Engine timing questions.

[PunkST]

Do these cars have an external fuel filter? Or just the sock in the bottom of the tank? If we have one its another easy thing to check.

 

[AZSP33D]

The microphones on the engine are sensitive to the slightest micro knock, (perhaps even a little too sensitive) and the engine is very quick to adjust, and it’s designed this way to handle and learn an 87 octane fill up or a 100 octane fill up, and adjust as necessary.

Having it tuned to force a big adjustment is where it can be dangerous or too conservative depending on the direction. If you always see +6.0 it means that the tune is adjusting to the limit and will not adjust further, and the timing is too conservative for the fuel and conditions. Occasional slight plus or minus indicates a sweet spot for the mapping.

If your logging corrections for all 4 Cyl you can tune to adjust the timing per cylinder per RPM. Mine needed a little bit less timing on #1 and when this was set, all four were pretty much in sync... and the engine can at the same time add timing to one and remove timing from another.

The Octane setting is the indication of long term memory, and most tuners set this to start out at -1 after a clean flash.

There’s documentation online from COBB on this, if you would like to read more about it.

 

[M-Sport fan]

^^^I was always wondering just how sensitive the knock sensors are on these engines.
They were so 'hair trigger' on my LS1 Z28, that they were set off by the spherical rod ends/heim joints on the LG/Bilstein coil overs I had on that car knocking when going over bumps/road imperfections, despite them being located in the V-8's valley cover!

It got so bad that I had to replace them with some hard rubber bushed mounted Koni Sport yellows, converted to coil over (and I also just could not stand the 'jack hammer' knocking all by itself anymore, on the street).

WHY I would NEVER put a spherical rod ended damper/coil over setup on this car, or even use sway bar end links, or control arm joints with them.

 

[AZSP33D]

The sensitivity is adjustable and it’s probably reasonable to reduce it by 10-20 % but thats something I wouldn’t recommend for other people to try that’s for sure, and probably off topic for the OP, sorry. Tuning is a problem solving exercise... here’s the problem or limitation, what’s the solution. Seeing occasional small negative corrections is certainly not a problem from my perspective, but perhaps let’s look at all four cylinders if we want to find room for adjustment or improvement.