Tuning for improved highway mileage
#1
Tuning for improved highway mileage
Have any of you guys bumped up the timing in the 40-70 load range, 2k-4k rpms? That's pretty much the highway cruising part of the map. I'm currently running the stock values for timing in that range, but I'm a bit hesitent to increase the timing due to the crap 91 cali gas I'm stuck with. Eh, I guess I can be the first to try!
Just wanted to see what experiences anyone else has had.
Just wanted to see what experiences anyone else has had.
#4
For those that were wondering, I just compared the stock high octane and low octane ignition maps for my 05. They have the same values for 40 and 50 load in the 3k-4k rpm range, 1 degree less timing at 3k rpms for 60-70 load (for the low octane vs. high), 2 degrees less timing for 3.5k-4k rpms.
I just bumped up the timing from stock in the 40-70 load range, 3k-6k rpm range by 2 degrees. Guess I'll find out tomorrow on the highway how it likes it (on my drive to visit family, so I'm not 'wasting' gas). Oh, and I was already getting 24-25mpg hwy with 70-80mph cruising, with a little bit of drafting
#5
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Why would you be 'going through the gears' tuning for highway cruising? It's in the 40-70 load range, mostly 3k-4k rpms; i.e. light throttle, just cruising.
For those that were wondering, I just compared the stock high octane and low octane ignition maps for my 05. They have the same values for 40 and 50 load in the 3k-4k rpm range, 1 degree less timing at 3k rpms for 60-70 load (for the low octane vs. high), 2 degrees less timing for 3.5k-4k rpms.
I just bumped up the timing from stock in the 40-70 load range, 3k-6k rpm range by 2 degrees. Guess I'll find out tomorrow on the highway how it likes it (on my drive to visit family, so I'm not 'wasting' gas). Oh, and I was already getting 24-25mpg hwy with 70-80mph cruising, with a little bit of drafting
For those that were wondering, I just compared the stock high octane and low octane ignition maps for my 05. They have the same values for 40 and 50 load in the 3k-4k rpm range, 1 degree less timing at 3k rpms for 60-70 load (for the low octane vs. high), 2 degrees less timing for 3.5k-4k rpms.
I just bumped up the timing from stock in the 40-70 load range, 3k-6k rpm range by 2 degrees. Guess I'll find out tomorrow on the highway how it likes it (on my drive to visit family, so I'm not 'wasting' gas). Oh, and I was already getting 24-25mpg hwy with 70-80mph cruising, with a little bit of drafting
#7
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I think that carbon guy was saying you can save the gas at cruise but all it takes is a moments aggravation or hurry and your back where you started.
I'm doing the open loop cruise mod, there are a couple of threads in ecuflash forum about doing this option. Even one that is based on a wide band emulating the narrow band, with a gas saving attitude.
Whichever way you go I don't think you will find lots of money left over when you fill up. Its like percents of percent. Every bit helps though.
I'm doing the open loop cruise mod, there are a couple of threads in ecuflash forum about doing this option. Even one that is based on a wide band emulating the narrow band, with a gas saving attitude.
Whichever way you go I don't think you will find lots of money left over when you fill up. Its like percents of percent. Every bit helps though.
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#8
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I just set up my LC-1's 1v output as the O2 source for my closed loop operation. I've got it leaned out to about 15.7:1 currently. The next time I take a trip I'll have something to report.
I had done the lean cruise mods before by forcing open loop and was running between 15.7 and 16.1 ... I got 320 miles on a tank at best. I can't remember the gallons on the next fill up, but that would likely be around 23-25 MPG. Not too shabby.
I had done the lean cruise mods before by forcing open loop and was running between 15.7 and 16.1 ... I got 320 miles on a tank at best. I can't remember the gallons on the next fill up, but that would likely be around 23-25 MPG. Not too shabby.
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I use the LC-1 at 15.5 - have my closed/open loop crossover higher so I can go into part throttle boost and still stay in closed loop, helps get the car up and moving from a light. I also added timing to the part throttle areas and I get less knock than on the stock timing at part throttle.......Also the car drives so smooth, very impressed so far in my part throttle tuning adventure.
I recently went on a trip w/ my gf, trunk loaded with our crap - the trip was part highway/city/country roads and I traveled 326 miles on 12.1 gallons of fuel.
26.9 MPG - I also live in PA (Hills & Mountains out the ying yang)
I honestly don't think 30 mpg is out of the question or close to it with less weight in the car and all highway with minimal elevation changes.
- My next move is an 87 octane map for my m-f commute since i don't really rip on the car anyway.....thanks to map switching going from 87 during the week and 93 on the weekend is no problem at all.
- First though I must install my nisei front mount and injectors
I recently went on a trip w/ my gf, trunk loaded with our crap - the trip was part highway/city/country roads and I traveled 326 miles on 12.1 gallons of fuel.
26.9 MPG - I also live in PA (Hills & Mountains out the ying yang)
I honestly don't think 30 mpg is out of the question or close to it with less weight in the car and all highway with minimal elevation changes.
- My next move is an 87 octane map for my m-f commute since i don't really rip on the car anyway.....thanks to map switching going from 87 during the week and 93 on the weekend is no problem at all.
- First though I must install my nisei front mount and injectors
Last edited by travman; May 30, 2008 at 07:46 AM.
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With regards to changing timing at low load areas, I've tried it before. I can't tell any difference from feel. with data I can't see any difference either. I'm under the assumption that if you change the timing then a different throttle percentage will be required to maintain whatever speed+load you were at before the change. Maybe the change was but I never noticed it.
#12
Interesting about the open loop mod and also the wideband mod. I'm not inclined to modify the basic ECU function/strategy as far as the open loop mod goes, and no wideband, so I'm just trying to optimize the timing maps a little
I ended up adding 2 degrees to the base timing from 2k-3k rpms also, 40-70 load range and didn't get any knock on the drive to work this morning (city streets so mostly 2k-3k rpms). Well, I did get some in the 100-120 load range... Hopping onto the highway tonight, so I'll see how it does in the 3k-4k rpm range.
Regardless, I also have the motorcycle for gas mileage, but figured I might as well optimize the car some
I ended up adding 2 degrees to the base timing from 2k-3k rpms also, 40-70 load range and didn't get any knock on the drive to work this morning (city streets so mostly 2k-3k rpms). Well, I did get some in the 100-120 load range... Hopping onto the highway tonight, so I'll see how it does in the 3k-4k rpm range.
Regardless, I also have the motorcycle for gas mileage, but figured I might as well optimize the car some
#13
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I just set up my LC-1's 1v output as the O2 source for my closed loop operation. I've got it leaned out to about 15.7:1 currently. The next time I take a trip I'll have something to report.
I had done the lean cruise mods before by forcing open loop and was running between 15.7 and 16.1 ... I got 320 miles on a tank at best. I can't remember the gallons on the next fill up, but that would likely be around 23-25 MPG. Not too shabby.
I had done the lean cruise mods before by forcing open loop and was running between 15.7 and 16.1 ... I got 320 miles on a tank at best. I can't remember the gallons on the next fill up, but that would likely be around 23-25 MPG. Not too shabby.
#15
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Interesting about the open loop mod and also the wideband mod. I'm not inclined to modify the basic ECU function/strategy as far as the open loop mod goes, and no wideband, so I'm just trying to optimize the timing maps a little
I ended up adding 2 degrees to the base timing from 2k-3k rpms also, 40-70 load range and didn't get any knock on the drive to work this morning (city streets so mostly 2k-3k rpms). Well, I did get some in the 100-120 load range... Hopping onto the highway tonight, so I'll see how it does in the 3k-4k rpm range.
Regardless, I also have the motorcycle for gas mileage, but figured I might as well optimize the car some
I ended up adding 2 degrees to the base timing from 2k-3k rpms also, 40-70 load range and didn't get any knock on the drive to work this morning (city streets so mostly 2k-3k rpms). Well, I did get some in the 100-120 load range... Hopping onto the highway tonight, so I'll see how it does in the 3k-4k rpm range.
Regardless, I also have the motorcycle for gas mileage, but figured I might as well optimize the car some
For the post above ... you are correct. Just changing the open loop maps will not lean out cruise or idle conditions. You have to modify the "open loop load" or "open loop throttle" tables to change the crossover point and then you can tune the curise areas.