NefMoto

Hello all,

I am loosing timing in the top end and it's not being caused by knock.  Is there a map/scale responsible for pulling timing out based on intake air temp?  I searched through the S4 Wiki and quickly on here and haven't come up with anything.

If there's anything else that would be pulling timing out?  Please let me know to check that as well.

For reference:

RS4 K04's
RS4 maf
RS4 injectors
RS4 intercoolers
RS4 Y-pipe
RS4 Airbox
044 Fuel pump

Thanks!
Nick

Logs?

Attached.

Mods added to original post in case that info is needed.

This is proactive to KR.

I can post the details when I get home, but you're better off advancing KFZW(2) if it's retarding for IAT and not knocking.

I did mess with KFZWOP/2 as well as KFZW/2.  Not sure if that may be hurting something...

I suggest that you stop "messing" with things.

Why did you modify KFZWOP(2)?

My point was that the IAT correction is pretty good as is in my experience. If there's more to be had at a specific load/rpm point, then it is best applied in KFZW(2) and preserving the IAT correction that will advance/retard ignition angle as needed.

Thank you for the suggestion.  I got the hint to "mess" with OP from a "professionally mapped" BIN file.  I will go back to stock OP timing maps and tweak KFZW/2 as advised.

I understand the point of IAT based timing adjustment however I wanted to adjust its strength.  I know from a tuning standpoint that the engine can have much more timing then it currently has at the given IAT and I am just curious as to where my timing is going in the top end when knock was relatively low in comparison.

When comparing it to other logs that I have from my APR software, the only difference I can see is IAT.  That's why I asked about that first.

The variable is dzwwl @ 0x380DA5 8 bit factor 0.75

The map is KFZWWLNM (nmot, tans) with load weighting factor FZWWLRLN (nmot, rl).

dzwwl also includes coolant temp correction KFZWWLRL (tmot, rl).

dzwwl = KFZWWLRL + (KFZWWLNM * FZWWLRLN)

Thank you and +rep.  I will do as advised and revert the OP maps first and go from there.  Then I'll tweak dzwwl if needed.

Thanks again!

If anyone else sees anything wrong in that log, please do advise.

Thanks phila. I really should add this to the tuning wiki.

odds are, you should just be able to increase requested timing, up until non-zero CF, which should more or less be the same for most IATs given the stock KFZWWLNM et al.

My requested timing in that log is much higher than actual in the top end though.  Almost 8* difference between 5000-6750.

That log has a TON of KR induced retard... nothing to do with IAT.

When comparing it to a log from my "safe and conservative" APR map the knock voltages arn't far off.  That's why I'm confused.

APR log attached.  Only HUGE difference is IAT... unless I'm missing something else.

Please advise.

Ignore voltages, they don't mean anything. Look at CF.

Heavily disagree.  Any knock means the engine is knocking.  For some reason the age old adage that CF is good and means you are making full power got locked in but IMHO its complete garbage.  Dont let it knock and it wont start trimming things and getting into different maps. 

I keep repeating this and eventually I will remember to take specific logs for it but it is very obvious once you tune this way, if you stay out of CF range you are actually riding the limit and making the most power on this car, your overall timing stays more consistent and actually higher.  You are seeing small det, once there is any CF, you are knocking and doing slow damage to your engine and immediate damage to power output.  When CFs are still at zero, there is KV, albeit minor and happy.  Try it.

I agree. In my experience, the closer to zero CF, the better your resulting timing will be, ESPECIALLY at peak boost. If you get any CF at peak boost, the rest of your pull will blow ass.

Keep your requested timing conservative; your butt dyno (and motor) will thank you for it.

I used to think along the lines ST said got "locked in" (CF is good!) but recently I have seen the light.

During extreme conditions (bad gas, overboost, high IAT) some CF is expected, but if it is cool and the car is running well, you shouldn't see any.

To clarify my post:

If you have a dyno, bump up requested timing until you see non-zero CF... then back it off until you start losing HP.... and initially you will GAIN HP.

Don't forget to reset adaptations between runs.

yup, we all use to tune to single digit CFs, like -9 was no big deal.  LOL, we were just not understanding it correctly.  homebrew days are where this got locked in as ok.