Page 7 of 26 FirstFirst ... 5678917 ... LastLast
Results 61 to 70 of 258

Thread: using 14.047 for desired AFR and not 14.63?

  1. #61
    Senior Member
    Join Date
    Feb 2008
    Posts
    162

    Default

    I was working with Greg and a protege of his on a Ford. We got into the discussion of fuel and E content. I started doing some research and found some basic formulas. Then I put them into action on my daily driver. WOW! It was like night and day. Next I started adjusting for it on some other car. Same results.

    I still need to figure out a Max Power formula for E content. It looks to be a curve, but I keep missing it. Maybe some of the known figures are wrong.

    also if Stoich is 9.0078 or 1.000 Lambda for E100 the WOT EQ ratio need to be 1.27 or .792 lambda.

    E0 Stoich is 14.68 or 1.000 lambda and WOT 12.7 and a EQ ratio of 1.15639 or .86476 Lambda

    I currently have been checking the fuel content and have found it to be 10% in my area. I switched the Target AFR to 14.4 just as a test and the target WOT EQ ratio to 1.17 and the car runs great. I am still doing some testing.

    BTW thanks again Greg

  2. #62
    Lifetime Member 98 tigershark's Avatar
    Join Date
    Nov 2006
    Posts
    304

    Default Maybe some of the known figures are wrong. :sly

    I agree!! I think the flash point is hotter with ethanol than with gasoline and might show the mixture to be richer than it really is. That is just a guess but the PIDs GM.HO2S11 and 21 go higher in my car with E10. In my car with gasoline they usually maxed out around .96-.98V, but with the E10 they went as High as 1.011V with the same EQ. Again I do not really know but you are on to something there, I think.
    98 tigershark`
    98 tigershark
    L92/427 w/L76 CC'ed heads n upgraded springs
    4.100 stroke, 4.068 bore w/ 11:1 comp
    Cam, 591 int, 613exhst, [email protected], 115*
    LG headers, High flow cats,
    RPM level 5 trans, RPM 3.42 gears, 2800 rpm trq convrt. .
    Special Thanx to Joe and Bruce!

  3. #63
    Senior Member
    Join Date
    Feb 2008
    Posts
    162

    Default

    I will add the max projected HP relevant to E content. Basically how much gain in theory you could get.
    Cal Editor aka A.J.
    Lead Calibrator at PCM Calibrators
    ASE Master Certified since 1988 -- ASE L1, F1 & A9
    GM Technician since 1999 -- GM World Class Technician since 2009
    CNG Installer -- CSA Inspector
    A handful of people out there who do have an intimate knowledge of GM Calibrations

  4. #64
    Lifetime Member 98 tigershark's Avatar
    Join Date
    Nov 2006
    Posts
    304

    Default Stock fuel Pumps and E fuels, My biggest new concern!!!

    In this post we or I have learned that the ethanol fuels require more fuel to reach stoich. With that said how many of us are running over 500 hp not to mention torque and the formula for IBPWs for peak torque, allot of us I bet. With so much more fuel being needed with the addition of E10+ I have been looking into fuel pumps for EFI. They all talk about HP and LPH but when you throw ethanol into the mix you have to consider is this fuel pump going to do the job. Certainly not the stock one. I went to an old buick forum 2002 site and read the comments on their turboed fueling issues and 11, 10, and 9 sec cars. It would seem that we also need a way to convert the performance expectations of our fuel pumps to a realistic view the we have to account for Ethanol.
    The blend of Sunoco racing fuel that was mentioned earlier in this post had allot of ethanol in it. Economy is another but similar issue also. How can we know for sure that our fuel pumps can handle our current configurations and still leave room for dreaming about going faster. Does anyone have a way to calculate the HP rating/flow rating for a fuel pump with the various ethanol blends?
    98 tigershark
    98 tigershark
    L92/427 w/L76 CC'ed heads n upgraded springs
    4.100 stroke, 4.068 bore w/ 11:1 comp
    Cam, 591 int, 613exhst, [email protected], 115*
    LG headers, High flow cats,
    RPM level 5 trans, RPM 3.42 gears, 2800 rpm trq convrt. .
    Special Thanx to Joe and Bruce!

  5. #65
    Senior Member
    Join Date
    Feb 2008
    Posts
    162

    Default

    take a look at this

    http://www.epi-eng.com/piston_engine...efficiency.htm

    A former employer (AC Nutter) had a link to it that I found a year ago. Interesting site.
    Cal Editor aka A.J.
    Lead Calibrator at PCM Calibrators
    ASE Master Certified since 1988 -- ASE L1, F1 & A9
    GM Technician since 1999 -- GM World Class Technician since 2009
    CNG Installer -- CSA Inspector
    A handful of people out there who do have an intimate knowledge of GM Calibrations

  6. #66
    Lifetime Member
    Join Date
    Dec 2007
    Posts
    1,156

    Default

    Quote Originally Posted by CalEditor View Post
    You could figure out off of the O2 sensors, but I am under the impression that is a ton of work. I think Mopars do it that way.

    This does not come with a Sensor

    Ethanol Content Analyzer

    Kost Moore Tools has a Fuel Composition Tester (J 44175) I use this tool to check fuel samples.
    http://cgi.ebay.com/ebaymotors/GM-Ke...241610003r9255
    Yes it requires the standard GM $400 sensor. :( But great idea.

    Quote Originally Posted by CalEditor View Post
    It appears that (E) is going to be pushed with the new admin. Minnesota may have tried to pass an E20 bill for conventional cars. Other states are looking at E30 to E50.

    • The landscaper is out whacking weeds in a 110° Hot & Humid day. Breathing in the Volatile E10. After a day at work he doesn't feel so well
    • [COLOR="Red"]Increase to E30 and the guy get and OWI driving home
    • EVAP Systems - The stored vapors will be greater and that will have an effect on the fuel strategy.
    Cal Editor - what's with these items? Knowing that the air in Brazil is claimed to be cleaner because of the high E contents they run there and have been for years, your points on the breathing E combustion byproducts in is a good question as E has its own pungent odour even at E10 levels. E85 even worse. Cold start it is really strong on E85.

    Catylised gasoline exhaust is mainly CO2 and water, so what is the bonus extra by-product with E I wonder.

    But...the evaporative output from E is much lower than with gasoline as the vapour pressure is higher and its natural "fume" level is much lower.

    Quote Originally Posted by mr.prick View Post
    I'd like to know how I can find out exactly what is in my tank without adding
    another sensor.
    Your ECM can tell you if you have access to a known non E fuel that you can approximately baseline off.
    Last edited by gmh308; September 5th, 2009 at 09:51 AM.

  7. #67
    Lifetime Member 98 tigershark's Avatar
    Join Date
    Nov 2006
    Posts
    304

    Default .50 bsfc

    I use .50 for my nat asp when calculating IBPWs for peak torque and since the AFR also used in the calc. would incorporate the correct the correct afr for the fuel used the E% should not matter for the BSFC . that is what I found in a few publications. So does Ethanol change the BSFC too? I may have found a sensor but I need to double check it later, my daughter just got here to visit.
    98 tigershark
    98 tigershark
    L92/427 w/L76 CC'ed heads n upgraded springs
    4.100 stroke, 4.068 bore w/ 11:1 comp
    Cam, 591 int, 613exhst, [email protected], 115*
    LG headers, High flow cats,
    RPM level 5 trans, RPM 3.42 gears, 2800 rpm trq convrt. .
    Special Thanx to Joe and Bruce!

  8. #68
    Lifetime Member mr.prick's Avatar
    Join Date
    Nov 2006
    Posts
    3,191

    Default

    In a 2002 GMC Yukon tune (12216125) {B3601} is a table for % of ethanol instead
    of a single value parameter.
    Maybe a conversion for GEN3,
    provided you can find out any sensor part numbers and what pinouts to add.
    Last edited by mr.prick; September 5th, 2009 at 10:38 AM.
    512k RoadRunner Firmware 12.14R
    FlashScan V2 Bootblock V2.07.04 Firmware V2.07.22 EFILive V7.5.7 (Build 191) V8.2.1 (Build 181)
    LC-1 WBO2

    _________________________________________________

  9. #69
    Lifetime Member
    Join Date
    Dec 2007
    Posts
    1,156

    Default

    Quote Originally Posted by mr.prick View Post
    In a 2002 GMC Yukon tune (12216125) {B3601} is a table for % of ethanol instead
    of a single value parameter.
    Maybe a conversion for GEN3,
    provided you can find out any sensor part numbers and what pinouts to add.
    http://www.zeitronix.com/Products/ECA/ECA.htm

    If there is a table in the OS for stoich values, and you want to change it, simply change the first value - the 0% value. And optionally the second value. Why ? Have seen GM OS's (the ones with the tables) show the ethanol content as 3%, so setting the second value (6.25% ?) to your chosen stoichiometric AFR ensures that if there is some offset built (maybe as there is so much E in fuels these days) that it potentially has no influence.

  10. #70
    Lifetime Member
    Join Date
    Dec 2007
    Posts
    1,156

    Default

    Quote Originally Posted by 98 tigershark View Post
    I use .50 for my nat asp when calculating IBPWs for peak torque and since the AFR also used in the calc. would incorporate the correct the correct afr for the fuel used the E% should not matter for the BSFC . that is what I found in a few publications. So does Ethanol change the BSFC too? I may have found a sensor but I need to double check it later, my daughter just got here to visit.
    98 tigershark
    Hey TS, yes the BSFC changes for the ethanol content. As BSFC (imperial) units are pounds per horsepower hour, and with E85 ethanol there is around ~45% higher fuel flow, if the BSFC of an engine was 2lbs per horsepower hour on gas, then it may be something like 3 pounds per horsepower hour on E85.

    (These are simplistic numbers as there are other characteristics of ethanol that mean that its BSFC could be more than a little higher than its mere energy content dictates, like the amount of oxygen it carries (35% by weight?) which supports a higher excess fuel level (PE), its heat of vaporisation (it cools more than gas as it vaporises), and its higher octane rating.)

    FYI we found that with 42# injectors with E85 these would see duty cycle get into the mid 90's at 6000rpm (LS7), so they were virtually hitting the wall. There was no leaning out though at WOT so must certainly be on the edge there.

    Fuel pump on that example was a 340lb per hour Walbro which is 42.5 lb per hour per injector so the fuel pump is around the end of its range as well.

    Great thread guys!
    Last edited by gmh308; September 5th, 2009 at 11:38 AM.

Page 7 of 26 FirstFirst ... 5678917 ... LastLast

Similar Threads

  1. B0720-FRP: actual or desired?
    By killerbee in forum Duramax 06 LLY / 06+ LBZ & LMM
    Replies: 14
    Last Post: November 11th, 2009, 05:55 AM
  2. Desired Airflow Map, not quite right, help
    By kwhiteside in forum Gen III V8 Specific
    Replies: 4
    Last Post: September 8th, 2009, 07:14 AM
  3. Desired Shift Time
    By A6sportsracer in forum 6 speed/8 speed RWD/FWD Transmission Tuning (incl T43, T76, T87)
    Replies: 6
    Last Post: June 27th, 2009, 11:45 AM
  4. How does desired boost work?
    By pistonrings in forum Duramax LLY
    Replies: 2
    Last Post: May 30th, 2009, 04:47 AM
  5. Desired Airflow
    By Thumper in forum Gen III V8 Specific
    Replies: 7
    Last Post: April 23rd, 2008, 02:23 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •