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Low low end power - High timing retard.

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dikidera
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Post by dikidera »

S60 2005, 140->170hp with Magnetti ETM

For a while now I've experienced low low end torque. So much so the car feels dead before 2000 or so rpm. My diagnostics have established that the car routinely has between 5 and 10 degrees of timing pulled most consistently, with or without premium fuel across the RPM range.

Image

Base spark is what the ECU would command if all conditions are perfect. Actual spark is where we are at actually and KCS retard is knock compensation due to some form of detonation/pinging or false knock being detected.

But this graph shows something else. Between 750(idle) and 1200 rpm, the car has negative timing when I mash the pedal aka launching, despite positive being requested. Then at the 1000 rpm mark is where knock compensation also kicks in and makes me go negative.
Problem is this robs me of power down low and makes quick take off in roundabouts or heavy traffic areas almost impossible.

I was wondering if anyone has a clue why not just down low, but across RPM range I would be getting so much knock compensation, unaffected by premium fuel.

vtl
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Post by vtl »

Quick take off on AW55?

chrism
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Post by chrism »

What would happen if you unbolted the knock sensor from the block (but still connected to the wire)? Would you still get all that knock compensation?

dikidera
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Post by dikidera »

vtl wrote: 27 Aug 2026, 07:33 Quick take off on AW55?
It will happen, it can...I am sure of it. Right now it is too slow, like you can tell its not normal and my logs prove it.

vtl
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Post by vtl »

dikidera wrote: 27 Aug 2026, 10:15
vtl wrote: 27 Aug 2026, 07:33 Quick take off on AW55?
It will happen, it can...I am sure of it. Right now it is too slow, like you can tell its not normal and my logs prove it.
When I push pedal on my 2.5T from standstill, the RPM jumps to above 2000 instantly. Not sure what the engine is doing at around 1000 RPM is important to the process, since it happens in a fraction of a second.

What did you do? Just reflashed ECM? B5244S and S2 camshafts are the same?

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