5.0Thunder
Active Member
- Jan 31, 2018
- 128
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Thats cool I am talking to a rocket scientist! what a field of work that must be... I just train people on the basics of electrical theory and how to become a decent inside wireman [electrician].. such is life.My old Excel program says 90mm Lightening MAF Transfer Curve.xls is unrecognized format.
I read somewhere about the 90mm Lightning MAF, different versions & different flow curves.
Looks like this is where @stanglx2002 got your data from.
https://www.efidynotuning.com/maf.htm
I do know that my flow curve has a higher upper end because C&L had the flow bench to test more than MAF's. He also tested rocket engine nozzles for NASA. I spoke to "L" several times, since we were both "rocket scientists".
I acquired all his original flow curves & some how he was able to take flow measurements above what the sensor could output (4.3v out of 5.0v). The old sensors did have a voltage limit.
Thanks for all the good info. You clearly have more experience with more vehicles. I only have one, mine. Finally got cold idle & warm idle to stabilize with one setting, which you also have set like mine. Closed loop idle settings-->Use last value or table-->Use Initial Value table.
It's running so well, am reluctant to even install the 47's in place of the 30's. I only bought the 47's because they came with the adapters (which are no longer available) & the 30's would be at 100% duty cycle at full boost (13 lbs), which I never do. I can get 2 lbs boost in 5th gear at 2k rpm at WOT. Probably need a better sensor than the old Ford one. It would have to have the same end dimensions to retain the existing hose adapters.
Drive train & me are too old to do any heavy mechanical work. The car is now just an antique cruiser.
Actually, I was an electrical controls engineer, but worked for a while in a building called Rocket Support. Tested all our equipment on unused rocket engine test stands. I figure that makes me a rocket scientist.Thats cool I am talking to a rocket scientist! what a field of work that must be... I just train people on the basics of electrical theory and how to become a decent inside wireman [electrician].. such is life.
The idle settings took alot of playing with before i found the settings that worked best for this combo, when i do remote tunes i usually get the car to idle well the 'easy' way and then attempt to emulate these settings, sometimes it is a flop.
I am limited at around 11PSI on this build do to pulley combinations but it will make boost right off idle, the bypass valve was necessary to mitigate compressor surge and lower intake temps.
Well I like to take a scientific approach to my tuning methods, it is also an excersice in learning. I use tables like these to troubleshoot tune anomalies all the time, I figured I would just share a use for them with an example.This is a much more extensive approach than I used, and in the end, it's only going to give you a "good guess" of how to plot the one correction curve, right?
Why not just let the engine get hot at idle and drag the datapoints in the curve to whatever values give you the best AFR? I mentioned this above and it took like 5mins to get it done. Maybe I'm missing some of what you're gaining with this approach but from my perspective it looks like a lot of overthinking.
UPDATE: after I compiled the drive data from yesterday and this morning i have come to the conclusion that MAT temperatures in my particular build have no direct correlation to the AFR swing I am experiencing. One would expect a linear [or somewhat linear] curve to show itself in the data. This has not happened, I also dont believe that the curve can go rich and then lean within a 5* MAT difference. I will chalk this one up to lambda delay and runner fuel propagation/standoff. I can provide the datalogs from the drives for review if someone wants to see them.
that is correct. ; I also disabled all ego feedback to run only on the VE tableAhh, this makes things interesting. So say you're driving stop light to stop light. It might be rich at idle for a couple stop lights then it'll be lean for a few, then rich again? All the while MAT is somewhat steady?
1. ...i have come to the conclusion that MAT temperatures in my particular build have no direct correlation to the AFR swing I am experiencing.
One would expect a linear [or somewhat linear] curve to show itself in the data. This has not happened, I also dont believe that the curve can go rich and then lean within a 5* MAT difference. I will chalk this one up to lambda delay and runner fuel propagation/standoff. I can provide the datalogs from the drives for review if someone wants to see them.
2. Ahh, this makes things interesting. So say you're driving stop light to stop light. It might be rich at idle for a couple stop lights then it'll be lean for a few, then rich again? All the while MAT is somewhat steady?3. that is correct. ; I also disabled all ego feedback to run only on the VE table
1. I would have guessed that.
2. I have seen this, too. I don't worry about AFR at idle.
3. Looking at your trim table, it seems very low in the low load cells. Supercharger should increase VE significantly. Is your BOV close point set too high? Completely closed at 0-10in-Hg is about right. You want it to be fully open at high vacuum & fully closed at no vacuum.
BTW, just because you take a scientific approach to this doesn't mean that you're analyzing facts; you could be analyzing fiction, which is, what I think, you have found out.
Relatively speaking, the MS2 cpu isn't all that fast, but the larger issue is, what is the value in seconds of the real-time control loop? I'm not sure, but I suspect he has to continuously loop through the firmware for data acquisition & control. The cpu is a 16-bit micro controller, Motorola (now Freescale) MC9S12C, with 128kB of flash memory. The firmware is a simple ASCII file, not compiled or machine language, so there must be a lot of overhead in interpreting it in something close to real-time. It's also very possible that the firmware doesn't take advantage of all the features that the micro controller has available.