guys - just wanted to hear your view on this - my car seem to be knock prone when the throttle is "waving" and then goes into full throtlle - see attached picture - the light blue line is the TPS. Under this scenario it is very common for me to have 4-5 counts.

If I have constant throttle and then go 100% - on the pulls - no knock (or max 1-2).

Any idea what is going on there?

This was a 5th gear driving with some overtaking done

 

I sees no picture my friend.

 

for me, adjustment of the open loop tables made more of a difference. A lot of guys decrease timing in those 60-90 areas. Maybe try a little of both. But I would recomend decreasing your throttle open loop tables so your out of closed loop earlier.

 

sorry - picture is now attached in the first post.

lemmonhead - thanks - I will change the open loop throttle - to get into open loop earlier and I will check

 

Hmm, your timing is suddenly dropping, really fast from 41 to 17 degrees, and going from 14.16 afr to 11.6 afr. Thats some pretty fast changes all within the 0.4 second change.

I think lemmonhead might be right, try reducing the part throttle timing to make it more of a smooth transition.

I spent a lot of time doing part throttle timing to try and get rid of knock just like that.

And, your log shows 239.7kPa at 3720 with only 68.6% throttle. Is that 34.76psi at 3720rpm, or am I doing something wrong? If that's right, you went from 8.8psi to 34.76psi in 1.07 seconds. Damn.

 

That 239.7kPa is absolute pressure - so it means only 139.7 kPa boost (cca 100kPa is barometric pressure here) - so it is just 20.25 psi.

Thanks for the comments and directions - I will decrease the part throttle timing andmake it go open loop little bit earlier as well - will see what it makes.

 

any updates if it worked?

 

I have decreased the timing in the map from 38 to 37 and set open loop throttle to 35% (previously it was stock around 60%). I did a test ride and the problem seems to be gone (or at least did not occur during my tries to repreduce the same scenario).

One more question - any idea why the log was showing ign timing of 43 - where as in the map the max value was 38?

Thanks for the advice.

 

there is a thread on this topic of ECU adding timing.
https://www.evolutionm.net/forums/sh...d.php?t=318623
it might be related to your observation. But as long as your not knocking, i think its cool that the ECU adds timing for ya to get ya more power

 

Hmm - during some normal driving there have been again some occasions on knocking during these transitions. Somehow my car doesnot like to run on part-throttle....

http://www.disco3.co.uk/gallery/albu...13782/logs.pdf

 

well I guess you can try to take out 2-3 timing in those delicate areas, maybe add some fuel.

 

In my experience the smoother you can make those transition areas (fuel and timing), the less knock you will have there. Smooth out your fuel curve.. instead of going 14.7, 11.6, 11.1... try 14.1, 13.5, 12.2 11.1.

 

i dunno about adjusting the fuel that much, going from 11.6 to 13.5 is a pretty big jump, but if the wideband shows ok then why not try it.

 

The fuel map is not making this jump - however - when the load suddenly changes - it jumps over several cells. I am attaching my maps fyi - the logs shown above were with a Shell V-Power Racing fuel (claim to be at least 100 octane).

Surprisingly the log (attached) shows even some knock below boost (below 100 load)

 

Also, you might try tuning with lean spool disabled (you'll have ot retune your fuel map), For me taking that out of the equation helped tame the spool up areas.