Low Load/Cruise Timing?

sponners · Nov 5, 2009, 11:24 AM

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?

JohnBradley · Nov 5, 2009, 11:26 AM

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.

dude · Nov 5, 2009, 11:59 AM

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.

sponners · Nov 5, 2009, 02:11 PM

isn't maximising torque maximising effiency?

.....just wondering if anyone has any methods for getting close to MBT on the road?

rolly1818 · Nov 5, 2009, 07:19 PM

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).

evonut270 · Nov 5, 2009, 09:08 PM

Quote:

Originally Posted by rolly1818

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).

take it this is done by altering the open loop low load points?

SWOLN · Nov 6, 2009, 11:49 AM

What periphery for open loop again ?

rolly1818 · Nov 6, 2009, 01:15 PM

go to evo ecu wiki search it on google.

it has all the bit information

todd6027 · Nov 6, 2009, 02:36 PM

Quote:

Originally Posted by SWOLN

What periphery for open loop again ?

full time open loop,Ecu Periphery FAA set bit4 to 0

sponners · Nov 7, 2009, 02:02 PM

on this thread I'm after info on low load ign timing for better economy (forget the fuelling for now)