Have you thought about a Flexi Fuel strategy?

[Wez]

Hey Guys,

Just wondering if you have thought about adding a flexi fuel strategy which could utilise a flex fuel sensor.

[jezzpalmer]

That would be nice for if/when we get E85 in the UK.

Just been reading some details of this on the megasquirt forum, would save messing with duel tanks etc.
Flex sensors appear to also return fuel temp (though would need processing), so you could utilise that too.
http://www.megamanual.com/flexfuel.htm

Here's some handily sized injectors for when E85 is available.
http://www.bmotorsports.com/shop/produc ... ts_id/1588

[Wez]

Some info from another site describing how a Motec handles the Flex Fuel sensor

Here is a writeup I did about a Viper I set up. Should give you an idea of what is possible:

The MoTeC ECU allows a user definable 4th dimension to both the fuel and timing maps (the Z axis). Picture a typical fuel map, only now with up to 11 "layers" that are each a complete fuel map (rpm vs load). In our case I set the flex fuel sensor up to move the system on the "Z" axis, so as the ethanol content changes, it changes to different complete fuel maps automatically. The same happens with the timing maps. All seamless, all automatic based on input from the flex fuel sensor.

So first order of business was a pump gas tune, which ended up in the 700whp range with 10psi boost (very small turbos, instant spool). Wastegate springs were at 5psi, and due to traction issues I set the gear dependant boost up to be 5psi in 1st, 7psi in 2nd, 9psi in 3rd and 10psi in 4th+.

Now we proceeded to fill it with E85, and the flex fuel sensor data changes VERY fast. This of course tracks the system to a different "Z" axis fuel and timing "layer", and we proceeded to tune the car to 15psi of boost and 980whp (we were out of injector and fuel pump). Keep in mind the Motec is controlling the boost, and of course a tank of E85 does not solve our traction issues so this is how it was setup (all auto adjusted based on data from the flex fuel sensor). With the flex fuel sensor reporting back 85% ethanol, the boost targets become the following: 1st gear is 5psi, 2nd gear is 7psi, 3rd gear is 11psi and 4th gear is 15psi.

Now to add a special touch to the driveability, I tweaked the hot/cold start tables to include the incoming flex fuel data (to adjust start fueling based on ethanol content), acceleration enrichment values are trimmed based on ethanol content, etc.

Once the ground work was done, I then tuned a couple of blends to bring the two "ends" as it were together, in a seamless transition of 5 "Z" axis layers to go between pump fuel and E85 (and a couple out the far end in case we run into some strong Kentucky 'shine, given the home state of the car). The boost control shown above also does a linear transition between the two points illustrated above based on ethanol content. The fuel trims/start fueling/etc also have the same transistion tuned into them.

This is all done with one calibration file, no laptop is needed to switch things, it is all automated by the ECU. The car also has a keyed "valet" switch wired in, which allows 4 overall boost settings: minimum boost in all gears, 50% reduction in boost across the gears, 25% reduction in boost across the gears, and then maximum permitted by the control (see above values).

[Wez]

When calculating your fuel system requirements, It would seam you would need to add about 35% of additional fuel over normal fuels; but I think you may look into adding at least another 50% worth of fuel delivery ability. I have noticed that E85 cars generally use more than the standard 35% more fuel.. but once I found this E85/E100 chart I understood:

Fuel AFRst FARst Equivalence Lambda
---- ----- ----- Ratio -----
=======================--

Gasoline stoich 14.7 0.068 1 1
Gasoline Max power rich 12.5 0.08 1.176 0.8503
Gasoline Max power lean 13.23 0.0755 1.111 0.900

=======================--

E85 stoich 9.765 0.01235 1 1
E85 Max power rich 6.975 0.1434 1.40 0.7143
E85 Max power lean 8.4687 0.118 1.153 0.8673


=======================--

E100 stoich 9.0 0.111 1 1
E100 Max power rich 6.429 0.155 1.4 0.714
E100 Max power lean 7.8 0.128 1.15 0.870


=======================--


Max rich power on E85 is .71 Lambda; That is a LOT of fuel..

So if you think you will make @ 750rwhp on E85, just go ahead and plan on 1200 or 1600cc injectors and at least triple fuel pumps.

According to E85.com, raw alum will decay at 1 mil per year, if fully submersed in the fuel 24/7. that is not a lot when you are talking about billet hangers, or fuel rails.... but it is alot if you have raw fittings on your fuel lines... Get the anodized fittings.

[jezzpalmer]

That's a good read, Wez.

I hadn't realised the corrosive properties of E85 (thought it only applied to methanol), that's a pain for my in tank 044, though I guess in E85 land I'm going to be needing 2 external pumps anyway so a steel cased lifter pump can go intank.

Yes you need lots of E85, injectors are a particular issue on big power 4 pots, I'm not sure I've got enough free outputs to run 8 injectors and I don't think that 1680's are going to cut it on E85.

Of course, the UK needs to acquire a good E85 network first; there are two Morrisons stations 'near' to me, but they are 22 and 40 miles away.

[Wez]

Of course, the UK needs to acquire a good E85 network first; there are two Morrisons stations 'near' to me, but they are 22 and 40 miles away.

This is the problem, you can buy Race E85 but its not cheap at £3ltr.

http://www.aaoil.co.uk/racing-Racing-fuels-Methane

[Jez]

You can get it for 85p + VAT per litre from http://www.greenergy.co.uk if you buy 50 litre drums - although that price was given in November 2008

[jezzpalmer]

You can get it for 85p + VAT per litre from http://www.greenergy.co.uk if you buy 50 litre drums - although that price was given in November 2008

Now that's more appealing.
What's the legality of storing 150l of fuel in your garden shed/garage?

I wonder, as Green Energy supply Tesco's with their 99, if Tesco will be forerunners in the E85 rollout; or for that matter if Morrisons will roll it out further?

[Wez]

Doesnt look like greenergy supply it anymore

-------------
Hi

We do not supply E85 due to limited demand. Morrisons supermarket are the only retailer that has significant availability of E85 on their forecourts. If you check their website you should find a list of locations.


Regards

Ewan Alexander
Group Product Manager
Greenergy International Ltd.
198 High Holborn
London
WC1V 7BD

tel 020 7404 7700
fax 020 7400 4799
www.greenergy.com
-------------

[greg]

Im new to this forum so hello peeps

That's a good read, Wez.

I hadn't realised the corrosive properties of E85 (thought it only applied to methanol), that's a pain for my in tank 044, though I guess in E85 land I'm going to be needing 2 external pumps anyway so a steel cased lifter pump can go intal

Ive used e85 a couple of times, i knew it had corrosive properties in my understanding it basically corrodes/perishes rubber.
does anyone know if viton is resistant to e85?
also does anyone have a list of fuel system products that are resistant to e85, think it would be really useful