MBC issues

[Nutari]

no weather and temperature play a huge roll in how your whole car will react to any situation. suspension in the 30's isnt going to work like in the 70's. same as your motor. cold air is way more dense than hot air so your vehicle is going to run differently, combust fdifferently etc... if your getting +/- 3 with roughly the same weather and conditions then....well....that sucks. lol. sorry to hear that. mbc's need constant adjustment and if you havent had to in [previous cars sweetness for you. also if you hit the gas from 2000 rpms or 4000 rpms your going to have different results with boost. if you run the car 3-4 times and stop inbetween it will effect your boost. im sure you know this and i hope your not taking offense to me stating some obvious things. boost isnt always the easiest thing to control. i think anyways.

I know what you are trying to say, but its just not correct.

Atmosphere has no effect on boost controls. In most cases, the wastegate alone governs boost levels. It has a spring that will open the wastegate once its spring rate is reached via the boost pressure venting the excess boost into the exhaust.

With the Ms3, there is the ECU that governs when the wastegate opens according to various condition, IE What gear you are in, traction, etc.
There is still the wastegate spring. It is set to open at 5psi.

With the XEDE, the computers control is totally bypassed for wastegate control. You are able to input exactly what boost you want at all times.

The best possible book to read on turbocharging is https://www.amazon.com (commissions earned)

 

[Cue]

I know what you are trying to say, but its just not correct.

Atmosphere has no effect on boost controls. In most cases, the wastegate alone governs boost levels. It has a spring that will open the wastegate once its spring rate is reached via the boost pressure venting the excess boost into the exhaust.

The MAP sensor reads temperature as well, and when this exceeds x degrees, the ECU boost maps change; lower.... and of couse, this is all influenced by the outside temperature, and length of driving, type of driving etc. When your temps are low, you will boost much higher.... when they're hot, you get 12, 11, 10 psi.

You're right when you say atmosphere has no effect on boost... the MAP temps have effect on boost... but the atmosphere influences big time the MAP temps....

 

[Nutari]

The MAP sensor reads temperature as well, and when this exceeds x degrees, the ECU boost maps change; lower.... and of couse, this is all influenced by the outside temperature, and length of driving, type of driving etc. When your temps are low, you will boost much higher.... when they're hot, you get 12, 11, 10 psi.

You're right when you say atmosphere has no effect on boost... the MAP temps have effect on boost... but the atmosphere influences big time the MAP temps....

I've never heard of our ECU changing boost due to outside temp. Then again, I live in Hawaii so I've never had to deal with that.

I do stand corrected. Thank you.

 

[Cue]

I've never heard of our ECU changing boost due to outside temp. Then again, I live in Hawaii so I've never had to deal with that.

I do stand corrected. Thank you.

Won't change due to outside temp.... will change do to engine temp.... I'm just saying that outside temp greatly influences the engine temps (temp of air coming in affects the engine temps)

 

[mazdaspeed32007]

ok well....in theory, we all ake a valid point. put them all together and get.....THE RIGHT ANSWER!!! WOOOOOOO!

 

[dread]

autoeuphoria, the problem with your car is that you have no cat's which is allowing for too much flow and your wastegate is maxed out. You can reduce boost in this situation by not opening the wastegate solenoid when boost is building and by limiting the throttle from opening completely. This way you will never build too much boost and the wastegate won't have to try and bleed off more air than it is capable of.