What's enough resolution?

[Bruce]

Why do, I rant about source code and resolution?

Well folks, here's the final product of what happens when you have a big cam, for a given amount of displacement. While 214/214 at .050 is not even warm for a 305, on a 231 (OK, was a 231), dial up the lift to +.5 (actual number classified), and you wind up with an idle in the 65-70 K/Pa range. Toss in using 60 PHH injectors, and you might wind up with a night mare.
Where in fact this setup runs like a watch, makes lots of boost and moves right along

Main Spark
Entries in dec, and need multiplied by .3 to approx degrees.

Map20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95100 Rpm:

FCB 30 30 30 30 30 30 30 30 30 68 68 68 68 68 57 57 57 400
FCB 30 30 30 30 30 30 30 30 30 68 68 68 68 68 57 57 57 600
FCB 30 30 30 30 30 30 30 30 30 68 68 68 68 68 57 57 57 800
FCB 30 30 30 30 30 30 30 30 30 74 74 68 63 63 57 57 57 1000
FCB 30 30 30 30 30 30 30 30 30 68 74 74 68 63 63 57 57 1200
FCB 30 30 30 30 30 30 30 30 30 68 84 84 78 68 63 57 57 1400
FCB 30 30 30 30 30 30 30 30 30 68 84 84 84 68 63 63 63 1600
FCB 30 30 30 30 30 30 30 30 30 68 86 86 86 74 68 63 63 1800
FCB 30 30 30 30 30 30 30 30 30 68 86 86 86 74 63 63 63 2000
FCB 30 30 30 30 30 30 30 30 30 68 86 86 86 74 74 63 63 2200
FCB 30 30 30 30 30 30 30 30 30 68 86 86 86 74 74 74 74 2400
FCB 30 30 30 30 30 30 30 30 30 68 86 86 86 74 74 74 74 2800
FCB 30 30 30 30 30 30 30 30 30 68 86 86 86 74 74 74 74 3200
FCB 30 30 30 30 30 30 30 30 30 68 86 86 86 74 74 74 74 3600
FCB 30 30 30 30 30 30 30 30 30 68 86 86 86 74 74 74 74 4000
FCB 30 30 30 30 30 30 30 30 30 68 86 86 86 74 74 74 74 4400
FCB 30 30 30 30 30 30 30 30 30 68 86 86 86 74 74 74 74 4800

MAIN VE
Map 20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100

FCB 0 0 0 0 0 0 0 0 0 60 60 65 90 110 190 240 240 ; 400
FCB 0 0 0 0 0 0 0 0 0 60 60 65 90 110 190 240 240 ; 600
FCB 0 0 0 0 0 0 0 0 0 60 60 65 90 110 190 240 240 ; 800
FCB 0 0 0 0 0 0 0 0 0 36 68 75 90 115 150 190 190 ; 1000
FCB 0 0 0 0 0 0 0 0 0 36 72 81 95 130 160 180 180 ; 1200
FCB 0 0 0 0 0 0 0 0 0 36 78 86 100 145 165 175 180 ; 1400
FCB 0 0 0 0 0 0 0 0 0 36 82 96 105 145 165 185 185 ; 1600
FCB 0 0 0 0 0 0 0 0 0 36 89 100 105 155 170 185 185 ; 1800
FCB 0 0 0 0 0 0 0 0 0 36 94 105 110 160 185 190 195 ; 2000
FCB 0 0 0 0 0 0 0 0 0 36 101 110 115 155 185 195 195 ; 2200
FCB 0 0 0 0 0 0 0 0 0 36 100 115 115 155 185 195 195 ; 2400
FCB 0 0 0 0 0 0 0 0 0 36 105 110 120 165 190 195 200 ; 2800
FCB 0 0 0 0 0 0 0 0 0 36 130 135 155 175 180 195 200 ; 3200
FCB 0 0 0 0 0 0 0 0 0 36 133 135 155 175 180 195 200 ; 3600
FCB 0 0 0 0 0 0 0 0 0 36 125 140 160 170 185 190 195 ; 4000
FCB 0 0 0 0 0 0 0 0 0 36 125 140 160 180 185 190 195 ; 4400
FCB 0 0 0 0 0 0 0 0 0 36 125 140 160 180 185 190 195 ; 4800

While it might look like a waste of table space at the lower loads, that's fine, since if I change cams or play some other games, I have the resolution to do that.

And for anyone that says SD is that much more difficult then MAF, well, you can believe what you want, but with a WB and some experience there's little to no difference in getting the tune right, at least in my experience. There's some areas in the MAP that I'll never see, and those were worked out on the ecm bench, and in this case is about 1/2 the entries.

Not to mention some of the other lil dodads to compensate for things like lots of boost, water injection, etc, etc.

Source code, the Final Answer..........

__________________
Simplicity works,
as long as it's complicated enough.

[Dave Jones]

A question regarding your VE tables...how low does the MAP go when you've got a few RPMs built up, and then snap the throttle blades closed?

I'm just wondering if your car never sees anything below 55 KPa, -- or if it does, is that a strategy to cut off fuel for that moment of "overrun?"

Or is there still some fuel there, from the way the $58 BPC works? (not familiar with that code...yet)

Dave

(tried a frosted flakes decoder ring on the source code yesterday, but it didn't help)

[Bruce]

A question regarding your VE tables...how low does the MAP go when you've got a few RPMs built up, and then snap the throttle blades closed?
I'm just wondering if your car never sees anything below 55 KPa, -- or if it does, is that a strategy to cut off fuel for that moment of "overrun?"
Or is there still some fuel there, from the way the $58 BPC works? (not familiar with that code...yet)


Lowest I've seen is 60.
And if it drops under that, it still doesn't matter, since the fuels basically off anyway. The stock GM codes have deccleration enleanment as well as Decleration Fuel Cut Off, but for me I just perfer turning the fuel off in the VE table rather then having a bunch of qualifiers for it's application.

BTW, this is from my own code.
I use one of the extra A/D channels and have a true 3 bar MAP 12277148 ecm. 1 bar VE table, and then a 2 bar boost multiplier table. It took a couple tries at getting the boost multiplier strategy right, but it works incredibly well.

BPC is a really interesting concept. Since you can run any value you want, and it changes the *weight* of the VE table, and thus the weights/influuences of the other corrections, and allow for really fine tuning.
Well, if you have the code to support that sort of complexity.