BMW N54 On3 Single Turbo Review

BMW N54 On3 Single Turbo Review

 I purchased the On3 Performance BMW 335i N54 Top Mount Single Turbo System (vband) back in January 2018. No sponsorship or discount, so all my own money and no bias. The first thing I can say about the experience is the shipping was incredibly fast. Considering the stories that’s been floating around about other vendors in the same marketplace. It came to my doorstep in about 5 days from payment.

How Was the Install

Since I was out of town, I wasn’t able to do the install until April 2018. All in all the install took me cumulatively about 18 hrs. I worked on it here and there for the span of two weeks when I had a moment to spare. I had no fitment issues with the hardware but did have trouble with the oil drain and the provided oil drain hose. With the oil drain, it was not allowing the turbo to clock correctly. I ended up ordering a longer one from eBay for about $8 shipped.

For the oil drain hose, it is very strong and sturdy, but for the life of me, I could not get the fittings to go into it. I placed the end into some hot water to make it more pliable, and pure brute strength but neither worked. I finally tried using some "CRC 05361 Silaramic Brake System Grease - 05361". In which I put a little on the edge of the hose and it slipped right on. 

If you still can't get it on, then you can go to your local auto parts store and get  some hose that's rated to carry oil. If you get the wrong one the returned oil from the turbo will burn through the hose. Everything went together smoothly afterwards.

Hows the Turbo & Wastegate?

Most people will omit the provided turbo and throw on a Precision or some other vband turbo. But I decided to try out the 61mm GT35 Journal Bearing Turbo. It is now 15 months from install and the turbo is still putting in work without any shaft play. The only thing I don’t like about it is the compressor housing material is soft. I’ve taken the turbo off about 4 times, and on the last time, I had to buy bigger width screws to bolt the housing up. The original bolts kept spinning and wouldn’t hold. This is partially my fault since I initially hulked the bolts, which is not needed. If I just snugged then tightened down the bolts a little I most likely wouldn’t have this issue.

The spool is pretty good, I’m at full boost at about 3.8k. It could be better but depends on how good of a tuner you have. I tuned it myself, and that’s where I landed since I didn’t tweak the vanos table, etc.

The wastegate was kind of a scary thing for me to try but I went ahead and used the wastegate that was provided with the kit. I didn’t see an issue with the initial state of it except the diaphragm was pinched. Before I installed it, I lightly sanded the shaft with a 2k sandpaper and made sure to re-lube the shaft, and made sure the diaphragm fit within the housing and was free. So far no issues and working as it should as of today (knocks wood). Doesnt matter if it is a Tial or whatever else I would highly recommend looking over the whole assembly. Especially since the wastegate is pretty much impossible to reach with the turbo on. Unlike the bottom mount folks who can access theres quite easily.

Final Verdict

If I was to get another n54 powered car, I would buy this kit again. The main thing is it works and no fitment issues except those mentioned but are corrected currently. One thing to note is just because this setup is affordable there is still misc accessories you have to address. Such as wire, hose, and fittings to relocate your coolant reservoir. Or tuning solution, I went with flash only and had to get the Motiv Boost Box, which was a godsend.

In the near future I will change out the turbo, but I don’t foresee it blowing anytime soon. 

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