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    • N55 tuning goes to the next level - Vargas N55 turbo upgrade with BMS JB4 tuning dyno results - 468 wheel horsepower

      Finally the N55 motor is getting some love! Up to this point the twin turbo N54 engine has dominated modern BMW turbo tuning and the N55 has been left in its shadow. BimmerBoost is proud to report that vendors BMS and Vargas Turbo Tech were able to work in collaboration and show a successfully tuned and installed turbocharger upgrade for the BMW N55. This is still very early on and there is more to come but N55 owners finally have a realistic turbo upgrade option to look forward to.


      Notes from Terry@BMS:

      I think the data speaks for itself but here are a few notes:

      1) Boost with the fix is overall what I expected it would be from the start. It's able to hit ~20psi in the midrange and hold ~18psi @ 6000rpm. There is probably another psi or so of midrange boost in there with a 3.5 bar MAP sensor if we want it. It makes a little less down low which is to be expected. The gains up top are now well worth anything lost. On the street it's spooling faster now and feels great.

      2) Tuning is done using JB4 ISO v5.2. We also reworked the back end flash for the E50 + meth fuel and found MBT around 9 degrees peak. The flash is loaded using a Cobb AP. Currently, they only support 2011-early 2012 models. Hopefully more models are added soon. The turbo can be used with the OEM flash but only with E85, or E85 + meth. We'll write pump gas maps for the turbo in the coming weeks for those who are using the back end flash and want to run 91 or 93.

      3) With a little more boost and some other tuning tweaks 500whp might be possible with this setup. For now I'm very happy to have 120whp over stock @ 6000rpm. At 468rw this car should have enough power to run mid 11s full weight. I hope to find out this weekend.

      4) This car finally lives up to it's "Dr N55" plates.







      This article was originally published in forum thread: Vargas N55 Turbo Upgrade Dyno - Take 2! started by Terry@BMS View original post
      Comments 145 Comments
      1. VargasTurboTech's Avatar
        VargasTurboTech -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        I have to say I'm pleasantly surprised how popular the N55 stuff is getting.

        I don't know if this platform will ever rival the N54 for tuning popularity but this motor sticks around longer it just may.
        Doesn't surprise me at all, the N54 is done, never to me manufactured again. BMW is throwing this N55 into anything and everything it can. That's the kind of platform you want to make upgrades for..Click here to enlarge
      1. Terry@BMS's Avatar
        Terry@BMS -
        Click here to enlarge Originally Posted by benzy89 Click here to enlarge
        Haven't seen STFTs or LTFTs.... Was just wondering where they stand, especially since you're running an ethanol blend
        Trims can be whatever you want them to be with a back end flash. Fuel pressure on E85 only will likely require an inline pump. On E85 + meth, zero issues so far on a 100% stock fuel system. Not unlike many N54s running around at 500rw+ on E85 + meth on a stock fuel system.
      1. fastgti69's Avatar
        fastgti69 -
        Click here to enlarge Originally Posted by Terry@BMS Click here to enlarge
        Trims can be whatever you want them to be with a back end flash. Fuel pressure on E85 only will likely require an inline pump. On E85 + meth, zero issues so far on a 100% stock fuel system. Not unlike many N54s running around at 500rw+ on E85 + meth on a stock fuel system.
        Is the n55 the same as the n54 in terms of intank fuel pump? Can you add a 255 just like that?
      1. benzy89's Avatar
        benzy89 -
        Well I know the N55 is running a different Injectors (not sure about other fueling system components), just presumed that without meth you're approaching the max capacity of the OEM fueling system. I also know that a few N55 owners that have tried the N54 LPFP upgrades are seeing fault codes on their iDrive screen.


        Regardless, greet numbers -- Eager to see some Pump Gas & Performance Numbers (1/4 miles, 60-130s)
      1. Terry@BMS's Avatar
        Terry@BMS -
        Click here to enlarge Originally Posted by fastgti69 Click here to enlarge
        Is the n55 the same as the n54 in terms of intank fuel pump? Can you add a 255 just like that?
        Not had the need to get involved with it yet but seems to be the same parts. We'll cross that bridge when fuel pressure starts tanking. Click here to enlarge
      1. bigdnno98's Avatar
        bigdnno98 -
        This + X1 AWD FTW!

        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        I'm liking this for an X3.
      1. paradoxical3's Avatar
        paradoxical3 -
        Click here to enlarge Originally Posted by bigdnno98 Click here to enlarge
        This + X1 AWD FTW!
        I'm not sure which turbo solution I will be going with, but I will be upgrading the turbo on my X1. Should put me low-mid 11's.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by paradoxical3 Click here to enlarge
        I'm not sure which turbo solution I will be going with, but I will be upgrading the turbo on my X1. Should put me low-mid 11's.
        You do not really have several choices at the moment. This would definitely put you in the low 11's.
      1. paradoxical3's Avatar
        paradoxical3 -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        You do not really have several choices at the moment. This would definitely put you in the low 11's.
        If I want to run a backend flash I don't have ANY choices at the moment since Cobb can't figure out how to work with 2012+ ECU's.

        I will see what happens as this and the impending PTF solution mature, then make a decision once Cobb fixes the tuning situation.
      1. VargasTurboTech's Avatar
        VargasTurboTech -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        You do not really have several choices at the moment. This would definitely put you in the low 11's.
        Its gonna be a long ways off before any other N55 upgrades hit the market, all of the ones on the horizon get rid of everything, and bolt on completely new manifolds, turbos, piping, etc, etc, etc. Meaning if you have any warranty left, keep your car away from the dealer as one look down there and its most likely voided. We went the hybrid approach because it leaves warranties intact, and has the potential for good power gains, can it match the power potential of a full bolt on system, it cannot. But they will be more expensive, invasive, and 90% of people are happy with 500 / 550 street cars.

        The wait for the other kits may let tuning catch up, which would be a good thing, as trying to tune a stage 3 style system without a flash, back end or complete tune would be pointless.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by paradoxical3 Click here to enlarge
        since Cobb can't figure out how to work with 2012+ ECU's.
        I think that's a bit unfair. They are working on it. Saying they can't implies they never well.

        In their defense nobody has those things cracked. BMW decided to screw everyone.
      1. max@'s Avatar
        max@ -
        great work guys!!
      1. Terry@BMS's Avatar
        Terry@BMS -
        I'll be taking this car to Famoso tomorrow. Conditions will be good. Hopefully no tuning issues crop up preventing good times down the 1/4. I did a couple VBOX runs last night just to ensure it would make it down the track and traps were in the 122mph range full weight. Should be good for mid 11s with traction. RB N54 335s full weight run around 125mph on average so we're not that far off. Click here to enlarge
      1. bigdnno98's Avatar
        bigdnno98 -
        VERY NICE! Hopefully it holds up LOL. N54 guys better look out.

        Click here to enlarge Originally Posted by Terry@BMS Click here to enlarge
        I'll be taking this car to Famoso tomorrow. Conditions will be good. Hopefully no tuning issues crop up preventing good times down the 1/4. I did a couple VBOX runs last night just to ensure it would make it down the track and traps were in the 122mph range full weight. Should be good for mid 11s with traction. RB N54 335s full weight run around 125mph on average so we're not that far off. Click here to enlarge
      1. VargasTurboTech's Avatar
        VargasTurboTech -
        Click here to enlarge Originally Posted by Terry@BMS Click here to enlarge
        I'll be taking this car to Famoso tomorrow. Conditions will be good. Hopefully no tuning issues crop up preventing good times down the 1/4. I did a couple VBOX runs last night just to ensure it would make it down the track and traps were in the 122mph range full weight. Should be good for mid 11s with traction. RB N54 335s full weight run around 125mph on average so we're not that far off. Click here to enlarge
        Looking forward to see what it will do. Some more boost and timing, this turbo will run away from the back pressure, and shaft speed limited N54 stock frames. The GTX3076 is rated at over 3 bar of boost, or 44 psi. We will never see anything close to that. But running 25psi+ should not be an issue. With some further tuning, these N55's with this turbo should perform better than any N54 with stock frames on it, and do so with more reliability.

        Garrett blurb on the GTX3076
        "GT35R power in a GT30 package and spool. Do you like high boost? this turbo will run in upwards of 3bar without back pressure skyrocketing. A great turbo for road racing on a 2.0 or 2.5L engine, also a good street strip turbo that makes up to 640hp. Dual ball bearing, oil lubricated/water cooled CHRA"

        Yes this is in native housings, but these N55's are so efficient we will see very high WHP numbers even with the small housings.
      1. Sticky's Avatar
        Sticky -
        What is the transmission on this car? Sorry if I missed it.
      1. sA x sKy's Avatar
        sA x sKy -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        What is the transmission on this car? Sorry if I missed it.
        AT I think.
      1. Linracing's Avatar
        Linracing -
        If its the 135 it is DCT.
        If its the 335 f30 8 speed auto
      1. VargasTurboTech's Avatar
        VargasTurboTech -
        AT
      1. Terry@BMS's Avatar
        Terry@BMS -
        Click here to enlarge Originally Posted by VargasTurboTech Click here to enlarge
        Looking forward to see what it will do. Some more boost and timing, this turbo will run away from the back pressure, and shaft speed limited N54 stock frames. The GTX3076 is rated at over 3 bar of boost, or 44 psi. We will never see anything close to that. But running 25psi+ should not be an issue. With some further tuning, these N55's with this turbo should perform better than any N54 with stock frames on it, and do so with more reliability.

        Garrett blurb on the GTX3076
        "GT35R power in a GT30 package and spool. Do you like high boost? this turbo will run in upwards of 3bar without back pressure skyrocketing. A great turbo for road racing on a 2.0 or 2.5L engine, also a good street strip turbo that makes up to 640hp. Dual ball bearing, oil lubricated/water cooled CHRA"

        Yes this is in native housings, but these N55's are so efficient we will see very high WHP numbers even with the small housings.
        There is definitely a little more power in there. We'll have to find some way to get a bung on there to measure the back pressure. We're running around 85% duty cycle now @ 20psi on a cold night. On timing, the motor has a pretty tight combustion chamber compared to the N54. For example on the stock turbo it's making peak power at only 8 degrees advance on E85+meth. We may have it over timed a bit right now at 9 degrees. I did a little work on the dyno adding +1 degree, etc, and power didn't really pick up. But didn't have time to do the full normal sweep I'd like to do. It will come with time though. Shifting around 6000rpm seems to give the best "power to the ground" through the gears as currently tuned.