Is my tuner dumb
TQ numbers on a dyno are not that hard to screw around with.
Need to make sure we have an apples to apples comparison.
1. The advance is a piddly 7* at 3600 and then 28* at 4000. Unless your engine works in the 4th dimension where it magically removes the locomotive cam and installs a racing cam above 3600 RPM, that is simply wrong. Transitions should always be smooth. The tuner was likely just very lazy. Actually 28* is aggressively high for these engines.
2. The VE table shows the highest values, which corresponds to the highest torque in the 4400 RPM column, exactly the same as a stock cam. With your hot cam it should be more in the 5200 or even 5600 column. Again, the tuner was lazy.
3. The PE table has a very lean 1.13 starting at 4000 RPM. Many people here have found that 1.16 to 1.18 is best up to max torque and then perhaps leaning out a bit.
Now it is possible that he enriched everything somewhere else, but IMHO that would be non-standard. In any case you don't lean out until after max torque which with your cam is around 5600 RPM.
With the 28* advance and the lean PE table and lean VE tables near your max torque, I suspect you are getting a bunch of Knock retard. You might not hear it, but a log will show it.
In short, IMHO the combination of these issues is costing you a lot of torque; maybe 40 ft/lbs.
Again, I'm no expert, and if an expert refutes everything I wrote, I will go and have myself spanked.
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1. The advance is a piddly 7* at 3600 and then 28* at 4000. Unless your engine works in the 4th dimension where it magically removes the locomotive cam and installs a racing cam above 3600 RPM, that is simply wrong. Transitions should always be smooth. The tuner was likely just very lazy. Actually 28* is aggressively high for these engines.
2. The VE table shows the highest values, which corresponds to the highest torque in the 4400 RPM column, exactly the same as a stock cam. With your hot cam it should be more in the 5200 or even 5600 column. Again, the tuner was lazy.
3. The PE table has a very lean 1.13 starting at 4000 RPM. Many people here have found that 1.16 to 1.18 is best up to max torque and then perhaps leaning out a bit.
Now it is possible that he enriched everything somewhere else, but IMHO that would be non-standard. In any case you don't lean out until after max torque which with your cam is around 5600 RPM.
With the 28* advance and the lean PE table and lean VE tables near your max torque, I suspect you are getting a bunch of Knock retard. You might not hear it, but a log will show it.
In short, IMHO the combination of these issues is costing you a lot of torque; maybe 40 ft/lbs.
Again, I'm no expert, and if an expert refutes everything I wrote, I will go and have myself spanked.









