The Best N54 Single Turbo Kit for BMW 335i or 135i

I tried MMP Stage 3 twin turbos, but never felt the “wow” factor I was hoping for. After worrying about wastegate rattle and smoking turbos for too long, I decided it was finally time to go big or go home. Meet the Doc Race 135i/335i N54 single turbo kit!

Once I decided to convert my N54 from twin turbos to a single turbo, I spent countless hours researching what kit I should go with, which parts needed to be replaced, what upgrades needed to be done, etc.


To save you that same hassle, I will share all the information you need to know below. With this complete list, I was able to safely make 749whp on the stock motor in my BMW 135i. Even if you’re not after a ton of horsepower, this is a great kit to go with when getting rid of the stock turbos.

If you want to read about my journey converting my N54 to single turbo, check out my previous post. Otherwise, all of the information and products are linked below.


I ordered the Doc Race N54 single turbo kit with a ball-bearing 6266 turbo.

In my opinion, this is the best single turbo kit on my market. I would suggest opting for the ball-bearing turbo like I did. However, if budget is a concern, you can save $1000 by going with the journal bearing 6266 turbo kit. If you have AWD, you will need the X-Drive specific kit instead.

The fitment is perfect. This kit includes much more than others. The parts are top-notch quality. The serviceable areas (O2 sensors, wastegates, etc.) are easy to access. Their customer service is amazing. I could go on…

You can click each item below for a direct link to the product.










After putting a couple thousand miles on the exact setup above, I couldn’t be happier with my decision. The car makes great power and has been very reliable for me because of a diligent installation with proper parts. Cheers to another couple thousand miles!

This page contains affiliate links. If you purchase anything using the links above, I will earn a small commission at no extra cost to you. Win-win!

10 Replies to “The Best N54 Single Turbo Kit for BMW 335i or 135i”

  1. Thank you very much for sharing this information. Really helps to cut through the noise in planning modifications.

    Question if you don’t mind, did the Doc race kit come with an installation guide? Do you have any additional soruces for installation?

    Thank you.

    1. No problem! The kit does not come with an installation guide, but if you look up “Budget Bimmers” on YouTube, they have a video or two that guides you through the installation with a DIY style.

  2. i have an 09 335i manual. im having the wastegate issue that these engines have. So im looking into a single turbo. Ive been reading and came across your post. just curious on costs…how much were the parts and how much did installation cost. Just trying to get an idea. Also, how long would it take to get this project completed on average. Thanks

    1. The kit itself is the most expensive part. If you’re not shooting for a ton of horsepower, you don’t need much else besides the kit. I have another post on my website that highlights a few other parts to replace while you’re installing the kit. But overall, this job probably takes 12 hours to install from someone who knows what they’re doing.

    2. Do you know much about how easily this setup could be done in E89 Z4, say 2011?
      I know a couple of the DocRace kit parts must be modified, but what about “all the rest”?
      What I like about your configuration is that it emphasizes all components in order for engine to safely generate such power?
      How long now do you expect your engine to hold up?
      And how easy is it to run this setup somewhat more “mildly” most of the time – pump gas?
      Sorry for so many questions, but you seem to know so much about a “responsible” setup and I don’t find a lot of info on Doc Race single turbo kit on Z4 versus 135i, 335.

      1. Hi Woody – sorry for the late response! I believe just the downpipe has to be modified to fit the Z4. Not 100% sure, but that’s what I’ve heard. As for engine longevity, I believe that at modest power levels it will last for a long time. Anything under 600whp and you should be okay. You won’t be going higher than this on pump gas anyways.

    1. Yes, I believe so. If you’re budget oriented and concious of your spending. Buy used parts when possible, find deals on as many parts as you can. 600whp is easier than 750+whp. Pick and choose items from my modifications list and save money when possible.

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