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Has anyone ever used the M800 to run two different fuels?

 
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MrDomino



Joined: 01 Oct 2009
Posts: 190
Location: Indianapolis, IN

PostPosted: Fri Sep 16, 2011 10:47 pm    Post subject: Has anyone ever used the M800 to run two different fuels? Reply with quote

I was looking at the M800 manual the other night and it got me thinking about whether or not you could set up the calibration to run on pump gas for most of the time but inject some E85 or other high octane fuel depending on the engine speed and load. This way you could drive around a high compression motor and use only premium fuel most of the time. However, at higher loads where spark advance would be knock limited, a second set of injectors could kick on and a higher octane fuel could be injected.

I wanted to see if anyone has attempted or even finished something like this before. If you have, it'd be much appreciated if you could share one of your calibration files that shows how you set it up.

Thanks!
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turbotwig



Joined: 05 Dec 2005
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Location: Newport Beach, CA

PostPosted: Tue Sep 20, 2011 5:29 pm    Post subject: Reply with quote

Yes, it's completely possible. The tricky part you may run into is the total number of injector drivers and if you want it to remain fully sequential. If you're doing this on a 4-cylinder engine, then I think you're golden and you can run fully sequential even with the secondary injection setup. If you're trying to do this on a 5+ cylinder engine, you're probably stuck doing batch fire (aka semi-sequential in Motec parlance) because I believe it only has 8 total injector drivers. What you'll set up in the config file is a "secondary balance table" [under Fuel > Secondary Injection > Secondary Balance Table] with whatever axes you choose to define that table. You mentioned RPM and load... which would seem to make a lot of sense. If you hit F1 in the balance table, the help file says:

--------------------------------------------------
The Fuel - Secondary Balance Table determines the balance between the
Primary and Secondary Injectors (if used).

The balance is normally adjusted at various RPM points and optionally at
various Efficiency Points. To select the desired channels select
'Axis Setup' from the Tools menu.

The value is percent of primary.

eg. 100% All fuel is delivered by the Primary Injectors.

50% 50% fuel is delivered by the Primary Injectors and 50%
is delivered by the Secondary Injectors.

0% All fuel is delivered by the Secondary Injectors.

Primary and secondary injectors are normally used as High / Low injectors
in multi runner manifolds.

The Setup Parameter 'Secondary Inj Ratio' must be set to specify the
relative flow rates of the primary and secondary injectors (even if the
injectors have the same flow rates).

--------------------------------------------------

The mechanical setup is relatively straightforward. You'll basically just have to run two separate tanks, pumps, regulators, fuel rails, etc.

In case you haven't done a lot of calibration work before... the tuning of this is probably going to take a lot of work to get dialed in correctly. Normally, the High/Low setup is there to change atomization, so the balance is generally optimized based on the torque output through a sweep across RPMs. What you're talking about throws in a weird twist to the tune in that you're not only changing fuel composition, but also going to be changing the volumetric fuel requirements because of that balance (I think?). Either end of the spectrum is fairly straightforward... but the transition areas may end up becoming difficult to make smooth. Then again, it may prove to be completely transparent, and I'm full of crap. :)

My advice is to ask yourself if the added complication is really worth the hassle of the tuning. I start to become wary of ideas when they try to do everything under all conditions. Sure, anything is possible with enough development... but you have to ask yourself if it's really required (or worth it) for what you're trying to do. If you can live with one fuel or the other, and just have multiple maps, then it's probably more useful than doing the dual setup.

-Kirk
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MrDomino



Joined: 01 Oct 2009
Posts: 190
Location: Indianapolis, IN

PostPosted: Wed Sep 21, 2011 9:58 pm    Post subject: Reply with quote

I know it'd be easier to just stick with one fuel but I like tackling things that are difficult. I should be able to do some calculations to get the fueling and spark timing decently close from the get go and then from there I can work on fine tuning everything.

Do you know anyone that has done this before?
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turbotwig



Joined: 05 Dec 2005
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Location: Newport Beach, CA

PostPosted: Thu Sep 22, 2011 2:53 pm    Post subject: Reply with quote

Let me guess... this will also be an engine with variable valve timing and a turbo? Also your first tuning project? ;)

I don't recall hearing about anyone doing this before, but I'm sure someone has.

Another thing to think about would be using an ethanol sensor (like on GM "flex fuel" vehicles) to measure and adjust the fueling and ignition timing. Those maps are fairly straightforward to do, and would probably cause much less of a headache. At least then you would only have to package/carry one fuel system and you could adjust your hoon-level to whatever blend you put in your tank at that point. No matter what, if you make a non-adaptive map, you're going to need to keep both tanks full enough so that you don't run out of either fuel. The tune will be linked to those different fuels. I don't know much E85 you have in your area, but here in California (and *most* places) it's relatively difficult to find. Plus, if you want to save money at some point but you've tuned to having that fuel available, then you're SOL. Then you have to end up making a straight pump fuel base map either way.

-Kirk
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keithmac



Joined: 14 Nov 2010
Posts: 233

PostPosted: Sun Oct 09, 2011 12:56 pm    Post subject: Reply with quote

Other things to consider is wether you`ll have your secondary fuel system/ pump(s) on full time or on demand, if it`s on demand the pump has to be primed and the lines primed prior to fuel injection start.

Best bet would be to have the second system armed by a button, which would also allow higher boost from the turbo so you can select it when necessary and get the secondary pump running/ lines purged etc.

I did similar with a Methanol injection system (bar the regulator), ended up adding 20% Methanol by volume in the fuel tank, found it gave me the best compramise between fuel economy and increased octane rating.
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TurboNova



Joined: 08 Dec 2004
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PostPosted: Sun Oct 09, 2011 1:08 pm    Post subject: Reply with quote

With the FAST system I have set this up before with the flex fuel sensor and making a offset to gas stoich ratio.

What about even more simple like two different tunes on a switch, change fuel then change tune.
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RootesRacer



Joined: 04 Apr 2005
Posts: 485
Location: Arvada, Colorado

PostPosted: Sun Oct 09, 2011 2:12 pm    Post subject: Reply with quote

TurboNova wrote:
With the FAST system I have set this up before with the flex fuel sensor and making a offset to gas stoich ratio.

What about even more simple like two different tunes on a switch, change fuel then change tune.


What then when you are between fuels (like no E85 available and you mix 1/4 tank E85 and 3/4 tank pump fuel)?

Unless you are running closed loop lambda control, neither map will run well.
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MrDomino



Joined: 01 Oct 2009
Posts: 190
Location: Indianapolis, IN

PostPosted: Sun Oct 09, 2011 10:54 pm    Post subject: Reply with quote

Do either of you guys have maps that you could share with me? I know that FAST is going to be different from the MoTeC but I'd still be interested in seeing how you set it up.

Thanks.
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Turboivo



Joined: 09 Mar 2006
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PostPosted: Mon Oct 10, 2011 12:12 am    Post subject: Reply with quote

RootesRacer wrote:
TurboNova wrote:
With the FAST system I have set this up before with the flex fuel sensor and making a offset to gas stoich ratio.

What about even more simple like two different tunes on a switch, change fuel then change tune.


What then when you are between fuels (like no E85 available and you mix 1/4 tank E85 and 3/4 tank pump fuel)?

Unless you are running closed loop lambda control, neither map will run well.

Here is another standalone example relying solely on flex fuel sensor to adjust maps, boost, etc.
http://www.youtube.com/watch?v=a1CzmmMUy50
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Amir



Joined: 30 Nov 2011
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PostPosted: Wed Nov 30, 2011 6:39 am    Post subject: Reply with quote

I have had mine setup to run two fuels. However the same fuel system is utilised
Just had a switch installed and a tune setup for both fuels. The Secondary map was a % map taken from the 1st one. The switch lights up an led so I know which map is being used, and the car works on both fuels fine.

I do have a fuel drain switch installed though to ensure the fuel is completely drained before the E85 is put in.
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C. Ludwig



Joined: 29 Sep 2006
Posts: 354

PostPosted: Wed Nov 30, 2011 8:59 am    Post subject: Reply with quote

Mr. Domino, what you're describing would be fairly easy to accomplish with most any system. The challenge would be packaging two completely separate fuel systems. All you'd really need is an ECU that can operate a secondary injection system and bring that system online based on load and/or RPM. That's very common. The only oddity in what you want to do would be the fact you're using a completely separate fuel system for secondary injection and injecting a different fuel.

A more rudimentary example of what you're describing is the water/methanol injection systems that are very popular. We've used these, in various forms, with good success.

Flex fuel, which is another matter all together, seems to be a little different scope than what your first post describes. But, again, there are quite a few ECUs that can handle this well with the addition of the flex fuel sender and properly calibrated offsets.
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Bugermass



Joined: 13 Aug 2007
Posts: 96

PostPosted: Sun Jan 22, 2012 1:21 am    Post subject: Reply with quote

I've done this before and it works well. Was on a ProEfi though. All I had to do was set the stoich point for the primary fuel rail and the stoich point for the 2ndary fuel rail ( different fuels ) then put how much blend I wanted in my injection split map and the ECU did the rest. was seamless. had 1000CC primaries and 2150CC secondaries. I can post a screenshot if you want to get an idea what it looks like, I may even have some logs saved showing how it blends.

I'd be interested to see how you set this up in an M800 when you get it all sorted and working. I have a good idea how to do it but still like to see what you come up with.
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MrDomino



Joined: 01 Oct 2009
Posts: 190
Location: Indianapolis, IN

PostPosted: Sun Jan 22, 2012 7:36 am    Post subject: Reply with quote

I'd definitely be interested in seeing how you set it up. This is still something that's in the planning stages now and it may end up being a while before I get to it but I'm going to do it eventually.
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Bugermass



Joined: 13 Aug 2007
Posts: 96

PostPosted: Mon Jan 23, 2012 8:49 pm    Post subject: Reply with quote

PM me your email and I'll send you some screen shots. I don't feel right posting ProEFI screen shots in the Motec section.
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maverick



Joined: 25 Jan 2012
Posts: 2

PostPosted: Wed Jan 25, 2012 10:37 pm    Post subject: GM Sensor in Mx00 Reply with quote

turbotwig wrote:
Let me guess... this will also be an engine with variable valve timing and a turbo? Also your first tuning project? ;)

I don't recall hearing about anyone doing this before, but I'm sure someone has.

Another thing to think about would be using an ethanol sensor (like on GM "flex fuel" vehicles) to measure and adjust the fueling and ignition timing. Those maps are fairly straightforward to do, and would probably cause much less of a headache. At least then you would only have to package/carry one fuel system and you could adjust your hoon-level to whatever blend you put in your tank at that point. No matter what, if you make a non-adaptive map, you're going to need to keep both tanks full enough so that you don't run out of either fuel. The tune will be linked to those different fuels. I don't know much E85 you have in your area, but here in California (and *most* places) it's relatively difficult to find. Plus, if you want to save money at some point but you've tuned to having that fuel available, then you're SOL. Then you have to end up making a straight pump fuel base map either way.

-Kirk


Hey Kirk, I'm running an M48 and looking to make the upgrade to a Mx00 for this one of a few reasons. I'd like to use the sensor for another dimension to the fuel and ign tables. But can anyone confirm if the Mx00's will work with the gm sensor?

Many thanx
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turbotwig



Joined: 05 Dec 2005
Posts: 149
Location: Newport Beach, CA

PostPosted: Sun Jan 29, 2012 2:49 pm    Post subject: Reply with quote

For more info on the sensor, check out this link:
http://www.megamanual.com/flexfuel.htm
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