Quote:
Originally Posted by Megahurtz
If you are already tanking the high side, raising rail pressure will do nothing.
Also, keep in mind that the SOI table is also linked to airmass.
I think you are overthinking it too much. Move your WOT spark rows up to the lower airmass rows. Do the same with your SOI. Lower your MAF. Adjust Torque Coefficients and/or Virtual Torque.
Leave commanded rail pressure and injector settings stock.
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Thanks for more insight Jason. I had wondered about SOI, and you confirmed it. Thank you for continuing to help. I think others will find it useful, too, and that's super generous of you
Quote:
Originally Posted by jlaudio11
Raise fuel pressure desired in the areas you need more fuel, so the higher cylinder airmass zones. This by itself will translate to more fuel per injector pulse. The computer knows this so it will lower ipw. It may solve your problem all together but if not, then go back to your fuel pressure multiplier tables and play with them. Either letting the direct injection cover the extra fuel need or the port, however you want to do it.
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I'm almost done with part of this. I read your last couple posts again, and think I have a better idea of what you're saying now (in spite of my overthinking, lol). Hear me out...
I've tried continuing to
lower DESIRED FUEL PRESSURE as low a 16mPa. I had continued to adjust [33355/33354] in this area, by increasing the multiplier to about 35%
more than stock, as that was about what I was told I'd need for my combination. This last version, I dropped DESIRED to 16mPa for WOT and blended down, raised my E92 MAF to where it needed to be, and put all my PE back (.83). It
SEEMS like the DI is behaving better, but IPW does start to slowly increase from the low 5s and creep to the upper 5s. Also - I had to pedal the throttle (one time) on a couple hits and as soon as I got back into it, IPWs didn't really try to recover, and dwelled in the 11s. It was still only in the 70s when I was able to get out there, so there's still cold weather to think about, too. I was pretty much tapped out at the maximum multiplier in the 16mPa cell, so I can't get much more out of it, so I'm not looking at a last ditch effort to try 15mPa, which gives me more, theoretical headroom. I think I dropped it to about a 40% multiplier, and blended into 12mPa or something. I copied that MULTIPLIER 3 to the MUTL. 2 table, so that should transition from PROFILEs okay. I think this is the last ditch effort for this version, because, in spite of what the instructor said, maybe I'm at the limit of this method.
I think I'm finally seeing a trend that maybe other have, and a couple have seemed to allude to. Under WOT, it seems like most of the time, so far (at least into the upper 60* temps, I can maintain good fuel control. BUT - if I have to pedal the THROTTLE for traction, it seems like the fueling just goes crazy and doesn't come back. I understand that lowering DESIRED FUEL PRESSURE will result in
increased IPW, but I've been combatting that, effectively, with
increasing [33355]. The issue is, that [33355] has a GM-hard-coded-limit factor of "2.0000" which doesn't lend to a lot of compensation. It seems to only allow up to about 28% or so, theoretically, if I'm calculating that right. So - unless I'm missing something, it would seem that, for a stock-cam-type build, this might be the end of the line. I have a couple more videos I want to re-review, but unless there's an injector characterization that would help in a WOT-type-scenario, I may be stuffed, and will have to start pulling from PE, and if that's not enough, break down into the E92 MAF, which is what all of this was trying to avoid... boo...
jl' - Your suggestion, if I understand it correctly now, will represent my last foray into this method. It looks like I'll put most of my DESIRED [17071] changes (go back to changing 20mPa and up; putting 20mPa and lower back the way I had them) back to the way I had them earlier, and try raising the DESIRED to maybe 22mPa. I've seen the instructor we watched and Ben Charles say that up to about 24mPa is just fine on these LT4 pumps, so I imagine I'd see a positive reaction to this change pretty easily. My goal had been to
lower DI system demand, but it's also not like I'm running WOT all the time, so I realize I'm over reacting.
Let's see what happens...