LeeE Posted November 29, 2021 Report Share Posted November 29, 2021 My GTR R33 is pretty much stock. I am attempting to configure knock control and want a knock free baseline audio recording. If I retard the GTR basemap ignition table by 5 degrees and run off actuator spring pressure boost of 0.7 bar (stock is 0.8 bar) would this guarantee a knock free run, assuming the base ignition timing and fueling are OK? I have attached the GTR basemap ignition table, both default and retarded by 5 Degrees for reference. I'd appreciate any ideas or feedback. Thanks Quote Link to comment Share on other sites More sharing options...
Adamw Posted November 29, 2021 Report Share Posted November 29, 2021 Yes, that would likely be knock free on stock compression ratio and common "western" fuel. Note however, when you increase advance the engine noise will increase, so this strategy of building a threshold based off a retarded run is not always very useful. LeeE 1 Quote Link to comment Share on other sites More sharing options...
LeeE Posted November 30, 2021 Author Report Share Posted November 30, 2021 Thanks Adam It is a stock compression motor using 98 octane fuel. At the moment I am only trying to establish what knock/no knock sounds like for this engine, not set a threshold. Would you expect this modified map to be knock free when running a boost of 1 bar (max) given the octane level of the fuel being used? Quote Link to comment Share on other sites More sharing options...
Adamw Posted November 30, 2021 Report Share Posted November 30, 2021 Our GTR base map came from a near stock car one of our tech support guys tuned on pump gas. I pulled a few degrees out of it already before making it a "base map". I cant remember how much exactly but from memory something like 3-5deg in the boost areas. LeeE 1 Quote Link to comment Share on other sites More sharing options...
LeeE Posted December 7, 2021 Author Report Share Posted December 7, 2021 Thanks for the reply. I've been attempting to induce some knock to compare to the audio recording from a previous run that should have been a knock free run. I've tried gradually advancing the timing for map rows 80 kPa to 120 kPa to a max as per the table below. However, other than being noisier, I can not detect any other difference to the knock free recording. Would you expect the timing table below to produce knock or am I going about this the wrong way? Quote Link to comment Share on other sites More sharing options...
Adamw Posted December 7, 2021 Report Share Posted December 7, 2021 I havent tuned an RB for a long time, but I suspect you would need more like 50-55deg @3000RPM, 100/120kpa to get some decent knock. LeeE 1 Quote Link to comment Share on other sites More sharing options...
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