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E85 sensor

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^ Terrible English there, and no way to edit.  Base map was initially for straight petrol, I scaled it up by around 20% and my 4D fuel tables have -20 for 0% ethanol... and everything else scaled to suit.  

Works very well, though it'd be nice if there was a way to have a way of trimming crank enrichment for ethanol percentage as well.  I've done a rangi-work around (I'm actually using 4 and 5d fuel adjustment) and tried offsetting 0-400rpm with the theory that say 15% enrichment at 0-400rpm on 85% eth will effectively create a makeshift crank enrichment trim, and a 0% enrichment from 400-1000rpm should stop interpolation from messing with idle mixtures... and just hope rpm never dip under 500rpm after the car has started.  

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Hi Richard

2200ohms 1/2watt. THe reason is the internal pull up is too stiff for the sensor to work with.

Edge will not matter.

Our testing was done with the GM sensor.

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Just curious. Does the LINK G3 run dual fuel maps. Just wondering if I run 98ron then which to E85 would the ecu notice the difference or would I need something to read/sensor the difference in RON fuel ratios? It would be handy to have a ethanol sensor but do I need it?

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Hi Brett,

The G3 ECUs are capable of running dual fuel tables. However the G3 firmware does not have support for an ethanol content sensor. There are a couple of things you could do.

1. Tune one fuel table for 98 and then tune another for E85 and manually switch between the maps when running different fuels.

or

2. Upgrade the firmware in your G3 ECU to G4 firmware, install an ethanol content sensor and then use 4D (overlay) fuel and ignition tables that will compensate based upon ethanol content.

Option 2 would be the better option, as it means you could run a mixture of fuels. Note that there is a charge for upgrading your G3 to run G4 firmware, but the ECU does not have to be returned to us. If you are interested in this option please email sales@linkecu.com for more info.

Cheers,

Scott

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Hi Scott

I have a g3 and will upgrade to the g4 firmware.

I am wondering if I go option 2 above does this mean I can have one fuel table that will allow the car to run on a mixture of fuels? anything from pure 98 ron to pure e85 and a mixture of both say 50/50 for argument sake, though in all likely hood I would run one to empty and fill with the other fuel.

or would i need to still have two fuel tables and switch between them?

 

cheers

Jules

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Hi Jules,

 A basic setup would involve this:

You would setup fuel table 1 as your normal fuel tune (no ethanol) and then setup a 4D fuel table, you could set this table to have only one axis and make it ethanol content. You would then fill out the table to add the extra fuel required depending on the % of ethanol. 

The 4D fuel table would be on all the time and adjust the amount of fuel put through the injectors depending on the ethanol/petrol blend.

Note that because Ethanol contains approx 34% less energy than petrol you may need to put a fair bit more ethanol through your injectors depending on the type of blend you run. For some factory injectors this may mean they run out of duty cycle at the top end.

Cheers,

Scott

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Great txs Scott.

 

The car is fully kitted out ready to run the e85.  injectors rated to  850 cc, two bosch fuel pumps etc etc.

So All i have to do is pay for the software upgrade and get a ethanol sensor and get my tuner to sort it all out.

 

txs

 

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I've setup a 4D fuel map with ECT (-20 to 90) on one axis and Ethanol percentage (0-100) on the other. This allows injecting a bigger percentage of ethanol fuel as the ethanol percentage increases when cold starting vs hot starting. This should simulate having extra crank enrichment for ethanol when its cold (which it needs) and it is working well so far.

 

As ethanol does not vaporize very well at low temparatures (compared to gasoline) you need to add a significant increase in the amount of fuel injected for cold starting when running high ethanol percentages such as E85.

 

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Hi Kevin,

You probably know me better as Lith - nice, so you have tried it out then?   I actually use the dual fuel table as an overlay for cranking enrichment and only have it enabled if the rpm is <400rpm.  

Here's a clip of a flexfuel Silvia (stock SR20, fairly mild overall setup) I tuned running on E60 at Manfeild 

http://www.youtube.com/watch?v=b8TbZ-cDw3A&t=4m35s'>

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I found that with even up to E75-E80 areas that there didn't really need to be any difference in cranking enrichment for  starts above 50degC ECT, the 10deg (I had to get the S14 starting nicely in winter) up to 30degrees... particularly on first start were the more challenging ones and the cold starting didn't really start taking more cranks until we started getting up to 50% or so from memory.   It would also often start a lot better the second time even at 40degC even on higher ethanol blends so it can be a bit misleading when nutting that out.

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Yes, I found the same that once it had started even for a few seconds, it was then much easier to start again even at low temps and high ethanol percentages. By what percentage did you increase the cranking fuel for E85 at say 10 degrees?

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Patrick - have only dealt with the Siemens sensor, but Haltech have said that it is for all intents and purposes the same as the GM/Siemens sensor so I assume that means the signal output is pretty much identical.

Kevin - Is that an improvement over what you previously had?   It typically starts first time for us, though maybe a crank or two more than petrol.

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I've just had another look at my 5D fuel map and I now see that you can set RPM on the X-Axis and Ethanol percentage on the Y-axis. I don't know why I didn't see this before, but this will allow me to add cranking fuel based on Ethanol percentage from 0% to 100% by adding more fuel below 500rpm only. I'll give this a go later tonight.

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Just tried starting the car on E85 (displaying E82) and it started on the second crank from cold. Very pleased now.

 

The 5D fuel table with RPM on one axis (0 to 500) and the ethanol percentage (0 to 100) on the other has allowed for much improved cranking fuel values.

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