I'm trying to figure out how to get the injecter stageing right on my sprint RE. I've got 2200cc Injecters all around running E85. I was told I should stage them at 0.0 psi but how should I scale the map if I do that? Because with the Haltech don't I have to put a column right after 0.0 that's really close to 0.0 for the staging? And idk if I should set it to primary hold or common? If some one could elaborate on the two and give some input there that would be great!

 

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Nothing? Not even a hint? This is kinda like my biggest problem right now can't find the answer anywhere can't get my transition in to boost right or get the tune right unless I get this figured out!

 

It's more important you get your dead times correct as that will make transitions more noticeable. I'm running 2200x4 on gasoline on a megasquirt ECU and the transition is completely seemless. If my deadtimes are not perfect, it's a definite hump in AFRs.

 

Dead times only effect fuel v. battery voltage. Really has no effect on staging.

Move your staging bar higher. With it at 0 psi, you're all over the secondary injectors in normal driving. With big primary injectors, there's no reason to bring the secondaries on line until well into positive pressure. I'd stage them at about 6 psi. No less. You probably don't need them until 10-12 psi with gasoline, really. So go to the fuel setup page an enter 6 psi for the staging load. Assuming you're using psi or psi/inhg as your load units.

Next, open the software and go to Tools>Options and set Pressure to kPa. Now, go to the fuel setup page and see what the value of the staging load is. Make a note of it. Go to your main fuel map, hit F3 and make a load column with this exact value. That will be the last load site that uses primary injectors only. There is a gotcha in the software that can skew pressure numbers that are not entered as kPa. So, if you set everything up in psi, you can get some weird stuff going on. Nothing that can't be tuned out, the map may just not look like you think it should. Next, make the next load column 1.0 kPa higher. This eliminates dwell between the two load sites and the need for large interpolation. Once you have that setup, you can back and change the load units to whatever you're comfortable with.

Now, start tuning. With equally sized injectors, the first load column with both injectors firing should be roughly half the pulse width as the last load column with just the primaries to start. The staging load bar map should be half way between those two. For example, if the last load column with just the primaries is 6ms, the first load column with both injectors would be 3ms and the staging load bar map would be 4.5ms. That will get you going. Once you start tuning, you'll probably notice the last column with primaries only will actually be lower than what you would expect and the first column after the secondaries come on may need to have a higher pulse width. But the above will get you in the ballpark.

I've typed all that before on here. Typing that again takes my time away from my wife and kids. You all should think about that the next time you need EMS gear.

 

Well first off thank you for taking the time to help! You are the first person to give me a good solid answer! Is it really that hard to make it work with psi/inhg? Because right now I'm tuning in psi/inhg and I have it staged at 0.0 with a 0.0 column and a 0.1 column right next to it and the map goes up drops straight down then kinda goes down just a little and then goes back up again. I mean I've been street tuning it for the past few days and I've got the transition feeling pretty good. I will just hit a tinny little hiccup every now and then but I just still feel like somthings not 100% right. I want to tune in psi/inhg if I can just because that's what I'm used to and that's what I like to tune with. Staged inj disenrichment is set at 0.050.

 

 

Love it!

"How do you make this work?"
This is how it works.
"That sounds hard. Can I be lazy?"


Here it is again with a virtual pat on the head. Program the load columns in kPa. Once that's done, change the load units to whatever you want.

 

PM me your email and Ill send you my map. Currently running 2200 primary but for secondary it's running four 2200 and two 1000s.

 

Having incorrect dead times does actually make a difference in how smooth the transition is.
If your dead times are off by 0.1ms and you're commanding 4ms with 100% primaries, you're actually getting 3.9ms of fuel.
If it transitions to say 50% prim/sec, how you're getting 2ms+2ms, but its actually 1.9+1.9.
You go from actually getting 3.9ms to getting 3.8 or a 2.5% drop in fuel.

If you curb your VE map to make up for this, it'll be okay, but if you make you're VE map smooth like it should be, you'll get a lean spike at transition.

 

I see what you're saying. But, there's only one correct value for dead times. Buy good injectors with accurate info and program it in. Then calibrate the fuel map.

As far as your percentage calculation, that would depend on the size of the injector and the duty cycle. Your 2.5% guesstimate is flawed.

I've spelled out how to do it and the OP is still looking for short cuts. When it blows up, I'm sure he'll wonder why.

 

Very true, sounds like a future v8 swapper to me

 

i could never figure out how to stage teh secondaries, and i was tuning in inhg/psi, didnt know about the kpa trick. I gave up and now i just run two 2200cc injectors, only have one fuel rail lol