this may seem like a stupid question to some but i cant find answers anywhere .


alright i understand how a external wastegate regulates boost by the spring pressure and it opens at any over a certain amount of pressure and relives the excess gasses through a dump tube

but what i dont understand is how does a manual boost controller adjust boost if theres a wastegate because wouldnt it not mtter what the mbc was set at because the wastegate would just let the pressure off at x pressure anyway

 

doing a manual boost controller on the stock WG or even an electronic boost controller on a stock wastegate will only make it leak off boost later than the stock WG actuator is designed for, not sooner. it limits how much boost the WG actuator see's so it thinks its only getting the stock 8psi or 10psi or what ever when your at what ever you want......

 

^^^Very good explanation^^^ Kudos to you.


MBC I like to say tricks it into reading less then what is acutally there. Anyway, you do the HMT style MBC be VERY careful. Tuning for a certain psi is VERY meticulus and hard to hit just right. When adjusting it just watch the gauge like a hawk because a small inward turn in for 10psi soon turns into a 15psi "WTF was that?!?!" run.


JP

 

I don't mean to jack your thread but I have a Turbosmart MBC. My boost is set to 7 lbs but it seems to jump to 8 before settling at seven. Does anyone know if this 1 lb "spike" normal?
Thanx

 

Yep. It's called "boost creep". It's normal.


JP

 

i agree with samson, however as he mentioned before. if it's a MBC then you might actually accidently have it set to 8psi and are haveing boost leak which brings you back down to 7psi. Highly onlikely with the second idea but I just wanted to put that out there for anyone else. Be careful with those MBC's!!