to what extent does the boost sensor control timing?

 

I've finally had time to analyze Henrik's data dump, and I found an interesting trend...

Comments are added on the right...

Timestamp was eliminated, since Henrik said they were screwed up.


RPM AFM boost AFMtemp IAT ms, CT, "boost"correction

1860, 198, 1.1in, 31.9, 39.4, 7.0, 81.2, 14.8%
1882, 197, 0.2in, 31.9, 39.4, 7.1, 81.2, 14.8%
1870, 194, 0.0psi, 31.9, 39.4, 7.1, 81.2, 14.8%
1896, 197, 0.2psi, 31.9, 39.4, 7.0, 81.2, 14.8%
1884, 187, 0.4psi, 31.9, 38.8, 7.5, 81.2, 14.8%
1908, 191, 0.5psi, 31.9, 38.8, 7.1, 81.2, 14.8%
1912, 184, 0.7psi, 31.9, 38.8, 7.5, 81.2, 14.8%
1924, 186, 0.7psi, 31.9, 38.8, 7.3, 81.2, 14.8%
1950, 183, 1.0psi, 31.9, 38.8, 7.7, 81.2, 14.8%
1930, 182, 1.1psi, 31.9, 38.8, 7.6, 81.2, 14.8%
1946, 180, 1.3psi, 31.9, 38.8, 7.7, 81.2, 14.8% AFM > 179
1962, 178, 1.3psi, 31.9, 38.8, 8.0, 81.2, 19.9% AFM < 179
1966, 179, 1.7psi, 31.9, 38.8, 8.2, 81.2, 19.9%
1998, 174, 1.9psi, 31.9, 38.8, 8.4, 81.2, 19.9%
2000, 176, 1.9psi, 31.9, 38.8, 8.1, 81.2, 19.9%
2012, 169, 2.1psi, 31.9, 38.8, 8.8, 81.2, 19.9%
2008, 170, 2.3psi, 31.9, 38.8, 8.5, 81.2, 19.9%
2030, 171, 2.5psi, 31.9, 38.8, 8.5, 81.2, 19.9%
2030, 166, 2.6psi, 31.9, 38.8, 8.7, 81.2, 19.9%
2040, 166, 2.8psi, 31.9, 38.8, 8.9, 81.2, 19.9%
2058, 166, 2.9psi, 31.9, 38.8, 8.8, 81.2, 19.9%
2066, 162, 2.9psi, 31.9, 38.8, 9.2, 81.2, 19.9%
2090, 161, 3.3psi, 31.9, 39.4, 9.0, 81.2, 19.9%
2098, 161, 3.5psi, 31.9, 39.4, 9.1, 81.2, 19.9%
2124, 158, 3.6psi, 31.9, 39.4, 9.5, 81.2, 19.9%
2106, 158, 3.7psi, 31.9, 39.4, 9.4, 81.2, 19.9%
2116, 158, 3.9psi, 31.9, 39.4, 9.3, 81.2, 19.9%
2152, 158, 4.1psi, 31.9, 39.4, 9.3, 81.2, 19.9%
2174, 157, 4.2psi, 31.9, 39.4, 9.3, 81.2, 19.9%
2164, 153, 4.3psi, 32.5, 39.4, 10.0, 81.2, 19.9%
2188, 152, 4.4psi, 32.5, 39.4, 9.9, 81.2, 19.9%
2208, 150, 4.8psi, 32.5, 39.4, 10.0, 81.2, 19.9%
2228, 150, 4.8psi, 32.5, 39.4, 9.9, 81.2, 19.9%
2216, 148, 5.1psi, 32.5, 39.4, 9.9, 81.2, 19.9%
2238, 149, 5.1psi, 32.5, 39.4, 9.8, 81.2, 19.9%
2258, 149, 5.2psi, 32.5, 40.0, 9.9, 81.2, 19.9%
2252, 153, 4.8psi, 32.5, 40.0, 9.7, 81.2, 19.9%
2276, 159, 3.3psi, 32.5, 40.0, 8.8, 81.2, 19.9%
2278, 176, 1.2psi, 32.5, 40.0, 7.1, 81.2, 19.9% AFM < 179
2304, 198, 0.9in, 32.5, 40.0, 5.6, 81.2, 14.8% AFM > 179
2294, 198, 2.5in, 32.5, 40.6, 5.7, 81.2, 14.8%
2300, 224, 5.1in, 32.5, 40.6, 4.8, 81.2, 0.0%


Notice, the boost increases also coincide with the AFM values dipping below a certain value.&nbsp; I dunno what this "boost correction" came from, but it's not obvious from the data dump that it's connected soley with the boost sensor.

We really need to get the stock ECU code cracked...


-Ted

 

OK Ted, you have prompted me to look a little closer too.

The data dump covers rpm range from 1882 to 2300 - not a very interesting range.

Throttle position is unknown but essential information.

"boost correction" is undefined and is preumably a calculated value - what is the formula?

The maximum injector duty cycle in this small example is 37% - again not very interesting (but not surprising given the low rpm).

In my view this data is completely ambiguous.

 

Let me see if I've got this sorted out (please excuse a newbie).

The ECU has a system that simply cuts fuel at a certain boost pressure. All an FCD does is cut that system out, and the ECU continues providing fuel until the fuel map gives out based on air volume readings? There was another debate on this board about that before, about how an FCD does not allow you to access the fuel maps in the ECU that supposedly go up to 10-11psi, and simply keeps you at the amount of fuel pumped at the boost the FCD transmits to the ECU.

 

is this how it works...

------------------------------------------------------------------
AFMs reading closed starts at 200 and decreases as more air flows and the door opens further
------------------------------------------------------------------
RPM AFM boost AFMtemp IAT ms, CT, "boost"correction
1860, 198, 1.1in, 31.9, 39.4, 7.0, 81.2, 14.8%
1882, 197, 0.2in, 31.9, 39.4, 7.1, 81.2, 14.8%
1870, 194, 0.0psi, 31.9, 39.4, 7.1, 81.2, 14.8%
1896, 197, 0.2psi, 31.9, 39.4, 7.0, 81.2, 14.8%
1884, 187, 0.4psi, 31.9, 38.8, 7.5, 81.2, 14.8%
1908, 191, 0.5psi, 31.9, 38.8, 7.1, 81.2, 14.8%
1912, 184, 0.7psi, 31.9, 38.8, 7.5, 81.2, 14.8%
1924, 186, 0.7psi, 31.9, 38.8, 7.3, 81.2, 14.8%
1950, 183, 1.0psi, 31.9, 38.8, 7.7, 81.2, 14.8%
1930, 182, 1.1psi, 31.9, 38.8, 7.6, 81.2, 14.8%
1946, 180, 1.3psi, 31.9, 38.8, 7.7, 81.2, 14.8%
1962, 178, 1.3psi, 31.9, 38.8, 8.0, 81.2, 19.9%
1966, 179, 1.7psi, 31.9, 38.8, 8.2, 81.2, 19.9%
1998, 174, 1.9psi, 31.9, 38.8, 8.4, 81.2, 19.9%
2000, 176, 1.9psi, 31.9, 38.8, 8.1, 81.2, 19.9%
2012, 169, 2.1psi, 31.9, 38.8, 8.8, 81.2, 19.9%
2008, 170, 2.3psi, 31.9, 38.8, 8.5, 81.2, 19.9%
2030, 171, 2.5psi, 31.9, 38.8, 8.5, 81.2, 19.9%
2030, 166, 2.6psi, 31.9, 38.8, 8.7, 81.2, 19.9%
2040, 166, 2.8psi, 31.9, 38.8, 8.9, 81.2, 19.9%
2058, 166, 2.9psi, 31.9, 38.8, 8.8, 81.2, 19.9%
2066, 162, 2.9psi, 31.9, 38.8, 9.2, 81.2, 19.9%
2090, 161, 3.3psi, 31.9, 39.4, 9.0, 81.2, 19.9%
2098, 161, 3.5psi, 31.9, 39.4, 9.1, 81.2, 19.9%
2124, 158, 3.6psi, 31.9, 39.4, 9.5, 81.2, 19.9%
2106, 158, 3.7psi, 31.9, 39.4, 9.4, 81.2, 19.9%
2116, 158, 3.9psi, 31.9, 39.4, 9.3, 81.2, 19.9%
2152, 158, 4.1psi, 31.9, 39.4, 9.3, 81.2, 19.9%
2174, 157, 4.2psi, 31.9, 39.4, 9.3, 81.2, 19.9%
2164, 153, 4.3psi, 32.5, 39.4, 10.0, 81.2, 19.9%
2188, 152, 4.4psi, 32.5, 39.4, 9.9, 81.2, 19.9%
2208, 150, 4.8psi, 32.5, 39.4, 10.0, 81.2, 19.9%
2228, 150, 4.8psi, 32.5, 39.4, 9.9, 81.2, 19.9%
2216, 148, 5.1psi, 32.5, 39.4, 9.9, 81.2, 19.9%
2238, 149, 5.1psi, 32.5, 39.4, 9.8, 81.2, 19.9%
2258, 149, 5.2psi, 32.5, 40.0, 9.9, 81.2, 19.9%
-----------------------------------------------------------
around here gas pedal was released
BOV blew out pressure possibly?
airflow is lessened and AFM resets to 200 soon
-----------------------------------------------------------
2252, 153, 4.8psi, 32.5, 40.0, 9.7, 81.2, 19.9%
2276, 159, 3.3psi, 32.5, 40.0, 8.8, 81.2, 19.9%
2278, 176, 1.2psi, 32.5, 40.0, 7.1, 81.2, 19.9%
2304, 198, 0.9in, 32.5, 40.0, 5.6, 81.2, 14.8%
2294, 198, 2.5in, 32.5, 40.6, 5.7, 81.2, 14.8%
2300, 224, 5.1in, 32.5, 40.6, 4.8, 81.2, 0.0%
----------------------------------------------------------
how does that sound?

thats just my opinion.. tell me if im wrong.

 

Yeah, pretty much.

The RPM range is pretty low.

I was expecting the air temps to start climbing a lot faster, or is the IC that efficient?


-Ted

 

Ted:

Like I said, its not AFM, in the same log you can see boost crosses 1.2psi at the points you've marked.

There was a long thread on the nopistons site about the stock IC efficiency which had some surprising results - better than what the general retoric gives it credit for.

fe1rx:

It was a convenient range for a number of reasons. The meaning of the percentage is increase fuel over base by this much where base is a fn(afm, rpm, air t, ATP)

Ted/fe1rx:

One more question you should ask is did it blow below 3800rpm?

-Henrik

 

'nother log, same fields except timestamp and TPS added after boost. (I see I need to adjust it from line 1600).

N332,L,1576,2318,179,5.1in,4.7,32.5,37.5,6.8,81.2, 0.0%
N332,L,1577,2386,171,0.9in,4.7,32.5,37.5,7.3,81.2, 14.8%
N332,L,1578,2472,166,0.0psi,4.7,32.5,37.5,7.5,81.2 ,14.8%
N332,L,1579,2550,159,0.5psi,4.7,32.5,37.5,7.8,81.2 ,14.8%
N332,L,1580,2666,150,1.2psi,4.7,32.5,36.9,8.4,81.2 ,14.8%
N332,L,1581,2770,143,1.8psi,4.7,32.5,36.9,9.2,81.2 ,21.1%
N332,L,1582,2914,132,3.0psi,4.7,32.5,36.9,10.2,81. 2,21.1%
N332,L,1583,3052,122,4.3psi,4.7,32.5,36.9,12.1,81. 2,29.7%
N332,L,1584,3308,116,5.2psi,4.7,32.5,36.9,12.7,81. 2,29.7%
N332,L,1585,3520,110,5.7psi,4.7,32.5,36.9,12.9,81. 2,29.7%
N332,L,1586,3732,105,5.7psi,4.7,32.5,36.9,13.1,81. 2,29.7%
N332,L,1587,3936,103,5.7psi,4.7,32.5,36.9,6.7S,81. 2,29.7%
N332,L,1588,4188,100,6.0psi,4.7,32.5,36.9,6.7S,81. 2,29.7%
N332,L,1589,4444,96,6.2psi,4.7,32.5,39.4,6.8S,81.2 ,29.7%
N332,L,1590,4764,94,6.0psi,4.7,32.5,39.4,6.6S,81.2 ,29.7%
N332,L,1591,5060,89,6.2psi,4.7,32.5,39.4,6.9S,81.2 ,29.7%
N332,L,1592,5408,83,6.5psi,4.7,33.1,39.4,7.2S,81.2 ,29.7%
N332,L,1593,5856,81,6.2psi,4.7,33.1,44.4,7.3S,81.2 ,34.0%
N332,L,1594,6028,79,6.2psi,4.7,33.1,44.4,7.5S,81.2 ,34.0%
N332,L,1595,6364,77,6.2psi,4.7,33.1,44.4,7.5S,81.2 ,34.0%
N332,L,1596,6780,76,5.9psi,4.7,33.1,44.4,7.3S,81.2 ,34.0%
N332,L,1597,7136,76,5.7psi,4.7,33.1,44.4,7.0S,81.2 ,34.0%
N332,L,1598,6588,314,20.4in,2.1,33.1,53.8,1.5,81.2 ,0.0%
N332,L,1599,6072,476,23.5in,1.0,33.1,53.8,1.1,81.2 ,0.0%
N332,L,1600,5616,586,24.2in,0.7,33.1,53.8,1.0,81.2 ,0.0%
N332,L,1601,5124,198,16.9in,4.5,33.7,53.8,3.0,81.2 ,17.2%
N332,L,1602,4964,114,2.8in,4.7,33.7,53.8,7.6,81.2, 17.2%
N332,L,1603,5000,98,2.8psi,4.7,33.7,49.4,5.8S,81.2 ,28.1%
N332,L,1604,5196,88,6.3psi,4.7,33.7,49.4,6.8S,81.2 ,29.7%
N332,L,1605,5352,85,6.7psi,4.7,33.7,49.4,7.0S,81.2 ,29.7%
N332,L,1606,5572,83,7.1psi,4.7,33.7,49.4,7.2S,81.2 ,29.7%
N332,L,1607,5716,81,6.9psi,4.7,33.7,51.9,7.4S,81.2 ,29.7%
N332,L,1608,5864,80,6.9psi,4.7,33.7,51.9,7.5S,81.2 ,34.0%
N332,L,1609,5968,80,7.0psi,4.7,33.7,51.9,7.4S,81.2 ,34.0%
N332,L,1610,6160,78,7.1psi,4.7,33.7,51.9,7.5S,81.2 ,34.0%
N332,L,1611,6312,79,6.6psi,4.7,34.4,51.9,7.3S,81.2 ,34.0%
N332,L,1612,6244,195,13.8in,3.1,34.4,58.1,2.8,81.2 ,29.7%
N332,L,1613,5712,408,22.3in,1.6,34.4,58.1,1.2,81.2 ,0.0%
N332,L,1614,5280,583,24.0in,0.7,34.4,58.1,1.0,81.2 ,0.0%
N332,L,1615,4748,597,24.0in,0.7,33.7,58.1,1.0,82.5 ,0.0%
N332,L,1616,4372,612,24.0in,0.7,33.7,55.0,1.1,82.5 ,0.0%
N332,L,1617,4036,587,23.7in,0.7,33.7,55.0,1.1,82.5 ,0.0%
N332,L,1618,3744,598,23.7in,0.7,33.7,55.0,1.1,82.5 ,0.0%
N332,L,1619,3496,598,23.7in,0.7,33.7,55.0,1.1,82.5 ,0.0%
N332,L,1620,3216,595,23.7in,0.7,33.7,55.0,1.2,82.5 ,0.0%
N332,L,1621,2964,346,22.5in,0.7,33.7,52.5,2.1,82.5 ,0.0%
N332,L,1622,2690,391,20.9in,0.7,33.7,52.5,1.9,82.5 ,0.0%

Here you can see the IC at work (or not) as well as the secondaries coming on (the 'S' in the injector ms) and fuel cut on decel (injection going to 0.7)

-Henrik