Greetings,

I have ran the Hallman manual boost controllers on all of my cars and we always come across the same question about boost levels in the winter vs the summer. I know that in the Hallman Boot Controller FAQs website it indicates that weather does not affect boost levels on this type of manual boost controller (not bleeder type), however we see a difference of about 2 psi less in the summer vs the winter, is this normal? Is this due to warmer air (warmer air = higher pressure) coming from the boost source/turbo line into the MBC with more pressure in hotter days and thus pushing the spring inside the MBC to open the wastegate just a few PSI short of intake manifold target boost level set in the winter?


Thank you very much in advance for any input,


Alex


Naples Fl

 

I also have the hallman mbc and would be interested in learning about this.

 

I guess it must be a very tough question based on the lack of responses

 

with my personal experience i always notice a pressure drop in the summer because of the hotter air. and also goes alot richer obivously due to air density. i always turn down my hallman pro about half a turn in winter. i run 31psi daily and if i dont mess with it coming back into summer its about 28-29psi and runs slightly richer.

edit: i also dont live in a place where it gets cold enough to snow either(Texas)

 

Yes it's normal to have a difference in boost pressure based on outside temperature when using an MBC.

Also, you're in Florida. You don't even HAVE a winter season

 

Qft. I feel like air density goes very non linear below 40*f.
Not a physics major myself just a north east mbc guy feeling

 

The temperature outside affects the hardness and flexibility of the spring inside the MBC. Just like plastic its easier to break a plastic tab off of something working on the car in the winter than in the summer because in the summer its more pliable. I have my hallman fastened to the rad fan on the radiator so it gets the same temperatures all year around so the spring inside will always work the same every time no matter the temp outside.

 

ok that makes sense, thanks guys!
Alex

 

There exists an inversely proportional relationship between changes in ambient air temp and manifold boost pressure. As a rule of thumb, figure approximately a 1# incease in peak boost level for every 10*F. drop in ambient air temp and vice versa. So, as ambient air temps rise, you'll see a 1# decrease in peak boost level for every 10*F. rise in ambient air temp.

As Rpf1evolution, mentions above, this is a variable that must be taken into account if you are using an MBC to control peak boost. This is especially true in climatic zones where there are pronounced swings between hot afternoon daytime temps and chilly overnight temps.

EBC's and ECU/BCS setups, on the other hand, compensate for varying air temps maintaining the same peak boost level regardless of ambient air temp fluctuations. Maybe someone can chime in with how the hybrid boost control setups react to changes in ambient.