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advice on adjusting the waste gate acuator

789 views 4 replies 2 participants last post by  turboAERO 
G
#1 ·
so me and my old man have been tinkering around with my 9-3 a little and after running an mbc for awhile and never been very satisfied with the random performance i would get from it....random overboosting and sometimes not enought kinda got sick of it.:roll:
we decided to try the old trick we did with all of are old c900's and shorten the wastegate acuator rod and adjust it to ~15psi boost level and now im running 15 from 1st to 5th really smoothly and am loving it a lot better....except for going to school today right after adjusting it getting a lovely 50 in a 40 really made my day go from good to $hitty;oops:
but just wondering if anyone knows of any harm i can cause by running it this way, i know obviouly overboosting but i think i have that all squared away, but any advice on doing this or concerns let me know, just want to make sure im not going hurt anything
 
#2 ·
That is not recommended, you could blow your motor! You cannot dump boost if the motor needs too. Running 15psi of base boost is crazy on the little stock turbos, the egt's are high anyway and by you not allowing it to dump back to the normal 5.5 psi of base boost, you are taking a real chance with your motor in my opinion... If you get one tank of bad gas and it causes pre-ignition and
detonation or knock, your ecu or wastegate will not be able to dump boost to save the motor. That is what the trionic system is all about;)

You are running the risk of running very high egt's and that can melt pistons, and detonation can break rings, crack pistons and blow head-gaskets!

Change it back!

John
 
#4 ·
turboAERO said:
that makes sense, but what would be the difference then to adding a mbc to it...it would still be running the higher boost that is not intended?
running the higher boost is not a problem, as long as you're wastegate is capable of expelling this boost. yours isn't at the moment as you've effectively tightened it shut:nono;

have you thought of trying the mbc+a
 
G
#5 ·
by no means at all is the acuator tightened all the way...i only ended up tighting it about a cm worth of turns so it holds a little longer

and i have used a mbc,....not sure what the +a is (stand for "adjuster"), but didn't see much out of it so tried this instead, and it does add a lot more but i do understand and believe what john said and have toned it down
 
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