Cell 18 at WOT and 47 degrees of spark advance on launch.
10-30-2008, 08:37 PM
#1
Cell 18 at WOT and 47 degrees of spark advance on launch. Two questions.
1. Is it normal for the engine to be in cell 18 at WOT thewhole time during a 1/4 mile run?
2. When reving the motor in preparation to dump the clutch, I am hitting 45-47 degrees of spark advance. As soon as the clutch is dumped, the advance quickly drops (if the RPM's drop some) to what appears to be more desirable. Is this a problem or should I get the timing lower when dumping the clutch?
1. Is it normal for the engine to be in cell 18 at WOT thewhole time during a 1/4 mile run?
2. When reving the motor in preparation to dump the clutch, I am hitting 45-47 degrees of spark advance. As soon as the clutch is dumped, the advance quickly drops (if the RPM's drop some) to what appears to be more desirable. Is this a problem or should I get the timing lower when dumping the clutch?
10-30-2008, 09:46 PM
#2
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The reason why the timing is so high when you are revving it up because there is no load on the engine. Look at your map values they will be very low. When you let the clutch out you are loading the engine raising the map values thus lowering the timing. The map sensor is like a load sensor. The higher the KPA the higher the load. When you hit 90-100 kpa (full load) at say 2,000 rpms your timing is going to be very low, and then the timing will build as the rpms raise. I bet when you were revving it up and saw that timing your Kpa was around 30-45 kpa.
10-31-2008, 05:43 AM
#3
The reason why the timing is so high when you are revving it up because there is no load on the engine. Look at your map values they will be very low. When you let the clutch out you are loading the engine raising the map values thus lowering the timing. The map sensor is like a load sensor. The higher the KPA the higher the load. When you hit 90-100 kpa (full load) at say 2,000 rpms your timing is going to be very low, and then the timing will build as the rpms raise. I bet when you were revving it up and saw that timing your Kpa was around 30-45 kpa.
10-31-2008, 08:32 AM
#4
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The timing thing is normal, that's stock timing tables on the low end witch isn't a horrible thing, your not going to gain anything by changing it. The cell 18 thing im not to sure. I would look at you LTFT and make sure the go to 128 and stay there once power enrichment is enabled. From what i searched over on camaro z28 the definition of cell 18 is rolling with your foot off the gas at idle rpms. They said being stuck in cell 18 can be attributed to having a high voltage at either the Tps sensor or the VSS. Honestly I would worry more about the ltft staying at 128 and looking at afr with a wideband for WOT. Some of the other stuff is trivial. That is of course unless you have a driveability issue.
10-31-2008, 08:36 AM
#5
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Found thread for you over on Camaro z28 about cell 18. http://www.camaroz28.com/forums/show...hlight=cell+18. And this just scroll down to the cells part. http://www.injuneer.com/ScanMast.html#step%2016 But like i said again there is really nothing to gain by knowing what cell its in just make sure your ltft's are around 128 for part throttle, Maybe smooth out the spark tables, log wideband at WOT make adjustments, call it a day.
Last edited by Jditlfm; 10-31-2008 at 08:47 AM.
