LT5 on E85

[tpepmeie]

Man, getting these engines to run on E85 is not easy. Granted it's a 14.5:1 compression, 430 CID. With rather large cams.

http://www.zr1.net/forum/showthread.php?t=24966&page=3

calibration is going to be challenging. Changed the obvious Stoich ratio to 9.8:1 for E85. All the cranking and startup enrichment variables will need changed. The meter pegs at 1.1 lambda within a few seconds of startup, equivalent to 16:1 on gas. Engine ran smashingly on 93 octane, but cant hold an idle on E85 yet. On throttle it's incredible. Great responsiveness. (And no raw fuel smell)


Ah. More work to do.

[XfireZ51]

What size injectors Todd? Would love to integrate FlexFuel sensor.

[tpepmeie]

Originally Posted by XfireZ51

What size injectors Todd? Would love to integrate FlexFuel sensor.

30lb bosch III's (ford). 30 lbs @ 39psi the way Ford rates them. More like 44lbs at my new rail pressure (75psi).


Flex fuel sensor? why? either run E85 or don't. why complicate things?

can it be done, yes. But why bother?

[XfireZ51]

I would imagine PW at idle would present a challenge. U’ve modified the Voltage Offset for the injectors taking into account the higher pressure.

[Hog]

Originally Posted by tpepmeie

30lb bosch III's (ford). 30 lbs @ 39psi the way Ford rates them. More like 44lbs at my new rail pressure (75psi).


Flex fuel sensor? why? either run E85 or don't. why complicate things?

can it be done, yes. But why bother?

Why bother? Because unless its from a drum, E85 isnt always 85% "E".

[tpepmeie]

It doesn’t vary enough to matter. Buy a $20 tester if you really have to know. The KISS principle applies here, imo. But to each his own.




Sent from my iPhone using ZR-1 Net Registry

[Hog]

Just some info on ethanol.

The stoichiometric ratio that GM uses for earlier straight gasoline was 14.6:1. Then in the mid 90's, E10 gasohol was in full swing up here in Canada and the stoichiometric ratio was around 14.1:1 and now E85 is about 9.8:1.

Here's a quick table I'm copying.
C16: 14.8:1
Pump gas: 14.7:1
Diesel: 14.6:1
Q16: 13.6:1
E85: 9.8:1
Methanol: 6.4:1

In the Americas there are 3 separate volatility classes of E85 fuels depending on the season.
Class 1 E-85-requires the fuel have a minimum of 79% Ethanol.
Class 2 E-85 requires the fuel have a minimum of 74% Ethanol.
Class 3 E-85 requires the fuel have a minimum of 70% Ethanol.

These different classes are required because the more hydrocarbon in the fuel, the lower the flash point to ignite the fuel when starting.

You can enter your ZIP code at this site and find out what class of E85 is sold and at what time of the year. You can also find E85 and E15 gas stations along your planned route here.
https://getbiofuel.com/fuel-finder/

The amount of variation that is allowed in E85 is the same difference between straight gasoline(e-0) and gasohol E-15.
While I agree that for most applications recalculating for E-0 to E-10 isn't a requirement. There are some applications where recalculating would be beneficial. A "white hot" ECM calibration would be one.

*********************
The following is just some info about ethanol usage in vehicles outside North America.

Here is a Chevrolet Celta engine in a Brazil spec car. It has a secondary fuel tank in which gasoline is used for starting the engine only. This secondary gasoline fuel starting system is only used when the ambient temperature is below 15 °C (59 °F). After the engine is running, the fuel system automatically switches to the main fuel system and operates the engine on E100 or 100% as is commonplace in Brazil. GM dropped this system in subsequent years and instead of having the separate gasoline fuel system for starting, they added a heating element that heated a small quantity of E100 to be used for starting only, then the engine would continue to run on regular temperature E100. This newer system allowed E100 vehicles to be started at ambient temperatures as low as -5ºC/(23ºF). This just happens to be the lowest temperature that can ever be expected in an Brazil territory.



The Koenigsegg CCXR is a specific version of the CCX that uses the same 4.7 liter V8 engine with twin superchargers as the "regular" CCX, but the "R" versions ability to run on E85 and E100 raises its output to 1004hp@7000rpm and 782lb/ft torque@5600rpm.
9.2:1 compression. 23.2psi boost pressure.
Fuel useage: on E85 fuel(85% Ethanol)
Highway: 18 L/100km/15.68mpg(Imperial)/13.1mpg(USA)
Combined:22 liter/100km, or 13mpg(Imperial) or 11mpg(United States).
The CCXR required modified fuel injectors, upgraded fuel lines and piston rings, and a higher boost setting on the superchargers. It can also run on 98 octane gasoline.
Dry weight: 1280 kg (2821 lbs)

The CCX version makes 795hp@7,000 rpm and 679lb/ft torque@5,700rpm whilst running on 91 octane gasoline. All on a 8.2:1 compression ratio, using 20.3 psi of boost.
Fuel consumption:
17liters/100km/16.62mpg(Imperial) /13.85mpg(USA)combined
13 liters/100km 21.73mpg(Imperial)/18.09mpg(USA) highway
Dry weight
1280 kg (2821 lbs)

I'll take the extra 209hp for the possible inconvenience of having to run E85/E100 or 98 RON (approx. 93-94 using the Anti Knock Index=AKI= RON+MON)/2 which is how gasoline antiknock properties of fuel are rated in North America.
RON=Reasearch Octane Number
MON=Motor Octane Number

[XfireZ51]

My interest in integrating a Flex Fuel meter is to enable use of E10 and E85.
When I tune, I use a 14.3:1 stoich in the calibration because of the E10 prevalent in the Midwest.

[tpepmeie]

Originally Posted by Hog

Just some info on ethanol.



The stoichiometric ratio that GM uses for earlier straight gasoline was 14.6:1. Then in the mid 90's, E10 gasohol was in full swing up here in Canada and the stoichiometric ratio was around 14.1:1 and now E85 is about 9.8:1.



Here's a quick table I'm copying.

C16: 14.8:1

Pump gas: 14.7:1

Diesel: 14.6:1

Q16: 13.6:1

E85: 9.8:1

Methanol: 6.4:1



In the Americas there are 3 separate volatility classes of E85 fuels depending on the season.

Class 1 E-85-requires the fuel have a minimum of 79% Ethanol.

Class 2 E-85 requires the fuel have a minimum of 74% Ethanol.

Class 3 E-85 requires the fuel have a minimum of 70% Ethanol.



These different classes are required because the more hydrocarbon in the fuel, the lower the flash point to ignite the fuel when starting.



You can enter your ZIP code at this site and find out what class of E85 is sold and at what time of the year. You can also find E85 and E15 gas stations along your planned route here.

https://getbiofuel.com/fuel-finder/



The amount of variation that is allowed in E85 is the same difference between straight gasoline(e-0) and gasohol E-15.

While I agree that for most applications recalculating for E-0 to E-10 isn't a requirement. There are some applications where recalculating would be beneficial. A "white hot" ECM calibration would be one.



*********************

The following is just some info about ethanol usage in vehicles outside North America.



Here is a Chevrolet Celta engine in a Brazil spec car. It has a secondary fuel tank in which gasoline is used for starting the engine only. This secondary gasoline fuel starting system is only used when the ambient temperature is below 15 °C (59 °F). After the engine is running, the fuel system automatically switches to the main fuel system and operates the engine on E100 or 100% as is commonplace in Brazil. GM dropped this system in subsequent years and instead of having the separate gasoline fuel system for starting, they added a heating element that heated a small quantity of E100 to be used for starting only, then the engine would continue to run on regular temperature E100. This newer system allowed E100 vehicles to be started at ambient temperatures as low as -5ºC/(23ºF). This just happens to be the lowest temperature that can ever be expected in an Brazil territory.







The Koenigsegg CCXR is a specific version of the CCX that uses the same 4.7 liter V8 engine with twin superchargers as the "regular" CCX, but the "R" versions ability to run on E85 and E100 raises its output to 1004hp@7000rpm and 782lb/ft torque@5600rpm.

9.2:1 compression. 23.2psi boost pressure.

Fuel useage: on E85 fuel(85% Ethanol)

Highway: 18 L/100km/15.68mpg(Imperial)/13.1mpg(USA)

Combined:22 liter/100km, or 13mpg(Imperial) or 11mpg(United States).

The CCXR required modified fuel injectors, upgraded fuel lines and piston rings, and a higher boost setting on the superchargers. It can also run on 98 octane gasoline.

Dry weight: 1280 kg (2821 lbs)



The CCX version makes 795hp@7,000 rpm and 679lb/ft torque@5,700rpm whilst running on 91 octane gasoline. All on a 8.2:1 compression ratio, using 20.3 psi of boost.

Fuel consumption:

17liters/100km/16.62mpg(Imperial) /13.85mpg(USA)combined

13 liters/100km 21.73mpg(Imperial)/18.09mpg(USA) highway

Dry weight

1280 kg (2821 lbs)



I'll take the extra 209hp for the possible inconvenience of having to run E85/E100 or 98 RON (approx. 93-94 using the Anti Knock Index=AKI= RON+MON)/2 which is how gasoline antiknock properties of fuel are rated in North America.

RON=Reasearch Octane Number

MON=Motor Octane Number

Thanks. I think (?). Where you going with this?




Sent from my iPhone using ZR-1 Net Registry

[Hog]

Originally Posted by tpepmeie

Thanks. I think (?). Where you going with this?




Sent from my iPhone using ZR-1 Net Registry

Not going anywhere, just a friendly deposit of some ethanol related info that I found while perusing. Many people reading this are interested in ethanol fuels.