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How to add more fuel in Megatune

Old 08-26-2009, 04:44 PM
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Exclamation How to add more fuel in Megatune

Ok, so i want to add 30% more fuel across the entire VE map. Is there a way to just select the entire VE map and add 30% to every value?

I cant figure out how to do it.

Thanks, Taras
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Old 08-26-2009, 04:57 PM
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You can select all the cells. Click and drag the courser from say top left to bottom right.

Once that is done you a few little boxes will appear on the upper right hand side of the VE map. From there you can enter in a value and add or subtract however much you want to adjust.
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Old 08-26-2009, 05:03 PM
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Old 08-26-2009, 06:19 PM
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Thanks a lot! I found the Mega Manual and found how to do it. I went to Shift and added 30 fuel.

What does it take to convert to e85?
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Old 08-26-2009, 07:23 PM
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Originally Posted by Rushin

What does it take to convert to e85?
A lot more than just +30 fuel.

Fuel lines, pumps, ect. I think there is a thread about it. Search for it.
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Old 08-26-2009, 09:59 PM
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To add 30%, you don't shift by 30, you scale by 1.3.

E85... Chris Swearegen's MS2 is set up for it. Not sure if he actually started using it. Injector size probably needs to go up, depending on how high your DC% is on gasoline.

Lines & seals are somewhat a matter of speculation. Some say that most cars built in the last 20 years or so are ok with it. And that since we're all running E10 anyway, you'd know if there was a problem already. All we know is, he's called The Stig.
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Old 08-26-2009, 10:08 PM
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Lol, at 14psi I got to 60% duty cycle. So I think if I go down to 11-12 on e85 I should be ok. In the mega manual it said to shift by 30 to add 30% across the board.
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Old 08-26-2009, 10:38 PM
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When you shift a table, you increase (or decrease) the value of every cell by the amount entered.

If a cell was at 200, then it goes to 230, which is a 15% increase.
If a cell was at 100, then it goes to 130, a 30% increase.
If a cell was at 60, then it goes to 90, a 50% increase.
If a cell was at 30, then it goes to 60, a 100% increase.

Got it?

Now by contrast, if you scale a table by 1.3, then the value of every cell is multiplied by 1.3, which gives every cell a 30% boost.
100 becomes 130.
60 becomes 78.
30 becomes 39.
(200 wraps around and becomes 4, because of a stupid bug in the way they handle overflows.)

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Old 08-26-2009, 10:51 PM
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I see. I will do that then. Thanks a lot!
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Old 08-26-2009, 11:56 PM
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Originally Posted by Joe Perez
When you shift a table, you increase (or decrease) the value of every cell by the amount entered.

If a cell was at 200, then it goes to 230, which is a 15% increase.
If a cell was at 100, then it goes to 130, a 30% increase.
If a cell was at 60, then it goes to 90, a 50% increase.
If a cell was at 30, then it goes to 60, a 100% increase.

Got it?

Now by contrast, if you scale a table by 1.3, then the value of every cell is multiplied by 1.3, which gives every cell a 30% boost.
100 becomes 130.
60 becomes 78.
30 becomes 39.
(200 wraps around and becomes 4, because of a stupid bug in the way they handle overflows.)

Informative and hilarious!
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Old 08-26-2009, 11:58 PM
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Originally Posted by naarleven
A lot more than just +30 fuel.

Fuel lines, pumps, ect. I think there is a thread about it. Search for it.
Some kid I know from a "tune shop" around here did a test with a honda OEM Gas tank. Filled it 1/2 full of E85, dumped a fuel rail, injectors, pump, plastic, rubber, hose, etc inside and let it sit for almost a year. Shook it up now and then, never damaged a thing...


I'm kind of skeptical of all the stuff they claim you need to replace..
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Old 08-27-2009, 01:02 AM
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Originally Posted by elesjuan
Some kid I know from a "tune shop" around here did a test with a honda OEM Gas tank. Filled it 1/2 full of E85, dumped a fuel rail, injectors, pump, plastic, rubber, hose, etc inside and let it sit for almost a year. Shook it up now and then, never damaged a thing...


I'm kind of skeptical of all the stuff they claim you need to replace..
Goes to show the random bs i've read on e85. Guess there is only one way to find out.
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Old 08-27-2009, 02:07 AM
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and they way to do it is for me to switch to e85 as soon as i run out of pump gas.
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Old 08-27-2009, 02:35 AM
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So when i start tuning for e85, what AFRs should i be looking for at wot? It looks like stoich for e85 is richer than gas. Right now at wot i am running 10.5 or so. So should i be tuning for 8?
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Old 08-27-2009, 02:39 AM
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I'm pretty tempted to make the switch to E85 if and when I can ever get a turbo put on my car...

Time will tell.

IMO 10.5 is WAY too much fuel for gasoline. I'm not super familiar with boosted afr's on gas, but I think most of the guys on here run upper 11:1s in boost...
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Old 08-27-2009, 03:25 AM
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yeah i know its a bit too rich but for some reason my tuner tuned it like that. Thats probably why i am only making 190 at 12psi

Originally Posted by elesjuan
I'm pretty tempted to make the switch to E85 if and when I can ever get a turbo put on my car...

Time will tell.

IMO 10.5 is WAY too much fuel for gasoline. I'm not super familiar with boosted afr's on gas, but I think most of the guys on here run upper 11:1s in boost...
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Old 08-27-2009, 05:39 AM
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stoich for E85 is 9.76 fyi
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Old 08-27-2009, 07:35 AM
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Bear in mind something about measuring AFR with fuels other than gasoline.

All wideband O2 sensors (and narrowbands as well) do not actually measure AFR directly, they measure Lambda, which is written as λ.

Lambda is not a constant, at least not insofar as AFR is concerned. Instead, lambda represents the ideal stoichiometric mixture for any fuel. No matter what you're burning, be it gasoline, propane, alcohol, etc., 1 λ always represents stoichiometric for that fuel.

Now, we tend to think in terms of AFR for some reason, so wideband controllers are programmed to do a conversion between lambda and AFR. Specifically, they have either a lookup table or a formula that tells them how the varios values of λ correspond to various AFRs for whatever fuel you are using. With gasoline, 1 λ = 14.7 : 1, so when the controller receives a signal that the sensor is measuring 1 λ, it puts 14.7 on the display.

Of course, you have to tell it which fuel you're using in order for this to be true.

So let's say that you have a wideband system that's calibrated for gasoline, and instead you start running E85 in the car. Anytime your actual AFR is at 9.765 : 1, that's 1 λ. The sensor will read 1 λ and pass this information to the controller, which will decode it and display 14.7. You're not actually running at 14.7, you're running at 9.765, but all the sensor knows is that you're at 1 λ, and all the controller knows is that when it gets a signal for 1 λ, it's supposed to show 14.7 on the display.

And that's fine, just so long as you know what's going on.

Moral of story: You can run any fuel you want, or any blend of fuels. No matter what you've got in the tank, when your WBO2 display says 14.7, you're at stoich.


Obviously more advanced devices like the LC1 can be re-calibrated for E85, or any other fuel for that matter. The AEM cannot, so if you have one of those, you can either switch it to pure Lambda display and re-learn how to think (bigger numbers = richer mixtures, the opposite of AFR) or you can just leave it in the gasoline cal and blissfully ignore everyone who tells you that you're wrong.


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Old 08-27-2009, 07:43 AM
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Few of my buddies have been running E85 for the last two years and have yet to replace any seal, injector nothing! There is a local ST guy that plans on just replacing things once they start failing, and they have yet to fail.
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Old 08-27-2009, 08:42 AM
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Originally Posted by Joe Perez
Obviously more advanced devices like the LC1 can be re-calibrated for E85, or any other fuel for that matter. The AEM cannot, so if you have one of those, you can either switch it to pure Lambda display and re-learn how to think (bigger numbers = richer mixtures, the opposite of AFR) or you can just leave it in the gasoline cal and blissfully ignore everyone who tells you that you're wrong.
but what if you want to run a controller and not follow the directions to hook it up? How can we bash the LC-1 here?
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