A friend of mine self-tuned his car and I datalogged it for him and got some interesting results.


I have a datalog included below of what I consider the pertinent info.
I have a pic of his fuel and timing maps (high octane)

I'm curious to see what y'all would do to change his tune.
Since he doesn't have a wideband, my initial thoughts are to decriment his fuel values at the LoadCalc values where there is knock.
And then to retard some timing (decriment values) as a safeguard.

Suggestions?

 

maybe some where it is knocking above 5 retard the timing alittle!?

 

Show us the narrowband o2's to see if thats the culprit for the knock.

 

Was that a guess?

Err. What I'm looking for is just confirmation really...that my thinking is correct.

I'd find knock. Look to see the loadCalc and RPM.
Go to that part of the fuel or timing map and make adjustments.

 

Timing Changes I would do ..

7000/180 - 16
7500/180 - 16
11000/180 - 16
7000/200 - 14

AFR, dunno cause can't tell what kind of AFR's you're running..

 

Yes, do that.

And even if you're not in a certain load cell, it does effect your timing.

7000/180 = 17 degrees
7000/200 = 15 degrees
7000/220 = 14 degrees

The closer your 200~load cell goes to lower 200's your timing will be higher than if you're near 218 load - where it'll be lower as it transitions to 14 degrees.

 

the infamous 6800rpm knock, i have the same thing. after a lot of testing i'm pretty confident that it's phantom knock - but it's still hurting performance.

 

No knock 6800rpmish :O

 

Can you explain your thinking?
I don't have a clue why I'd look at narrowband 02 readings.

 

you're also running super rich - 10.5:1 at 6200rpm? what are your IDCs like?

 

You have no wideband so.. something is better than nothing.

O2 value of .89 is definitely leaner than .92. You seem to lean out at 6593 RPM.. just a instant before you crack 7 knocksum. Maybe you should add some fuel there.. make it read at LEAST .9165, maybe richer.

Narrowband O2 is not accurate but try it out and see if your knocksum lessens.

 

I can see the reasoning behind the changes you've suggested.
Except for the 6500/200 -14
Currently 6500/200 is at 15 degrees of advance and he gets 2 and 3 counts of knock right around there.

By the way, your response is much appreciated. I'm learning a lot.

 

That run wasn't that good, 99%~. Tis why my fuel pump is being installed tomorrow

 

Ahh. I see. You're trying to gauge the AF from the narrowband.

Yeah I suggested for him to get a wideband in there ASAP.
In the meantime, we may make richening adjustments asap.
I'm trying to finger out how much of a change will correspond to what sort of change in AF.

So if I go from a value of 9.0 (Af = 11.5) to 8.9, what sort of changes in AF will I be expecting?

 

I meant to type 7000/200 change to 14.

My bad, typo.