[Cpatel]

M340i 2021

Planning on getting my ECU femto unlocked. Going to get DP, charge pipe, exhaust, and whatever else is needed for stage 2.

I’m planning on getting an upgraded turbo, thinking PURE 800 but I’m not yet decided. Turbo will happen a few months after stage 2. I want to feel what stage 2 is like with FBO before I add turbo.

1. If I upgrade turbo, what other accompanying hardware do I need? My goal is just a fast daily.

2. Once I install the turbo and accompanying hardware, do I need a custom map to fully utilize the turbo or will the stage 2 OTS map be enough?

[GA/\/\/\/\A_CT]

Others will chime in, but I would consider:

Cooling upgrade package like CSF radiators
XHP transmission tune
Potentially a Pure Transmission upgrade
Intake manifold

[jpowers36]

Yes, the above would be nice in addition to the turbo upgrade but it’s not completely necessary unless you have high power goals and push the car constantly. Would definitely run XHP with your stage 2 setup on stock turbo. Pure 800 will drop in and you won’t need anything else besides a custom tune. If you just run the OTS tune, then you’re not going to see the benefits of the bigger turbo. You could get a tune that will factor in longevity and keep torque lower to keep the transmission happy. Another thing to think about is fueling and if you’re sticking with 91/93 octane, E40/E50, or full E-85.

[B58-M340iX]

The mods you need will mainly depend on fueling since you're just looking for a fast daily.

On US 91/93 octane, you'll be octane-limited and not fuel-volume-limited, so you wouldn't need to do anything from an HPFP/injectors standpoint.

You'll need a fueling upgrade for going full e85 as the stock HPFP won't handle more than e50 while sustaining typical higher boost pressures like the OTS stage 2 tunes (to add, sometimes even on the stage 2 e50 OTS tunes the HPFP will crash when it is cold out - I've experienced it myself). The CustomROM features of BM3 allow you to run e85 with the stock fuel system, but you'll be down on power compared to e50 without the fuel upgrade due to the fuel requirements/limitations of running higher boost pressures.

For full e85 on stock turbo/Pure 800, you have the option of going port injection or installing something like the recently available Dorch DS25-350 HPFP. It's expensive (their sale just ended), but you'll be able to run full e85 using what amounts to a plug-and-play drop in part without having to deal with buying a separate set of port injectors, control board (etc.) while retaining the DME-controlled features and safeties. The LPFP will be fine and does not need to be upgraded.

The S58 injectors also drop in for our gen2 cars, but you'll need a custom tune to run them which shouldn't be a problem given that you're looking to install a Pure 800 turbo anyway.

Dorch HPFP and injectors links:
https://dorchengineering.com/product...5-hpfp-upgrade
https://dorchengineering.com/product/s58-oem-injectors

[mike@x-ph.com]

You will eventually need a custom map for your turbo, so I recommend you start by picking a tuner and then discussing your power goals with them.

Based on your power goals, they will let you know which upgrades are needed.

[Cpatel]

Thank you all so much for your well written responses!