E85 and the BigStuff3 FTMFW! Thanks DieselGeek!

[ProRauder]

This last weekend I *finally* got around to taking the BS3 tune Scott (dieselgeek) modified for me and putting it on the car. Scott, all I can say is *WOW*! It not only idled and ran, but it ran GOOD!

I modified the settings in my AutoMeter wideband to set stoich at 10.7 and watched it. Both the BS3 dashboard and the autometer tracked it at a perfect 10.7 when warmed up. We've still got Winter blend E-85 so I set it to look for E-70 and that what it was.

So, knowing I am running th E-70, what would be the next step to enable automatic O2 correction in the tune?

I am guessing I need to modify the AFR table and multiply all the values by (10.7 / 14.7) to account for the new stoich target, but what actually turns it on?

Cheers and a big Thanks!

John

[dieselgeek]

Re: E85 and the BigStuff3 FTMFW! Thanks DieselGeek!

Got your email over the weekend, sorry for the late reply - we were thrashing on another car and I didn't have time to reply...


Can you resend me your file again? there's a menu option to disable closed loop correction, all I did was turn that off just to make sure your e85 tune would be close. We got lucky that it's that close - I am glad to hear it runs good!!

If you don't see the menu option, send me your tune and I'll go through it. I don't have it committed to memory, too many systems out there to remember. lol

[ProRauder]

Re: E85 and the BigStuff3 FTMFW! Thanks DieselGeek!

I know you're a busy man!

I will look for the option to enable/disable O2 correction again. As for the AFR table, am I correct in thinking I just need to modify it by applying the the math (10.7/14.7) to the whole table?

I'll send a copy of it back to you regardless so you can file it away in case someone else needs it.

BTW, I did talk to BigStuff3 last week and was told they are close to releasing an update that uses the GM flex-fuel sensor and adding a bunch of features to support E-85. I just couldn't wait and tried your solution.

Cheers!

John

[dieselgeek]

Re: E85 and the BigStuff3 FTMFW! Thanks DieselGeek!

I know you're a busy man!

I will look for the option to enable/disable O2 correction again. As for the AFR table, am I correct in thinking I just need to modify it by applying the the math (10.7/14.7) to the whole table?

I'll send a copy of it back to you regardless so you can file it away in case someone else needs it.

BTW, I did talk to BigStuff3 last week and was told they are close to releasing an update that uses the GM flex-fuel sensor and adding a bunch of features to support E-85. I just couldn't wait and tried your solution.

Cheers!

John

you are correct, since you rescaled your wideband output, you want to just set up your target tables to go for the correct AFRs you seek. You could also have left the wideband output un-scaled, and just targetted the same AFRs that were in the existing tables already, although you're looking at incorrect AFRs. It shouldn't really matter.

Take Sean's advice though, and note that when you get different batches of fuel from different suppliers, you will see AFRs varying wildly. Don't trust your closed loop correction to be any good for more than about 10% (it reacts too slowly) especially for WOT pulls. I.e., keep an eye on AFRs at all times and don't fall into the habit of letting it correct itself perfectly...

[ProRauder]

Re: E85 and the BigStuff3 FTMFW! Thanks DieselGeek!

I understand. I picked up two 55 gallon plastic fuel drums and a plastic pump from a friend this last weekend. I plan on waiting till they get the summer blend at the pump and then filling these. Once I have it tested to know exactly what it is, I will use this only for racing and know that it won't change and tune accordingly for the season. Between races, I can put whatever is at the pumps and keep an eye on it.

As long as the tune is extremely close in closed loop during testing, I'll leave it in open-loop for racing. Don't want a bad O2 sensor to ruin my day, week, month, motor...

LOL!

[horsewidower]

Re: E85 and the BigStuff3 FTMFW! Thanks DieselGeek!

Careful, our experience has been that e-85 will seep through some plastic containers. test your containers first. You need to keep it out of heat and light.

Ethanol is hygroscopic (sp?) it has an affinity for water at the molecular level. We left it in a vented fuel cell in our racecar and it absorbed enough water over a 6 month period to be unusable. You can buy a Zeolite molecular sieve to dry it out, that's what I'm trying to buy right now, but it can't be stripped of the water by most normal methods. I bought a "water blocker" filter from Tractor Supply Company, once I got it home there was a big note on the directions saying that it would not strip water from alcohol.

We have another 100 gallons in a couple of 55 gallon metal drums, I'll check those to see if they have absorbed too much water. I'm going to be pissed if its bad, its a blend of 100 octane racefuel and ethanol.

Bob

[ProRauder]

Re: E85 and the BigStuff3 FTMFW! Thanks DieselGeek!

The guy I got the drums from sells race fuel and made sure the seals and o-rings were in good shape. He explained to me the ins and outs of storing fuel, sealing the drums between uses and such. All good advice as shown above.

However, I play the BS card on Ethanol weeping from the drums. It would have to be damaged for that to happen. With Ethanol being corrosive, I would think that metal drums would be worse than plastic. But this is my first rodeo with this so I could be wrong.

<smile>

[horsewidower]

Re: E85 and the BigStuff3 FTMFW! Thanks DieselGeek!

I have no experience with the drums you sourced. We had problems with a white plastic dump can. Maybe it was an isolated experience.