I looked back at a logged drive today and saw a couple of pretty steep knock retard points. The most was 20 degrees of knock retard. It occured at 2775 RPM, MAP Kpa 97.1, TPS % 49.4. I have made several VE table mods but have not touched the spark tables yet. How should I approach the spark table? Or should I try adding more fuel first. O2 Volts were at 788 at the 20 degree knock retard point. After looking back at several other logs I notice there is quite a bit of retard in the lower RPM higher MAP ranges. Where to start? I would email a couple of .uni files if someone would look at them for me and give me an opinion.

 

i dont know the finer points of you rengie but id say its a pretty strong indicator to pull some timming. drop 2 degress at a go and see where that gets you. you could also tos some fuel in there to cool things off a bit. adding some AE might help.

 

Should I pull a couple of degrees out across the whole table for now until I get to messing with the timing more or just a couple of degrees where it needs it? I am going to put a few gallons of 114 in it today and see what it does. I really didn't expect that much retard at part throttle no boost. I got a 749 ecm ready to swap but I thought I would try to dial in the part throttle stuff with the 730 first so I would have some VE tables for comparison.
Also, when you mention add a little more AE, which one? Delta TPS or MAP/MAP?

 

Remember there is some latency from the knock and the reported knock.So pull timing before it registered is a good place to start.

 

Do you have the PE enable set fairly high?.
20d is a whole bunch. Are you sure that it's not a rattle of some sort?.

You need to start to cure that problem some point ahead of when it's reported. Cool the chamber with a little fuel, and or removing some timing.

 

I have the TPS to PE currently set to 99.6% but at the time of the onset of knock retard it was only at 34.9% TPS. I notice it happened three times during the log. BLM were at 123 at time of knock and jumped to 139 then back down to 128 as knock retard regressed.

RPM..........MAP..........TPS%..........Spark Retard
1250..........86.7..........34.9..........0
2075..........90.1..........37.3..........9.8
2650..........89.7..........37.3..........20
2850..........89.3..........37.3..........20
2875..........97.8..........52.9..........17.8
3150..........103.7........69.0..........17.8
3375..........103.7........81.2..........17.2
3575..........103.7........90.6..........17.2
3675..........103.7........93.9..........15.1
3750..........103.7........92.5..........13.4

seems like spark retard deminished as RPM's increased even though TPS increased with no P.E.

 

sure as rpm goes up there less time for detonation to occur.

 

So I should pull timing in the range a couple of frames before spark retard. How close should the VE tables be before I reset the TPS to PE back to stock and mess with timing and AE. I am not getting in a hurry but I just don't want to be pissing in the wind if I mess with spark now instead of later. But on the other hand I don't want to rebuild the motor either.