Inyector Opening
- Thread starter jowy
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NY Twin Turbo
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- Dec 10, 2014
Do you mean "injector opening time vs. voltage"? Each brand and size has it's own curve. The files for most are in the software. On my car, getting the right one made a big difference.
NY Twin Turbo
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- Dec 10, 2014
Which XFI do you have? 2.0?
Do you mean Injector opening retard? If so, leave it at zero for now.
Opening time is on a graph.
NY Twin Turbo
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- Dec 10, 2014
Did it run well with that? Who set those parameters originally? Or, did you just buy the box used and that's what was in the tune? If so, I suggest seeing what voltage you have at idle. Then finding an "opening time vs. voltage" graph for you injectors. For example. If your Idle is 13.5v find that time on the graph. Then enter that as the number.
Or, you can just do what Cal says.
Or, you can just do what Cal says.
NY Twin Turbo
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- Dec 10, 2014
First change the injector size to what you have. Don't change anything else. Then start it. See what happens. Your set-up most certainly will require an entire re-map on just about everything. But mostly, it should start if the box was on a Buick. I would look into finding someone XFI knowledgeable in your area to give you a hand with the set-up. The details can be quite difficult to explain all at once in this forum.
That won't really work, since the curves of the two graphs are probably quite different. Also, the 1.34 software isn't necessarily using the value you input for your idle voltage. It trims that value based on different voltages. You would be much better of just adjusting that number until the A/F gets close with normal values (35-40) in the VE table at idle. Once it's close, trim the VE Table
If the car ran good with 60# injectors and you just upgraded to 95#, the VE Table should be real close. You will just need to change injector size in the "Fuel Calc Parameters" table and highlight the following tables and multiply by 63% (60#/95#):
Cranking Fuel Table
AE VS TPS Rate of Change
AE vs MAP Rate of Change
If you upgrade to 2.0, you will need to modify several tables not just the injector opening.
NY Twin Turbo
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- Dec 10, 2014
Yes, but wouldn't be most noticeable at idle if the opening time was off? What I'm asking is if you can't duplicate the whole curve isn't most important to get the opening time spot on at idle?. If this is correct then the other parts of the curve that you can't duplicate will end up getting blended in to the VE. No?
I believe he bought his box with the 60lb tune in it. That means his entire tune may need re-mapping. The car it came from may have a totally different motor build. Heads? Cam? Turbo? Displacement? I wouldn't trust a tune from someone else's car without looking deeper than just changing the Injector flow rate.
That's why I said he may need a little more help.
Yes, it is most important to get it correct at idle. That is why I said to do the way that I did rather then trying to use the value on the curve@13.5 volts like you wanted. The value you are putting in the 1.34 software is not at 13.5 volts. I will have to double check, but I believe it's at 12 volts. If so, then the actual injector offset is going to be lower than the value you put in the calibration. This is because you are actually at 13.5v instead of 12v. As the voltage changes at idle (fan cycling, hit the brakes, turn on the lights, etc..), you will have to rely on the O2 correction to keep things close. IMO, the battery offset table was the biggest improvement in the 2.0 upgrade.
NY Twin Turbo
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- Dec 10, 2014
Actually, I used 13.5v as an example of voltage. If that was the case and it was that number... or some other number, it wouldn't matter. As long as typical idle voltage is used to calculate opening time from the injector's graph. Yes, the rest of the graph may be off, but who cares? It's going to be right where it's most noticeable.
I agree, the offset table was a huge help when I upgraded to 2.0. I have 160's and this made all the difference!
I'm afraid we are getting off track here, but my point was I wouldn't want to use the offset table of that injector like you posted. You are wanting to input the value at whatever his idle voltage is, yet the XFI thinks that value you input is NOT at typical idle voltage but at 12v. If you do it like I posted and adjust that value and get the idle A/F as close as you can, your VE numbers will be close to accurate. The resolution of that value is a tenth (1.1ms, 1.0ms, 0.9ms, etc..) so you are only going to get it so close.