TAGS: 2009+, BMW 335i, N55, Top Mount Turbo Kit, Single Turbo Kit, On3 Performance
Over the last two years On3 has been developing an N55 Big Single Turbo system. Building on the support the N54 community has shown and continuing to provide for BMW guys by moving this knowledge to the N55 platform. There are not a lot of options and those that are would generally require you to take out a small loan. On3 has 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.
The On3 N55 single big turbo system starts with a completely custom designed manifold. Designed from an extremely thick schedule 40 tubing and 304ss for the construction. This manifold is designed to use the On 3 Performance 44mm v-banded wastegate to control boost. Out of the box your kit will be setup to make around 7.5psi on wastegate pressure, with options available to increase up to 15psi and anywhere in between. Coming out of the wastegate, it is setup to vent 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. On3 builds a lot of carsand this N55 engine rolling into boost sounds like nothing else! 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.
The On3 BMW 335i N55 single turbo system was designed around a few of their already popular turbochargers. The first option is going to be the 55mm GT30 turbocharger. If you are looking for the quickest spooling option and sticking to around 400-450hp max range, this will be the option for you. Although spool time will be almost identical (~300rpm slower), the 61mm GT35 is a great upgrade for the guys looking to make 450-550hp. This is a decent step up in power potential over the GT30. Then there is the Billet Wheel GTX67mm, 6466, and 6766 that have capabilities to take your N55 engine to 700+hp, these will be slower to spool but the power potential enormously different. You can select which turbo option you want when ordering. If you arent sure which turbo option best suits you, please feel free to call in and get assistance from TurboKits.com. We also carry options for selection as journal bearing turbos or ceramic ball bearing turbos, these are offered for a small upgrade charge. All Turbo options will use 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 exhaust out of the turbocharger, a 3″ downpipe was designed from 304ss. This will take the gases back to the factory exhaust location and split into duals. Each kit also includes the necessary stainless steel v-band clamps to secure the turbo in place, downpipe, as well as the needed clamp for the turbo manifold. To make this N55 kit that much easier to install and to keep it a direct bolt on, a set of billet fittings are included to help with a number of complications. When removing the factory turbo, oil draining as well as water passages used for cooling the stock units are left wide open.
The On3 N55 kit includes custom machined billet fittings made to do the following:
- Billet Plugs Factory Water Ports
- Billet Plugs For Turbo Water 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 boosted air coming out of the turbo, a short 2.5″ charge was designed and connected to the massive 7″ core 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 starts to deliver hot air to the engine. As that warms up, the computer starts pulling timing, leaving a lot of power on the table. Cool the air with the new 7″ 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, On3 didn’t stop there. They improved upon what most see and what is already on the market. A custom throttle body charge pipe was designed and included with each turbo system at no additional cost. This is a 3″ polished aluminum charge pipe with an integrated 50mm flange for the On3 50mm Blow Off Valve (BOV). Each system will come with the 50mm On 3 blow off valve as well. This not only sounds good, but fights 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 there is a map sensor bung welded in as well, so its ready for a plug and play install.
Dyno / Boost Details
All customers looking are clearly going to 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. You are sitting at just 15psi right now with the car and its starting to lean out so the factory low pressure pump is only going to support roughly 420awhp. This is 120hp over stock form with back to back dyno testing. Guys willing to do a port injection upgrade and swap to e85 or race gas will be capable of 700+hp on this same exact kit.
Intercooler Technical DATA:
On3 initially base lined the test car with the factory intercooler at ~17psi of boost. Since then, they upgraded the car to the 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, they only saw about a 10 degree rise in temps. 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. The boost was down 1psi at 16#, but 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 (Contact Us) for Serious power potential and to keeps the IAT’s in check. This intercooler is also included with your turbo system at no additional charge, so your going to have the most efficient setup and coolest air charge temps possible.
Coolant Overflow Tank Relocation Info: The coolant tank in the front on the passenger side, simply gets moved to the driver side. Clips into the factory core support just as it does on the passenger side.
|Brand||On 3 Performance|
|Type of Part||Turbo Kits|