Shifted wrote: ↑Sun Dec 20, 2020 8:36 am
I would be surprised if you don't have to make timing adjustments on a motor with any significant level of forced induction. Especially one without an intercooler. Unless, it's already been tuned to eliminate knocks?
My assumption is that the original EZK tune by the vendor/installer is close. I have the maps saved, but since the ST has no "off-line" mode it's not worth it just this minute to compare them to a stock EZK map.
Shifted wrote: ↑Sun Dec 20, 2020 8:36 amYou've mentioned your personally written software several times. So, please elaborate. What language is it written in? What does it actually do, specifically? How does it interface with the SharkTuner hardware (or, does it just process SharkTuner logs)?
I probably emphasized that too much. LoL. What it does is eat a SharkTuner log file parse out the data into LH and EZK cells. For each cell it displays a histogram of A/F ratio along with some useful parameters which are... from memory: WOT/cruise/idle, current trim value, last trim value, sample count, knock count,... a couple of others. I haven't even started it up in years. It also shows 3d surface graphs of the maps, diffs between maps.
I just fired it up. It still works. Miraculous. Although, staring at it, I don't remember half of what the crypic glyphs are telling me. It's a paragon of something written by the user for the user and no one else. Lol.
Come Spring it's probably a good excuse to kick the tires on Coreman's Shark Plotter.
Shifted wrote: ↑Sun Dec 20, 2020 8:36 am
That's really interesting that it took so long to dial in your car. That's not been my experience on my car for any aspects of tuning, but maybe I just got lucky.
It's not like I went out every day to tweak start, warm-up, and warm start. It didn't take that many iterations. But, I can't control the outside temperature. Furthmore, unlike my software, the tuning needed to be good for everybody and not just me. So, I wanted to be totally certain that it started in all weather. I was done by Summer but had to wait for the following winter to be sure.
There are also characteristics of the D.R. twin-screw that complicate tuning. Long story. Not important anymore.
Shifted wrote: ↑Sun Dec 20, 2020 8:36 am
I assume that the car is already tuned for the supercharger and you're just going to confirm that it runs ok and make a few minor changes as needed?
I assume that it started with maps from the vendor/installer that were (as I wrote above) adjusted for a 928 with a mass-air sensor on the way out, IMS bypassed due to bad plug wires (i.e. tuned when misfiring) and, apparently, tuned using the simulated NB output from an LSU 4.2 and LC-1 since there was zero accommodation for getting a WB signal into the Shark Tuner.
Oh, and I forgot, the LH is showing early signs of failure.
I assume that only the fuel map was tweaked under those conditions.
However, since I've never tuned a boosted 928 with a bad mass-air sensor, that was mis-firing due to bad plug wires while running on a failing LH... I'm going to not make predictions on how far off it is. And, thinking about it again, predicting only a couple of logging/tuning runs may be optimistic.
Shifted wrote: ↑Sun Dec 20, 2020 8:36 am
That's a bit scary when you consider what must be happening internally as a result.
Understatement.
The disconnected y-hose (see picture way above) was essentially an always-on bypass valve. Of course since the BOV vacuum was hooked to the other end of the y-hose, the BOV wasn't working though. I did test the BOV before putting it back on. Seems to work.
Not sure why it wasn't popping seals or the MAS off all over the place. It sure was puking oil though. 'course there's more to that story than just the SC.
Shifted wrote: ↑Sun Dec 20, 2020 8:36 am
What crank case and valve cover breathing configuration did you do on the car?
It's breathing now, from both right-side cam cover elbows, the filler neck right-side top port (GTS neck), front left cam cover elbow. So, four ~5/8" lines. Twice the N.A. breather capacity. I expect further development of the 'system' once I am able to do some testing in the Spring.
This one is going to get flat-bedded home since all the roads have been salted. So, no testing at all can happen until Spring.
Shifted wrote: ↑Sun Dec 20, 2020 8:36 am
Who designed and sold the supercharger kit?
VCB. Also installed by Victor. Then later stuff was done to it by someone else, likely in an attempt to 'fix' it without doing any diagnosis. It's not clear to me that the breather configuration it had when Victor finished is the same as when it was dragged to me. The pictures I have of the as-installed configuration are inconclusive.
The work I did on this is probably worthy of its own thread. It's a paragon of "novice" product management coupled with "expedient" repairs interacting with power add-ons and how it all goes sideways eventually. However, if I do "pull back all of the curtain" there's going to be a lot of noise from the shattering of several glass houses. I don't know that there's an upside for that. And, I'm under no illusion that I might find glass in my house where I didn't expect it.
928 picture: Nobody ever cleans and re-oils these damn things.
Hanlon’s Razor: Never attribute to malice that which is adequately explained by stupidity.
Heinlein’s Corollary: Never underestimate the power of human stupidity.
The Reddit Conjecture: Sufficiently advanced stupidity is indistinguishable from malice.
Worf’s Razor: Never attribute to stupidity that which is adequately explained by laziness.
Worf’s Identity: Sufficiently advanced laziness is indistinguishable from stupidity
Worf's Law: Once you've mitigated risk from stupidity and laziness in your endeavors, failure is usually the result of insufficient imagination.
My 928 Inspection Guide