Controlling external wastegate with the DME?

wheela

Lieutenant
Jun 4, 2021
539
302
0
Twin Cities, MN
Ride
2015 e84 X1 35i Msport
Hello all. This question may be more suited for the advanced tuning section, but that's n54 specific and I'm n55, so I put it here.

Those of you running external wastegates, are any of you controlling it directly with the DME? Or is everybody using some kind of boost controller and a mac valve?

I really like the load-based control of the DME, and for my own personal preference, I'd really like to avoid adding any extra controllers to my car. However, turbo upgrade options that run on a vacuum-driven normally open wastegate are very limited unless I stick with hybrid options.

From my reading, I think some of the challenges to running an external wastegate without an external controller are that the stock pressure converter/boost solenoid tends to break apart if you run boost pressure through them vs. vacuum. But then mac solenoids are desiged to run on low (30 hz-ish) duty cycle frequency, whereas the n55 dme runs much higher duty cycle frequency (300 hz I believe?), so controlling a mac valve without some kind of intermediary may not be practical.

I'd really like to run an off-the-shelf aftermarket turbo, but it looks like that means I'll probably be stuck with an external wastegate.

Does anybody know of any proven solutions to control a traditional normally closed pressure driven wastegate with the DME - without any additional controllers? I could just run spring pressure, but that feels like a pretty compromised solution for a daily-driven car.

Any thoughts?

Thanks!
 

wheela

Lieutenant
Jun 4, 2021
539
302
0
Twin Cities, MN
Ride
2015 e84 X1 35i Msport
Thanks for responding! I see boost box was just n54 (i'm n55) and is now discontinued.

Motiv Reflex+ obviously has a lot more capabilities than boost box, I'm assuming this would also allow DME control of an external wastegate? Is the level of DME integration for n55 to the point where we can log the reflex parameters through MHD like on n54? It would be cool to be able to add additional sensors through the Reflex and be able to log them through MHD.