Ignition tables

[skiptownmcat]

Is there a timer to control the rate of advance? Could we set a quick advance time an then just increase the max values for any benefit?

[mituc]

while we're waiting.. can you guys share your OL timing tables? with the loads you're reaching

Take a look at the Base 93/98 for High Flow downpipe. That one has pretty aggressive timing (the most aggressive timing from all OTS maps) and I used it for a while. I only got some light ignition retard at very low load values, below the 0.6 area and I had to adjust that just a touch. You have mine attached along with a Cobb SRI maf cal - in case you need it.

[mrQQ]

why are CL tables lower than OL? why are some of the Max'es lower than Normals?

In CL operation, you are more likely to be cruising at a steady state and move towards the "Max" timing table values. In OL operation, you are most typically accelerating and not operating at a steady state. So, in OL, you are less likely to move towards the "Max" table. The "Max" name is a bit of a misnomer since there are some places where the values are lower than the normal table. Very low load decel is a case where it has higher timing on the normal tables.

but even Max tables in CL are lower than the OL counterparts.. does that mean that better fuel economy is achieved at lower advance?

[mrQQ]

also, do you have any clue as to why the ignition map seems to be all other the place - i've tried graphing different load advances vs rpm, and different rpm advances vs load, and they don't follow any kind of pattern.. 1.5-2 load series seem to be the same pattern over rpm range, but lower load series just look like random, they jump around, intersect, etc

i'd like to make sense of what's the logic behind all of this..

[Steve @ VersaTune]

The oems do computer modeling to build a base then they do dyno testing with in-cylinder pressure transducersto determine optimal timing. Things like fuel pressure and chamber turbulance affect optimal timing too. The best that we can do is dyno test and monitor for knock.

[Sassimac]

Hello All...

The approach I took to set advance was to use the ECU's own logic to some advantage.

Armed with the theory the ECU will in CL mode move from the normal table to the max table, I gave the normal table only a few degrees in the range 1500-300rpm, loads 0.8 - 1.6. This was to give me better part throttle acceleration as the CX7 can be sluggish. The rest of the table is standard. However, the max table I addedd 5 degrees to the 1500-3000rpm range in the low load area. This is the cruise range. The idea is to let the ECU grab as much timing as it wants in the cruise range. If it knocks, it will retard as it wishes.

Remember, it starts at the normal table and seeks to move towards the max table.

Currently, the car returns awesome economy consistantly. It has great acceleration, and part throttle pull.

[mrQQ]

while we're waiting.. can you guys share your OL timing tables? with the loads you're reaching

Take a look at the Base 93/98 for High Flow downpipe. That one has pretty aggressive timing (the most aggressive timing from all OTS maps) and I used it for a while. I only got some light ignition retard at very low load values, below the 0.6 area and I had to adjust that just a touch. You have mine attached along with a Cobb SRI maf cal - in case you need it.

you forgot to attach the file also, 93/98 high flow seems to have almost standard timing table, only with few cells adjusted. are you sure you're talking about that one?

[mrQQ]

The oems do computer modeling to build a base then they do dyno testing with in-cylinder pressure transducersto determine optimal timing. Things like fuel pressure and chamber turbulance affect optimal timing too. The best that we can do is dyno test and monitor for knock.

do you suggest, when increasing timing, to cover all the range, or just the WOT range? I'd prefer to improve performance in all the scenarios, however, with, seemingly random timing, it's very difficult to do so..

[mrQQ]

Armed with the theory the ECU will in CL mode move from the normal table to the max table, I gave the normal table only a few degrees in the range 1500-300rpm, loads 0.8 - 1.6. This was to give me better part throttle acceleration as the CX7 can be sluggish.

are you talking about CL or OL table? or CL/OL transition table? did you add few degrees to all the cells, or did you do percentage increase? can you show your table?

[Sassimac]

Hello There...

I am only talking about CL tables.

Most of my driving is on local roads, so I do not need to focus on 6000rpm. Anyway, on a CX7 auto that rpm is pretty much useless and almost never used. So I decided to consider the CL tables for economy and all round driving performance.

1: I added 3 degrees in the 1500-3000rpm range in the 0.8-1.6 load area as this is where I logged part throttle acceleration. This was applied to the CL normal table. NO OTHER cells were changed. I ONLY did this as the CX7 is a sloth in this RPM range. I believe you can leave this table basically stock. If you want to "perk" up this low part throttle, log the rpm and load when you part throttle accelerate. This will tell you what rpm/load points to add timing.

2: I added 5 degrees to the 1500-3000rpm range in the low load (cruise) range to the CL max table. This is to allow the ECU to grab as much timing as it can to help increase economy.

You can download my version 1.14 file from my CX7 thread. However, it is a CX7 file, and not Speed3.