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Thread: E85 tuning issue with timing

  1. #1

    E85 tuning issue with timing

    After a while of finally being where I can run E85 only in my wifes Tahoe I ran a log with it because I was getting a bit of KR* and noticed some unreal timing that I can't see where it's commanding it from. I am wondering if the AFR spark table continues on from where I can't see it. Tomorrow I'm going to 0 out the multiplier for spark/afr correction and try it out. Here is a log and a copy of the file.

    The specs are

    2003 LQ4
    5.3L heads milled .015 with Ferrara 2.0" intake valves
    LS6 springs
    TR224 cam on a 112LSA
    Stock cat back, cats, transmission, 3.42 gearing, stock airbox, etc. Truck is tuned for SDE since the maf calibration was just a pain in the ass to get right. Everytime I got the maf calibration correct since it was so far off it would end up needing adjustment again a few thousand miles later. Milage is just over 20mpg with the a/c on highway milage. Towing from Michigan to Las Vegas I seen between 12-15mpg with 3 tankfulls over 15mpg towing 4k lbs in 3rd gear. Anyway, here are the odd logs and copy of the tune.

    Zippy

  2. #2
    Still wondering on this one. I think my current solution to this problem is going to be to edit this with my tunercat and then actually do the rest of the work with my HPT. Here is a screenshot of an example file and tab open in Tunercat.



    Is it possible to have this added to the Gen III stuff? I've done plenty of E85 conversions and some of those I plan to convert over to actual Flex fuel operating systems with the sensor (05' and older). It would be nice to be able to have better timing control when the system switches over. My Tahoe as an example doesn't run anywhere near the commanded timing in my high octane spark table when the sensor is reporting 85% alcohol.

  3. #3
    Advanced Tuner
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    after looking at this tune i see it is way off Do you know what stoich AFR if for E85? Your injector data is off Why is it straight across on your flowrate vs kpa, that is only done with a super charger,Why are all the PE enable settings set for zero?
    2000 Firebird,2002 O.S.,LQ4 370,Borg Warner S475,truck mani.,Eagle crank,Callies Compstar Rods,Wiseco-11 4.030 pistons 9.4:1 comp.,LS3CNC heads,LS3 intake,NW92mm throttle body,ID1000 injectors,BTR trunion upgrade,LJMS STG3 cam,LS7 Lifters,ARP Studs-bolts,Frozen Boost A to W intercooler,JGS 60MM BOV,2 40mmJGS Wastegates,4L80E trans wth segment swap,CircleD 3400 single disk,MOSER 12 3.31gears ,BMR K-Mem.,2 Walboro 450 pumps,Returnstyle fuelsystem MAGNAFUEL regulator.
    LS1Tech sig KRAZY K 2000 TA

  4. #4
    Advanced Tuner
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    2000 Firebird,2002 O.S.,LQ4 370,Borg Warner S475,truck mani.,Eagle crank,Callies Compstar Rods,Wiseco-11 4.030 pistons 9.4:1 comp.,LS3CNC heads,LS3 intake,NW92mm throttle body,ID1000 injectors,BTR trunion upgrade,LJMS STG3 cam,LS7 Lifters,ARP Studs-bolts,Frozen Boost A to W intercooler,JGS 60MM BOV,2 40mmJGS Wastegates,4L80E trans wth segment swap,CircleD 3400 single disk,MOSER 12 3.31gears ,BMR K-Mem.,2 Walboro 450 pumps,Returnstyle fuelsystem MAGNAFUEL regulator.
    LS1Tech sig KRAZY K 2000 TA

  5. #5
    I appreciate your thoughts, but keep trying. The tune is now way off. Maybe your ability to read the tune. The stoich afr table is actually still stock. If you know how to read that it works via readings from the sensors input of ethanol content. At 85% ethanol the stoich afr is a commanded 9.73:1 or so. That is on par with the commonly used numbers for E85 and is the number factory set by GM for running on E85. I'm happy with a commanded afr of 14.63:1 for 100% gasoline, 14.1:1 or so for E10, 9.73:1 for E85, and all the way down to 8.77:1 for E100. The flow rate table is actually still stock. I'm guessing you haven't done many trucks. Trucks that are 2003 and older have a return fuel system with a vacuum referenced fuel pressure regulator. All returnless systems use a flow rate chart which changes the IFR via vacuum. Return fuel systems however are not calibrated that way because as engine vacuum comes up fuel pressure is actually reduced. Download some 03' and older truck files and you'll see what I mean. The power enrichment enable settings are at zero because while I'm tuning it I want to control p.e. enable via tps. I don't need an rpm delay, vacuum enable, torque % enable, etc while I'm tuning. The trucks will commonly have a problem with delay and sometimes worse with not even going into power enrichment at all. What in that would you say is way off????

    I'm very familier with running E85. I've done many conversions and not a problem with any of them. I think you have misunderstood my point with the post. Some of the trucks and sport utilities built with 5.3L's such as my personal truck and Tahoe are built with a flex fuel operating system meaning they are factory built to be run on E85 and/or gasoline and go back and forth between the two. The 05 and older flex fuel systems use a sensor that goes inline of the fuel system and can detect how much ethanol is actually in the fuel allowing the pcm to change timing and commanded afr based on the content of ethanol in the fuel running through the system. The 06' and newer flex fuel vehicles make these changes based on a complicated operating system that makes changes via fuel trims to decide how much ethanol is in the system. The 05' and older O.S. is very desirable since it allows you to run all the E85 you want, yet be able to put gasoline in there also if you can't locate E85 and the flex fuel sensor inline will pick that up. The ability to go back and forth with gasoline and E85 without having to reflash the computer everytime you do this is what makes this operating system a thing of beauty.

    My point of this post is that the system is designed to alternate afr and timing both depending on which fuel is in the fuel system at that time. HP Tuners has the setup for the afr to change, but doesn't have the ability at this time to make changes to the spark table based on E85 content as you can see that Tunercat has available.

    Here is a stock 02' Tahoe table to look at which I've found in the HPT Repository.
    Last edited by zippy performance; 08-08-2010 at 10:43 PM.

  6. #6
    sorry for off topic, but since you are runing e85...
    I would like to see how e85 GM timing map would look for LS1. Where i can find such info? thanks
    2018 mustang gt a10 with headers and e85

  7. #7
    That I know of there were no tru LS1's with flex fuel capability from GM. If there were they would be export only. I'd have to jog the brain a bit, but until the flex fuel 6.2L came out there wasn't any other GM V8's that were built with flex fuel systems other than the 5.3L. With that being the case I'm not sure that there is a true GM LS1 E85 tune out there.

  8. #8
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    are you trying to only run this on E85 thats what my impression is?I do see that the newer trucks IFR vs KPA are flat across, I only bumped my timing up two degrees in the area where it stays for cruis and adjusted the timing at wide open as you would any other fuel.
    2000 Firebird,2002 O.S.,LQ4 370,Borg Warner S475,truck mani.,Eagle crank,Callies Compstar Rods,Wiseco-11 4.030 pistons 9.4:1 comp.,LS3CNC heads,LS3 intake,NW92mm throttle body,ID1000 injectors,BTR trunion upgrade,LJMS STG3 cam,LS7 Lifters,ARP Studs-bolts,Frozen Boost A to W intercooler,JGS 60MM BOV,2 40mmJGS Wastegates,4L80E trans wth segment swap,CircleD 3400 single disk,MOSER 12 3.31gears ,BMR K-Mem.,2 Walboro 450 pumps,Returnstyle fuelsystem MAGNAFUEL regulator.
    LS1Tech sig KRAZY K 2000 TA

  9. #9
    I run the truck on both. E85 is my main fuel, but when I take road trips with it I sometimes run into it not being available. The truck is designed to run both fuels. I'm not sure you see what I'm getting at here. I don't really have any problem with running the truck on E85. My problem is that there is a table in the pcm that allows me to adjust the timing seperate from the main high octane table and this table is only active when I'm running E85. My problem is that Tunercat has this table available to me and HP Tuners doesn't. Imagine having an F body for example that you run on E85. You've set your commanded afr and tuned in your spark table for the E85. You now go somewhere that you need to run it on gas. You then pretty much have to load another tune in to do so. The truck L59 calibration does all of this for you. The truck pcm will switch the commanded afr for you when you go from gas to E85 or E85 to gas and also has the ability to add or reduce timing based on the fuel of choice that you are running. With HP Tuners I have access to the commanded AFR table that actually does it's job in stock form, but I don't have access to the spark table designated for when the pcm detects E85 as you can see in the Tunercat snapshot. Understand that my only tuning issue is that in order to tune this table I have to switch to my other software to do so and I'd rather just do this in HPT especially since my Tahoe is tuned in 1 bar SDE.

  10. #10
    Tuner Delft Calais's Avatar
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    Have you actually tried contacting support to see if they can add it? thats the only way your going to see it, a general post here aint going to do much for you.
    Contact support and request the table in question and if they can add it they usually will.
    Give it a go yourself first, if it doesnt work out then pay someone.

  11. #11
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    I know what you are talking about Zippy.
    The other brand and TC have this table as you are saying.
    I noticed this last winter with my wifes tahoe.

  12. #12
    I've gotten response from the on things in here before, but I need to send this to support. I sent it once last year, but it was around the time that I was having e-mails that didn't seem to go anywhere but cyberspace. At least I'm not the only one then that has noticed this.

  13. #13
    Quote Originally Posted by zippy performance View Post
    That I know of there were no tru LS1's with flex fuel capability from GM. If there were they would be export only. I'd have to jog the brain a bit, but until the flex fuel 6.2L came out there wasn't any other GM V8's that were built with flex fuel systems other than the 5.3L. With that being the case I'm not sure that there is a true GM LS1 E85 tune out there.
    I would like to compare 5.3l regular gas timing to e85 timing tables. Any idea where to find this info. hopefully hptuners support will add this table soon for you...
    2018 mustang gt a10 with headers and e85

  14. #14
    It would indeed be a nice table to have! It would be nice to tune my S10 with HPT and actual 2bar support with this. For now I am stuck to my hacked Tunercat 2bar tune.