9krpmrx8

iTrader: (46)

Yeah the ID's are. The PTP kits is not really coming along, I am just saving for the turbo itself and gathering smaller parts for the fuel lines and flex fuel adapter at this point. I have a parts car so I will mock everything up on that first.

This time I am doing everything ahead of time while being able to enjoy the car as it is now. I don't want a lot of downtime this go around.

yomomspimp06

use the sheet I sent you. Scale your MAF by the factor that corresponds to the e85 mix you are using. DO NOT scale the 1st 2 cells. you'll get a check engine light. I think Brettus mentions this in a post some time ago. I was trying to figure out why I had a check engine light but it went away after I changed those 1st 2 cells back. I think they are used during cranking? Brett might be able to shed more light there. It gave a crank sensor check engine light if I recall correctly. I suppose scaling the injectors would work just as well but I feel like you get a true IDC when the injectors are scaled correctly.(personal opinion on this. definitely not based on any factual evidence)
e85 is rarely e85. it's worse for those who live further west and north. in my area we get e85 year round.(which is more like e80...) There are seasonal blends that during the colder months can be significantly lower than the summer months: 1= e80 2+e74 3=e70
Blends1.png Photo by dasboodah | Photobucket

logalinipoo

I would think Idc would read true either way., but it might be worth doing both ways to look at different parameters. There's one guy who did e85 with only ve tables.

slash128

Thanks for the info yomom! Do you have any logs running E85? What does the AFR read in the log at idle/stoich? 14.7 like gasoline or 9.7? Or somewhere in between depending on your blend? My thought is that the O2 sensor simply reads oxygen content in the exhaust, which means that even running full E85 at stoich you would still see 14.7 in the log, even though stoich for E85 is 9.1:1 and 14.7:1 for E85 would be really lean...

It's going to be a bit before I can try for myself, unfortunately. We had snow, then rain, now supposed to get more snow in a day or two...

I was also thinking about scaling injectors as opposed to the MAF, but I don't know which would be a better approach yet. I was going down the injector path just because I'd like to see the true(ish) g/s airflow. VE table could be a good strategy as well...

logalinipoo

Humm. Thinking about how the sensor works. Below 14.7 there should be no o2 left in the exhaust. It measures o2 left but will actually move o2 into the exhaust to measure how much below stitch you are.

If running e85 and stioch is 9. Then it might trim until stioch is reached as it's trying to hit 14.7 or no oxygen. It'll be a while but in Jan if I remember I'll swap my lc1 to e85 mode and see how the readings compare to the cobb.

slash128

Right, but the sensor doesn't measure actual AFR for a given fuel. It measures the oxygen in the exhaust and represents it as a voltage. This is what I understand to be lambda. For example lambda = 1 means all the available oxygen was consumed to burn all the available fuel. Leftover oxygen would be lambda > 1 (aka lean) and extra fuel would be lambda < 1 (aka rich). Some fuels require more oxygen to burn completely, some less. The ECU reading the voltage needs to be calibrated to represent the lambda value as a specific fuel AFR value. So my bet would be that a log from one of our cars running full E85 would still show 14.7 at stocih idle, provided the injectors (or MAF, VE, etc.) has been adjusted to deliver the additional fuel required, even though the true air to fuel ratio for E85 at stocih is 9.7:1.

Some links I've been using as reference:

http://www.aquamist.co.uk/vbulletin/...ead.php?t=1531

http://bikearama.com/theory/what-is-...io-and-lambda/

This got me thinking about my ProSport gauge. I recalled seeing a chart on the instructions and based on this I think it confirms my line of thinking:

http://prosportgauges.com/instructio...rb/EVORWWB.pdf

But of course I am open to the fact that I am completely off my rocker, wouldn't be the first time or the last

All this is academic, but also useful for determining tuning strategy. I just need to know what to look for in my logs and on my gauge

yomomspimp06

tomorrow I will hook up the AP to my wife's laptop and see if I can pull any logs off.
Tuning for e85 is the same as tuning for gas. Don't get so caught up in the different lamba values. Pretend you're not using e85 and shoot for the same values. Enjoy the knock suppression and cooling properties by either running more timing or leaning it out a bit.

slash128

This is EXACTLY what I was after! Cool man thanks!!!

Going back and rereading previous posts I think maybe my question was misleading Logan. I wasn't thinking that our cars could determine the particular AFR/Lambda value of any given fuel, I just wanted to figure out what to expect in logs and gauges. Sorry if I made it confusing

hoss -05

iTrader: (4)

I don't agree with this, every seriously tuned car running E85 is running a fuel sensor that I have seen... and for a good reason. If you went down to your local racing fuel stop and picked up five gallons a week or whatever you needed i'm sure you would be fine. Saying all e85 at the pump is the same is not correct. cornahaul more readily takes up moisture and at a low volume pump you will not have as good of a octane rating.

slash128

I don't plan on going full E85. Just looking at options to add a safety margin. I don't think Yomom is full E85 either.

yomomspimp06

I think you are misunderstanding what I'm saying here. I'm saying not to tune for 9.0 AFR of on gas reading wideband. shoot for the same numbers you would while running gasoline.

Read other forum platforms. most closely related forum(7club) even states the same exact thing. tune for the same AFR on the wideband as you would 93. Most tuners have stated that they found more power by going slightly leaner with no added timing vs. going richer with more timing...

since no flex sensor is available for cobb ap, I believe summit sells an e85 tester. For peace of mind, one of those could be used to judge the actual content of e85 being used. I personally never did that though. I just put 3 gallons in, scaled my maf, and let it eat. how do you know if your e85 mix is off? check fuel trims. if your tune was solid on 93 alone, then it will be after the scaling/mix if calculated correctly.

slash128

This is exactly what I was thinking about as I was drifting off to sleep last night. If the mix turns out to be E70, etc., then it will show up in the fuel trims.

9krpmrx8

iTrader: (46)

Well I'm glad you guys are the guinea pigs,

slash128

Aw c'mon and live a little

Brettus

iTrader: (2)

We want to see 500whp E85 dyno Slash ................ Do eeet !

logalinipoo

/\this

slash128

Haha that should get me in the 12's in the 1/4 mile for sure!!!

yomomspimp06

oink oink

QFT
he needs to get some bigger primaries first!

slash128

^--I gave my wife my Christmas list

slash128

Choices

Brettus

iTrader: (2)

wow ....lucky you !

9krpmrx8

iTrader: (46)

I am lucky as well, I have a brand new station near my house with E85 I just can't travel beyond 200 miles once I start running it,

slash128

Being new to this do stations normally carry multiple blends at the pump?

slash128

I thought that's what the flex fuel sensor and adaptronic is for? Worst case I just plan to have a few different tunes loaded on my Cobb. But then again, I hardly drive my 8 outside of town anymore. I hate bugs on the windshield and bumper

slash128

So I had half a tank of 92 E10 in the tank, according to the gauge. I filled up the remaining with E50 which wound up being 7.7 gallons. If our tank is 15.9 gallons that means I had 8.2 gallons of E10 already in the tank. Working out the math this fortuitously put me right around an E30 blend, which is what I was after as a starting point. I estimated this would throw my trims off by roughly +10%. Prior to the mix my LTFT was 0% at idle and my STFT was fluctuating around +/-1%. After driving around for a while and running some errands I got home and had driven about 30 miles, so I figure I've got a pretty good mix flowing now and my idle STFT is now around +12%. So far I am feeling good about the readings and mix...