• Vargas Stage III Turbo upgrade for 335/135 N54 motor hits 572 wheel horsepower on 91 octane pump gas (no meth injection) with Cobb flash

      Well here are some results for the Vargas Stage III upgrade that has caused the N54 forum section to basically be engaged in chaos for the past few months. From accusations of vaporware, to comparison to single turbo upgrades, to countless other arguments the day has come and the Stage III Vargas Turbo upgrade dyno'd on 91 octane with no meth 572 horsepower to the rear wheels. This is with a Cobb flash tuned by BimmerBoost vendor Pro-Tuning Freaks.


      Impressive? Yep, sure is and this seems to also be a 91 octane pump gas only world record for the N54. Now keep in mind this is just the beginning. What will it do with meth? What will do on E85? What will it do with race gas and big boost? What about different turbos? Sky appears to be the limit but for now this kind of performance on pump gas sure is a big boost (hah, get it?) to the N54 scene.

      Congratulations to all involved, Vargas Turbo Tech, Pro-Tuning Freaks, Cobb, and just the N54 community as well. The impossible just became possible. Pictures, video, and dynograph below.



      This article was originally published in forum thread: 572WHP 537WTQ - ACN 91 Octane, no meth - VTT Stage 3 Early Dynos PTF / COBB Protune started by VargasTurboTech View original post
      Comments 575 Comments
      1. maximumpsi's Avatar
        maximumpsi -
        Nice numbers!
      1. vasillalov's Avatar
        vasillalov -
        I apologize if this has been discussed before, but I am wondering what is being used for a boost sensor? Is it the N20 boost sensor? I ask because if my memory serves me right, the N54 boost sensor goes reliably only up to 21psi.
      1. dzenno@PTF's Avatar
        dzenno@PTF -
        Click here to enlarge Originally Posted by vasillalov Click here to enlarge
        I apologize if this has been discussed before, but I am wondering what is being used for a boost sensor? Is it the N20 boost sensor? I ask because if my memory serves me right, the N54 boost sensor goes reliably only up to 21psi.
        Yes, the N20 3.5bar replaces the N54 OEM 2.5bar.
      1. mightmouse's Avatar
        mightmouse -
        nice work tony I will give a call on Monday
      1. JoshBoody's Avatar
        JoshBoody -
        Click here to enlarge Originally Posted by Terry@BMS Click here to enlarge
        With a higher low pressure more fuel is pushed faster in to the HPFP cavity, which has a relatively narrow opening compared to the fuel line feeding it, effectively augmenting its capacity.
        Increasing pressure will increase flow, but thats not the issue here evident in the steady LP (depending how the actual logs look). IMO, first action is new pump and/or potentially lowering rail pressure by a 1/4 to 1/3. Let's see just the pressure logs with rpm DZ.
      1. Terry@BMS's Avatar
        Terry@BMS -
        Click here to enlarge Originally Posted by JoshBoody Click here to enlarge
        Increasing pressure will increase flow, but thats not the issue here evident in the steady LP (depending how the actual logs look). IMO, first action is new pump and/or potentially lowering rail pressure by a 1/4 to 1/3. Let's see just the pressure logs with rpm DZ.
        I think you're confused. We want to increase pressure at the high pressure pump inlet to more efficiently fill it's cavity, so that it can in turn provide a higher volume of high pressure fuel out.
      1. JoshBoody's Avatar
        JoshBoody -
        Click here to enlarge Originally Posted by Terry@BMS Click here to enlarge
        I think you're confused. We want to increase pressure at the high pressure pump inlet to more efficiently fill it's cavity, so that it can in turn provide a higher volume of high pressure fuel out.
        If the HPFP needed more fuel it should show in a pressure drop on the LP side. As long as the pumping cavity is full, thats all that matters...which seems to be the case with steady LP. Trying to "push" fuel with pressure won't help, cause flow pontential is Xcfm per rpm/rail pressure. Anyway, I'm no engineer though.
      1. cstavaru's Avatar
        cstavaru -
        I think that the single turbo spools faster than the twin-turbo, for these two particular setups. The single turbo is fed by 3 liters of exhaust flow while each of the twins is fed by 1.5 liters of exhaust flow and the combined flow of the twin-turbos is higher than the single. Basically the twin-turbo setup tested here is largely oversized for a nice balance, it's made for outright power (I suppose this isn't a bad thing for most but it is for those who seek "balance" more than power).


        My opinion is that using larger turbos compromise the trademark low-end torque of the N54 engine. The 10.2:1 compression ratio of this engine does not allow timing advance to be raised too much at lower RPMs (as I found out by playing with ATR on RBs), and the turbos do not provide the necessary pressure. So the low-end becomes weak. Even with RBs. I would say that's why Alpina chose a lower compression ratio for the N54 engine that they used in the previous B3 car.


        Some solutions that I would see:


        - Tune and use the "Timing (Spool)" map of the ECU (which is by default disabled in Cobb maps)
        - Choose the turbos for the exact final power target - there is technical documentation available on this
        - A twin-scroll single-turbo setup (this would be the most "correct" and also the most cost-effective solution, why hasn't this been attempted until now ? I read HPF is working on this)
        - Smaller turbos for the bi-turbo setup
      1. idriveslo's Avatar
        idriveslo -
        Click here to enlarge Originally Posted by VargasTurboTech Click here to enlarge
        We were heat soaking pretty bad, and at that point running up against the HPFP limit. We ran the meth for 1 run, iat's plummeted and fuel trims went -20 DME still has some control to keep things safe, it saw more fuel and cooler charge and responded with some extra power, trust me I told the people there this is not going to add any power, we just want to see if it helps with the fuel issues. Ran it up lifted at 5900 looked up and was like wtf. I'll post the graph when I get home. Just kinda let us know how much more is in there with a few small changes. LM, that's really my only reasoning as to why because it made no sense to me either. Extra fuel when you are getting close to a ceiling, and a cooler intake charge go a long way.
        I know i speak for quite a few who have zero interest in running meth in our cars for the added hassle and variables. I would personally much rather run e85. Do you plan on putting together a straight e85 package with no meth, or some variant thereof? e85>pump+meth for sure, really hoping to see this route taken with this.
      1. Terry@BMS's Avatar
        Terry@BMS -
        Click here to enlarge Originally Posted by JoshBoody Click here to enlarge
        If the HPFP needed more fuel it should show in a pressure drop on the LP side. As long as the pumping cavity is full, thats all that matters...which seems to be the case with steady LP. Trying to "push" fuel with pressure won't help, cause flow pontential is Xcfm per rpm/rail pressure. Anyway, I'm no engineer though.
        This is just a theory at the moment. But, here is a diagram of the high pressure pump. #6 is the low pressure inlet. Fuel is then regulated by a control valve (which, is 100% open when high pressure is under target), through a check valve, in to the fuel chamber where it is compressed up to 2000psi+.

        I think what is limiting the pump output is the diameter of its internal low pressure passages in to the fuel chamber. At 70psi they can flow a certain amount. We've found if pressure drops to 50psi, the pump output drops. Presumably because a lower volume of fuel can make it in to the fuel chamber. So it stands to reason that upping that low pressure to 100psi will increase pump output.

        Consistent with the theory is that Tony says he is (inadvertently) running 80-90psi low pressure currently, and has a dyno showing more torque than I've never seen the stock pump supply.
      1. Legionofboom's Avatar
        Legionofboom -
        Click here to enlarge Originally Posted by cstavaru Click here to enlarge
        I think that the single turbo spools faster than the twin-turbo, for these two particular setups. The single turbo is fed by 3 liters of exhaust flow while each of the twins is fed by 1.5 liters of exhaust flow and the combined flow of the twin-turbos is higher than the single. Basically the twin-turbo setup tested here is largely oversized for a nice balance, it's made for outright power (I suppose this isn't a bad thing for most but it is for those who seek "balance" more than power).


        My opinion is that using larger turbos compromise the trademark low-end torque of the N54 engine. The 10.2:1 compression ratio of this engine does not allow timing advance to be raised too much at lower RPMs (as I found out by playing with ATR on RBs), and the turbos do not provide the necessary pressure. So the low-end becomes weak. Even with RBs. I would say that's why Alpina chose a lower compression ratio for the N54 engine that they used in the previous B3 car.


        Some solutions that I would see:


        - Tune and use the "Timing (Spool)" map of the ECU (which is by default disabled in Cobb maps)
        - Choose the turbos for the exact final power target - there is technical documentation available on this
        - A twin-scroll single-turbo setup (this would be the most "correct" and also the most cost-effective solution, why hasn't this been attempted until now ? I read HPF is working on this)
        - Smaller turbos for the bi-turbo setup
        The reason the single seems to spool "faster" is because its max airflow is around 650whp, These are the largest twins available from VTT, they are capable of pushing 850whp, they have been "detuned" because of the 91 oct. Fuel that was used.

        If you want more low end torque you can choose one of the smaller twin options and have even faster spool!
      1. klipseracer's Avatar
        klipseracer -
        Click here to enlarge Originally Posted by E90SoFlo Click here to enlarge
        These are the largest twins available from VTT,
        Pretty sure there is one size larger that he is offering which will present a 950 potential.
      1. Legionofboom's Avatar
        Legionofboom -
        Click here to enlarge Originally Posted by klipseracer Click here to enlarge
        Pretty sure there is one size larger that he is offering which will present a 950 potential.
        I was un-aware of this. Thanks!
      1. klipseracer's Avatar
        klipseracer -
        Click here to enlarge Originally Posted by E90SoFlo Click here to enlarge
        I was un-aware of this. Thanks!
        You've already quoted me on it but I'm pretty sure Click here to enlarge
      1. Legionofboom's Avatar
        Legionofboom -
        Click here to enlarge Originally Posted by klipseracer Click here to enlarge
        You've already quoted me on it but I'm pretty sure Click here to enlarge
        I thought these were the largest he was offering, I'm not sure why I thought that.

        These were the GTX2863R's right?
      1. 654's Avatar
        654 -
        Click here to enlarge Originally Posted by E90SoFlo Click here to enlarge
        I thought these were the largest he was offering, I'm not sure why I thought that.

        These were the GTX2863R's right?
        Yes, these are 63R's. You were thinking that probably because these are way too big for most of us already. However, you could plug in a pair of GTX2867R as well for 950hp.
      1. Legionofboom's Avatar
        Legionofboom -
        Click here to enlarge Originally Posted by 654 Click here to enlarge
        Yes, these are 63R's. You were thinking that probably because these are way too big for most of us already. However, you could plug in a pair of GTX2867R as well for 950hp.
        Good to know! +1 rep for you! lol
      1. klipseracer's Avatar
        klipseracer -
        Click here to enlarge Originally Posted by E90SoFlo Click here to enlarge
        Good to know! +1 rep for you! lol
        So I'm not crazy... Today. Now, it looks like we await ProEFI and the port injection, which I've been advocating for years from the piggies with batch fire injection. Even one injector somewhere around the TB with a spacer of some kind could do wonders. Potentially difficult to tune however. At this point, i think buying a spacer and some fueling lines would be a simpler solution than dancing around this wacky HPFP that seems to never be solved. Also easier than buying a brand new manifold and the whole ProEFI unit which is going to be costly. In fact I think I'm going to make a thread about it.
      1. JoshBoody's Avatar
        JoshBoody -
        Click here to enlarge Originally Posted by Terry@BMS Click here to enlarge
        This is just a theory at the moment. But, here is a diagram of the high pressure pump. #6 is the low pressure inlet. Fuel is then regulated by a control valve (which, is 100% open when high pressure is under target), through a check valve, in to the fuel chamber where it is compressed up to 2000psi+.

        I think what is limiting the pump output is the diameter of its internal low pressure passages in to the fuel chamber. At 70psi they can flow a certain amount. We've found if pressure drops to 50psi, the pump output drops. Presumably because a lower volume of fuel can make it in to the fuel chamber. So it stands to reason that upping that low pressure to 100psi will increase pump output.

        Consistent with the theory is that Tony says he is (inadvertently) running 80-90psi low pressure currently, and has a dyno showing more torque than I've never seen the stock pump supply.
        The diagram is not so easy for me to understand. But simply fuel enters chamber when there's a differential (piston downward position) and displaced into the rail (piston upward). Check valves keep the fuel flowing in 1 direction. Large swings in pressure could point to a flow issue, not pressure. Reducing the restrictions would help flow of course, but no need and no advantage in increasing pressure setpoint. A fluid dynamics person could easily add some helpful insight.

        It would be fairly simple to increase LP though as an experiment.
      1. Terry@BMS's Avatar
        Terry@BMS -
        Click here to enlarge Originally Posted by JoshBoody Click here to enlarge
        The diagram is not so easy for me to understand. But simply fuel enters chamber when there's a differential (piston downward position) and displaced into the rail (piston upward). Check valves keep the fuel flowing in 1 direction. Large swings in pressure could point to a flow issue, not pressure. Reducing the restrictions would help flow of course, but no need and no advantage in increasing pressure setpoint. A fluid dynamics person could easily add some helpful insight.

        It would be fairly simple to increase LP though as an experiment.
        The low fuel sensor is located before the pump assembly so it won't see much of a pressure swing. A better way for you to think of it might be if you could imagine the low fuel pressure sensor located inside the fuel chamber instead. In that scenario you would see a big pressure drop on the low pressure side. The idea behind raising low pressure above the factory levels is to allow more fuel to flow through the pump assembly in to the fuel chamber. Remember the passages are fixed so the only way to get more fuel through those fixed openings is to push it in at a higher fuel pressure. Or to open the pump and port them out. The latter would be ideal but until someone offers that our options are limited.