Low Load/Cruise Timing?
Nov 5, 2009, 10:24 AM
#1
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Low Load/Cruise Timing?
Just wondering how you guys go about tuning the low load/rpm parts of your ignition map (to get best economy) on the road.
is a dyno the only way to get these parts of the map spot on?
is a dyno the only way to get these parts of the map spot on?
Nov 5, 2009, 10:26 AM
#2
I cheat.
I use the EGR advance map to do most of the work, but I will set the timing map "bvase" value at 35-38* and add 8* on the EGR map and let it do what it wants.
Couple it with open loop lean cruise or WB feedback determined lean cruise and voila its better than it was. 25-27 is my normal on the big turbo now with large cams. S1s and my 275s still saw 26ish with a Green.
I use the EGR advance map to do most of the work, but I will set the timing map "bvase" value at 35-38* and add 8* on the EGR map and let it do what it wants.
Couple it with open loop lean cruise or WB feedback determined lean cruise and voila its better than it was. 25-27 is my normal on the big turbo now with large cams. S1s and my 275s still saw 26ish with a Green.
Nov 5, 2009, 10:59 AM
#3
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Well I guess you wouldn't really need a dyno for what you're aiming for. A well calibrated wideband is all you need, then just aim for about a 15.5-16.3 to 1 AFR ratio. Like Aaron said above, there are a couple different ways to achieve the end goal.
Now, maximizing torque at low load/cruise is what you would need a dyno for. Most likely the eddy current variety to hold a certain load cell while you adjust your AFR and timing to produce the maximum tractive effort for that particular Load and RPM. Could be pretty time consuming, especially with bigmaps now, but the livetuning patch would make it a whole lot faster. Although I don't know if anyone has done this and posted their results, but even then, it would only serve as a very rough guideline since all cars and mods are different. YMMV.
Now, maximizing torque at low load/cruise is what you would need a dyno for. Most likely the eddy current variety to hold a certain load cell while you adjust your AFR and timing to produce the maximum tractive effort for that particular Load and RPM. Could be pretty time consuming, especially with bigmaps now, but the livetuning patch would make it a whole lot faster. Although I don't know if anyone has done this and posted their results, but even then, it would only serve as a very rough guideline since all cars and mods are different. YMMV.
Nov 5, 2009, 06:19 PM
#5
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i did exactly what aaron said, well he did it for me 
works great, i dont use the EGR part though, just get AFRs up (15.7 to 16.2 on a IX) and lock the car in open loop at that point (between 60 to 80 load).
works great, i dont use the EGR part though, just get AFRs up (15.7 to 16.2 on a IX) and lock the car in open loop at that point (between 60 to 80 load).
Nov 5, 2009, 08:08 PM
#6
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take it this is done by altering the open loop low load points?
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Nov 23, 2009, 08:50 PM
#11
I cheat.
I use the EGR advance map to do most of the work, but I will set the timing map "bvase" value at 35-38* and add 8* on the EGR map and let it do what it wants.
Couple it with open loop lean cruise or WB feedback determined lean cruise and voila its better than it was. 25-27 is my normal on the big turbo now with large cams. S1s and my 275s still saw 26ish with a Green.
I use the EGR advance map to do most of the work, but I will set the timing map "bvase" value at 35-38* and add 8* on the EGR map and let it do what it wants.
Couple it with open loop lean cruise or WB feedback determined lean cruise and voila its better than it was. 25-27 is my normal on the big turbo now with large cams. S1s and my 275s still saw 26ish with a Green.
Nov 24, 2009, 06:17 AM
#13
Are you saying I should just increase it on my main map? I already know how to do that and smooth it in. It just seems to me that more timing advance in the cruise area makes the car less snappy and smooth as it would be with less timing advance. Like right now I have 2 different maps that I will switch for either long distance driving or for more aggressive driving.
