• 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 143 Comments
      1. Flinchy's Avatar
        Flinchy -
        how is it 120hp over stock? do you mean stock + tune? if so, that's a meaty turbo upgrade for sure.
      1. curare's Avatar
        curare -
        Click here to enlarge Originally Posted by Flinchy Click here to enlarge
        how is it 120hp over stock? do you mean stock + tune? if so, that's a meaty turbo upgrade for sure.
        I think its about 80whp over FBO+meth? Their car made about 390hp prior to the upgrade right?
      1. lulz_m3's Avatar
        lulz_m3 -
        Click here to enlarge Originally Posted by Flinchy Click here to enlarge
        how is it 120hp over stock? do you mean stock + tune? if so, that's a meaty turbo upgrade for sure.
        Are you looking at the power difference up top? Stock turbo is down to around 330ish whp at 6.5k whereas the VTT2 is around 440. Pretty darn close to 120hp over a maxed out stock turbo in kill mode. I guess i never realized how pathetic the stock n55 turbo is up top.
      1. maxnix's Avatar
        maxnix -
        Click here to enlarge Originally Posted by lulz_m3 Click here to enlarge
        I guess i never realized how pathetic the stock n55 turbo is up top.
        It's not as bad as BMW tunes it. Nowhere near the back pressure as on the N54 twin turbos.
      1. Terry@BMS's Avatar
        Terry@BMS -
        Click here to enlarge Originally Posted by lulz_m3 Click here to enlarge
        Are you looking at the power difference up top? Stock turbo is down to around 330ish whp at 6.5k whereas the VTT2 is around 440. Pretty darn close to 120hp over a maxed out stock turbo in kill mode. I guess i never realized how pathetic the stock n55 turbo is up top.
        Yes it's simply awful. Even mild tunes routinely run 100% duty cycle over 5000rpm.
      1. Flinchy's Avatar
        Flinchy -
        Click here to enlarge Originally Posted by lulz_m3 Click here to enlarge
        Are you looking at the power difference up top? Stock turbo is down to around 330ish whp at 6.5k whereas the VTT2 is around 440. Pretty darn close to 120hp over a maxed out stock turbo in kill mode. I guess i never realized how pathetic the stock n55 turbo is up top.
        yeah i got confused with the wording, it sounded like stock turbo stock tune and all no tune, 330WHP sounded a bit high. but stock turbo with a tune makes sense Click here to enlarge

        Click here to enlarge Originally Posted by curare Click here to enlarge
        I think its about 80whp over FBO+meth? Their car made about 390hp prior to the upgrade right?
        not sure what it made at most before, all i know is it's finally getting to where it should be! Click here to enlarge
      1. lulz_m3's Avatar
        lulz_m3 -
        Click here to enlarge Originally Posted by maxnix Click here to enlarge
        It's not as bad as BMW tunes it. Nowhere near the back pressure as on the N54 twin turbos.
        You can preach about back pressure all you want, $#@! just doesn't make power bro. No need to get mad.
      1. hakentt's Avatar
        hakentt -
        Click here to enlarge Originally Posted by maxnix Click here to enlarge
        1024 bit RSA encryption is very difficult to break. We'll see. No one else has done it yet.
        With so much potential with any turbocharged engine and now that we see N55 engine is proving to be very potent engine. I can assume few years from now, someone will fill the demand for stock DME tuning.
      1. ezec63's Avatar
        ezec63 -
        Click here to enlarge Originally Posted by Flinchy Click here to enlarge
        yeah i got confused with the wording, it sounded like stock turbo stock tune and all no tune, 330WHP sounded a bit high. but stock turbo with a tune makes sense Click here to enlarge



        not sure what it made at most before, all i know is it's finally getting to where it should be! Click here to enlarge
        Its not just 120 hp over a stock turbo with a tune

        its 120 hp over stock turbo with JB4 + Cobb back end flash, down pipes, e85 + meth so FBO

        The fbo stock turbo car made 390 peak but fell off hard uptop to 330 at 6.5K rpm
      1. Flinchy's Avatar
        Flinchy -
        Click here to enlarge Originally Posted by ezec63 Click here to enlarge
        Its not just 120 hp over a stock turbo with a tune

        its 120 hp over stock turbo with JB4 + Cobb back end flash, down pipes, e85 + meth so FBO

        The fbo stock turbo car made 390 peak but fell off hard uptop to 330 at 6.5K rpm
        sorry i meant FBO+tune yes... 120whp is definitely a respectable figure first go with just the turbo upgraded for sure!
      1. maxnix's Avatar
        maxnix -
        Click here to enlarge Originally Posted by lulz_m3 Click here to enlarge
        You can preach about back pressure all you want, $#@! just doesn't make power bro. No need to get mad.
        I'm cool and have no idea what "$#@!" is nor why it doesn't make power.

        If you don't understand the problems of back pressure on the N54 turbos, that's your loss, not mine.

        Peace, love, happiness.
      1. Terry@BMS's Avatar
        Terry@BMS -
        Click here to enlarge Originally Posted by hakentt Click here to enlarge
        With so much potential with any turbocharged engine and now that we see N55 engine is proving to be very potent engine. I can assume few years from now, someone will fill the demand for stock DME tuning.
        With the JB4 the only things we can't easily do on the tuning end are set advance higher than the OEM maximum setpoint or retime the valvetronic. With the OEM & Vargas turbo OEM maximum setpoint is pretty close to MBT for E85. So I don't think there is much in there with more timing. On the N54 we picked up 4-5hp with VANOS tuning so maybe that or double it can be had once we can retune the valvetronic? Not holding my breath there for much either.

        http://www.n54tech.com/forums/showpo...25&postcount=1
      1. lulz_m3's Avatar
        lulz_m3 -
        Click here to enlarge Originally Posted by maxnix Click here to enlarge
        I'm cool and have no idea what "$#@!" is nor why it doesn't make power.

        If you don't understand the problems of back pressure on the N54 turbos, that's your loss, not mine.

        Peace, love, happiness.
        I mean, back pressure is back pressure, right? Does the N54 have some special back pressure? Are you saying that the N55 turbo at "full retard" somehow magically doesn't produce back pressure? If we could somehow magically apply the wastegates of all 3 turbos to the same position and measure backflow, would the N55 turbo not produce as much back pressure? I'm really trying to understand the baseless argument here. I've seen empirical data on the back pressure of upgraded stock frame turbos for the N54, do you have the same data for the N55 oem turbo?
      1. maxnix's Avatar
        maxnix -
        Click here to enlarge Originally Posted by lulz_m3 Click here to enlarge
        I mean, back pressure is back pressure, right? Does the N54 have some special back pressure? Are you saying that the N55 turbo at "full retard" somehow magically doesn't produce back pressure?
        Yes, exactly. This limits the flow of the stock N54 turbos at higher RPM. The N55 has a larger housing and better flow and back pressure is not a problem at higher RPM. It is rather the small compressor turbine. Since Tony seems to be using OEM housing which are modified and increasing the size of the compressor turbine, it stands to reason he is seeing the success he is. As I understand it, similar efforts with the N54 were not so successful because of the impeller housing limitations. completely new turbos are required for credible gains, especially at higher RPM.

        I know someone who does have that data graphed. If they let me publish it, I will in a new thread.

        Now back to the N55 and Terry's efforts to tune Tony'w excellent upgrade.
      1. Terry@BMS's Avatar
        Terry@BMS -
        Hey guys,

        Got the JB4 N55 3.5 bar TMAP sensor programming done and did some more tuning with the car. Spent around 2hrs on the dyno trying various combinations as high as 25psi (which was as high as the turbo would go) and as high as 11 degrees total advance. But ultimately settled on a set of curves I felt comfortable with as a "street" setup and another more aggressive setup as a "track" setup. In all the various tests done 475rw was the highest power output reached. Levels over 23psi showed basically no gain and from 21 to 23psi keeping advance the same showed only a marginal gain. Compared to the "street" setup the "race" combination of more boost and more timing resulted in around 15rw more throughout the curve.

        Click here to enlarge

        Click here to enlarge

        Click here to enlarge
      1. curare's Avatar
        curare -
        Thanks for the update terry. Why not target a higher redline than 17psi?
      1. Terry@BMS's Avatar
        Terry@BMS -
        In other runs I targeted 21psi at redline but the turbo would only produce 19psi and made the same power as it did at 18psi. So it was definitely beyond its efficiency curve there. The car should be shifted around 6200rpm to maximize power under the curve during a race.
      1. VargasTurboTech's Avatar
        VargasTurboTech -
        Click here to enlarge Originally Posted by Terry@BMS Click here to enlarge
        Hey guys,

        Got the JB4 N55 3.5 bar TMAP sensor programming done and did some more tuning with the car. Spent around 2hrs on the dyno trying various combinations as high as 25psi (which was as high as the turbo would go) and as high as 11 degrees total advance. But ultimately settled on a set of curves I felt comfortable with as a "street" setup and another more aggressive setup as a "track" setup. In all the various tests done 475rw was the highest power output reached. Levels over 23psi showed basically no gain and from 21 to 23psi keeping advance the same showed only a marginal gain. Compared to the "street" setup the "race" combination of more boost and more timing resulted in around 15rw more throughout the curve.

        http://www.PorscheBoost.com/images/i...c1d13897-1.jpg

        http://www.PorscheBoost.com/images/i...c1d13897-1.jpg

        http://www.PorscheBoost.com/images/i...c1d13897-1.jpg
        Awesome results! Thanks Terry for taking the time to get that all programmed up and running. I have a feeling these actuators on the N55 are being pushed open as the BP rises, I've been testing more as cores come in and they are pretty weak to he honest. So basically we have a double whammy of BP starting to build and as it rises it's pushing the flapper open. I found a boost controlled actuator I think would work perfectly. But honestly I am not sure thete is tuning to control a boost actuated gate on the N55 right now. All in all we are very happy with 475 / 509 and excited to see more happy N55 customers keeping up with the N54's....Click here to enlarge As things on the N55 progress I think we will see a lot more cool stuff just like with the N54.
      1. Terry@BMS's Avatar
        Terry@BMS -
        Thanks. It's running pretty well. Definitely can kill any stock turbo N54 now. Maybe even some mildly tuned hybrid turbo N54s.. Click here to enlarge
      1. rdeterman's Avatar
        rdeterman -
        475whp and 509wtq is very respectable. Good work guys!