Close

    • DOC Race developing top mount BMW N55 turbo kit

      The N55 is having a good 2017 as the amount of turbo kit upgrade options continues to expand. DOC Race is well known on BimmerBoost for their N54 turbo package but also throughout the aftermarket for a variety of platforms. They are now tackling the N55 engine.


      This top mount kit is roughly 8 weeks away. Pricing is not available just yet but as you can see this takes some skill as it is a tight fit.

      Let's take a look at the manifold:


      Looks good, right?

      Quote Originally Posted by Doc Race
      Notice it has a v-band connection going up to the turbo. This makes installing the kit that much easier by just tightening one nut for a full connection. This was something that we wanted to do on the N54 but because of how the O2 sensors were setup with the twin turbos it required us to do twin scroll. We have free range on the N55 because they came factory with a single turbo. Some might be thinking we're going to lose some spool by going away from twin scroll but lets hold off on speculation until there are some results. We can always go back to twin scroll if needed.
      Let's look at some more details:

      Quote Originally Posted by Doc Race
      It's a tight fit but it's in there. This time around we had our own shorty air filter to use versus the turbo screen we used on the N54. The engine cover has to be trimmed but as you can see it can look very factory if done right.

      Twin Tial MVS wastegates are being used as they have been proven to control boost very well. They are mounted down low away from all the heat. This will make it easy to change out springs if needed. You will not have to take off other turbo kits components in order to service the kits. On the development car we have chosen to go open atmosphere dump, we want to hear when it hits full boost. There will be an option to go recirc when we start to manufacture the kits for guys that don't care for that.







      Quote Originally Posted by Doc Race
      One last thing I want to show is this custom billet machined coolant neck. The factory piece could have been left in place but if you have ever held one in your hand you will notice there are some kinks in it that may cause overheating issues down the road. The kink in the factory pipe is there to get around the factory turbo which we have tosed. I figured while we are here and about to double the factory horsepower rating we may as well help the cooling system as much as we can.

      BimmerBoost will bring you pricing details and dyno graphs as soon as we have them.

      Quote Originally Posted by Doc Race
      We have ourselves a new player in the N55 upgraded turbo game. With such great results with the N54 turbo kits I figure why change things. We will use all the same great parts (Precision, Tial, Vibrant) even the same size exhaust tubing, hell we are even using the same head flange. There have been some tweaks but the new kit is practically the N54 kit. We just had to make some small adjustments to accommodate the new chassis. So we know the kit is easily capable of 700+ hp. But we also know the N54 motor is known to hold much more power than the N55. We have decided to use a smaller 6062 Gen2 turbo for now until we throw a built motor in it which will max out at 650whp and will produce a very factory like spool. The one thing we made sure to focus on was to keep drivability. It's one thing to make 600hp, but its another to have that type of power and having the car start up and feel like it is completly stock.

      So far I have only put a few miles on the setup. I am running only off the wastegates right now which is set at 10psi. Terry has sent the single turbo firmware for JB4 so hopefully I will have time to load that up this weekend and start to control boost.

      This article was originally published in forum thread: DOC Race developing top mount BMW N55 turbo kit started by Sticky View original post
      Comments 11 Comments
      1. ///MPOSTER's Avatar
        ///MPOSTER -
        Tight fit , no doubt!
      1. Velocity26's Avatar
        Velocity26 -
        I look forward to seeing a dyno of that combination. I have always wanted to see a completed 6062 kit on the dyno and most disappear before posting any results. Even if the peak power is different, I would assume similar spool from the N55 & N54 on the same turbo.
      1. DOCRace's Avatar
        DOCRace -
        Thanks for the post! We are still testing and making sure the car sees everything it needs to be happy. Currently it is at 12psi without the MAC controller hooked up and is seeing full boost by 3700rpm. The JB4 is doing a wonderful job so far.
      1. tkong's Avatar
        tkong -
        Click here to enlarge Originally Posted by DOCRace Click here to enlarge
        Thanks for the post! We are still testing and making sure the car sees everything it needs to be happy. Currently it is at 12psi without the MAC controller hooked up and is seeing full boost by 3700rpm. The JB4 is doing a wonderful job so far.
        will this kit also fit e series n55's?
      1. DOCRace's Avatar
        DOCRace -
        Click here to enlarge Originally Posted by tkong Click here to enlarge
        will this kit also fit e series n55's?
        Nope, we are working on getting a kit made for the N55 E90.
      1. Terry@BMS's Avatar
        Terry@BMS -
        Just sent over JB4 MAC F series firmware to start testing out. Click here to enlarge
      1. Kirk@DOCRace's Avatar
        Kirk@DOCRace -
        Click here to enlarge
      1. Kirk@DOCRace's Avatar
        Kirk@DOCRace -
        Quick update! Still needs to be tuned, waiting on a few pieces to have it dyno ready.
        We did get the update firmware from Terry so we can give the car more throttle. Let me know if you guys have any questions. We are running dual Tial MVS wastegates just like the N54 kit and a Precision 6062.





        Apologies about the grainy video, YouTube noobs here!
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by Kirk@DOCRace Click here to enlarge
        Quick update! Still needs to be tuned, waiting on a few pieces to have it dyno ready.
        We did get the update firmware from Terry so we can give the car more throttle. Let me know if you guys have any questions. We are running dual Tial MVS wastegates just like the N54 kit and a Precision 6062.
        Looks beautiful under there!

        Now to see those tuned numbers...
      1. Dane083's Avatar
        Dane083 -
        Its a shame us RHD boys have a drive shaft in the way, looks like we have no chance of fitting that manifold. Regardless, thanka for the top work Doc!
      1. DOCRace's Avatar
        DOCRace -
        I hear you on that. It wouldn't be too hard for us to build a kit if we had a chassis to build on.