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Old 04-16-2015, 12:37 PM   #1
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Default Randomly richer than normal?

Hey guys, so a little more hand holding. I've noticed that as it gets warmer (I'm here in TX, so the weather is always wonky) the car runs a bit richer than expected.

I'm assuming it has an issue with the MAT tables. Could someone explain them to me?
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Old 04-16-2015, 12:54 PM   #2
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That doesn't look terribly dramatic to me.

When you view a log in MegaLogViewer, you can look at the individual modifiers which alter the requested fuel. Collectively, they are represented as the GammaE value. I believe that the one which deals specifically with air density (based on manifold temperature) is expressed as Air_Corr.
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Old 04-16-2015, 12:57 PM   #3
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That's Joe, I'll take a look at it.

Yeah it's actually not that bad, when it's cold I cruise 16.5, but when it's warm it's like 16.2. Not bad, but it is a little annoying. Guess I've got wideband OCD.
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Old 04-16-2015, 01:05 PM   #4
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Quote:
Originally Posted by ihiryu View Post
Guess I've got wideband OCD.
Uhm, yeah, I'd say you do.

The difference between 16.2 and 16.5 is so miniscule that I'd typically attribute it to measurement error, particularly in a system which is designed to oscillate under normal conditions.

It's also weirdly lean. Are you trying to hypermile this vehicle?
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Old 04-16-2015, 01:13 PM   #5
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Yes it only hits that on super low loads, or less than 10% throttle. If i drive it like a normal human being, it'll cruise 15.2-15.5. And when I go WOT, it'll richen up with boost.

So even on the highway cruising 3500 rpm's, I'm at 15.8-16, and if I go to WOT, it'll richen up to 13-12.8 then all the way to 11. Of course just depending on the load.

Just trying to achieve 300 miles to the tank. Since I'm using MS2E from Rev, it's got map switching, when I go road racing, I plan to use the secondary map for more fueling when I'm racing, since MPG's aren't really a concern at that point.
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Old 04-16-2015, 02:07 PM   #6
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There's a point where too lean is actually less economical than running a fatter AFR. For a time I was trying to cruise 16.2, but I believe I get better miles running 15.5-15.8, and it also seemed to run closer to target more often.

I haven't played with timing much, which I expect is pretty critical when you try to run so lean.
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Old 04-16-2015, 04:09 PM   #7
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I ran the last turbo car in the low to mid 16s on the highway. Was rewarded with 35.3mpg best tank. Typically 32-33mpg combined.

Most of my tanks were well over 300.
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Old 04-16-2015, 04:44 PM   #8
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Hustler (back when he drove instead of riding) published a long time ago, and had support, that 15.7 was more economical than 16.2 at cruise.

Concealor, that is indeed impressive.
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Old 04-16-2015, 06:23 PM   #9
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I was around 38mpg with a passenger and a trunk full of stuff. 15.7:1 cruising 65mph, 40psi in the tires. Though, this was my attempt at trying to hypermile it. Oh and i think my timing was somewhere around 36*.
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