what bov are you running?

boost control method?

 

No exhaust leak, and im runnig the ams 3" cooler.

Im running stock evo 9 bov only on 25psi but its holding and im usin a hallman mbc

 

i think what Aby@milspec was asking is how do you have your mbc set up. Is the boost reference coming from the turbo itself or another source like the bov or fpr?

 

It is comming straight from the turbo

 

a way to rule out the mbc; some may consider this risky- but its not if you dont fall asleep, simply remove the line from your w/g actuator.

if you feel boost ramp up hard below 4k in 3rd gear, quickly get off the gas & you know something is up with your mbc.

if it feels the same, swap out the bov for another 1 from a friend.

your car makes boost, it's just slow to ramp up.

 

On the dyno we tried 2 diffrent mbc and it did the same thing. What else could have caused this though?

 

Like this
https://www.evolutionm.net/forums/ev...ally-done.html

 

Any updates?

 

im thinking flapper / hotside / wga related.

 

Still the same thing went into a tune with a stock turbo and still happening. What else can be causing this. Like i said the only things that were changed prior to this tune was cams, and turbo. But the timing was checked and saod was perfect by 2 diffret shops

 

did you use a different wastegate actuator on the stock turbo?

 

Check the flapper to see if it's sitting tight. Had a similar issue but different turbo, same housing. Lost 400-500rpm from a loose flapper. May not be your problem but worth a check.

 

Dummy check your BOV psi setting and seal.

 

Sorry for the late update, but it was indeed the flapper not sitting correctly

 

Glad you got it sorted!