Official OpenFlash Tablet FA20 Tuning Tech Discussion Thread

[steve99]

Originally Posted by jdcorbitt3

Hello Shiv

I am waiting for delivery of my OFH. Is it safe to run the E85 stage 2 tune with stock intake and exhaust?

John

Hi John,

have a look at this thread

Stock car on E85 stage 2 tune

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

[jdcorbitt3]

I noticed in the above mentioned threads, they talk about the AF ratio being richer, but the number is higher than pump gas. Is because the ratio is in pounds and ethanol has more energy per pound?

John

[steve99]

Originally Posted by jdcorbitt3

I noticed in the above mentioned threads, they talk about the AF ratio being richer, but the number is higher than pump gas. Is because the ratio is in pounds and ethanol has more energy per pound?

John

I am no expert but see here

http://www.brighthubengineering.com/...ir-fuel-ratio/

Gasoline: 14.7

Ethanol: 9

but you have a mix ie E85 and it varies maybe to E70 sometimes

My understanding is Gasoline has more energy content per litre than ethanol, but ethanol has a much higher octane rating than gasoline.

luckily these tuner's have sorted all this out and apparently this tune is good for anything from E60 to E85 given a bit of learning time.

[Malt]

Originally Posted by steve99

I am no expert but see here

http://www.brighthubengineering.com/...ir-fuel-ratio/

Gasoline: 14.7

Ethanol: 9

but you have a mix ie E85 and it varies maybe to E70 sometimes

My understanding is Gasoline has more energy content per litre than ethanol, but ethanol has a much higher octane rating than gasoline.

luckily these tuner's have sorted all this out and apparently this tune is good for anything from E60 to E85 given a bit of learning time.

O2 sensors read stoichiometry so it's not different between gas and E85 from a tuning standpoint. Also the thought that ethanol has a much higher octane value than gas is a myth. I'll post a reference when I find it.

EDIT: http://en.m.wikipedia.org/wiki/E85
It has an octane rating of 94 - 96

[steve99]

Originally Posted by Malt

O2 sensors read stoichiometry so it's not different between gas and E85 from a tuning standpoint. Also the thought that ethanol has a much higher octane value than gas is a myth. I'll post a reference when I find it.

EDIT: http://en.m.wikipedia.org/wiki/E85
It has an octane rating of 94 - 96

"O2 sensors read stoichiometry so it's not different between gas and E85 from a tuning standpoint."

you would need different amounts of gas compared to ethanol or E85 to achieve stoichiometry ?, so it is kind of different


"Also the thought that ethanol has a much higher octane value than gas is a myth"

Well I suppose "much" is a subjective word , but pure ethanol (as opposed to E85 mix ) would have a higher octane rating that E85 ? which is kind of higher that 91-93 for gas

[Malt]

Originally Posted by steve99

"O2 sensors read stoichiometry so it's not different between gas and E85 from a tuning standpoint."

you would need different amounts of gas compared to ethanol or E85 to achieve stoichiometry ?, so it is kind of different


"Also the thought that ethanol has a much higher octane value than gas is a myth"

Well I suppose "much" is a subjective word , but pure ethanol (as opposed to E85 mix ) would have a higher octane rating that E85 ? which is kind of higher that 91-93 for gas

It's not different from a tuning standpoint. The O2 read how far from stoic the exhaust gas is. You are not going to see 9 as a reading on the O2 sensor when using E85, you'll see 14.7, which was my point.

I assumed that most people reading the word "much" would take that as difference greater than 2 octane points. Stations often label their E85 pumps as 105 or even 115 octane. That is not an accurate number and is misleading, which is why there is a common misconception about the octane level of E85.

[Cross]

Look AFR and Lambda are often confused.

Let me put it to you like this, a Wideband O2 reads in Lambda first then converts that to AFR via a conversion calculation based on the gas. in Lambda 1.00 is dead on Stoich be it gas or E85. (All O2's basically do, just with most widebands they will display numbers in Lambda most of the time)

Because this calculation is done to the Lambda number the only real change to make a Wideband read E85 vs Gas AFR levels is to the calculation after the Lambda base is read. This means 14.7 basically = 1 Lambda and Lambda does not care if its gas or E85 its still the same point it reaches 1.

So long story short the AFR you are seeing does not have to be changed because the calculation is still based off Lambda. You are reaching the correct levels and AFR is just a calculation added on top because people seem to be to lazy to learn Lambda.

[ame="http://en.wikipedia.org/wiki/Air%E2%80%93fuel_ratio"]Air–fuel ratio - Wikipedia, the free encyclopedia[/ame]

[Kodename47]

Ideally you'd want to output the O2 sensor as lambda for E85 useage, then use the calculation above to work out the actual AFRs. There is also a table to adjust the reading of the stock O2 sensor.

[Vmax911]

Hey guys, I've done a few pulls with 1.42, and notice my AFR is a bit leaner than it was stock. When I logged stock rom I was 11.9-12 WOT. With this tune I seem to be around 12.5 or so at WOT. Just have a drop in, test pipe, and catback. I'm also around 5200-5400ft. Would any of these cause a slightly lean condition. Is the AFR anything to worry about?


http://www.datazap.me/u/vmax911/142-...zoom=4204-4426


Multiple pulls here
http://www.datazap.me/u/vmax911/142-...g=0&data=1-2-9


Thanks for any helpful feedback!

[Shiv@Openflash]

Originally Posted by Vmax911

Hey guys, I've done a few pulls with 1.42, and notice my AFR is a bit leaner than it was stock. When I logged stock rom I was 11.9-12 WOT. With this tune I seem to be around 12.5 or so at WOT. Just have a drop in, test pipe, and catback. I'm also around 5200-5400ft. Would any of these cause a slightly lean condition. Is the AFR anything to worry about?


http://www.datazap.me/u/vmax911/142-...zoom=4204-4426


Multiple pulls here
http://www.datazap.me/u/vmax911/142-...g=0&data=1-2-9


Thanks for any helpful feedback!

Yes, you will run a little bit leaner than most due to your altitude and the fact that you aren't hitting the same engine load levels (g/rev) as those at sea level. Totally normal and expected.

[Vlady]

Hey all just wondering how you are posting your datalogs on here. I am clueless!

[TM]

Originally Posted by Vlady

Hey all just wondering how you are posting your datalogs on here. I am clueless!

Shiv posted a tutorial here.

After that, you can also export it and import it into Datazap to view and share with others.

[sprintamx]

I posted this in the 1.5x .dev thread, but maybe it's better to post it here (I'm still learning to work the OFT and OFT manager software):

Would someone mind briefly explaining--or pointing me to a thread--the file auto-generate feature? I know that the .bin files were released today, and that this may now be academic. But, I did try--unsuccessfully--to load the 1.5x .dev file. I erased the .bin files I had on the OFT, but kept getting an error message every time I tried to load the .dev file in the OFT database management section: "File size incorrect."

Obviously I didn't / couldn't load the .dev file and so I don't know what I should have expected to see on the OFT during the "write" process in the car.

So, either I did something "wrong" or there's another problem I don't know how to identify / diagnose.

Thanks in advance.

[steve99]

Originally Posted by sprintamx

I posted this in the 1.5x .dev thread, but maybe it's better to post it here (I'm still learning to work the OFT and OFT manager software):

Would someone mind briefly explaining--or pointing me to a thread--the file auto-generate feature? I know that the .bin files were released today, and that this may now be academic. But, I did try--unsuccessfully--to load the 1.5x .dev file. I erased the .bin files I had on the OFT, but kept getting an error message every time I tried to load the .dev file in the OFT database management section: "File size incorrect."

Obviously I didn't / couldn't load the .dev file and so I don't know what I should have expected to see on the OFT during the "write" process in the car.

So, either I did something "wrong" or there's another problem I don't know how to identify / diagnose.

Thanks in advance.

sounds like you did everything correct, deleting all bin tunes then loading dev tunes. probably have to ask the OFT guys.

looks like they removed .dev download link to 1.5 tunes, sorry can't help