Close

Page 1 of 2 12 LastLast
Results 1 to 25 of 34
  1. #1
    Join Date
    Mar 2012
    Location
    Cleveland TN
    Posts
    541
    Rep Points
    554.0
    Mentioned
    16 Post(s)
    Rep Power
    6


    1 out of 1 members liked this post. Reputation: Yes | No

    Octane vs Timing

    Here's something I've wanted to see for awhile and hopefully everybody will help out. Instead of just constantly upping timing and logging I always wanted a safe starting point. I went to http://www.intercepteft.com/calc.html and calculated the ethanol mixes for 93+E85 blends asuming 93 and 105 octane. I pulled one mid and high RPM entry for 180 load from the Stage 2+ 91 and 93 OTS maps along with E30. My main goal here would be to give somebody a nice starting point which would hopefully reduce the number of 130MPH runs on the highway people are doing with a dam AP in one hand as well as a curiosity of how much the octane additions play on timing.
    Fuel 91 93 E10 E20 E30 E40 E50 E60 E70 E80 E85
    Octane 91 93 93 94.6 96.2 97.8 99.4 101 102.6 104.2 105
    Max Timing 3.5k RPM 180 Load 2 3.5 3.5 12
    Max Timing 6k RPM 180 Load 5 6 6 13.5
    2008 135i - Cobb AP, JB4 G5 w/2Step&FSB, MS DP's, Berk street exhaust, AMS IC, VTT Inlets, UR Intake, ER CP w/Tial BOV, Spec 3+ & Steel FW, CDV delete, Quaife LSD, DSS Axles, M3 control arms, M3 rear SF bushings, M3 Trans bushings, SS brake lines. Pics

  2. #2
    Join Date
    Apr 2010
    Location
    NYC
    Posts
    3,089
    Rep Points
    999.1
    Mentioned
    104 Post(s)
    Rep Power
    10


    Reputation: Yes | No
    Edit - missed where he said for 180 load.

  3. #3
    Join Date
    Dec 2011
    Location
    Clarksville, TN
    Posts
    3,854
    Rep Points
    2,407.7
    Mentioned
    44 Post(s)
    Rep Power
    25


    Reputation: Yes | No
    This chart would assume that everyone runs the same amount of boost though. This could be dangerous for people that are running higher boost than others as their starting timing numbers would be lower. I have not tuned on ATR yet but I assume you can change the WGDC values in ATR to achieve higher boost? If this is true, I'm sure some people have tweaked their WGDC tables to achieve faster response or hold more boost to redline. This would then require lower timing values than others running lower WGDC values.

    Click here to enlarge Originally Posted by brusk Click here to enlarge
    Here's something I've wanted to see for awhile and hopefully everybody will help out. Instead of just constantly upping timing and logging I always wanted a safe starting point. I went to http://www.intercepteft.com/calc.html and calculated the ethanol mixes for 93+E85 blends asuming 93 and 105 octane. I pulled one mid and high RPM entry for 180 load from the Stage 2+ 91 and 93 OTS maps along with E30. My main goal here would be to give somebody a nice starting point which would hopefully reduce the number of 130MPH runs on the highway people are doing with a dam AP in one hand as well as a curiosity of how much the octane additions play on timing.
    Fuel 91 93 E10 E20 E30 E40 E50 E60 E70 E80 E85
    Octane 91 93 93 94.6 96.2 97.8 99.4 101 102.6 104.2 105
    Max Timing 3.5k RPM 180 Load 2 3.5 3.5 12
    Max Timing 6k RPM 180 Load 5 6 6 13.5
    2011 335is DCT, JB4 + MHD BEF, stage 2 LPFP, e50 + 50/50 meth, FBO, MT ET Streets when needed


  4. #4
    Join Date
    Jul 2012
    Posts
    217
    Rep Points
    305.2
    Mentioned
    7 Post(s)
    Rep Power
    4


    Reputation: Yes | No
    Interesting thought, although 180 load in cool weather at sea level is much different than 180 load at 6000ft asl and hot weather (I can't even reach it on stock turbos).

    One other thing I'd mention, at least for my conditions the E30 race map was a bit too aggressive for actual E30. I had to run about E50 to make that table work without a lot of knock issues. But maybe that's just due to the differences I mention in my first line above.

  5. #5
    Join Date
    Apr 2010
    Location
    NYC
    Posts
    3,089
    Rep Points
    999.1
    Mentioned
    104 Post(s)
    Rep Power
    10


    Reputation: Yes | No
    Click here to enlarge Originally Posted by Carl Morris Click here to enlarge
    Interesting thought, although 180 load in cool weather at sea level is much different than 180 load at 6000ft asl and hot weather (I can't even reach it on stock turbos).

    One other thing I'd mention, at least for my conditions the E30 race map was a bit too aggressive for actual E30. I had to run about E50 to make that table work without a lot of knock issues. But maybe that's just due to the differences I mention in my first line above.
    Are you either at elevation or in a cold weather area?

  6. #6
    Join Date
    Mar 2012
    Location
    Cleveland TN
    Posts
    541
    Rep Points
    554.0
    Mentioned
    16 Post(s)
    Rep Power
    6



    Reputation: Yes | No
    I'm assuming boost levels shouldn't change much as the maps are pretty much maxing out what the turbo's can do. Again I and thinking safe starting numbers like how the OTS maps should be. I found that in Dallas the OTS E30 maps stopped complaining right at E30 blend. I however also checked the mix in the tank and not just the assumptions of what I was mixing.
    2008 135i - Cobb AP, JB4 G5 w/2Step&FSB, MS DP's, Berk street exhaust, AMS IC, VTT Inlets, UR Intake, ER CP w/Tial BOV, Spec 3+ & Steel FW, CDV delete, Quaife LSD, DSS Axles, M3 control arms, M3 rear SF bushings, M3 Trans bushings, SS brake lines. Pics

  7. #7
    Join Date
    Dec 2011
    Location
    Clarksville, TN
    Posts
    3,854
    Rep Points
    2,407.7
    Mentioned
    44 Post(s)
    Rep Power
    25


    Reputation: Yes | No
    Click here to enlarge Originally Posted by brusk Click here to enlarge
    I'm assuming boost levels shouldn't change much as the maps are pretty much maxing out what the turbo's can do. Again I and thinking safe starting numbers like how the OTS maps should be. I found that in Dallas the OTS E30 maps stopped complaining right at E30 blend. I however also checked the mix in the tank and not just the assumptions of what I was mixing.
    Checking ethanol content is a must when getting it at a gas station and tuning for it. I tested ours and its currently e70. We're tuning for that and while its cold so it'll be the safest tune possible. Then when it warms up ill be running e112 they call it. E85 with the other 15% 112 race gas. And we'll adjust the tune up from there.
    2011 335is DCT, JB4 + MHD BEF, stage 2 LPFP, e50 + 50/50 meth, FBO, MT ET Streets when needed


  8. #8
    Join Date
    Mar 2012
    Location
    Cleveland TN
    Posts
    541
    Rep Points
    554.0
    Mentioned
    16 Post(s)
    Rep Power
    6



    Reputation: Yes | No
    Click here to enlarge Originally Posted by bigdnno98 Click here to enlarge
    Checking ethanol content is a must when getting it at a gas station and tuning for it. I tested ours and its currently e70. We're tuning for that and while its cold so it'll be the safest tune possible. Then when it warms up ill be running e112 they call it. E85 with the other 15% 112 race gas. And we'll adjust the tune up from there.
    That's the bad thing about pump gas. Even the 93 I've tested it was way inconstant I found as much as 12% and as low as 2% so far but in TX most were 5% or less out of the 7 I've now tested. On the plus side the 30 gallons of E85 I picked up was 89%.
    2008 135i - Cobb AP, JB4 G5 w/2Step&FSB, MS DP's, Berk street exhaust, AMS IC, VTT Inlets, UR Intake, ER CP w/Tial BOV, Spec 3+ & Steel FW, CDV delete, Quaife LSD, DSS Axles, M3 control arms, M3 rear SF bushings, M3 Trans bushings, SS brake lines. Pics

  9. #9
    Join Date
    Dec 2011
    Location
    Clarksville, TN
    Posts
    3,854
    Rep Points
    2,407.7
    Mentioned
    44 Post(s)
    Rep Power
    25


    Reputation: Yes | No
    Yeah I def find it best to get e85 or race gas by the barrel.
    2011 335is DCT, JB4 + MHD BEF, stage 2 LPFP, e50 + 50/50 meth, FBO, MT ET Streets when needed


  10. #10
    Join Date
    Jun 2012
    Location
    NJ
    Posts
    4,198
    Rep Points
    1,800.2
    Mentioned
    102 Post(s)
    Rep Power
    19


    Reputation: Yes | No
    Click here to enlarge Originally Posted by bigdnno98 Click here to enlarge
    Yeah I def find it best to get e85 or race gas by the barrel.
    Guaranteed quality & consistency -- But (more with E85) you lose the lower pricing
    COBB AP ProTune by Bren of ///Bren Tuning
    Akrapovic DP | Helix FMIC | Alpina TCM Flash | Walbro 450LPH Fuel Pump


    "The moment money becomes your motivation, you are immediately not as good as someone who is motivated by passion and internal will." -A. Senna

  11. #11
    Join Date
    Jul 2012
    Posts
    217
    Rep Points
    305.2
    Mentioned
    7 Post(s)
    Rep Power
    4


    Reputation: Yes | No
    Click here to enlarge Originally Posted by themyst Click here to enlarge
    Are you either at elevation or in a cold weather area?
    I'm in the Denver area and the temperature varies widely. On a hot day with Cobb boost control I can't get above a load of about 160. On a cool day I can hit 170. In the winter cold I may hit 180 but I don't know because I haven't been logging. My load target is 186 through all of this.

  12. #12
    Join Date
    Mar 2012
    Location
    Cleveland TN
    Posts
    541
    Rep Points
    554.0
    Mentioned
    16 Post(s)
    Rep Power
    6



    Reputation: Yes | No
    ok if we have anybody willing to throw some numbers out we could either add the last two or three load targets from the table or just know how much the other targets will need to be adjusted by. My main curiosity would be to know that for each bump in Octane or Ethanol percentage you can safely increase timing by X degrees. I'll probably never get over E50 as the closest one is 30 mins from my house but thought this would be a good learning piece for everybody else willing to play with ATR and E85 mixes.
    2008 135i - Cobb AP, JB4 G5 w/2Step&FSB, MS DP's, Berk street exhaust, AMS IC, VTT Inlets, UR Intake, ER CP w/Tial BOV, Spec 3+ & Steel FW, CDV delete, Quaife LSD, DSS Axles, M3 control arms, M3 rear SF bushings, M3 Trans bushings, SS brake lines. Pics

  13. #13
    Join Date
    Jan 2010
    Location
    SoCal
    Posts
    117,762
    Rep Points
    31,552.6
    Mentioned
    2064 Post(s)
    Rep Power
    316


    Reputation: Yes | No
    Very interesting topic although I'd really like to see the other numbers.

    I think the timing gain is really the reason to run E85.

  14. #14
    Join Date
    Mar 2010
    Location
    Toronto, Canada
    Posts
    6,677
    Rep Points
    3,327.5
    Mentioned
    225 Post(s)
    Rep Power
    34


    Reputation: Yes | No
    While its a good topic to discuss imho what you get from this is a good description on sort of off the shelf tuning..depending on what you do with boost, fuel and vanos you may end up with a lot more or less aggressive timing maps...speaking strictly in terms of timing without considering everything else is moot..just my 2c
    Click here to enlarge

  15. #15
    Join Date
    Nov 2011
    Location
    Florida
    Posts
    904
    Rep Points
    785.6
    Mentioned
    113 Post(s)
    Rep Power
    0


    Reputation: Yes | No
    That would be some work to get that timing vs E85 mixture completed. Since tunes differ from car to car such a chart can be held as an example.

    However though, would mixing race gas like the E85 results in the same similar timing ?

  16. #16
    Join Date
    May 2012
    Location
    Jacksonville, FL
    Posts
    2,936
    Rep Points
    2,858.8
    Mentioned
    78 Post(s)
    Rep Power
    29


    Reputation: Yes | No
    Click here to enlarge Originally Posted by BuraQ Click here to enlarge
    However though, would mixing race gas like the E85 results in the same similar timing ?
    I would say no. A strong indicator of this is Cobbs OTS E30 Race map and their OTS Race map. Both maps run the same timing and boost (IIRC), The E30 map is obviously 30% Ethanol, which is rather conservative in terms of strength of the mixture. However the Race map requires minimum 100 octane.
    2011 E90 M3 \ Melbourne Rot Metallic

    Click here to enlarge

  17. #17
    Join Date
    Dec 2011
    Location
    Roanoke VA
    Posts
    1,632
    Rep Points
    2,248.3
    Mentioned
    54 Post(s)
    Rep Power
    23


    Reputation: Yes | No
    Click here to enlarge Originally Posted by BuraQ Click here to enlarge
    That would be some work to get that timing vs E85 mixture completed. Since tunes differ from car to car such a chart can be held as an example.

    However though, would mixing race gas like the E85 results in the same similar timing ?
    "Race gas" is a very broad term and which race gas will dictate how close the mix will be to that of e85. 100 octane, MS109, or 110/CAM2 probably not. C16 or Q16 maybe...

    However, even with the N54's superhero ability to save your ass, I wouldn't just plug in some e85/race gas mix and assume all is well because a chart says so. Datalogging and tweaking, starting on the conservative side, are the only way to do it IMO.

    I can definitely appreciate what OP is getting at though.
    Click here to enlarge
    MOTIV750, MOTIV P-1000 PI, MOTIV/FUEL-IT! low pressure fuel system, AEM EMS/COBB AP, Aquamist HFS-3, ETS FMIC, SPEC stage 3+ clutch/SS flywheel, BC Racing coilovers and VMR wheels wrapped in Hankook RS3s.

  18. #18
    Join Date
    Jun 2010
    Location
    Chicago, IL
    Posts
    919
    Rep Points
    780.4
    Mentioned
    42 Post(s)
    Rep Power
    8


    Reputation: Yes | No
    How do you test fuel for ethanol content? Is there some sort of a portable home tester that you guys use?
    From all the things I've lost,
    I miss my mind the most!
    Click here to enlarge

  19. #19
    Join Date
    Dec 2011
    Location
    Roanoke VA
    Posts
    1,632
    Rep Points
    2,248.3
    Mentioned
    54 Post(s)
    Rep Power
    23


    2 out of 2 members liked this post. Reputation: Yes | No
    There is this tester from Summit to test the ethanol coming out of the pump.
    http://www.summitracing.com/parts/QFT-36-E85/

    You can then calculate the ethanol content in the tank.

    If we had easy access to the fuel tank we could use a kit like this. Unfortunately we don't.

    http://fueltestkit.com/instructions_..._test_kit.html
    Click here to enlarge
    MOTIV750, MOTIV P-1000 PI, MOTIV/FUEL-IT! low pressure fuel system, AEM EMS/COBB AP, Aquamist HFS-3, ETS FMIC, SPEC stage 3+ clutch/SS flywheel, BC Racing coilovers and VMR wheels wrapped in Hankook RS3s.

  20. #20
    Join Date
    Dec 2011
    Location
    Clarksville, TN
    Posts
    3,854
    Rep Points
    2,407.7
    Mentioned
    44 Post(s)
    Rep Power
    25


    Reputation: Yes | No
    That's the same tester I have. Easy and works great. Just have to be careful with the tube because its glass.
    2011 335is DCT, JB4 + MHD BEF, stage 2 LPFP, e50 + 50/50 meth, FBO, MT ET Streets when needed


  21. #21
    Join Date
    Dec 2011
    Location
    Roanoke VA
    Posts
    1,632
    Rep Points
    2,248.3
    Mentioned
    54 Post(s)
    Rep Power
    23


    Reputation: Yes | No
    Yeah, my buddy has it also. We're going to road trip this weekend to get a couple 55 galon drums worth of e85(e78 according to what the tester measured a couple weeks ago.)
    Click here to enlarge
    MOTIV750, MOTIV P-1000 PI, MOTIV/FUEL-IT! low pressure fuel system, AEM EMS/COBB AP, Aquamist HFS-3, ETS FMIC, SPEC stage 3+ clutch/SS flywheel, BC Racing coilovers and VMR wheels wrapped in Hankook RS3s.

  22. #22
    Join Date
    Jun 2012
    Location
    TX
    Posts
    103
    Rep Points
    174.0
    Mentioned
    4 Post(s)
    Rep Power
    2


    Reputation: Yes | No
    Click here to enlarge Originally Posted by dzenno@ProTUNING Freaks Click here to enlarge
    While its a good topic to discuss imho what you get from this is a good description on sort of off the shelf tuning..depending on what you do with boost, fuel and vanos you may end up with a lot more or less aggressive timing maps...speaking strictly in terms of timing without considering everything else is moot..just my 2c
    Is there a theoretical relationship that kinda ties all this stuff together? Understanding that the real world variables and differences between cars are pretty much impossible to model very accurately.

  23. #23
    Join Date
    Dec 2011
    Location
    Clarksville, TN
    Posts
    3,854
    Rep Points
    2,407.7
    Mentioned
    44 Post(s)
    Rep Power
    25


    Reputation: Yes | No
    Click here to enlarge Originally Posted by trufus Click here to enlarge
    Is there a theoretical relationship that kinda ties all this stuff together? Understanding that the real world variables and differences between cars are pretty much impossible to model very accurately.
    There is no table per se, but as long as everyone realizes the relationship between boost and timing they'll be fine. More boost=less timing period. You'll see in logs that during peak boost timing is lowest then as boost tapers toward redline timing ramps up. Boost and octane ore the main variables in this discussion and the thread is doing a good job of identifying octane. Just have to keep boost similar to get a good table going.
    2011 335is DCT, JB4 + MHD BEF, stage 2 LPFP, e50 + 50/50 meth, FBO, MT ET Streets when needed


  24. #24
    Join Date
    Jun 2010
    Location
    Chicago, IL
    Posts
    919
    Rep Points
    780.4
    Mentioned
    42 Post(s)
    Rep Power
    8


    Reputation: Yes | No
    Thanks for the link fellas! It's cheap enough to get one and periodically measure the E88 fuel at my local gas station. It's a good way of approximating E85 concentration in your gas tank.
    From all the things I've lost,
    I miss my mind the most!
    Click here to enlarge

  25. #25
    Join Date
    Mar 2010
    Location
    Toronto, Canada
    Posts
    6,677
    Rep Points
    3,327.5
    Mentioned
    225 Post(s)
    Rep Power
    34


    Reputation: Yes | No
    Click here to enlarge Originally Posted by trufus Click here to enlarge
    Is there a theoretical relationship that kinda ties all this stuff together? Understanding that the real world variables and differences between cars are pretty much impossible to model very accurately.
    You've pretty much answered your own question. There's really no equation to it but the OTS maps serve as great starting points and provide an approach. They also illustrate what highly seasoned tuners at Cobb see as proper tuning for this platform. Its obviously not the only way to tune this car but it is a way, and it works as we all know very well.
    Click here to enlarge

Page 1 of 2 12 LastLast

Tags for this Thread

Bookmarks

Posting Permissions

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