rio95

I know there are some differences between different ECMs and years, so I thought I'd just ask about my specific combo. I think this is a quick question for someone who knows.

I'm doing flex fuel on my NA setup and bought ID1050x injectors. Will everything work properly if I simply double stoich and halve IFR? Are there any advantages to doing it the long way by going into every affected table?

Thanks!

realcanuk

Should work fine. I have been running that way for 5 years through 2 different setups.

schpenxel

It'll be fine

Cut the IVT terms tables in half also. One is usually already 0 so probably just one table to do

rio95

What IVT terms tables are you referring to? Can you be a little more specific? I didn't think I had to change anything else, but I guess this is why I asked.

schpenxel

Fuel, general, "IVT Terms" section. AFR term and AFR^2 term are the two tables, cut them both in half (second one is probably already 0)

It's more of a "better off" than a "have to" but it's better that you do

rio95

Found them. Thank you for the advice. I'm glad I asked.

Now I just need to figure out how to plug in all the fuel injector data and set it up for flex fuel. I have Greg Banish's first DVD so I don't expect the injector data to be too challenging. I hear the flex fuel stuff isn't too bad either. If you have experience and time to offer any advice on that I'd appreciate it.

I tuned my car with a stoich of 14.2 for 0% ethanol knowing that is close to E10. I'm guessing I put this back to the stock value now since I'm adding a flex fuel sensor. If I do this I'm expecting my tune to still be good when running E10. Is my thinking correct here?

schpenxel

It should be very close.

Flex fuel is easy

Make sure stoich AFR table is setup like factory flex fuel cars, going from 14.68 to 8.97 (or twice that if you've doubling stoich)

There's a flex fuel enable setting under fuel, open/closed loop tab, flex fuel "enabled". If there's a sensor selection (virtual or sensor), select sensor

The default % I used 40% (only used if sensor fails), comp change threshold use 1%, delay volume will depend on where the sensor is, same for transition volume

And that's pretty well it

Oh, and set the PE EQ ratio (alcohol) to whatever you want it to run when on alcohol. Can make it the same as the gas one for now.

That's all I can think of

rio95

I found everything you mentioned except for PE EQ ratio (alcohol). I expected it to be right by the gas one. Do I need to have HPtuners add it or something?

I'm putting the sensor right after the firewall connection by the drivers side valve cover like most people do. Do you know what values I would use for delay and transition volumes?

I saw you reply in a G8 thread and there is mention of the following. Do I need to do anything with these things on my setup? I'm guessing at least some of this applies.

Engine>Fuel>Transient>Transient Fuel Mass Evaporation>Evaporation Factor Blend (copy from 2012 Holden 6.0L sedan file)
Engine>Fuel>Transient>Transient Fuel Mass gain>Impact Factor Blend (copy from 2012 Holden 6.0L sedan file)
Engine>Spark>Advance>Spark Correction>Flex Fuel Spark (copy from 2012 Holden 6.0L sedan file)
Engine Diagnostics>Airflow>Flex Fuel>Flex Fuel Sensor Diag>Enable
Engine Diagnostics>Airflow>Flex Fuel>Flex Fuel Diag delay >10sec
Engine Diagnostics>DTC?s>P0169> SES enable & 1-MIL on Second Error
Engine Diagnostics>DTC?s>P0178> SES enable & 1-MIL on Second Error
Engine Diagnostics>DTC?s>P0179> SES enable & 1-MIL on Second Error

I see you mentioned the table below as well. I didn't even know about these tables! It appears that this is yet another table that modifies spark even with my current setup and fuel. The gas table is currently adding 1-5 degrees up top by the looks of it. Seems like I would have noticed an adder this significant before.

"Mult vs Composition" under "Spark Correction" in the spark-->advance tab

schpenxel

Yeah, total brain fart. I completely forgot about spark.

To add timing you'll want to use the flex fuel spark table and the multiplier table

Spark, advance, "flex fuel spark"
Spark, advance "mult vs composition" (this is used to add a portion of whatever is in the flex fuel timing table based on E content)

If the sensor is right at the rail then transition and delay can pretty much be zero. Fuel trims may go a little wonky for a minute or two during a large transition but not a big deal and won't last long.

Yeah make sure you're in advanced view first (edit, view, advanced). If so, and PE EQ ratio alcohol still doesn't show up then send it in to support and see if they can add it

All the transient, open loop, etc. tables some people pull from other tunes, some leave what's in there stock. Ideally those would be dialed in the same way the gas transient tables are, but that's much easier said than done

rio95

This is a little more complicated than I was expecting. Can you explain how those two spark tables work?

If I run 100% ethanol (no I won't be doing this) will it reference the flex fuel spark table? How does the mult vs composition table come into play? What are some typical values that are used for the mult vs composition table?

What about the AFR Correction alcohol table? It's all zeros right now. Should I use the same values from the gas table?

schpenxel

It's not as bad as it sounds

Basically timing is going to be whatever your current timing is + flex fuel table * multiplier

If flex fuel table says add 5* and say the multiplier is at 0.5 for 50% ethanol then it will add 2.5*. It's just a way of ramping in/out extra timing depending on how much ethanol there is

AFR correction table I've got 0'd out for both. I've read varying accounts on how that table "actually" works but haven't messed with it. Correct way is to use the flex fuel table.

My mult table is basically 0, 0.25, 0.75, 1.0, 1.0

That means with E50 it'll add 75% of the timing in the flex fuel table. At E75 and higher it'll add all of the flex fuel table, with these values of course.

rio95

Hptuners told me that my operating system does not have a PE table for alcohol. How is that possible? It has all the other flex fuel stuff. Do I need to do a custom operating system or something?

schpenxel

Not too unexpected given C6's never came with flex fuel from the factory, the tables are just leftovers from other OS's that do get used with flex fuel. They aren't 100% consistent because GM had no reason to make the flex fuel tables consistent. I don't see that table in any 07 or 08 Z06 tunes that I hvave. It does appear in the 2009 files I have

I'm in the same boat.. 2005 (E40) doesn't have that table either

rio95

Luckily I bet my desired PE table would be pretty similar between gas and E85. I'll just tune it for E85 and maybe it won't be quite optimal for gas, but I guess that doesn't bother me too much. Sounds like there are some other tables I could use too, but I don't think I want to mess with them.

schpenxel

Yeah that's what I did.. not like I switch back to 93 unless I have to anymore..