for some reason i cant get my greddy 18G to keep over 7psi , ive turned the Apexi boost controller upi and the duty cylce reaches 90%, it will run up to 14 psi then float back down , seems like once the wastegare opens it OPENS and cant keep still.
I dont understand- ive heard of people running 15+ lbs of boost on this kit and dont know why i cant.

does anyone know if its a problem with location of the WG or is it that i may have a weak actuator, -- will getting a 14lb actuator help,
and please dont recommend an external wg because i cant afford it and i dont feel like getting a whole new setup.

 

Try plugging the Compressor port. And running the signal line to the Intake Manifold.

 

it probably isn't your wastegate. it is probably your blow off valve leaking boost off

 

i checked the bov, no leaks tighted it down and changed the gasket too,

as far as the compressor port-- there isnt one on the greddy kit, only a port on the mani...

if you take off the WG line, (basicall send no signal back -- you should have infini-boost) well thats what happens, the boost spikes to around 20psi and we let off because we cant guarantee whats gonna happen. without having a stable boost pressure we dont know how to tune it---

if we set the boost controller to hold say 14psi, it will run up there, then fall back to 7 because the WG is just opening up too much, its like once it opens just a bit-- it slams open and the spring cant hold it closed--- im confused...

 

no replies, so no one here has this prob huh? must be a fluke?

 

bump

 

i think you have some other problem. in order of likelihood:

too restrictive exhaust

too restrictive intake before turbo (did u remove the restrictor plate?) - also try a different filter.

exhaust leak around the turbo

something like that

 

hey, if u decide to upgrade the actuator, let me know. i need to replace mines cuz the connector for the vacumn line broke off =/ anyway, good luck with ur turbo, let me know if anything's up.

 

my boost falls off like that too. my turbo is tiny and my exhaust and cat are stock.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Bailhatch &raquo;</TD></TR><TR><TD CLASS="quote">my boost falls off like that too. my turbo is tiny and my exhaust and cat are stock.</TD></TR></TABLE>

You need to open up the air flow.

 

well im running an Apexi N1 catback-- that may be the prob. Its 2.3" piping all the way -- i DO have a 2.75" DP from the greddy elbow including the flex pipe , up to the CAt-- then it bottle necks to the cat at 2.3" all the way back--

could this be the prob??
thanks

 

I think many 18g wastegates have that problem holding high boost. No matter how much boost I run, it always ends up falling to 10 psi.

 

well ive ordered a new one from majestic turbo -- when it comes in well find out what the issue is-- i hope i didnt just waste 100+ dollars on this and the prob is now my exhaust--- i figured the 2/3 was enough for now and i could upgrade later with more money-- but maybe not???

 

any other suggestions

 

any luck?