E39 lfx kr

[gmh308]

If there are now 2618 pistons in the motor you will need to turn up the knock noise thresholds per cylinder. >> EDIT - Just saw you turned up the noise floor already. You could keep turning it up until you hear real knock (like Joe mentions) to establish whether you have real knock or not - the 2618's will handle it ok.

It depends whether they have offset pins as to how noisy they really are. "Dont you just love the sound of piston slap in the morning"

[joecar]

"...it smells like victory"

[gmh308]

"...it smells like victory"

ROFL. You got it Joe!

[Rhino79]

Could the kr pid be wrong or could the ecm's kr strategy be different than what we are used to seeing? today on the dyno, I had a flat 15* timing commanded and I had a spike at 5500 rpms where it said 5* of kr but it only pulled about 1* from commanded timing........Ill log with the mdi tomorrow first thing to see if anything looks different.

[GMPX]

Actually I think the final timing you are seeing is not taking in to account knock retard, I remember seeing that on our E39 car as well. So although the PID might be wrong, it is what it is, we can't change how the ECM reports timing via the PID.

[Rhino79]

SO i logged some on the dyno with the mdi today. At one point it showed 4.9* kr, Im commanding 18* and it only dropped it to 17*, sometimes it didnt drop at all. I have verified the kr and timing pid in efi read exactly what the mdi does. One benifit of the mdi was to see which cylinders it was triggered by, which I still dont buy into. Im running almost 10* less timing than the stock table on 9 psi, meth, and 1.5 less compression. Oh well , the pistons are forged, plugs look good, and it picked up 100 rwhp from 10* of timing to 18* and I was showing the same kr at 10* as I am at 18*. Gonna tidy up this 93 tune for the customer, then move on to e85. Will keep posted

[Rhino79]

501 rwhp on 93 octane, meth, and 15 lbs! E85 tomorrow!

[GMPX]

Yikes!

[Rhino79]

E85 is a no go, the di pump maxed out. SO tomorrow is race gas, and more boost! The 93 octane ended up at 532 rwhp, 450 rwtq!!

[Boost]

FWIW, my Cruze on a bone stock tune and 93 octane knocks terribly and audible. I made a high horsepower / boost tune where I actually sensitized it and it kept up with an Abarth to 110 mph with no knock. My worst knock always occurs at part throttle (burst?)

So back on topic I agree that it almost seems like audible knock is a design feature on some of these. How terrible...

I am still looking for a scientific article that is allegedly out there that claims knock is beneficial in cleaning carbon