I just thought I would start a thread detailing the information I learn and have learned on tuning for E85. As mentioned in the other thread, it is something I want to explore.
Sooooo any hints here? If not I will just wait for someone from the Cobb forums to respond I guess. My guess at this point is that I need to change the injector scaling. Then, I can use the tables that cobb provides in their tuning guide to dial in the AFR's I want and then log and see how it goes. From what I have been told so far, the stock sensor will read lambda but display it as if it were gasoline afr's...but actually it will be reading leaner than it is in reality...so a 14.7 reading will be like 9.77, etc.
Your BSFC will be alot higher on E85 obviously. E85 is a cheaper fuel but your car will require alot more of it so it almost negates the purpose of running it compared to 93 octane. Lambda 1.0=14.7 A/F on GASOLINE Lambda 1.0=6.4 A/F on Alcohol Lambda 1.0=9.7:1 A/F for e85 To my knowledge there are not many Widebands that will read lower than 10.0 A/F ratio. However, All widebands read lambda and then multiply by a constant for a given fuel type to calculate an air/fuel ratio. So its simply a matter of math to get the number youll want ie If your wideband is configured to read gasoline a/f(which almost all are), then just divide the a/f displayed by your wideband by 14.7 to get the lambda. If your Wideband Reads 14.7:1, the lambda is (14.7/14.7) = 1.0 If your Wideband Reads 12:1, the lambda is (12/14.7) = .82 If your Wideband Reads 11:1, the lambda is (11/14.7) = .75 since most wideband o2 displays dont read that low, you would either: have to change your wideband to display a e85 a/f ratio (which isnt likely) or tune for 1 lambda via your management software Read this thread, should help alot http://www.innovatemotorsports.com/forums/showthread.php?t=3175 in other words, you cant slap in a wideband and tune e85 via the display, it needs to be read in lambda, not A/F ratio.
Right, knew that, my question was actually Street tuner specific...when dealing with the afr's in the base fuel map, do you have to convert lambda of alcohol into an AFR for gasoline (o2 sensor is reading in lambda and thinks it is gasoline...so 1 lambda is actually 9.77 afr, but displays as 14.7 because the sensor and the computer still thinks it is running gasoline) and then put that value into the fuel map in the primary fuel tables?
I guess I confused WJM...no it is not stock for a Subaru...I know and I am sorry....it is not even JDM!
I think that is WJM's way of subscribing to a thread while not posting anything of merit ^^^my way of subscribing to a thread without posting anything of merit
IMO, and im sure more seasoned veterans like Dan, Doug, Siegel can comment an correct me if i am wrong.... Lambda is Lambda, it doesnt change. It is a constant. The fuel you are using changes. This is the whole reason for the Lambda scale to keep things consistent. If you tune to 1 Lambda, no matter what your "fuel numbers" are in your base fuel map, it will always be correct as long as you know what stoich your fuel is. 1 lambda for E85 is 9.77 afr 1 Lambda for 93 oct is 14.7 afr Since your wideband cant read lower than 10.0 AFR, youll want to read only LAMBDA since that number never changes. make sense? E85 stoich is ~9.7:1, depending on the blend of your favorite gas station. Typical gasoline stoich is 14.7:1. 14.7:1 = lambda 1 for gasoline 9.7:1 = lambda 1 for e85 All widebands read lambda and then multiply by a constant for a given fuel type to calculate an air/fuel ratio. Have you ever seen where you select the fuel type for a wideband's units, and the displayed a/f changes a LOT even though the car is running the same? If you set your wideband units to gasoline, it takes whatever lambda value it reads and multiplies if by 14.7. So, if your wideband is configured to read gasoline a/f, then just divide the a/f displayed by your wideband by 14.7 to get the lambda. If your PLX reads 14.7:1, the lambda is (14.7/14.7) = 1.0 If your PLX reads 12:1, the lambda is (12/14.7) = .82 If your PLX reads 11:1, the lambda is (11/14.7) = .75 don't think of lambda as an a/f ratio.. lambda indicates a rich or lean condition relative to stoich. (stoich is always 1 lambda and always the value at where no extra air/fuel is left in the mixture)... The fuel qualities of gasoline differ from the fuel qualities of alcohol and this results in different a/f ratio's to achieve the same lambda. for instance, .8 lambda relates to an 11.8:1 a/f ratio w/ gasoline and a 5.1:1 a/f ratio w/ alcohol. Google a lambda:air fuel ratio chart and you should be able to see how all the values relate. I don't know the actual e85 values that relate but if you tune for lambda you don't need to know Read these to http://www.megasquirt.info/flexfuel.htm http://www.megamanual.com/PWC/ http://e85forum.com/viewtopic.php?t=44 NOTE: I have never tuned E85, only 93 octane. An ive never tuned a subaru. Just merely throwing the info i know out there so feel free to cross check it with other more qualified tuners that i mentioned above.
the common O2 sensor, Oxygen sensor (otherwise known as a "narrow band"), does not read lambda, nor does it report AFR or lambda. It reacts to the oxygen content in the exhaust stream and reports a voltage difference back to the ECU. The ECU takes that data and does what it does with it. The actual OBD/Mfg specific datastream is actually translated data from the raw ECU data. For any standard O2 sensor reading the stream usually reports in raw form, voltage. The reading range of these sensors is 0.000 volts to 0.999 volts. Its only accurate in the 14.2 to 15.2 AFR range for gasoline. Wideband sensors are wrongly called O2 sensors. They may function the same by reacting to elements in the exhaust stream and reporting voltage back to the ecu, but thats where their similarities end. These wideband sensors, depending on application and manufacture, can be accurate within 0.01 AFR/Lambda with gasoline from 8:1 to 20:1. Since most vehicles operate in the 12.0 to 15.5 range, they are very highly accurate in that range. These commonly operate in the 0 to 5 volt range. Most commonly on OEM applications they have a typical output voltage of 3.1 to 3.5 volts. The SUBARU ECU is scaled such that 11.15:1 is the lowest value that can be translated. The SUBARU ECU uses mA differential across the bridge to determine AFR/lambda in its raw data.
also correct The only thing an OEM O2 sensor is good for is EMISSIONS. There are some o2 sensors out there that people will use for tuning, but id much rather trust a WIDE BAND from someone like PLX or Innovative than my on board factory o2 sensor. :coolugh:
Oh I agree...and I have an innovate LC-1 for tuning....I guess once I have scaled the injectors I can vary the AFR in the primary fuel table and try to work around the computer...trick it so to speak. Since the injectors will be scaled for alcohol 14.7 should be 9.77 and so on and so forth. That is the hope and that is what I was trying to confirm....The innovate works based off of lambda and is supposedly accurate with E85. That is what I use for tuning once I get the base tune...I am just trying to figure out the base tune for E85 at this point.
Yup. Altho some (not US makers, but most Euro and Jap) makers actually do use a REAL wideband AFR sensor...VW is one of them. SUBARU's front A/F is really accurate from the data logging I've seen...still, having a known good 3rd party involved is the best.
It is pretty dang close when compared to my LC-1. Usually only vary by around a tenth of a point until below 11.00.
Interesting, I'd never heard this, thanks for the informative post. Other than that I've got nothing else to add to this thread. I'd really like to see some locals make sick E85 numbers, I'm very interested in running it but its still too hard to find reliably. I'm thinking next weekend when I head to Fayetteville for the meet down there I'll fill up with some E85 and see how the JDM ECU reacts. It really loved when I ran toluene so I'm anxious to see how it reacts to the high alcohol count of E85. Alex this means I'm going to be getting in touch with you later on in the week for some datalogging on 93 vs E85 after I top off since I'm lacking a laptop and Tactrix cable and you're nearby.
I found this funny! Do you really think someone that makes their living tuning will tell you how to tune?
Actually Scott has been amazingly wonderful about that. Most occasions that I have talked to him he has been very free with information. Not only that many of the big name tuners are quite willing to share over on NASIOC and on then there is Christian on Cobb tuning's site.
From what I understand, down to about 33% E85 is ok for the stock computer. After that it starts getting a little confused. Just make sure and give it plenty of time to adjust and realize that it is going to need to give more fuel in pretty much all areas of the map. Till it figures this out it is going to be running quite lean!
Most tuners are very free with basic (for them) knowledge. Its when it gets into tips and tricks that they start getting tight lipped. Christian from Cobb didn't really want to come off with the info on coolant temp tables when we were on One Lap Scott had to really hound him about it and to this day Scott, Dan, and Christian are probably the only tuners that know what the secret to getting the car to run with high coolant temps is. I'm not telling anyone else and I don't think they are going to either. Matt
All I can say is that this is the information age...nothing stays a secret for too long with the internet up and running, lol!:beer:
Hey man I am always learning...the pros were all joes once upon a time. The difference with me is I am not seeking to do it for a living. I am just doing it for a hobby and sharing what I learn with other enthusiasts. Actually...that's what this site is all about!!
Well, I am now running a E20 blend....actually E17.xx, but close enough. What I was able to do was to put it in and make a rough guestimate of needing 5% more fuel. I then made my injectors 5% smaller through scaling them down. From there I was able to fine tune using the tuning worksheet that Cobb puts out. I was able to adjust the intake calibration until fuel trims were spot on! I was pretty close. It actually ended up needing 7% more fuel at this level (instead of the 5% I originally put in) running the same values converted to lambda that I had for gasoline. First impressions are that the ECU loves this stuff!! It pulled hard! Advance was up a little, but not much, but then I did not mess with it much. I just gave a bit more advance on the high load areas and it still kept the IAM at 16. After getting the fueling dialed in a bit better, I could not make the IAM go below 16, lol. But I did not want to push things too far. I'll let you guy know how things go as this little experiment progresses, but for now, the car seems to LOVE it!! Assometer says some increase. I have a before dyno, so after I get it running on 100% E85 I will dyno again and see how it does.
Up to E30 at 17.0 psi of boost and still have some room left in the injectors...but that was at 75 degree ambient temps...I predict that in the winter they would be maxed! Odd thing is that it seems that as I dial in more fuel, the ecu is adding a touch still in the low rpm, low load areas of the map, but it is still pig rich in the upper areas of the map. I was seeing 10.33 afr (calculated for gasoline) on the wideband. But in the lower load areas it was actually having to add a bit of fuel back in. I wonder if that is a function of the ECU or if it is something related to how the fuel flows with the added ethanol?
Some odd things I am noticing. On the ECU Knock Learning page, which for those not familiar shows where the ECU is pulling or adding timing...pulling indicated by negative numbers, adding by positive, I am seeing positive numbers popping up around peak torque. Previously it was pretty much zeroed out. I might see a +.50 or -.50 in a certain area depending on outside temps and such, but now I am seeing +4.0, +5.0 all around the peak torque are of the map...3200-4200 rpms. Pretty crazy that I have raised the boost a bit, added in a couple degrees in the timing and the ECU is giving it even more! This definitely corresponds to the fact that it feels like it is pulling harder than ever before...this is on E30 still. With these results, I can't wait to see what it does on 100% E85
I'm running 50% e85 in my n/a car without tuning and it's worked great so far. A lot of people have run 50,000 miles in their car already with this mix and have been quite happy. I'll be getting tuned in the next week or so and see everything has been holding up.
Great! Is it modified much or just stock? There are several conversion kits I have seen online for stock cars to convert to 100% e85. The one I have seen that looks nice is the FFI platinum. I spoke to the owner who runs it on his H2 and he has put over 60,000 miles on the hummer using it and has seen good results including a 40 hp increase on the dyno. But I know for a fact that my injectors don't have enough in them to run 100% E85. The IDC's are just too high as it is. But on a stock car with stock boost it works fine apparently. He even has a kit developed specifically for the Subaru boxer motor. Seems he has done several of them now with all good results.
Car is modified with bolt-ons. I've got a Greddy Emanage Ultimate installed but untuned so far. Car feels great and it's cheap. Gas at that particular station was 3.82 for regular and 3.50 for e85.
Well, got the fuel pump on the way. Getting injectors tomorrow and then debating on just modding them myself or sending them off to get cleaned, flow tested and modded.
Modding the injectors are easy. i modded mine myself by very carefully sanding along the weld on the end. Then popped off the cap and then carefully smoothed out the roughness from the welds. Then I sent them to RC Engineering to have them balanced and cleaned and flow tested. 2 read 819cc, 1 read 820cc and the other read 821cc. Cost me $115 shipped back and all. I've also heard great things about WitchHunter as well. Also Deatchwerks will take your stockers as a $100 core and you can get what you want....I'd got that route since their's have a much better spray pattern than modded stockers.....theirs still have the caps on them for better atomization.
Nice part about witchhunter is that they will replace all o-rings, clean, mod and then if there is one that is not the same as the others, they will replace it with another that matches from their inventory. All for $25 per injector. These are "temporary injectors" till I get the funding to get the 2.5 block in the car and a different turbo. At 800cc +- they would be good for a little better than a 16g on E85.
No I would have been fine with 565's but when you mod injectors...unless you send them off to some place like DW the cap is either on or off...with it off it is ~800cc/min +- . So no, it won't be needed at this point, I can scale them back and it should be just fine and if I decide to change turbos or something, then I still have room to play. The basic number I am seeing is a 30% increase in fuel...so 440cc X130%= about 570cc so the Sti pinks or DW would be perfect.
Some more interesting findings. It seems that pre-boost, on spool up it is taking out .5-1.0 degree of timing and then adding 4.0-5.0 degrees after the boost starts to come on...not sure what causes that. Just something odd that I encountered. I am sending the injectors off to witchhunter.com this week. They will be cleaning them, modding them and flowtesting them. All for only $100. I am pretty excited. That and the Walbro and I will be switching to 100% E85.
Yup, just the corn based ones that are operating on old technology and have done nothing to attempt to streamline their plants. I just read another article about a co-op style plant that is doing very well (on corn surprisingly) because they have made improvements to their technology, are selling the byproducts back to local farmers and burning other byproducts to help fuel the energy for the plant. But I would really like to keep this thread a little more about the tuning and less about discussion of E85
i suspect the people in this thread that have tuned E85 are mainly in business for themselves. I doubt any of them are going to comment on anything of value that will help you. I mean would you give out your secrets and hard fought data to someone else or a competitor? you are doing the right thing, only way to learn is do it yourself.
The funny part is that I am discovering that it is not hard at all...not only that, there are quite a few resources out there that are publicly available...to include cobb's tuning worksheet. If they want to be secretive and elusive, that is fine. I am finding the information, and learning quite a bit. It just takes a little searching and the investment of some time. Personally, I like to help out the Subaru community and have no motives behind it. I'm not in this for the money, not in this to gain any customers. That is SUPPOSED to be what these forums are about, not attempting to garner business. But I realize that the sponsors are attempting to make a living and are trying to get business. I don't have a problem with that. As for giving all my secrets and hard fought data to someone else? ABSOLUTELY. That is what I am doing with this thread and others. I'm in it for the love of cars, not to be secretive and hide things. THAT is why I joined WRXAtlanta. Not to find out where I could get tuning or get parts installed.
Mike I think what you have been doing is great. I just finished tuning my 240 on pump gas and I'm about ready to go start the E85 tuning. I"m really looking foward to it. By the way the 240 made 350hp and 350tq on 12.4lbs on pump gas, we shall see what it does on E85
Well I did answer your question...you asked if I would share all my information and secrets of tuning The answer is absolutely. Battleground: Is that a turbo car or a supercharged car? That sounds like a pretty beefy engine to start with. I will be curious to see what you are able to do on 105 octane E85!
It has Forged Pistons and Rods, I'll probably tune it to 18lbs on Pump and then try the E-85. I suspect I can probably work my way up to about 25 26 lbs before I run out of fuel pump. Turbo Chared
running a single walbro or dual? I am guessing single if you are worried about running out at 25 psi.