Lowering knock sensitivity [Archive] - Mitsubishi Lancer Register Forum

Lowering knock sensitivity

Stu VI
31-03-2009, 15:38
I am getting phantom knock in the low load from 2000-3000 rpm off boost.

It has been checked with det cans and is definately phantom knock.

Is it possible to lower the knock sensitivity in this rev range?

Cheers

johnbanks
31-03-2009, 15:42
If you are running an Evo 7-9 ECU and Ecuflash - yes.

Stu VI
31-03-2009, 15:44
Hi john, I am running the VII ecu with tephra mods.

It just seems to happen now and again, just slow flashes on the CEL.

johnbanks
31-03-2009, 16:19
There is a monster thread on this on evolutionm.net, I think I put up the info for 90550001. http://forums.evolutionm.net/ecuflash/382625-knock-control-load-vs-rpm-table-found.html

sponners
31-03-2009, 16:24
I think in load load areas the knock sum needs to be a lot higher than normal before it affects timing

grayw
31-03-2009, 16:25
Is it lowering the octane flag?

johnbanks
31-03-2009, 16:27
Knock sum still reduces timing by the same amount, but the octane doesn't drop until slightly higher RPM as it is controlled by a separate RPM vs load table.

sponners
31-03-2009, 16:38
Knock sum still reduces timing by the same amount, but the octane doesn't drop until slightly higher RPM as it is controlled by a separate RPM vs load table.



ah, so we do need to try and filter this 'phantom knock' out.


....or is there a way we can alter the amount of timing pulled in that load area?

grayw
31-03-2009, 16:59
John, are you saying the timing reduces even though the octane flag stays at 100%, or were you answering Spooners:)

Knock sum still reduces timing by the same amount, but the octane doesn't drop until slightly higher RPM as it is controlled by a separate RPM vs load table.

johnbanks
31-03-2009, 19:28
Yes, timing reduces in response to knock sums even when octane stays at 100. About 1/3 of a degree per knock sum, I calculated the exact value somewhere on evom. There is a spot where knock sum is working before octane adjustment is active as well, they don't turn on at exactly the same RPM.

You don't always see a change in timing because the logging is only to the nearest degree, but internally, it is trimming to about 1/3 of a degree.

grayw
31-03-2009, 19:36
That's interesting to know, did not realise it trimmed by such a small amount. Are the thresholds the same for all roms, or is it dependant on the base noise levels?

You don't always see a change in timing because the logging is only to the nearest degree, but internally, it is trimming to about 1/3 of a degree.

Oracle
31-03-2009, 19:50
open air filter causes false knock at those rpms too.

johnbanks
31-03-2009, 20:04
That's interesting to know, did not realise it trimmed by such a small amount. Are the thresholds the same for all roms, or is it dependant on the base noise levels?

The retard is the same across all ROMs I've looked at.

Thresholds are similar between ROMs, they are load and RPM based for whether knock control and octane control are active, not noise based.