39MPG, got it today!! |
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39MPG, got it today!! |
toon1 |
Mar 8 2015, 10:19 PM
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#1
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Senior Member Group: Members Posts: 1,849 Joined: 29-October 05 From: tracy,ca Member No.: 5,022 |
I've been working with Megasquirt with timing and Fueling. The car has been responding well to the changes.
I had to take a trip to the foothills today and decided to take the 914 and really test the changes. Most of the driving I had been doing had been around town so I wasn't sure how the car would respond to a long freeway trip. while cruising up hwy 5 the cht's were 340.....I pulled up Tuner studios and leaned out the area around cruise a bit. Suprisingly the CHT's dropped about 5 * and were stable. I kept the setting there and was wondering how this would be when I started climbing hills, again I was suprised how good the head temps were. nothing over 370(which was for a very short time) on the long climbs. I don't have my 02 sensor connected yet so I can't say what the AFR is. At the end of the trip, I drove 176miles and it took 4.5 gallons to refill....39.1mpg......NICE!!! |
barefoot |
Mar 9 2015, 10:53 AM
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#2
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Senior Member Group: Members Posts: 1,281 Joined: 19-March 13 From: Charleston SC Member No.: 15,673 Region Association: South East States |
I've been working with Megasquirt with timing and Fueling. The car has been responding well to the changes. I had to take a trip to the foothills today and decided to take the 914 and really test the changes. Most of the driving I had been doing had been around town so I wasn't sure how the car would respond to a long freeway trip. while cruising up hwy 5 the cht's were 340.....I pulled up Tuner studios and leaned out the area around cruise a bit. Suprisingly the CHT's dropped about 5 * and were stable. I kept the setting there and was wondering how this would be when I started climbing hills, again I was suprised how good the head temps were. nothing over 370(which was for a very short time) on the long climbs. I don't have my 02 sensor connected yet so I can't say what the AFR is. At the end of the trip, I drove 176miles and it took 4.5 gallons to refill....39.1mpg......NICE!!! From my combustion chemistry, max combustion tempeerature occurs at stoiciometric A/F, that is wheere exactly the correct amount of oxyger surrounds the fuel molecules , no more/ no less. Either richer or leaner from that and tempeeratures drop, so looks like you're now running a bit lean. Our modern direct injection gas engines run that way lots of the time, that's how imporved fuel economy figures are emerging. here's a graph: http://en.wikipedia.org/wiki/File:Flametemp.jpg Barefoot |
toon1 |
Mar 9 2015, 11:16 AM
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#3
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Senior Member Group: Members Posts: 1,849 Joined: 29-October 05 From: tracy,ca Member No.: 5,022 |
I've been working with Megasquirt with timing and Fueling. The car has been responding well to the changes. I had to take a trip to the foothills today and decided to take the 914 and really test the changes. Most of the driving I had been doing had been around town so I wasn't sure how the car would respond to a long freeway trip. while cruising up hwy 5 the cht's were 340.....I pulled up Tuner studios and leaned out the area around cruise a bit. Suprisingly the CHT's dropped about 5 * and were stable. I kept the setting there and was wondering how this would be when I started climbing hills, again I was suprised how good the head temps were. nothing over 370(which was for a very short time) on the long climbs. I don't have my 02 sensor connected yet so I can't say what the AFR is. At the end of the trip, I drove 176miles and it took 4.5 gallons to refill....39.1mpg......NICE!!! From my combustion chemistry, max combustion tempeerature occurs at stoiciometric A/F, that is wheere exactly the correct amount of oxyger surrounds the fuel molecules , no more/ no less. Either richer or leaner from that and tempeeratures drop, so looks like you're now running a bit lean. Our modern direct injection gas engines run that way lots of the time, that's how imporved fuel economy figures are emerging. here's a graph: http://en.wikipedia.org/wiki/File:Flametemp.jpg Barefoot So you may be the guy to ask... Mt theory is, With enough timing and a leaner mixture at cruise, you are not making a hotter exhaust gas which in turn will make for a cooler discharge. Am I close? |
barefoot |
Mar 9 2015, 11:46 AM
Post
#4
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Senior Member Group: Members Posts: 1,281 Joined: 19-March 13 From: Charleston SC Member No.: 15,673 Region Association: South East States |
I've been working with Megasquirt with timing and Fueling. The car has been responding well to the changes. I had to take a trip to the foothills today and decided to take the 914 and really test the changes. Most of the driving I had been doing had been around town so I wasn't sure how the car would respond to a long freeway trip. while cruising up hwy 5 the cht's were 340.....I pulled up Tuner studios and leaned out the area around cruise a bit. Suprisingly the CHT's dropped about 5 * and were stable. I kept the setting there and was wondering how this would be when I started climbing hills, again I was suprised how good the head temps were. nothing over 370(which was for a very short time) on the long climbs. I don't have my 02 sensor connected yet so I can't say what the AFR is. At the end of the trip, I drove 176miles and it took 4.5 gallons to refill....39.1mpg......NICE!!! From my combustion chemistry, max combustion tempeerature occurs at stoiciometric A/F, that is wheere exactly the correct amount of oxyger surrounds the fuel molecules , no more/ no less. Either richer or leaner from that and tempeeratures drop, so looks like you're now running a bit lean. Our modern direct injection gas engines run that way lots of the time, that's how imporved fuel economy figures are emerging. here's a graph: http://en.wikipedia.org/wiki/File:Flametemp.jpg Barefoot So you may be the guy to ask... Mt theory is, With enough timing and a leaner mixture at cruise, you are not making a hotter exhaust gas which in turn will make for a cooler discharge. Am I close? My comments are only on mixture strength. Timing may have it's own unwanted temperature consequences. Sorry not enough theory to go on here. |
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