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Old 12-31-2005, 01:31 PM   #1
KramS4
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Default FINALLY - S4 with K04 and running Alcohol - FATS inside


After more than 6 months since my K03 gave up, I finally logged my car with a VAG.

My car is running on K04, piggie DP, no cats, 3inch exhaust, stock IC, UNICHIP (piggyback), 2 auxiliary injectors, 2 parallel fuel pumps.

Ethanol has ~35% less energy, but due to a 43% more volume for stoich mixture, it is 11% more powerful than gas. It has 120oct equivalent.

I`m running 17,5psi for a while to test this configuration. I did few logs and I am not used to VAG yet.

UNICHIP was adjusted with 15 to 25 degrees more on timing advance than stock. My CFs are between 3 to 9 (similar to a stock RS4). For fuel it was adjusted on the rich side using a WB lambda meter.

The auxiliary fuel injectors are running on the bipipe and cools the intake at WOT. Due to the High Heat Specific of Ethanol my IAT comes from 80oC to 20oC when WOT. It is summer here and the outside temperatures are on low 30oC.

Here is my first FATS (remembering the difference that I found on gearing). Stock car at sea level with me and my brother (190kg).


http://img409.imageshack.us/img409/21/fats4rw.jpg


I am very happy with the results and I am going to improve it with new injectors and more boost.


Regards,
Mark

PS: I would like to thank every one that helps me in the last months with my very difficult problems to solve (it was a faulty ECU).
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Old 12-31-2005, 01:52 PM   #2
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Default holy crap, what just hapened?

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Old 12-31-2005, 01:54 PM   #3
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Default So are you runing gas with alky injection, or straight alky?

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Old 12-31-2005, 02:05 PM   #4
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Default Appears alky injection - looks like he's in Australia

I don't understand the FATS calculations - Euro & US?
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Old 12-31-2005, 05:04 PM   #5
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Default the "euro" fats is equiv to our times based on mph, the "usa" fats is equiv based on rpm

his transmission has a different 3rd gear ratio.
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Old 12-31-2005, 06:36 PM   #6
KramS4
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Default Full Alcohol. All the stock injector plus 2 suplementary on the bipipe.

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Old 12-31-2005, 06:39 PM   #7
KramS4
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Default I`m in Brazil. We have the choice for Ethanol on every gas station.

The 3rd gear is different from the US-Spec. So I did like ENIGMATIC said. Did a "FATS" based on speed to be compared to the US cars and one with the full 4200-6500rpm.
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Old 12-31-2005, 06:45 PM   #8
KramS4
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Default The ECU started to work weird. But first we tried almost every single sensor in the car.

The ECU worked for almost everything. My car was running on alcohol.

After changed to K04 I went for a new calibration for the UNICHIP. Whatever we did to richen up the fuel, the ECU (we didn`t know that was the ECU) pulled back. We open the suplementary injectors full on, and the stocks went off to lean the mixture. There was no errors and no other sign comming from the ECU. So after many many tries we finally found another S4 (it is very few in Brazil) to swap the ECU and make a test.

It was not as simple, cause the Euro-spec need the big key from Germany to unlock the immobilizer with the new ECU and so.....


I`m happy that it is ready for the new year.
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Old 12-31-2005, 09:50 PM   #9
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Default Could you elaborate on how ethanol ends up being more powerful than gas. As I

understand it, ethanol has in the neighborhood of 60% of the heating value of gasoline, about 12k BTU/lb for ethanol versus ~20k BTU/lb for gasoline. If 14.7:1 is stoichiometric for gas, and for ethanol is 9:1, then you are burning about 1.6 pounds of ethanol to 14.7 pounds of air, what it takes to burn 1 pound of gasoline. If you compare the energy content of 1.6 pounds of ethanol (~19-20k BTU) to 1 pound of gasoline (~20k BTU), the heat energy produced is almost identical for the two. I'm wondering how you got that ethanol is 11% more powerful?
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Old 01-01-2006, 05:13 AM   #10
KramS4
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Default Ok, I`m not used to non-metric system, but you can accounts for certain

differences on your statement. Ethanol has 29,9MJ/kg and gasoline ~44MJ/kg. The difference on stoichiometric is 14,7/9=1,63. So 1,63/(44/29,9)=~1,11.

And that is not the end. Ethanol burns much slower (more work due to more timing advance) and burns much cleaner, so no deposits. There are other benefits like raising the dynamic compression due to "less" volume to the same amount of air (~43% more fuel in volume, giving about 5% more dynamic compression).


Alcohol is great!
The problems are very low autonomy and the cold weather start.
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