^ Unfortunately a wideband will not be able to tell the fuel composition. Wideband measures lambda only, and it's the same for any fuel you burn.

I'm not sure what you mean by "A" part.... But the purpose of WI is to decrease burn temperatures in the combustion chamber, it makes the burn "cooler". And again WI is good with whatever fuel. Ethanol burns cooler than gas, but water is still much better than ethanol when it comes to heat removal.

 

^+1

Not sure about the burn rate of ethanol, I'll have to look that up, but in general the higher the octane the slower the burn rate not the other way around.

 

Oh, i think i got it A stands for alcohol
You're right injecting ethanol with ethanol doesn't make much sense, it makes a little bit of sense especially when E70 is available instead of E85.
But water injection is still beneficial, even if just for added protection/margin. I am thinking about adding that to my car at some point. I would tune without it though, and then turn it on, so that i don't have to worry about failsafe's.

 

You're talking about gas. And higher octane gas burns slower than lower octane gas. Ethanol though is different from gas, and yes, its burn rate is quicker than that of gas.

 

high octane gas does not burn slower than low octane. they have the same laminar flame speed.

 

Ok, I'm confused. So can you or can't you tell E85 - E70 content with a wideband? The only thing holding me back is I live in colorado and 9 months out of the year it's probably E70. So it's important to know whats in the tank. You mix E85 with E70 etc... Is there a more conservative setup that would allow for a min of E70 and a maximum of E85 with a single map. Or is it as simple as running lower boost or using a boost taper with and EBC.

 

You wouldnt be able to tell the blend directly with a wideband, but you could tell if there was more or less ethanol than when you tuned your AFR depending on if you are leaner or richer in open loop, and also by looking at how your closed loop fuel trims are changing. I also think a single tune could work fine if you tuned the timing and boost on the winter blend, and left room for the AFR to lean out a half point or so. You would have to log it though the seasons to make sure though..

 

Well you can't use a wideband to tell what kind of fuel u have or what is ethanol content in the fuel. If your tune is SPOT ON and each time you step on the fun pedal you see the exact same AFR, and then one day you see a richer AFR you can guess that there's less ethanol and more gas in the fuel. But AFR's change because of a number of reasons, for example weather.. So you can tell, but it's not concrete evidence.
A much better way to tell is to either have a gauge or have a free very simple CEL knock mod by Tephra... You can get tuned for E85 and reduce boost once you start seeing knock or you can get tuned for E70 and leave it at that like Merkzu suggests which is a safer solution if you don't do any tuning yourself.

 

Yeah that's what I meant lol.

Anyway, I had a big explanation of AFR that I deleted because mplspilot is basically right, and the suggestion about the CEL mod is a good one as well. I assume he's referring to the mod that will blink your CEL when you knock. And knock is really all you are trying to prevent anyway.

Of course, if you are going to self tune, you need a wideband anyway

Merzku, what do you do out of curiosity? Tune to winter and leave AFR room like you suggested? Or retune seasonally?

 

EDITED: Sorry! Redundant info!

 

I just retune when I need to. It's not that much work to do really. I really hope for an ecu mod to allow regular gas on the low octane maps and ethanol on the high octane along with modded ecu boost control so the ECU can just handle all the boost/fuel/timing changes itself. That would totally rock.

The Saab 9-5 Aero Biopower ECU will adjust boost/fuel/timing automatically from the factory. An Evo that could do that would be freakin awesome. http://www.carpages.co.uk/saab/saab-...r-03-01-06.asp

 

Here's a DLL from a couple of weeks ago, highway 3rd gear, had to stop the pull at like 6500, but you get the idea.. No correction. Waves are from wrong heat range plugs that i had in at the time and not perfectly tuned boost error correction (ecu boost control). fwiw. This is ~26 to 21.5 psi

 

Damn nice looking graph man!

Do you have any graphs of what hp/tq levels you were hitting on the stock turbo with E85?

 

Mplspilot those are some impressive numbers! Green turbo+green gas=FTW!

 

Thx! I can't find any graphs..., i got a million logs, i tried to go through some, but it would take a while I was hitting around 340tq/hp with my stock 9.8 16G. Actually it was probably 350 or so...