Evo 16g bad boost creep

[93jdmlaser]

I have an evo 16g on my 1g gsx. With the boost controller it will spool to the setting at low rpms but once I hit like 5500 the boost will start goin up very fast. Like boost creep but fast. I am not sure what is causing this. Is it possible the internal wastegate is bad? I was just gonna get an external. Already checked for leaks in the lines. Thanks

 

[BOOstGhost]

turn down your boost controller and drive it and see if it still spools up very quickly, also see if it goes past stock boost. I don't think you have boostcreep

 

[CanadianTSi]

Mine creeps really badly due to my Wierd MBC. Where I had it set it would spike a bit and then hold 20psi, I turned it down 2 clicks and now it doesn't spike but it creeps like mad.

My solution, EBC

 

[93jdmlaser]

I have an ebc ( older apex) with it on or off, doesnt matter the boost just goes crazy and just keeps goin up.

 

[GPTourer]

Why not get a cheap MBC, swap it out and see what happens?

 

[93jdmlaser]

I did try a mbc and no controller at all just the plain line and they all gave the same result.

 

[BOOstGhost]

it could be you internal wastegate, how much psi are you planning on running??

 

[Jehu]

If you hook the WGA directly to your boost source and boost still climbs up after a certain RPM, you're creeping. Evo16s are notorious for doing it. I had to really port out the entrance to the wastegate to finally get rid of creep. Still won't go below 16psi when my cutout is open but 16psi is as low as I'd ever run anyway...

 

[PaleDSM]

Boost creep isn't caused by the boost controller. Running lower boost will not help as the wg is already not bypassing enough of the exhaust gasses to maintain your boost level.

Boost creep is common on 16G apps where people run nice free flowing 3" exhausts. The exhaust takes the path of least resistance and it will usually choose the 3" open pipe of an exhaust over the 34mm (or smaller) wastegate passage. The cure is to open up that wg pathway. Larger flapper, larger external wastegate, or take the demand off of the wastegate by running more boost. Porting the passage and O2 housing are your first stops to try to cut down on the creeping boost.

 

[blcknspo0ln]

your WG could be stuck open. try pressurizing your WGA and make sure it's working right.

just like pale said, i did the following to rid my creep:

7cm gasket matched exhaust mani [ yes i know it's preturbo, but i did all my porting at 1 time ]

opened up the WG hole slightly

ported WG area on exhaust housing

ported 2g o2 [ ported the ENTIRE thing, not just the openings ]

i ordered a ported SBR evo3b16g

 

[miteclgst]

I would agree with blcknspo0ln saying that you should port match anything that you can. I did all the same stuff he did to mine this past winter and didn't get any creep.

 

[truwarrior]

My downpipe is a little bigger then the exit on the 02 housing...think if I port out the o2 housing a little more it will help with creep? I can do that with out taking the turbo of the car...I think

 

[blcknspo0ln]

nope, wont help.

boost creep happens because the exhaust gas is NOT going through the wastegate side. porting where the o2 meets the DP will do nothing for creep. you must port the wastegate runner and enlarge it.

p.s., just use an angle socket to get the last bolt off of the o2.. dropping the o2 isn't that hard

 

[blcknspo0ln]

p.p.s. i can't believe you brought up a dead thread

 

[90blacktsiawd]

i just installed my gm mas blow through set up and im havin the same problem. I have a sbr evo 16g. ported exhuast inlet w/ a 34mm wastegate flapper adn a tubular o2 housing and mine still creeps to 20 psi. im gonna try to port out the tubro some more and once i get my 660's in im gonna turn it up to 18 psi so maybe i wont have a prob anymore.