Timing advance (aggressive set up)

[fassi1]

I managed to test timing advance table just before rr meet at Eurospec on 22nd which is 1 degree greater for load 120+ than what I was running on the day of rr meet on the dyno.
Below we have: timing advance table, difference between custom table and stock high octane table, knock log table, AFR log table.
It only started knocking above 6700rpm but there was definitely slithly too lean AFR 12.7-13.5
Apart from that there is no knocking at all. I wonder what would be the result on the dyno.
There is still more to dig out of it with tiny adjustments.

[Davezj]

this is great info, it looks like you have done a lot of testing on this, there is a lot of timing added right across the table.
this is going to be a great place for me to aim for.

so as a start point, i was thinking of using your difference table and taking 2 degrees off each of the changes, test it see what happens when i log this and then move up one degree test it and see what happens.


i do have one question for you chris, Why don't you use kenneth's rom 1.03 it has extended fuel and ignition timing tables. it would give you a much larger area of table to play with in the 100 to 280 load area.

Kenneth's rom table size.jpg

[lateshow]

Actually good question. I have suspected the lookup function to perform - well - a bit oddly. I don't have a good log file to present but sometimes I could swear that it reads from a load column that has smaller load. At least in our flexifuel and I have traced it back to the original lookup (can't tell is the original or did Kenneth made it). The original vr4 rom however uses neatly just the advance you want. So fassi1: You must have logs with timing advance: just examine that it is just what you "ordered".

Going too far with less knocking fuel could be a bad thing. But waiting for your dyno results

[fassi1]

Actually good question. I have suspected the lookup function to perform - well - a bit oddly. I don't have a good log file to present but sometimes I could swear that it reads from a load column that has smaller load. At least in our flexifuel and I have traced it back to the original lookup (can't tell is the original or did Kenneth made it). The original vr4 rom however uses neatly just the advance you want. So fassi1: You must have logs with timing advance: just examine that it is just what you "ordered".

Going too far with less knocking fuel could be a bad thing. But waiting for your dyno results

Yes Lauri I do have logs with timing advance and lots of other data.
I can't upload full log file but I did 2 screen shots with 3rd gear runs just like on dyno.
I didn't use Kenneth's rom for simple reason. I didn't want to use ready prodact, I wanted to develop my own rom which includes all common changes and my custom changes based on testing. By looking at log file it looks like ECU picks correct table cells so it applies correct timing advance.
It is always risky when doing fine tunning which means getting closer and closer to danger zone, but if you don't take the risk you will never achieve it.
I could wait months or years for somebody to test it and post up some results and ready tables but I'm not so patient.
All my changes were always followed by testing and logging so I never did some stupid adjustments without testing it hoping for huge power gains.

My results are here
http://www.clubvr4.com/forum/showthr...ch-2014/page11

[Davezj]

Actually good question. I have suspected the lookup function to perform - well - a bit oddly. I don't have a good log file to present but sometimes I could swear that it reads from a load column that has smaller load. At least in our flexifuel and I have traced it back to the original lookup (can't tell is the original or did Kenneth made it). The original vr4 rom however uses neatly just the advance you want. So fassi1: You must have logs with timing advance: just examine that it is just what you "ordered".

Going too far with less knocking fuel could be a bad thing. But waiting for your dyno results

Lauri,
slightly off topic i know but i thought i would ask.
when you chnage the ignition and fuel tables do you change both Hi 1 and Hi 2 octane tables or just one of them. i am asking this because i seem to remeber a thread suggesting the Hi 2 could be a table designed to run with if other stuff occurs, like air con is on, or something like this. effectively having one switchable map. I might even have been you that proposed theis originally.

i was just wondering if you were only changing one of the Hi tables which is why you don't seem to get the value you asked for as the ECU is switching between these 2 Hi tables.

this is only a theory as i have never found a reason/explanation as to why there are 2 Hi and 2 Low tables, apart from switching between them.

[Trotty]

Iirc I read somewhere they are hi &low octane maps. I know it is possible to manually switch these maps by grounding certain pin outs in the ecu

[Davezj]

Iirc I read somewhere they are hi &low octane maps. I know it is possible to manually switch these maps by grounding certain pin outs in the ecu

what i was refering to is there are 2 hi octane tables and 2 low octane table for fuel and ignition. i know due to various perameter (knock amonst others) that the ECU interpolates between the hi and low octane tables depending on the (knock value amonst other things) to ensure the engine is not put at risk. the only time the engine runs on the hi octane table fully is when there is no knock at all and all other perameters are within acceptable limits, so the ecu continuosly interpolates between the hi and low table but i don't know when the other hi and low octane tables are used.
The have always understood the accepted method of modifying the fuel and ignition tables is to change both hi octane tables to be the same and both lower octane table so they are the same. due to not knowing why there are two of each.