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voda1
June 1st, 2007, 07:42 AM
Knock sensor calibration

Upgrading pcv system for 97Vette to 04Vette where the valley cover contains the pcv valve and 2nd design knock sensors. The 2nd design knock sensor was introduced during 1998 model year. I've compared 3 stock .tun files for the 97,98, 99 Vette manual trans looking for any differences. The 97 and 98 values are the same, however, for the 98 file I don't know if it has the 1st or 2nd design knock sensor. Here is the list of the differences I found:
Year 97/98 99
B6223 Octane Scaler Threshold | 0.395508 | 0.593262 |
B6224 Octane Scaler Increment Rate | 0.002197 | 0.00293 |
B6225 Octane Scaler Decrement Rate | 0.007568 | 0.00293 |

B6204 Knock Retard Limit Not in PE Mode (Degrees)
@50 | 0 | 0.021973 |
@55 | 0 | 0.021973 |
@60 | 0 | 0.021973 |

B6210 Burst Knock Delta Air Mass (Grams)
This table not used in 97/98

B6212 Burst Knock Retard (Degrees)
All valves are 0 but the 97/98 use MAP values and the 99 used RPM

B6240 Knock Sensor Initial Threshold | 175.006697 | 244.995812 |
B6241 Knock Sensor Minimum Learned Threshold | 144.99683 | 210.001255 |
B6242 Knock Sensor Maximum Learned Threshold | 199.997966 | 244.995812 |
B6248 Average Background Noise Filter | 0.333008 | 0.100098 |

B5913 Spark High Octane Table
99 table contains 5 more columns.
The values used are all the same as the last column of the 97/98 table
additional 99 columns 1.04 1.08 1.12 1.16 1.2
Otherwise the values are identical.
B5914 Spark Low Octane Table

Read somewhere that the knock control in the PCM has its' own chip for knock calculations. Did that chip change between 97 and 99? Any suggestions as to what values I should change?