Dyno timing issue
Moderator: Matt
Dyno timing issue
Hi... I had my z32 on the dyno for adjustments. When adjusting the timing on the dyno we where able to advance to 32 deg btdc with no knocking. I guess this is not possible.... On the road i had knocking with this value and we had to retard back to 22 deg btdc.... I guess something is retarding the timing when on the dyno. but i have no clue..??? Any suggestions??
Re: Dyno timing issue
When you do the dyno run (and road tune) take a log file in stream mode
Then playback the log and watch the 'ignition timing' in the 'trace' window. This will show you _actual_ timing which you can monitor against your timing maps
You can also do this live (on the dyno) and watch your timing gauge to make sure it is what the maps are showing. Z32 ECUs without feature pack also have knock timing maps, so make sure these have same values as the main maps
If the timing deviates from the maps, then ECU knock detection would be pulling timing back
Then playback the log and watch the 'ignition timing' in the 'trace' window. This will show you _actual_ timing which you can monitor against your timing maps
You can also do this live (on the dyno) and watch your timing gauge to make sure it is what the maps are showing. Z32 ECUs without feature pack also have knock timing maps, so make sure these have same values as the main maps
If the timing deviates from the maps, then ECU knock detection would be pulling timing back
Re: Dyno timing issue
Ok.. Makes sense.
But how come the ecu dosnt detect knock when on the road (go to knock map).... Could it also be temperature related, i mean if the cooling of the car is insufficient on the dyno, especially for the sidemounted intercoolers ??
And by the way... Thank you for very fast reply...
But how come the ecu dosnt detect knock when on the road (go to knock map).... Could it also be temperature related, i mean if the cooling of the car is insufficient on the dyno, especially for the sidemounted intercoolers ??
And by the way... Thank you for very fast reply...
Re: Dyno timing issue
I cannot tell you why it is changing to knock maps under only particular conditions. Logs files of road runs will indicate when it does change over, but it will not give you a reason
The only way would be seeing if different load / rpm points are being reached between dyno/road which can be likely and then seeing if there is detonation (listening on the road using knock headphones). Engine noise can also cause false positives and the ECU could use this as a factor
The only way would be seeing if different load / rpm points are being reached between dyno/road which can be likely and then seeing if there is detonation (listening on the road using knock headphones). Engine noise can also cause false positives and the ECU could use this as a factor