother stage. 60 is a nice point to start at.

ok i think i got it. but the car its running real good in the vac areas if i changes the scale factor to a different one would that affect the tune that i already have done in the vac areas.thanks

Changing the scaling factor will change the tune anywhere the secondaries were coming on.

Ken

ok good since im not have touch the boost part and im going to stages the secondaries at 6 psi so my tune and time tunning the vac area its not waste.

Uh, don't do that. Stage your secondaries where they should be in the first place, at around 3500 RPM and 90 KpA. If you stage at 6 PSI, you will find yourself out of fuel well before then and you'll end up having to retune half the map.

also if you get the settings wrong you could run really lean when you stage and at 6 psi that's not really ideal...

I would suggest either doing what aaron suggested, that's about how I have mine set up except instead of RPM I'm using injector duty cycle.

Actually, the way you're set up now (and the way I'm set up) allows for you to set staging between 0% staged and 100% staged or anywhere in between on a 6x6 table. It's not duty based at all.

It has also really smoothed out things for me, and makes it so I can freerev as high as I want with no sputtering, I can blip to downshift without staging coming on when I don't want it to, and I can't feel it stage at all... it's completely seamless. Looking at the AFR, it doesn't change at all in response to staging.

Ken

i have done it that way with others ecu and no problem at all but im going to try that 90 or 100 kpa and lets see what happen remember the primaries are 850 and thanks :icon_tup:

That's a bit of a scary way of doing things, but if it works for you then I guess it works. Personally I'd just set it up properly from the beginning as I don't see the advantage of not tuning it from the start.

i took the car for a spin and when the car boost 4 psi the aem read a lean condition so im going to try to stage at 90kpa and let you know what happen.thanks

Now I look like a dummy :p:

I had forgotten I had switched to the new beta staging code.

i need help from you guys i still dont get this stage injection to work i will post a msq and a datalog when i get home.

here are the msq and a datalog

:)

ok i can get this attachment to work i need some help here too.:dunno:

ZIP it, then attach.

still :dunno: can i send you the msq and the datalog.

What is the error or problem?

for some reason i cant zip files on my old laptop.

Download something like iZarc, a free ZIP utility.

i think i found the problem im going to try again soon.

problem solve car was running so good until the rear plate crack now its time to get a rear plate and back to the tunning.

If the rear plate cracked, something is seriously wrong. Ridiculously lean mixtures, ignition noise, etc. Fix it or you will crack more plates.

the only thing im thinking its previous leans condition due to previous problem with the injector wiring or the boost cut that i hit it a couple times but its set to cut spark and this should not be a problem i think .i dont think i have noise in the ignition because i dont see any noisy rpms in the datalogs rpms seen very clear and the a/f are in the 10s.