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Rich AFR causing knock? Issue with knock setup?


M1tch
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Hi all,

Currently doing some road tuning with my Link, I seem to keep coming up with an issue where the knock control keeps coming on and pulling timing, I have a feeling it might be a false positive as it coming on at sometimes only 10 degrees advance and I have pulled a lot of timing out of my map.

I have attached a log of the last logged run, knock control is set to 7khz as I believe the 79mm bore knocks at 7.3khz, my MAP sensor is reading full vacuum in the high 90s on WOT - on WOT the fueling seemed to drop to around 10.5:1 however I am unable to tune these cells as the knock control was active so it doesn't seem to log it on the mixture map.

Is there an issue with my knock protection settings? Does running rich trigger the knock control? Please also note that the speed isn't reading correctly and the coolant temp is around 7c too cold vs the sensor reading.

Basically just need a hand trying to see if I am getting a false positive on the knock readings as I really don't think the engine is knocking - previous tune on the PFC has ignition advance at around 32 degrees with very little knock.

Initial new basemap.pclr

 

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I am guessing there isn't a way to road tune the car using the narrowband knock sensor to get in the ball park? I know it won't be perfect without a dyno and better equipment but was able to get a rough idea where the limits were on the stock knock sensor and the PFC.

The fueling is pretty much there now with the majority of cells being within a small margin of error vs the AFR table.

I am tempted to copy over some of the tables from the basemaps for the ignition and VVTi - at least I know those values would be safer?

I noticed that on the 350z map the ignition timing at the top end at full vacuum is at around 22 degrees whereas I have retarded my map back to around 10 at the top end - have I retarded the map too far?

It's about the same on the Monsoon basemap, I am happy with my fueling table as well as idle, cold start etc even without closed loop enabled at the moment, should I:

  • Copy the ignition table from the Monsoon basemap
  • Copy the VVTi inlet table from the Storm black basemap or 350z basemap

I will be getting a decent Bosch doughnut knock sensor - issue being is that its impossible to get to at the back of the engine, will be swapping it out when I put in the new engine - the current engine is simply a test bed as its high mileage so not too concerned if something happens as its a learning platform for me to get the Link all setup ready for the new engine. Is the knock logged if the knock control is turned off btw?

Really sorry for all the questions, I know there was a marked step up in drivability between the stock ECU and the Power FC when tuned, currently the Link feels like its holding back a bit and I know its probably around ignition looking at the PFC map I have. I think my issue is slightly compounded by the fact that the engine is high mileage as well as the gearbox so there would be additional noises and resonance going through the engine which doesn't help!

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39 minutes ago, Adamw said:

Is this an NA engine?

 

Its an NA engine, I will be turboing the new engine (fully forged) at some point but will initially also be run as an NA - will be going to a tuner when I do go turbo on the engine though. Just looking to get a solid map running on the car that might not be 100% fully maximising the engine but will still be a step up from the OEM ECU.

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A modern 4 valve pent roof NA engine like this will not be knock limited with typical pump gas and intake air temps.  What that means is there is no point using knock detection to tune the ignition table as peak torque (optimum advance) will be achieved well before knock occurs.  Even if it was knocking you are unlikely to do any harm - it will need sustained long term knock under significant load to hurt it.

I would expect it will want somewhere around 25 deg advance at the torque peak (say 4500), ramping up to say 28 at redline will be a reasonably safe place to be.  The Monsoon sample map ignition table would be fine. 

 

 

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20 minutes ago, Adamw said:

A modern 4 valve pent roof NA engine like this will not be knock limited with typical pump gas and intake air temps.  What that means is there is no point using knock detection to tune the ignition table as peak torque (optimum advance) will be achieved well before knock occurs.  Even if it was knocking you are unlikely to do any harm - it will need sustained long term knock under significant load to hurt it.

I would expect it will want somewhere around 25 deg advance at the torque peak (say 4500), ramping up to say 28 at redline will be a reasonably safe place to be.  The Monsoon sample map ignition table would be fine. 

 

 

Thank you, I am running high octane fuel as well which is why I was wondering why it was showing knock at quite retarded ignition timing, think it might be a false positive - I was thinking mid to high 20s would be about right for ignition advance as you mention - will turn the knock control off until I swap out to a better sensor and start to look at running boost.

Should I update the VVTi table as well or just see how the monsoon ignition map runs first? I know the VVTi table isn't something you want to mess with etc.

Thanks again for your help on this!

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44 minutes ago, M1tch said:

Should I update the VVTi table as well or just see how the monsoon ignition map runs first? I know the VVTi table isn't something you want to mess with etc.

Copy the Inlet VVT table out of the V10 WRX map, this will be better than zeros.

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2 hours ago, Adamw said:

Copy the Inlet VVT table out of the V10 WRX map, this will be better than zeros.

Many thanks, I have copied over the Monsoon ignition table into my current map, turned knock control off, I have also noticed that there is a setting that seemed to be advancing the ignition timing when the engine was cold/warming up - its retarding the timing top end which is correct but have zeroed out the timing advance when cold. I have kept the VVTi table as it is - there are some tuned valued in there from the file sent over from the engine it was tuned on.

Next on the list to sort is the temperature gauge - its out by around 8 degrees C and also the speed source, will be looking to use an ABS sensor to get the direct signal (although its a 48 tooth ring) - DI1 speed source is already in MPH but I can't seem to be able to use it. I have set the calibration to 1.6 as there are around 1.6 km in 1 mile (the speed source arrives from the ABS ECU as 1hz = 1mph - rather than the frequency of the actual ABS ring). Looks like I will have to get the actual sensor data from the ABS ECU to be able to use traction control though.

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