ca18det 3-4k timing drops

[mr_ca18det]

I wired a 1 meg ohm resistor to the comp and ground went for a test drive still same thing? Any ideas of anything else. I did find it will do it 4-5k or 5-6 when first spooling will drop to 10 degrees or below.

[raddy]

I have similar problem with timing drop in specify map area (similar to yours), but I dont think its knock related, I even dont think that ca18det ecu can pull out timing automatically when knock is detected...Anyway, my opinion is that this is (at least at my case) interpolation error at that area, becouse of biggers steps in TP columns and fast change of TP during spool up. As soon as ecu begin read same TP column, timing interpolation comes back to the map values, regardless of boost or timing set. In my case I need to raise TP in spool up area and also get out low load timing pretty fast, so cannot set really smooth transit area. In this area ecu calculate timing about 4deg less than values in map (I think that interpolation error is reason, it comes down from about 20deg to about 15-16deg for about 500-700rpm, than quickly back to map values). I can raise timing to any value in that area, it will allways resulted in that way... Before and after that area timing correlate with map values. Oh and my knock sensor probably doesnt work at all, as I get pernament knock sensor error, but as I described, it change timing in relation to map only in area of bigger TP steps...

EDIT: I just checked your logs and its really like I described above. Choose filtered timing values and than you can find that as soon as same (last) TP column is read, timing value begin to correspond with map value closely. Its OK until about 3400rpm, when TP begin to raise more rapidly and also map values decrease. At about 4100rpm it reach last column and interpolation is correct again. Try to use same timing value from TP 60 up to TP 88, let say fill it with 17 (13deg at max. is still pretty low timing) and carefully test it on the road...Only area with wrong timing calculation is 3400-4100rpm, all other parts are OK by my opinion...

[mr_ca18det]

Will try this after work today has this worked for you?

[raddy]

I still have small drop that I was not able to filter completelly, it last for about 300-500rpm, I cannot feel it really in car acceleration, but I would need more colums in map to make transition area more smooth...In your map you are using pretty conservative timing, I dont know your engine configuration, but for ca18det at power level around 350hp there is usually no really need to go under 17-18deg timing with at least 98octane fuel at spool up area, or even at max. torque area. If you can raise timing values safely in map, than this timing drop will be about same as delta, but from higher value, so resulted timing will be higher than before, and less noticeable, thats my experience.

[mr_ca18det]

I know its real conservative but i live in america we have 93 octane i'm not exactly sure whats the ron rating equivalent but once i get this sorted i will be heading to a dyno to further tune. I did have it up to 18-19 up top and it was running like a beast with no knock

[raddy]

I think that your 93 octane is equal to EU 98RON, here is abstract from wikipedia
However most European pumps deliver 95 (RON) as "regular", equivalent to 90–91 US AKI=(R+M)/2, and deliver 98, 99 or 100 (RON) (93-94 AKI) labeled as Super Unleaded - thus regular petrol sold in much of Europe corresponds to premium sold in the United States.
http://en.wikipedia.org/wiki/Octane_rat ... variations

[mr_ca18det]

there was a def improvement now it dips down to about 13-14 degrees which it doesnt bog as bad but is still noticable. can you send me a copy of your ca bin file so i can look at your tp scale and rpm to get and idea of what mine should be to further correc this.

[raddy]

Problem is that I was not able to filter out timing dip completely, as I mentioned before, I must use pretty steep TP scale and as there is fixed table resolution, I cannot do really nothing more with it, but I cannot notice it at the acceleration. What is important is to understand that this situation is not result of detonations and most probably its not automatic timing retard action from ECU. If we can believe that its due to interpolation error, there is only one way how to solve it-try use as smooth as possible TP/RPM scale at problematic area and also try to use increase timing values there to get acceptable interpolation result (in map it can look strange to have significantly increased timing in spool up area, but result of interpolation is important). In my opinion is good to have slightly retarded timing in boost transition area, so dip to 17-18deg is not bad thing...If you can get this, I would let it be...
Carefully test timing change at different acceleration condition to be sure that interpolated result is acceptable and safe.

[Matt]

Just make sure that you keep main and "knock" timing tables the same since they are both used (ie results from both tables used) when doing the final timing figure calculation. CA18 is the only ECU to do this with the timing maps

[raddy]

thats very usefull info Matt, anyway, at least in my case are both maps allways same. But this can add some more possiblity how to affect calculated timing.

[mr_ca18det]

So i should make the the load values closer together in the 3-4k spoolup range or space them out. Thats the only thing i'm kinda confused about and i use knock copy for both maps.

[raddy]

TP should be definatelly closer (check it at the IGN LOAD SCALE graph), same for cell values, ideally same value all around area of interest. But be carefull to not create another hole in the TP values, specially above 4000rpm. you can save some space at the low load areas.