CES eth content sensor installed, flex fuel patch coming soon - Page 3

evo8dad · Jul 14, 2009, 06:24 AM

Quote:

Originally Posted by mrfred

If you are using the toggle to switch from low to high boost, then for sure it will go away in m1 because the ethanol content signal will be fed into ADC_0F which is the same input used for toggle-switch based map switching. If enough people want low/high boost, I may be able to implement some alternative means, but that wouldn't happen until m2.

Just caught this. So If we are using TPS as the toggle switch than we will still retain the ability for map switching since it is not on ADC_0F??

Quote:

Originally Posted by mrfred

I could, but it would save me a lot of time if I did it with my own ROM which I have much more extensively annotated. If tephra doesn't send me something soon, I might do the 96530706.

96530706 may reach a broader base of testers though

mrfred · Jul 14, 2009, 09:01 AM

Quote:

Originally Posted by evo8dad

Just caught this. So If we are using TPS as the toggle switch than we will still retain the ability for map switching since it is not on ADC_0F??

...

Possibly, but I would need a good reason for it work like that because it would take quite a bit of additional effort to code it. What reason would you want it?

evo8dad · Jul 14, 2009, 09:06 AM

Quote:

Originally Posted by mrfred

Possibly, but I would need a good reason for it work like that because it would take quite a bit of additional effort to code it. What reason would you want it?

My thought was that since e85 hasn't become all that popular in the northeast (not yet at least) I'd like to have the ability to run e85 on my car as well as customers' cars through the alternate fuel/timing maps and be able to switch to those maps using the TPS. Although in this case the e85 would be from a supplier such as Rocket Fuel or VP (if they make an e85) so the e85 content should be just that - 85% Ethanol.

The problem is that most people would simply dump the e85 into their tanks with very little 93 left in the tank, however, that 93 and e85 would still mix and reduce the e85 somewhat until the 93 has made it through the system and its pure e85. Until than though it would be nice to have this feature so that the ECU can use the mapping in the way your describing for the 93/e85 mix until it is pure e85.

Thoughts?

logic · Jul 14, 2009, 09:15 AM

mrfred, are you factoring in fuel temp with this patch at all, or are you skipping that for now?

spdracr · Jul 14, 2009, 09:16 AM

the only thing i would be worried about is will the boost beable to interpolate like the fuel and timing maps.....obviously you would have to run ecu boost control but i would imagine it cant really interpolate boost tables accurately? can it maybe im wrong i hope i am lol

mrfred · Jul 14, 2009, 10:55 AM

Quote:

Originally Posted by evo8dad

My thought was that since e85 hasn't become all that popular in the northeast (not yet at least) I'd like to have the ability to run e85 on my car as well as customers' cars through the alternate fuel/timing maps and be able to switch to those maps using the TPS. Although in this case the e85 would be from a supplier such as Rocket Fuel or VP (if they make an e85) so the e85 content should be just that - 85% Ethanol.

The problem is that most people would simply dump the e85 into their tanks with very little 93 left in the tank, however, that 93 and e85 would still mix and reduce the e85 somewhat until the 93 has made it through the system and its pure e85. Until than though it would be nice to have this feature so that the ECU can use the mapping in the way your describing for the 93/e85 mix until it is pure e85.

Thoughts?

I'm definitely planning to keep alt maps. I just don't intend it to be operable when the flex fuel option is selected.

Quote:

Originally Posted by logic

mrfred, are you factoring in fuel temp with this patch at all, or are you skipping that for now?

Skipping that, probably permanently because the fuel temp value is not converted to a 0-5V analog value, and even if it were converted to analog, then another spare ADC input would be needed.

evo8dad · Jul 14, 2009, 11:01 AM

Quote:

Originally Posted by mrfred

I'm definitely planning to keep alt maps. I just don't intend it to be operable when the flex fuel option is selected.

Is it possible to have the flex fuel option on alt maps for the reasons I mentioned? Or is this what you were referring to as alot of coding on your end?

mrfred · Jul 14, 2009, 11:31 AM

Quote:

Originally Posted by evo8dad

Is it possible to have the flex fuel option on alt maps for the reasons I mentioned? Or is this what you were referring to as alot of coding on your end?

What you are asking for will be covered by the flex fuel option. With a flex fuel option enabled, the ECU will interpolate between two sets of maps depending on ethanol content. If one set of maps represents pure 93 oct and the other set represents pure E85, then it seems that the flex fuel option should do exactly what you ask.

Now if you are asking for some kind of flex fuel interpolation over a narrow range with no flex fuel sensor (an expensive flex fuel sensor and gauge has little value for people who mostly run 93 oct), that's definitely not possible.

evo8dad · Jul 14, 2009, 11:59 AM

Quote:

Originally Posted by mrfred

What you are asking for will be covered by the flex fuel option. With a flex fuel option enabled, the ECU will interpolate between two sets of maps depending on ethanol content. If one set of maps represents pure 93 oct and the other set represents pure E85, then it seems that the flex fuel option should do exactly what you ask.

This is exactly what I was referring too. Although the more I think about maybe its not really necessary for those of us running mail ordered e85 since it should ("should" be the key word) be pure e85 with consistent batches. It may still be a good idea though to run the patch even if we are running mostly 93 for daily commuting and racing with e85 that way if a bad batch (less than pure e85) is used the ECU will compensate for this.

It would also be a good thing to have for the mixing period of 93 and e85 when the e85 is initially put in with a little bit of 93 left in the tank. That way the ECU will interpolate for the mixing of the two than for the pure (or close to it) e85.

This sounds really cool

If you need a 96530706 tester let me know as I'll have one ready with this exact setup (albeit also running SD) in a few weeks.

bustin · Jul 14, 2009, 12:17 PM

This is something that I have been talking about ever since I learned how the flex fuel vehicles worked. I thought it would be awesome to have the ECU compensate for the fuel that its seeing. Now, thanks to MrFred, we have that option.

Thanks man. Once I see this released I will definitely have to give it a try!

mrfred · Jul 14, 2009, 12:20 PM

Quote:

Originally Posted by bustin

This is something that I have been talking about ever since I learned how the flex fuel vehicles worked. I thought it would be awesome to have the ECU compensate for the fuel that its seeing. Now, thanks to MrFred, we have that option.

Thanks man. Once I see this released I will definitely have to give it a try!

You'll need a GM flex fuel sensor and a Zeitronix ECA as well.

TTP Engineering · Jul 14, 2009, 12:43 PM

Quote:

Originally Posted by mrfred

You'll need a GM flex fuel sensor and a Zeitronix ECA as well.

We have the Zeitronix ECA in stock.

Unfortunately however without a Siemens content sensor, you won't get a reading.

Shortly we will be selling them with the sensor as a package.

merkzu · Nov 6, 2009, 11:16 AM

Quote:

Originally Posted by mrfred

I finally got around to installing my ethanol content sensor and CES ethanol content display. It took three evenings, but it turned out really well. The F-V converter is mounted behind the glove box, and the display rests freely in the glove box. I just have to open the glove box to see the display. Nice stealth installation.

I've also got the analog output wired into ADC_0F, so everything is in place to make use of a flex fuel patch. As soon as tephra releases an 88590715 for testing, I'll begin work on a flex fuel patch for that ROM (and then other v7 ROMs as requested). If anyone wants to use the flex fuel patch, you'll need to do two things:

1) You'll need to have an ethanol content system that has a 0-5 V analog output. Wire the analog output into ADC_0F.

2) Make sure your ethanol content analyzer is wired into an IG1 power source. This is needed so that the analyzer continues to function while the engine is starting. Fuses 1-4 in the cabin fuse box are all IG1. I used a mini-add a circuit from Autozone to tap into fuse #4.

Hey mrfred, this still something you're working on?

mrfred · Nov 6, 2009, 03:48 PM

Quote:

Originally Posted by merkzu

Hey mrfred, this still something you're working on?

Now that v7 is out and I've finished my foray into the fuel control routines, I'm ready to begin work on the flex fuel patch. Just have to finish a few jobs for a few people.

logic · Nov 6, 2009, 04:17 PM

Those other people are unimportant. Pay them no mind. Flex fuel is all that matters.

Seriously, I'll get a posse together if people are bothering you. It's only, what, four days of driving to get to WA from Chicago?

(In a related vein, and I'm totally out of my area of expertise here, but wouldn't it be relatively easy to whip up something to do conversion from frequency to voltage with an arduino, or something even simpler, built around a $2 F-to-V chip? I'm sure Zeitronix's product is fantastic, but I don't really need a $200 display.)