Are FQS bits continuously polled durring DME operation?

[wild man]

I need more fuel, to support the HP level that I am shooting for with my coming upgrades. Upgrading to 55lb injectors (or higher) would be the proper way to do it, IF there was a "proper" MAF chip available that is calibrated specifically for them (not looking good, at this point). If worse comes to worse, I'm told that an MAF chip for stock injectors will work with 55's, so that option will still be on the table, but I don't really consider it to be "proper". My plan B amounts to getting the stockers to flow enough. Option 1 would be to go 3 bar. That raises the stock injectors' flow to 42lb/hr. But that still leaves me shy of what I think I'm going to need (somewhere in the neighborhood of 50lb/hr). If the answer to the question is YES, then options 2, 3, and 4 (+3% fuel, +6% fuel, and -2.73 degrees timing) would be available, as I want to go back to stock (or even -3%, considering that option 1 can't be turned off on the fly), when not on boost. Option 5 (the 5th) will still be available (turned on and off via a pressure switch), if 1 through 4 don't cut it, but I would like to avoid it, if possible, since it would add to the already complex plumbing.. If the DME only polls the FQS bits at startup, it would make options 2, 3, and 4 less attractive, although still somewhat viable.

[Rogue_Ant]

The DME continuously polls the FQS.

[wild man]

Thanks for the quick response! Good news, if the option of being able to make on-the-fly changes is desired, if good for nothing more than fine-tuning. BUT I still need to decide on what will become my "primary" fuel boost option. At this point, I'm reconsidering option "F", or the FMU. What I am envisioning, is that a valve will kick the vac/boost signal that goes to the stock FPR, over to the FMU, when intake flow exceeds what the injectors can deliver on. It would also need to also be fine-tuned, via a bleed-off valve.

[Rogue_Ant]

Don't take this the wrong way - but every time I read your posts, it seems like you are trying to hack something together... And are not starting with the correct info.

The stock injectors @ 3 bar are not 42lbs/hr.
I thought you had the APE chips? If so, the stock FQS settings do not apply. Every APE chips I've seen is something like this:

Position :: Fuel :: Timing
0 :: 0% :: 0
1 :: +12.5% :: 0
2 :: -12.5% :: 0
3 :: +25.0% :: 0
4 :: 0% :: -2.73
5 :: +12.5% :: -2.73
6 :: -12.5% :: -2.73
7 :: +25.0% :: -2.73

I highly suggest taking a step back, and look at the whole picture. If you want a reliable, proper-running vehicle, then a systematic, deliberate approach should be taken. There are options out there, proven, and not unreasonably priced.


-Rogue

[wild man]

I'm running the ape MAF chips. I had no idea that they run higher plus and minus numbers then stock. I got no paperwork with the kit. Thanks for the info, but are you sure that the +12.5% and -12.5% are not reversed, because they do deviate from the expected format? The number I got (42) was from a website where you put the rated flow, it's normal fuel pressure, and the new pressure into a calculator, and it spits out the new flow number. If that's not correct, what IS the correct #? As for taking a step back, I HAVE been holding off on the project of upgrading the turbocharger and piping, for reasons of wanting to be sure that I am taking a reasonable approach to providing additional fuel (among other things), before it actually gets under way. I firmly believe in the concept of measuring twice and cutting only once. I've been asking lots of questions lately, in hopes of making better informed decisions, but summer is like half over now, and the pressure to get it done is mounting. With more than 4X the FQS range that I was figuring on, the 3bar option may yet be enough, to make the #'s work. But for the numbers to come up good, I do need an accurate flow number for the stock injectors running @ 3bar.

[Rogue_Ant]

Yes I'm sure of the +- numbers, and the format is the same as stock.
Note the FQS position - 0 is all the way counter-clockwise.

Stock injectors @ 3bar flow 370cc/min or ~35lb/hr.

And to figure out injector flow-rate change for different pressures is:

sqrt(new pressure / old pressure)


-Rogue

[wild man]

Originally Posted by Rogue_Ant

Stock injectors @ 3bar flow 370cc/min or ~35lb/hr.

Wait a sec! I thought that the 35lb/hr rating is at the stock pressure of 2.5 bar - is this NOT the case? WTF!

[wild man]

Originally Posted by Rogue_Ant

Yes I'm sure of the +- numbers, and the format is the same as stock.

Also, I thought stock was: 1 = -3, 2 = +3, 5 = -3, 6 = +3. Am I mistaken on that?

[Rogue_Ant]

Originally Posted by wild man

Wait a sec! I thought that the 35lb/hr rating is at the stock pressure of 2.5 bar - is this NOT the case? WTF!

No. The numbers I posted are correct.
At 2.5bar, the injectors flow ~340cc/min.

Originally Posted by wild man

Also, I thought stock was: 1 = -3, 2 = +3, 5 = -3, 6 = +3. Am I mistaken on that?

? Here is the stock FQS adjustment settings:

Position :: Fuel :: Timing
0 :: 0% :: 0
1 :: +3% :: 0
2 :: -3% :: 0
3 :: +6% :: 0
4 :: 0% :: -2.73
5 :: +3% :: -2.73
6 :: -3% :: -2.73
7 :: +6% :: -2.73


-Rogue

[wild man]

Thanks for setting me straight on those 2 things, rogue. What I have & what I am looking for in the soon coming upgrade is very similar to what you've got going, but I am too far away from E85 (about 85 miles), so compression will remain at stock level. And I'm only looking to max out at 400 crank HP (about 365WHP), & that would be @20psi. I have just purchased a chip burner (haven't received it yet though), so I will be able to do DIY tuning, etc. I am very interested in the true MAF code that you are running, as I haven't been too happy lately with the APE MAF setup that I am now running, for 335-340 crank horsepower. It hasn't been going into closed-loop operation very often, but maybe it's because the MAF sensor is getting too contaminated with oil. A turbo rebuild/upgrade is part of the coming agenda, so that should take care of the oil situation. But would you be able to provide me with more some detailed info on your setup, and maybe help me out with the DME code, as I am NOT a code writer? I now look at you as "da man"!