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Boost creep or Over boosting...? weird boost issue..?

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MarkyGsX

15+ Year Contributor
80
0
Aug 27, 2004
Carson, California
hey guys....just installed a pocketlogger on my 92 tsi and started to tune my 650's...me and my friend were having a hard time getting rid of knock because my boost just wouldn't hold at 16 psi on my 16g(i'm still unsure whether its small or big because my friend has a big 16g on his 1g and he thinks mine could be either) but any way...we turn the boost controller all the way down so that it would just open at stock boost(10psi)....
this got rid of a lot of knock we were getting....then it got weirder....i installed new plugs
and wires and a short ram cold air intake almost directly on the turbo and man my car felt totally different...almost no knock and sputtering the turbo pulled super strong top end...except too strong.....without adjusting the boost controller at all...the car now boost to 10 psi solid...then after about 4k or so will boost almost instantly way past 20 psi and seems to just keep boosting until i let off on the throttle....i know boost creep will go up maybe 5psi or so....but is creeping over 10psi and more normal...? it makes it really hard to fine tune since i can't go 100% throttle because im afraid of over boosting....can my mbc be installled incorrectly or is this just plain old boost creep...? im only trying to tune to 16psi for now because of the stock smic. i haven't updated my mods list so heres what im currently running: 92 tsi w/wiseco 8:5:1 pistons eagle rods and other internals,650cc,16g,safc2,3"gm maft(settings are zeroed out),3000gt tt rewired fuel pump,2nd gen exhaust mani(ported,honed),stock 02 housing(not sure if its ported but probally not)3" turbo back no cat.....ANY HELP APPRECIATED....THANKS
 
That happened to me once, turned out my flapper was only opening a 1/4" or so. It stopped the boost intially at the preset setting, but since so little air was going through the flapper it would boost like crazy about 600rpm later. I'd run boost source directly to your actuator, then check the WG actuator and flapper for proper operation.
 
Is your maft set up for 650's?? As for the turbo problem souns like boost creep to me. When I first put my buschur 3" tb on my 1g I was getting 15+psi boost creep on my 14b. You need to port to ish out of your o2 housing and around the wastegate flapper area. Its more than likely too late now but you would also see an improvement by uprgrading to a larger wastegate flapper(34mm or whatever it is). That's about all I can give you, you COULD throw on a high flow cat and that would get rid of any creep issues you had.
 
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