• BMW N54 COBB AccessPORT Now Supports Alternate Fuels - E85



      COBB Tuning is proud to announce that BMW N54 AccessPORT users can now tune for alternate fuels, such as E85, with the latest updates in AccessTUNER Race and AccessTUNER Pro tuning software. AccessPORT end-users and professional tuners can quickly update AccessPORT maps to accommodate fuels of different specific energy using the newly added Fuel Scalar tables, resulting in proper fuel trims during engine operation. This development opens the door for BMW N54 enthusiasts looking to take advantage of the performance and cost benefits of using E85 and other fuel blends.


      Prior to this development, BMW N54 enthusiasts were limited to the extent they could blend E85 with regular gasoline and still have the engine operate safely within the window that the ECU fuel trims could accommodate. By giving end-users and professional tuners the ability to manipulate fuel scalars on their own, this limitation has been removed, allowing the ECU to operate with alternate fuels in the same way it does with traditional gasoline and maintain fuel trims within a range of 1%-3% while producing impressive power gains with excellent power delivery characteristics.










      A Fuel Scalar table is assigned to each cylinder bank in the AccessTUNER software. For most ECUís, these tables are simple one-dimensional scaling factors that allow the user to adjust the fuel scaling up or down as needed. In the 1M ECU, the fuel scalar tables are two-dimensional 16x16 tables that scale fuel based on engine RPM and load.



      Non-1M ECU Fuel Scalar Table



      1M ECU Fuel Scalar Table


      Due to variation in fuel blends across the country, E85 Off-The-Shelf maps will not be available for download. Instead, the end-user is empowered to tune specifically for the fuel blend at their favorite fuel source using AccessTUNER software and data-logging to ensure proper performance. This also allows the end-user to blend different fuels to their liking and quickly tune for it. The BMW AccessTUNER Help Guide has been updated to include Fuel Scalar table descriptions as well as a reference chart for estimated Fuel Scalar values for different blends of ethanol and gasoline.


      To update AccessTUNER and acquire the latest Fuel Scalar tables, simply open the software, click on Help in the menu bar, select Updates and click Check for Updates. In the pop-up window, check the Beta Software box in the lower right corner. Click the Get Updates button and follow on-screen instructions to complete the software upgrade and start tuning for alternate fuels!


      Software Version
      AccessTUNER Pro: 1.9.1.0-4419
      AccessTUNER Race: 1.9.1.0-4414


      This article was originally published in forum thread: BMW N54 AccessPORT Now Supports Alternate Fuels started by COBB Tuning View original post
      Comments 75 Comments
      1. 654's Avatar
        654 -
        I need Cobb AP.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by 654 Click here to enlarge
        I need Cobb AP.
        Well buy it...
      1. enrita's Avatar
        enrita -
        Great news! Thanks cobb and PTF!
      1. Tzu's Avatar
        Tzu -
        This is awesome. PTF + Cobb FTW.
      1. 654's Avatar
        654 -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        Well buy it...
        Yes, I believe that's the best way to acquire one...
        Looks like what ever direction I take from home, I have an e85 station within five or ten minutes drive. I can't avoid this. Literally.
      1. Josh@Cobb's Avatar
        Josh@Cobb -
        Click here to enlarge Originally Posted by Snertz Click here to enlarge
        Awesome news, thanks COBB / PTF!

        Quick question since I'm running this on my 1M, is there any reason not to set one scalar value across the board?
        I would recommend using your calculated scalar as a multiplier for all of the values in the table.
      1. Josh@Cobb's Avatar
        Josh@Cobb -
        Click here to enlarge Originally Posted by lulz_m3 Click here to enlarge
        @Rob@Cobb , any chance of us I8AOS guys getting a scalar table like the 1M? I typically see higher fuel trims around peak torque and they 0 out up top. Would be great to be able to adjust by load and rpm!
        The DME is setup differently, but the single value scalar is a perfect, simple table to correct your fuel trims. If you try it, you'll see that your fuel trims will still be at (or close to) zero in the top end.
      1. lulz_m3's Avatar
        lulz_m3 -
        Click here to enlarge Originally Posted by Josh@Cobb Click here to enlarge
        The DME is setup differently, but the single value scalar is a perfect, simple table to correct your fuel trims. If you try it, you'll see that your fuel trims will still be at (or close to) zero in the top end.
        I'll have to do some playing this weekend, thanks!
      1. boosted-M's Avatar
        boosted-M -
        I have been waiting for this!!!! LOL, I just lowered to 30% E85 this morning as I was maxing out my fuel trims..
        Can't wait to burn thru this tank and fill up with 100% E85.. The fill up with E85 & pump gas was getting old..

        Thanks Cobb Click here to enlarge
      1. enrita's Avatar
        enrita -
        Is this calculation correct?
        On 50 ltr, 50/50 mix results in around 42% ethanol?
      1. Josh@Cobb's Avatar
        Josh@Cobb -
        Click here to enlarge Originally Posted by enrita Click here to enlarge
        Is this calculation correct?
        On 50 ltr, 50/50 mix results in around 42% ethanol?
        If your E85 is truly 85% ethanol, and assuming you have 10% ethanol in your pump gas (like most US gas), you would have a 48% ethanol concentration in the 50/50 mix.
      1. max's Avatar
        max -
        Good news here, thanks Cobb.
      1. COBB Tuning's Avatar
        COBB Tuning -
        X = % of E85 added to gasoline
        Y = actual % of ethanol in your E85
        Z = % of ethanol in your pump gasoline

        (X * Y) + ((1 - X) * Z) = overall ethanol content

        So if your E85 is really 85%, and your mix is 30% E85 to gasoline, and your gasoline is 10% ethanol from the pump...

        X = 30%
        Y = 85%
        Z = 10%

        (.30 * .85) + ((1 - .30) * .10) = .325 or 32.5% ethanol

        - Gary
      1. pho_e92's Avatar
        pho_e92 -
        WOOT GREAT NEWS for the e85 users. thank you COBB AND PTF.
      1. nafoo's Avatar
        nafoo -
        Here's a ethanol level calculator I use:

        http://www.intercepteft.com/calc.html
      1. Q4P's Avatar
        Q4P -
        Someone please, please run straight e85 and report results... timing, mpgs, miles to empty and dyno sheet. This is beyond sexy right now...
      1. Dfv2's Avatar
        Dfv2 -
        So assuming Cobb and PTF have been working with straight e85 for a while, and straight e85 tuning on a DI system is brand new to many, here's a million dollar question:

        Q) Assuming 4.02 OTS Stg2+ agg map, fuel-scaled for 100% e85, FBO stock turbo no meth; does one find more power at richer or leaner gas AFR values in the high-load columns of the main fuel tables?

        In other words I strap the car down on a dyno and everything is identicle between runs except for AFR. I do three pulls and change only AFR (as gas AFR) for all pertinant WOT cells; run 1 = 11.5, run 2 = 12.0, and run 3 = 12.5...

        Which nets more power? On stock turbos, which AFR strategy ultimately allows for highest MBT after timing changes are considered?

        Pretty straight forward for any PI platform and turbo combo, but I'm a n00b to DI and e85 tuning, thanks in advance!
      1. enrita's Avatar
        enrita -
        Click here to enlarge Originally Posted by COBB Tuning Click here to enlarge
        X = % of E85 added to gasoline
        Y = actual % of ethanol in your E85
        Z = % of ethanol in your pump gasoline

        (X * Y) + ((1 - X) * Z) = overall ethanol content

        So if your E85 is really 85%, and your mix is 30% E85 to gasoline, and your gasoline is 10% ethanol from the pump...

        X = 30%
        Y = 85%
        Z = 10%

        (.30 * .85) + ((1 - .30) * .10) = .325 or 32.5% ethanol

        - Gary
        This is very helpful thanks!
        shell vpower in sweden has 5% ethanol while std 93 octane has 0% . A 50/50 mix yields 99 octane! Almost race gas!
      1. lulz_m3's Avatar
        lulz_m3 -
        Be glad you have 0 Ethanol 93 octane available. Here in the states, the E10 93 octane is far more knock prone than 100% gasoline 93 octane.
      1. boosted-M's Avatar
        boosted-M -
        Click here to enlarge Originally Posted by Dfv2 Click here to enlarge
        So assuming Cobb and PTF have been working with straight e85 for a while, and straight e85 tuning on a DI system is brand new to many, here's a million dollar question:

        Q) Assuming 4.02 OTS Stg2+ agg map, fuel-scaled for 100% e85, FBO stock turbo no meth; does one find more power at richer or leaner gas AFR values in the high-load columns of the main fuel tables?

        In other words I strap the car down on a dyno and everything is identicle between runs except for AFR. I do three pulls and change only AFR (as gas AFR) for all pertinant WOT cells; run 1 = 11.5, run 2 = 12.0, and run 3 = 12.5...

        Which nets more power? On stock turbos, which AFR strategy ultimately allows for highest MBT after timing changes are considered?

        Pretty straight forward for any PI platform and turbo combo, but I'm a n00b to DI and e85 tuning, thanks in advance!
        I've tuned a few 700whp Civics, STI's, Evo's on E85 and I like to be on the conservative side. I found the beauty of E85 allowed me to run richer AFR's (11-11.3afr) and net basically the same power as a 12.0afr pull.. ~~~~HP loss was VERY minimal~~~~ These cars even picked up TQ with the richer AFR so why not build in a safety margin and run the richer AFR's if your fuel system can support the flow.. Timing wise I would leave it the same as pump/meth.. E85 is a faster burning fuel and the car will naturally pick up power compared to pump gas, all things equal......Now with the N54 platform and DI I would love to see some dyno results..!