10° This week. e85 or 93

[Luckrider]

Originally Posted by bfrank1972

I'd bet that Shiv's tune is very conservative considering that it has to work with a range of ethanol contents (E50-E90). If so, that means he's sacrificing ultimate power for safety (smart). Flex fuel/Race Rom would allow you to have multiple maps that are ideal for varying levels of ethanol content in your fuel - I believe Delicious Tuning made around 200whp with E85 on an otherwise stock car. I'd bet anything that car's ethanol content was a true E85 (vs something less like a 'winter' mix), and the timing was significantly more aggressive. I know I'm running significantly less than 85% ethanol in my tank, and my EL OFT tune (my car is stock) is not experiencing any significant knock at all.... but it doesn't feel like 200whp either (although it's peppy!).

It isn't safe because it is that conservative with e85 maps, it is safe because the computer is smart enough and has enough flexibility in the basic logic to adjust long term fuel trims to accommodate the provided fuel to match the fueling requirements.

[bfrank1972]

Originally Posted by 1086

According to Shiv, and my results, I am reaching very close to 200 whp. Here is my thread with results and details from the other day:

http://www.ft86club.com/forums/showthread.php?t=56452

Hmmm well I'll believe it when I see a dyno - my own personal experience butt dyno seems less, but maybe I'm just getting used to it I'll post up some logs in a bit.

[1086]

How many miles have you driven on a straight tank of only E85 thus far?

[bfrank1972]

Originally Posted by Luckrider

It isn't safe because it is that conservative with e85 maps, it is safe because the computer is smart enough and has enough flexibility in the basic logic to adjust long term fuel trims to accommodate the provided fuel to match the fueling requirements.

I undertand the flexibility of our wonderful ECU.

My point was that I am *sure* that I am not running full E85. I had some gas in my tank. My car starts just fine in 9 degree F weather. My fuel trims are minimally adjusted. My IAM is fine. Just seems to me that if I were running something like 60% ethanol on a tune that's ideal for 85% ethanol, I'd see bigger timing corrections and bigger fuel trims in my logs....

[bfrank1972]

Originally Posted by 1086

How many miles have you driven on a straight tank of only E85 thus far?

Hmmmm probably 150 - yeah I know it takes the ECU a bit to adjust itself. But logs seem stable... And it's not a straight tank of E85 - heck I'm not even sure what ethanol content the filling station is running. It's winter and I imagine I'm far enough north that the may run lower ethanol content at their ethanol pumps? Definitely had a gallon or two of 93 in the tank when I filled up.

[1086]

Right, well that right there could easily be holding back 10 horsepower give or take. I am in California, so our 'winter blend' could be totally different - which is likely the case. The E85 station I use has a label telling you the minimum ethanol content (70% for me), idk about others though.

I noticed that once I had a full tank of only E85 (nothing else) there was a noticeable difference vs. an 80%/20% mixture of E85/91

[bfrank1972]

Originally Posted by 1086

Right, well that right there could easily be holding back 10 horsepower give or take. I am in California, so our 'winter blend' could be totally different - which is likely the case. The E85 station I use has a label telling you the minimum ethanol content (70% for me), idk about others though.

I noticed that once I had a full tank of only E85 (nothing else) there was a noticeable difference vs. an 80%/20% mixture of E85/91

I guess that's true - I'm guilty of a lot of speculation on my ethanol content based on my logs. I really should try to analyze what I have in my tank if I want to be scientific about it. The thing that gets me is my fuel trims aren't that off - I'd think if I were losing power due to ECU compensation for the lower ethanol content I'd see >5% deviance in the upper LTFTs? Either way I'm happy - it makes the car pretty peppy now!

[Luckrider]

Originally Posted by 1086

Right, well that right there could easily be holding back 10 horsepower give or take. I am in California, so our 'winter blend' could be totally different - which is likely the case. The E85 station I use has a label telling you the minimum ethanol content (70% for me), idk about others though.

I noticed that once I had a full tank of only E85 (nothing else) there was a noticeable difference vs. an 80%/20% mixture of E85/91

That is the legal min allowed for marketing as e85. As far as power, more e% can't net more power NA because there simply isn't anything left to gain in fuel at that point from my understanding. FI is a totally different story though.

[SmsAlSuwaidi]

Originally Posted by 1086

Sounds like another want. But whatever makes you smiley-face

Oh i forgot you guys have the epic OFT that magically adjusts its self, ma bad


Sent from my IBrick

[bfrank1972]

Logs on my E85 'mix', 3rd gear run to redline, about 25 degres F (1.42 E85 EL map, completely stock car sans washable air filter in stock airbox).

http://www.datazap.me/u/bfrank1972/f...zoom=4094-4492

I'm still learning this stuff - but it looks terrific to me. @shiv@vishnu how does it look? FYI I have absolutely no problems starting the car whatsoever using the OTS 1.42 E85 EL maps even at 9 degrees F - though I do get misses and some minor intake backfire for a minute or so during cold idle cycle.

Also a question related to HP output - is it possible use MAF voltage logs to extrapolate HP increase? For instance, say I want to judge relative HP increase from the 91 stage 1 map to the E85 EL map I have - can I compare a MAF voltage log from the stage 1 map to a MAF voltage log from the E85 map and estimate a percent increase over the power curve?

[davehufnagel]

Can someone who did the flex fuel kit who wired the kit into the ECU please link me to the correct diagram showing where to wire into the content analyzer?

[w00t692]

Starting actual 85% ethanol in those temps is pretty much impossible. It's too much ethanol content to get proper atomization of the fuel to crank. This is why winter ethanol blends are between e60 and e70.

[CaptainSlow]

Your local stations actually have E85? The ones around here are running a winter blend of around E70. I ran through one tank of that and went back to 93 until spring.

My thing is that I can't use the extra power when the roads are covered in snow and the tires are hard as rocks, so there really isn't any point in running E85 until it warms up. It might be cheaper, but the mileage reduction balances things out pretty evenly, so it really comes down to power for me. That, and I'm not willing to risk any engine trouble from running less than 85% ethanol

[Luckrider]

Winter blend is certainly not e60 to e70 as all pumps around here (the few that we have) say 70% minimum. I myself have not been having major issues, but I have been working on making cold starts better for people with higher e% fuels.

As far as atomization is concerned, that isn't the problem, the problem is the flash point (the temperature at which the fuel turns to vapor) of e85 is way higher than gas.