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Thread: MPI and basic "flex fuel" working on MQB 2.0

  1. #1
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    MPI and basic "flex fuel" working on MQB/SIMOS18 2.0

    Hey guys, I have successfully enabled MPI and fueling-correction-only "flex fuel" with HP Tuners.

    2017 Audi S3 w/ PR 925cc MPI kit w/ continental ethanol sensor.

    First log is cold start. Once the wideband comes online you can see STFT increase to correct. Then around 2 mins in or 10:31, the ECU starts using the learned ethanol content and fueling is spot on. This is about E35 in the tank, using SAE PID 01 52 to display E content--also works with generic OBD scanner/phone app etc.

    Second log is a quick WOT log. Tune is super conservative and not complete by any means, but note that "Injector Pulse Width 1 Cyl 1" is DI pw and "Injector Pulse Width Cyl 1" is MPI. I have it triggered to activate around 250 lb-ft.





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    Last edited by aaronc7; 12-25-2020 at 07:13 PM.

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    OOOOOOHhhh. Now how do the rest of us get it??

    When are you going to tackle timing and boost?

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    Quote Originally Posted by earlyapex View Post
    OOOOOOHhhh. Now how do the rest of us get it??

    When are you going to tackle timing and boost?
    You'll need user defined parameters or I guess I could make some of the changes for you if you sent me your file. But, I only figured this out for my particular box code, so even that might not work. I don't have definition files for all box codes.... I have sent some of this in to HP tuners, hopefully they will add the tables/implement for the masses soon.

    The ECU has built in logic for both MPI and fueling-only flex fuel, I simply enabled it in the tune file. For timing and boost, some changes would need to be made / custom logic implemented in the application software / OS side. That's beyond my knowledge, plus hp tuners doesn't let you modify that. I really hope we can get full flex fuel going. I would be happy with just a simple timing adder and blend table. Boost/torque and other adjustments would just be icing on the cake for me. Beggars can't be choosers I guess lol.

    What's your car / box code??
    Last edited by aaronc7; 12-23-2020 at 06:57 PM.

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    How you wire the ethanol sensor?

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    Quote Originally Posted by luis1778 View Post
    How you wire the ethanol sensor?
    Luis,

    Wired into the ECU harness. I followed the PR MPI kit instructions. Pg16, Gray wire / Pin 71 is the signal wire. Plus any switched +12V and gnd.

    https://www.precisionraceworks.com/S...l_Guide_r2.pdf
    Last edited by aaronc7; 12-26-2020 at 09:24 AM.

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    Slowly but surely making progress with the tune.

    I think I've worked around most of the torque limiters. Still getting something that is lowering my MAP desired at spool up/slight overshoot/throttle closure, but not terrible. I was thinking modeled surge line related, but I don't think that's the case anymore.

    STFT at high RPM is getting down to -11, so I think I need to decrease my MPI injector constant a little bit more too.

    Feel good about the setup and can now finally start adding some timing in.

    https://datazap.me/u/aaronc7/aaron-r...14-15-16-24-29

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    Follow you

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    Anyone else using this on simos18? I know of like 2 other guys... Maybe pops n bangs will bring all the boys to the yard


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    Quote Originally Posted by aaronc7 View Post
    Anyone else using this on simos18? I know of like 2 other guys... Maybe pops n bangs will bring all the boys to the yard

    I work Pops n bangs on Edyne
    Its very similar on HPT

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    Yeah it's all built into the stock ECU logic, just a matter of enabling it and adjusting the correct tables. There's so much stuff built into the logic... it's a little overwhelming to read about and comprehend it all sometimes.


    When running flex fuel, my ethanol content always resets to 0 after I shut off the engine, and then takes a minute or two to come back online. No issues running relatively light blends right now, but I wonder if this would not quite be ideal for straight E85. I'm digging more into the logic to see if this is expected behavior or how I could go about the ECU "remembering" the last E content.


    I fixed the low rpm throttle closures on slight overboost/boost onset. Feeling good about the tune and how it's running.

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    Nothing real exciting....baby steps on a new tuning platform. Previously made 350/400 on 91 on this setup on Cobb. Current tune is almost there, still about 2-3* more timing to add. Seems about right. Stage 2 S3 "IS38" setup on 91 octane. 4300' elevation so just don't have the air to hold the boost well up top.


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    Quote Originally Posted by aaronc7 View Post
    Nothing real exciting....baby steps on a new tuning platform. Previously made 350/400 on 91 on this setup on Cobb. Current tune is almost there, still about 2-3* more timing to add. Seems about right. Stage 2 S3 "IS38" setup on 91 octane. 4300' elevation so just don't have the air to hold the boost well up top.

    Thats a fucking banger man, looks clean as hell.

    Good work!

    P.S. whats timing roughly at peak/redline?

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    Quote Originally Posted by TylerJDubbs View Post
    Thats a fucking banger man, looks clean as hell.

    Good work!

    P.S. whats timing roughly at peak/redline?
    About 7-7.5*. Aiming for around 10* for this boost curve.

    I could also push boost a bit more, but since I can't yet log Wastegate position with VCM scanner, I haven't really pushed it too much more. It's around 70-80% wastegate last I checked at high rpm.

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    Quote Originally Posted by aaronc7 View Post
    About 7-7.5*. Aiming for around 10* for this boost curve.

    I could also push boost a bit more, but since I can't yet log Wastegate position with VCM scanner, I haven't really pushed it too much more. It's around 70-80% wastegate last I checked at high rpm.
    nice man! super excited to see someone publicly posting progress in the euro community as its very rare sadly haha

    I'm not normally an advocate for "following" but have you looked at some of the mainstream MQB tunes? i see you're running what looks like a .87 on pump gas at peak load.... i know the big name tuners and others run close to .97-.93 at peak load with severely negative timing like -7-(-10*) have you had any experienced running the car like this?

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    Quote Originally Posted by TylerJDubbs View Post
    nice man! super excited to see someone publicly posting progress in the euro community as its very rare sadly haha

    I'm not normally an advocate for "following" but have you looked at some of the mainstream MQB tunes? i see you're running what looks like a .87 on pump gas at peak load.... i know the big name tuners and others run close to .97-.93 at peak load with severely negative timing like -7-(-10*) have you had any experienced running the car like this?
    Yeah I've looked at a lot of logs over time. With Cobb becoming very popular in the MQB world, you're starting to see the community a lot more involved in the tuning process, datalogging, etc.

    In FI setups I have never really seen an advantage to running lean...marginal power difference. And usually with richer lambda/AFR (within reason of course) you can run more boost/timing etc to easily make up for any sort of power loss you might see by running a lean AFR.

    That said I did run into something interesting. Stock tune on this car targets lambda of 1.0 all the time, even at WOT....after a long run it might richen up to .98 or something. On my very first tune revision, pretty much the only thing I did was add fuel to hit mid 12s by redline, and it knocked a bunch. I've heard of "rich knock" on DI and that definitely appeared to be a thing here. But once I turned up the boost, I haven't had any such issues and I'll always favor going on the safer side of things to try and keep the cylinder/piston etc from getting too hot for extended pulls or hard driving.

    Without pulling up the log, I think I'm at around -1, maybe -2, ign timing at peak load, and then it just comes up slowly and linearly to redline.

    All that said I'm not a pro and don't really have the time or resources to thoroughly test all these things. Just try to take cues from what seems to work the best for a particular car and start there.

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    Quote Originally Posted by aaronc7 View Post
    Yeah I've looked at a lot of logs over time. With Cobb becoming very popular in the MQB world, you're starting to see the community a lot more involved in the tuning process, datalogging, etc.

    In FI setups I have never really seen an advantage to running lean...marginal power difference. And usually with richer lambda/AFR (within reason of course) you can run more boost/timing etc to easily make up for any sort of power loss you might see by running a lean AFR.

    That said I did run into something interesting. Stock tune on this car targets lambda of 1.0 all the time, even at WOT....after a long run it might richen up to .98 or something. On my very first tune revision, pretty much the only thing I did was add fuel to hit mid 12s by redline, and it knocked a bunch. I've heard of "rich knock" on DI and that definitely appeared to be a thing here. But once I turned up the boost, I haven't had any such issues and I'll always favor going on the safer side of things to try and keep the cylinder/piston etc from getting too hot for extended pulls or hard driving.

    Without pulling up the log, I think I'm at around -1, maybe -2, ign timing at peak load, and then it just comes up slowly and linearly to redline.

    All that said I'm not a pro and don't really have the time or resources to thoroughly test all these things. Just try to take cues from what seems to work the best for a particular car and start there.
    Honestly man I've been looking at these thing the same way running around a .92-.90 at peak load compared to the .96-.93 the competition is running... that being said Im running about .3 bar more at peak on my aggressive tuned cars so i guess it all balances out

    nice to see another OG trying something different

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    Is this a 50-120Hz flex fuel sensor which precision raceworks uses?
    Have a Fuel-IT universal kit which is supposed to be able to be wired up to stock and aftermarket ECU's.
    But haven't figured out yet where to pin it to.
    Last edited by YvesT; 01-20-2021 at 04:15 PM.

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    Quote Originally Posted by YvesT View Post
    Is this a 50-120Hz flex fuel sensor which precision raceworks uses?
    Have a Fuel-IT universal kit which is supposed to be able to be wired up to stock and aftermarket ECU's.
    But haven't figured out yet where to pin it to.
    Yes, it's the standard continental / GM sensor. I got mine from Rockauto. Same thing that's included in the Fuel-it kit (which I also have/had). There's a few different models for the fuel it module... some output raw digital signal and some convert to analog and output that. I THINK the most common is analog output. Anyways, you need digital / hz output to be wired into the ECU.

    See reply number 5-- it has a link the PR instructions which had instructions for the pinning on the E sensor as well.

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    Quote Originally Posted by aaronc7 View Post
    Yes, it's the standard continental / GM sensor. I got mine from Rockauto. Same thing that's included in the Fuel-it kit (which I also have/had). There's a few different models for the fuel it module... some output raw digital signal and some convert to analog and output that. I THINK the most common is analog output. Anyways, you need digital / hz output to be wired into the ECU.

    See reply number 5-- it has a link the PR instructions which had instructions for the pinning on the E sensor as well.

    Thank you for figuring this out. Just got the new built motor back and about to install in the car, but gonna update the fuel line and install the flex fuel sensor inline this time.

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    Quote Originally Posted by spoooolin View Post
    Thank you for figuring this out. Just got the new built motor back and about to install in the car, but gonna update the fuel line and install the flex fuel sensor inline this time.
    What's your ECU OS? Might be able to help you with flex.