On 3 Performance BMW 335i N54 Top Mount Single Turbo System

(29 customer reviews)

$4,250.00 $2,800.00

No deletes from the kits, do not email or call about this!!


Over the past year we have been developing one of our newest turbo system options.  It was brought to our attention by a friend that the BMW’s needed a new option.  We know turbos well and figured it would be a change to get involved with the N54 platform 335’s.  There are not a lot of options and those that are would generally require you to take out a small loan.  We have set out to change the market and design an affordable, top mounted, single turbo system.  From a design standpoint, this application is a challenge with the tight engine bay and a lot of tubing to fit in a small space.  — Well clearly this first opening line to the description is very dated!  Our popular BMW system was brought to market back in  2015 and been an excellent product ever since.

Our system starts with a completely custom designed manifold that is a 2pc design.  We have designed it from an extremely thick schedule 40 tubing and only use 304ss for the construction.  By making this unique manifold, it allow for a much easier install.  Most of the single top mount kits also require you to modify the factory coolant line as its routed through the same area where the factory turbos are.  We took serious attention to detail and built around it so it retains the hard aluminum tubing.  This is not a good area to run rubber hose like some systems do.  Sure it would be easier but in the long run, we have a better design.  Our manifold is designed to use our On 3 Performance 44mm v-banded wastegate to control boost.  Out of the box your kit will be setup to make around 14psi on wastegate pressure.  Coming out of the wastegate, we have it setup to atmosphere.  Let me tell you personally, this car has factory exhaust and sounds pretty much like any other 335 driving around….until it rolls into boost.  We build a lot of cars around here and this 335 engine rolling into boost sounds like nothing else we have worked with.  The exhaust note is amazing and just right for for this caliber car that has all the comfort and now the power to back it up.  The 304ss dump tube routes down from the wastegate and terminates right at the factory exhaust connection.


Turbocharger Details

Our turbo system was designed around 2 of our already popular turbochargers.  The first option is going to be the On 3 55mm GT30 turbocharger.  If you are looking for the quickest spooling option and sticking to around 450-500hp max range, this will be the option for you.  Although spool time will be almost identical(~300rpm slower), the On 3 Performance 61mm GT35 is the top shelf and will yield the highest HP that we can offer.  You will be able to select when ordering your system two other options.  The standard option included is our journal bearing turbo and dual ceramic ball bearing is offered for a small fee.  This turbocharger is one of our newer models and has a very trick feature.  We had this exhaust housing cast from stainless steel and best of all it is v-banded inlet and outlet.  With any tight engine bay, this is key to allow for endless adjustments.  This will not only look great but when the install time comes, it will make life that much easier.

Moving the air out of the turbocharger, we designed a 3″ downpipes from 304ss.  This will take the gases back to the factory exhaust location and splits into duals.  With each kit we also include the necessary stainless steel v-band clamps to secure the turbo in place, downpipes as well as the needed clamp for the turbo manifold.  To make our kit that much easier to install and to keep it a direct bolt on, we also include a set of billet fittings to help with a number of complications.  When removing the factory twin turbos, that will leave oil ports for supply, draining as well as water passages used for cooling the stock units wide open.  We had custom machined billet fittings made to do the following:

  • Billet Plugs Factory Water Ports
  • Billet Plugs For Factory Oil Supply Ports
  • Billet Plugs For Turbo Water Drain
  • Billet Plugs For Factory Turbo Oil Drain
  • Custom Billet Oil Supply Fitting for New On 3 GT Series Turbo
  • Custom Turbo Oil Restrictor Fitting
  • Custom Billet Turbo Oil Drain (Into Engine Block)

Cold Side Technical

To address the cold side, coming out of the turbo we designed a short 2.5″ charge pipe out of the turbo to the massive 7″ core On 3 Performance air to air intercooler upgrade.  In order to maximize power to redline, the IAT’s with the factory intercooler will become a problem.  Airflow surpasses what the factory air to air will handle and start delivering hot air to the engine.  As that warms up, the computer starts pulling timing and that will become a power loss.  Cool the air with the new 7″ On 3 Intercooler and your not pulling timing, air temps drop and everything is good.  Although that is all that is required to get the car running, we didn’t want to stop there.  We wanted to improve upon what most see or already on the market.  So we also designed a custom throttle body charge pipe to include with each turbo system standard at no additional cost.  This is a 3″ polished aluminum charge pipe and also intergraded in our 50mm On 3 Performance blow off valve flange.  Each system will come with the 50mm On 3 blow off valve, this will not only sound good but fight compressor surge.  Most will look at this feature and like it for the sound but its a very crucial piece to a turbo system to keep the turbo alive.  Also hard to see but we do have the map sensor bung welded in so its ready for a plug and play install.  Another touch which was not required was the power steering reservoir.  We built a custom billet aluminum fabricated reservoir which contains a custom washable filter element.  This is simply a nice dress up item to the engine bay, clearly not required but looks sleek and how BMW should of produced the car.  They just forgot to call and ask us for our opinion

BMW N54 335 Top Mount Turbo System Options

  • $0.00


There is only so much reading one will do before losing attention, here is a few video clips from us strapping the car down and testing throughly testing this turbo system.  The video doesn’t do the car justice and it sounds amazing.  We are still testing with downpipe back factory exhaust.  Clearly we are leaving power on the table without upgrading that yet and still making the numbers.  Being that there is not any control currently for our tuning to adjust timing, we have so much more potential in the future with this car.  Keep in mind we are on an entirely FACTORY fuel system, 93oct fuel, no meth and all boost:

Here is a quick clip of the car doing a 40 roll on around 19psi, sounds AMAZING!


Back to the details…

Dyno / Boost Details

All customers looking are clearly going to be focus on power potential clearly with this turbo system upgrade.  Right now if you have a factory stock 335, you can compare our numbers simply to what you would/can make without other supporting fuel, trans, etc mods.  We are sitting at just shy of 17psi right now with the car and its starting to lean out so the factory low pressure pump is only going to support roughly 480rwhp.  We had to bow out at this point although we are more than pleased with the power and the level of boost currently running.  We hope to work with a new tuning software company, upgrade the fueling and go back for more testing.  Our target for this car is going to be around 525-550 wheel as thats going to bring us to the limit of the factory transmission(automatic).  This is also an important point as we would be making slightly more power with a manual transmission car so we are eating up a little power for those strictly interested in power numbers.


Intercooler Technical DATA:

We initially base lined our test car with the factory intercooler at ~17psi of boost.  Since then, we upgraded the car to our new 7″ Core 335i Intercooler and went back to the dyno for a few more pulls.  Not surprised, the IAT’s were down and from the start of the pull till the end, we are only getting about a 10 degree rise.  The pull was starting at ~100 degrees F and ends right at 110 degrees F.  This is a HUGE gain and by simply keeping the temps cool going into the engine.   We were down 1psi at 16# of boost and making 40 MORE HP to the tires at 6100rpm.  So if you are pushing the stock turbos or on an upgraded turbo setup, this is a must have.  We do sell the intercooler upgrade by itself so check out the BMW section for that specific upgrade if you are interested.  Serious power potential and keeps the IAT’s in check.  This is included with your turbo system purchase so your going to have the most efficient setup and coolest air charge temps possible  


Keep in mind with this car, its a completely stock 335i we started with, there is zero upgrades and it is an AUTOMATIC transmission so our numbers will be a little lower than a manual car(still making killer power).  We are running out of fuel so the stock low pressure pump needs upgraded if making anymore power than this.  We are more than satisfied with the system and easily going to crack 500rwhp after the pump upgrade.  That is the only thing holding us back right now and this is on pump 93 oct fuel, 7 degrees total timing!








Included With Each System:

  • On 3 Performance 2pc SCH 10 304 Stainless Steel Turbo Manifold
  • On 3 Performance Massive 7″ Core Air To Air Intercooler
  • 3″ 304ss 16 gauge Tig Welded Downpipe
  • On 3 Performance 55mm GT30 Turbocharger (Journal Bearing) *Upgrades Available
  • On 3 Performance SS Custom Cast Turbo Exhaust Housing
  • On 3 Performance Oil Feed System
  • On 3 Performance Oil Drain System
  • Billet Machined Custom Turbo Fittings
  • On 3 6061 Aluminum 2.5″ Charge Pipe
  • On 3 6061 Alumnum 3.0″ Throttle Body Charge Pipe
  • 5 ply Silicone Coupler Kit
  • Stainless Steel T-Bolt Clamp Kit
  • On 3 50mm Blow Off Valve Kit
  • On 3 44mm Wastegate Kit
  • Custom Billet Aluminum Power Steering Overflow Tank
  • Instructions and Support From The On 3 Performance Staff


Coolant Overflow Tank Relocation Info:  We get calls on the coolant tank and what needs to be done very often.  It cannot stay in the factory location as it interferes with the tubing and the way we have it routed.  It simply is relocated to the firewall, if you need photos, please let us know and we can send you exactly how we have ours mounted.  It doesn’t require any brackets or anything special, you can simply drill a few holes and bolt it right to the firewall on the Driver side.  We then run a new coolant hose to make the connection for the extended area and your good to go!


Want to see the prototype car run, photos, and anything new?  Follow us on instagram, On3Performance is our user account, that is where all the sneak peaks happen.  We already have some other photos and video currently posted

29 reviews for On 3 Performance BMW 335i N54 Top Mount Single Turbo System

  1. Kelvin Fedrick

    I’m waiting waiting on it

    • admin

      Follow us on Instagram, we are going to be posting some updates, photos, etc of this project on there by this weekend. Its coming along very nicely and the placement looks so good under the hood!

  2. Joe

    When is it going to be available???? My turbos are F-up! I was about to purchase new turbos from RB-TURBOS. When I saw these on a BMW forum. I’ve been driving with my Fup turbos…burning oil and blowing blue smoke..Not sure how much longer I can wait.. Please help! When are they goin to be available???

    • admin

      just posted the newest info at the top of the page, check it out

  3. Sean

    How far are we away from a release I need this kit

    • admin

      just posted the newest info at the top of the page, check it out

  4. Sam


    • admin

      just posted the newest info at the top of the page, check it out

  5. AJ

    I am waiting for this to be released! If you need a donor car let me know! I have a 335i auto and would love to see this run on my car.


    • admin

      just posted the newest info at the top of the page, check it out

  6. Zak Smith

    Updates on this kit?

    • admin

      just posted the newest info at the top of the page, check it out

  7. Udi

    Id love to see some videos on Instagram of it on the dyno

    • admin

      I was not there to watch, there will be videos of it eventually

  8. Mike

    Could you run this with a water/meth kit?

    • admin

      Sure there is no reason why you couldn’t

  9. Chris

    Hey was the 455whp run on only pump? No e85, meth , anything like that? I know Motiv’s record car was on 30psi or around there but with 85 and meth. I’m wondering if this kit is capable of mid to high 600whp on pump with a more aggressive map….I parked my car when I heard this kit was going to be released, can’t wait.

    • admin

      It was a simple 93 combo on a stock car, stock exhaust, etc. This is not even something you would compare to what they have done on 30psi as that was a fully purpose built car for maximum power. What we are proving is what most guys will do, daily drivers who want more power, might want the single turbo look under hood, etc. There is no doubt our car will make more but we were just getting our feet wet. This was low boost, stock intercooler even, we would have been close to 500 without much more I think if we just did an intercooler upgrade. The stock catback is killing us on power as well

  10. Gabe

    I’m stoked! I’ve found that in terms of performance per dollar the N54 platform is extremely potent. I took it over a CTS-V and don’t regret it one bit. It gets 30mpg on highway, docile enough to take the wife and kids on long trips and still puts down some serious times at the track especially with full bolt ons (FBO) and e85. That being said, mine desperately needs a turbo upgrade.

    If you keep the price point the same, you guys would be killing it in the single turbo department. I’ve looked at other kits and after talking with some of my mustang buddies they only had good things to say about you guys.

    I imagine most owners will be like me. I’ve already gone FBO (intercooler, Dp’s, jb4, BOV, etc.) and know for a fact the turbos are the weakest link right now. With a good e85 mix (luckily there is a station right by my house) I’m already peaking at 18lbs on the stock frames. Everything else looks good (trims, afr, etc) from the data logs but you can tell those poor snails are spinning their hearts out. I’m so ready to get rid of the tiny stock turbos that I can’t stand it.

    You guys have my interest and I would love to see more dyno vids, data logs and of course more pictures.

    • admin

      We will continue to post more, it was a little more tricky to get the car dialed in with the jb4 than we thought it would be. It wasn’t just a quick trip to the dyno so I wasn’t there when the pulls were being made. We left the car but trust me, there will be more videos to come. The customer is more than happy with it and said she is a beast, thats what matters in the end

  11. Lance

    Any updates or is the idea being scrapped? How much will you sell the hot kits part for?

    • admin

      It takes a long time to design and go into production for a bolt on system is all. The results were great and we are still running parts and getting things ready. Still expected to be shipping out kits by the end of next month. We are not going to offer partial systems

  12. Ryan

    will this fit XI models? cant wait till this releases, thanks

    • admin

      We did not test on an XI model but we are almost certain it will be good to go. A local Ohio guy was talking about running the kit so hopefully we work with him. I believe he holds the current record for the quickest factory turbo 335

  13. Tyler Pepper

    I have a 2009 335xi with jb4 that is having turbo issues I would love to see this project come through. If you need a test car I’m or want some other pulls done PM me.

  14. Steven

    I’ve been following this from the beginning and i am happy to say this kit looks amazing at an awesome price point. I am more than excited to get a kit and put it on to see what its capable of!!! Any updates as if right now?

    • admin

      We now have the intercooler upgrades in stock so we are ready to put that on the test subject and get it back to the dyno. We went up on the wastegate base pressure as well so we will be able to go up from the 16psi as well. We want to see 500-550rwhp to maximize the car for now since the trans and everything else is still bone stock including turbo back exhaust from the downpipe

  15. Jason

    500-550rwhp would be idea for a person with a 6 AT without an upgraded transmission. Too bad your test subject wasn’t full bolt on. If you need a full bolt on running 40% e85 and a flash tune (from the C-Bus area), I would be more than happy to lend my car (not looking for freebies). I am patiently waiting for this product and commend your shop for bringing a popular upgrade in reach of us guys that bought a nice used BMW and don’t have the money to drop 8k on a single turbo system. Hope all goes well.

    • admin

      No actually we want to prove a point on a rather stock car to show what possibilities are and really you don’t need full bolt ons to reach the goal we are after. We will maximize the performance of this car without bolt ons and saving the end user money if needed. Yes a catback will help and free up power and make the car sound better but its not required. Many people are still on a budget and thats what we are here to help with. I can sell a system that will bolt on and really make as much power as the stock transmission is going to hold safely. Thats the target market we are after, not many are wanting 700+ hp race cars and we want to focus on the general public and their street cars. This is going to be done with regular 93 oct and no need for e-85. We are close though, should be shipping the first kits out by the end of next month and taking order within a week or so

  16. Robert

    Will you be offering the intercooler kit separate?

    • admin

      We will have that live here in a few short minutes. Should have photos and all details later this week

  17. Brad

    I would like to know if you’re offering MHD maps for this or any kind of tuning/fuel advice.

    • admin

      We have heard a lot about MHD, going to put in an email to see if they want to support us and allow us to test with it. Right now what we have works and it seems like a lot of people want MHD. So if they want to fire a setup over for us to test and post with, Im all about it. We will swap and push the MHD if they want to stand behind us. I certainly would like to team up with one of the tuning brands. We will for sure offer tunes and install directly through our recommend local shop doing all the dyno testing for us, Crucial Performance

  18. Tim C

    Man I have been waiting for a kit like this since I bought my car! This is so badass! Keep up the awesome work guys! And um… Any idea when we can all start putting our orders in? Just give the word and I’m here… Ready to purchase! I feel like a kid on a really long Christmas Eve!! Lol!!!

    • admin

      We have everything here, we are welding in o2 sensor bungs to the downpipes and then they are ready to go out the door. So within the next week people will be seeing the kits that have them on order.

  19. Tim C

    Wait… So if I put in an order right now, I just wait till my kit is ready and shipped to me and the that’s it?

  20. Jason

    Speaking of running out of fuel on the lpfp side and looking into upgrading there was until recently only one vendor to choose from. I have recently found myself a company with a better price point with just as good hardware and diffrent options for your money. “Boost Concepts”, look them up for anyone who wants a stage 2 e85 rated pump that is hundreds cheaper than “Fuel-it”. I’m not affiliated but have recently bought and used the product and was spot on in every aspect of a company.

  21. random

    Is this kit available yet?

    • admin

      Yes we are currently shipping orders

  22. andrey


    • admin

      Im sure, we have shipped out plenty of these kits. We did proper tuning and fueling and made good power. Customer cars will be no different than the results that we came up with. We have tested with this car for almost 2 years now

  23. Blake

    do you ship to the UK? One of my turbos has the waste gate rattle and I’m thinking of turning it into a single turbo beast! could you send me a quote to with delivery?

    • admin

      We can ship anywhere in the world

  24. Greg

    Can you confirm fitment on a 2007 335xi? Ready to order soon as I need new turbos.

    • admin

      We are currently working with another shop to design a X drive downpipe. It can easily be made to work with a little trimming from what we have heard. We will offer a direct bolt on option though in the near future for those cars

  25. Victor Paris

    Any updates on the MHD tunning Maps?

    • admin

      No, we requested dealer info and for them to get us some sort of deal for our shop car to develop with and test. No response so I guess we will not be supporting their platform. Hopefully one day they decide they want to earn our business and generate business from us…

  26. Shawn

    Any kits for the N54 135i?

    • admin

      We have had several guys test with this and make it work. Greg at the shop is the guy you would want to talk to, give us a call. He can go over the details with you if you were wanting to run a kit

  27. tristan

    will it fit on awd?

    • admin

      On of our good customers is going to be bringing us their X model to mock up with soon. So we will be making the revisions soon so we can have it fit directly out of the box

  28. Brad

    Hi, I am seriously considering this now. What is NOT included in the kit to bolt up to the factory car and make it work? Does it mate right up to the factory exhaust? Everything ready to ship?

  29. Tj

    Is the kit selling yet ? Was looking for some review of someone who bought the kit

    • admin

      This kit has been selling for close to 1.5 years now. We have a dozen cars on our instagram page featured over the time we have been selling it. @henley_614 is the original car we designed on

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