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spark adder


will15
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This is an interesting one. It looks like ford have done something interesting to the ECT spark scaling table in HAEE4, I checked 4 of the stock files and they all are similar to this.

image.png.9ee418c489211241563282862e4b8282.png

image.png.9e938a28bbf62ed179557f5aa22db31d.png

At 68c you are 154f which would make it

((200-140) - (154-140)) / (200-140) = 0.76

0.76 * 40 degrees = 30.6 * 0.1 = 3.06 degrees timing

So 10 + 3.06 ~= your 13 degrees you are seeing

As 13.3 is less than your MBT table (~20 degrees) this all makes sense. This is why some people make their MBT identical to their Borderline table.

So it looks like this is your problem. 

as the MBT table is calibrated at 200F it makes sense that you can run an extra 4 degrees of timing at 140F, the -18 (1.8 degrees) would be for cold start/emissions purposes. Remember that these figures would have been for a stock turbo.

So easy solution is simple zero out all positive numbers in the IAT (auF0220) and ECT (auF0222) adder. It looks like you've already done that for IAT.

 

 

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16 hours ago, Roland@pcmtec said:

This is an interesting one. It looks like ford have done something interesting to the ECT spark scaling table in HAEE4, I checked 4 of the stock files and they all are similar to this.

image.png.9ee418c489211241563282862e4b8282.png

image.png.9e938a28bbf62ed179557f5aa22db31d.png

At 68c you are 154f which would make it

((200-140) - (154-140)) / (200-140) = 0.76

0.76 * 40 degrees = 30.6 * 0.1 = 3.06 degrees timing

So 10 + 3.06 ~= your 13 degrees you are seeing

As 13.3 is less than your MBT table (~20 degrees) this all makes sense. This is why some people make their MBT identical to their Borderline table.

So it looks like this is your problem. 

as the MBT table is calibrated at 200F it makes sense that you can run an extra 4 degrees of timing at 140F, the -18 (1.8 degrees) would be for cold start/emissions purposes. Remember that these figures would have been for a stock turbo.

So easy solution is simple zero out all positive numbers in the IAT (auF0220) and ECT (auF0222) adder. It looks like you've already done that for IAT.

 

 

Sweet thanks for that ford spark timing is a Weird strategy. Is there more info on spark timing and the tables, more of a how and why each table is used. I don’t really understand the point of the mbt table. All so can we change between f and c degrees. Cheers thanks for all your help.

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Regarding the borderline and MBT tables this is the reasoning:

If you use an 120 octane race fuel and find the maximum torque an engine can make then log the spark, this will be your MBT (maximum brake torque) table.

Then if you use 91 octane fuel (I think the US fuel is different again) and find the maximum spark the engine can take before knocking this is your borderline knock table.

Then you vary the lambda and see how much extra timing the borderline table can take and this creates your lambda spark table.

Now this may overlap, eg the borderline knock may be higher than maximum torque. Eg you canrun 50 degrees of timing at cruise however the vehicle will stop making more torque after about 40-45 degrees hence there is no point in running any more. The PCM takes the lowest value of these two tables for this reason.

The goal of all these tables and adders is so you can run the absolute maximum timing possible at all temperatures and load. Ford have done a great job of achieving this on a stock calibration, eg the car will run on the ragged edge of knock at all times getting maximum performance and maximum fuel economy (within emissions windows) on 91 fuel.

The issue with aftermarket tuning is you do not have the resources to hit each load cell at every single IAT and ECT combination to determine maximum torque and maximum timing. So you compromise and tune the vehicle for the worst case, this means in cold weather/transient conditions you are probably running far less timing than you actually could.

Setting the upper loads of the MBT and Borderline tables to be the same figures means you are safe in that you can be guaranteed the PCM will not ever run any more timing than this. It also means at low ECT/IAT temps you will be running less timing and hence less power than is possible.

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  • 1 month later...
On ‎7‎/‎28‎/‎2018 at 4:16 PM, will15 said:

hi im looking for a table that is adding spark to my base timing(power run about 3 deg), I have gone though all the spark tables I can find and zeroed them out to stop it. I am using the hp tuners scanner and when logging spark it looks like it is coming from timing advance and adding to border line knock.

alex fg ute pcmtech.tec 4.tec

check out the spark lamba blk correction table at 4000rpm and .7-.8 lamba it is adding 3 degs. I zero that table. or you just need to understand what is there will will explain the difference in the borderline knock number

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