bushido

Still hunting for the reason my boost as to why my boost is so unstable; able to hit 24psi with fluttering needle and able to hold a stable 17psi at times with BM turned off. I remember reading somewhere that it should be around 5-6psi with the N75 unplugged. Mine hit 5psi, then slowly went up and by redline, it was 10psi. Is my wastegate not working right?

Here's the engine mod list if it matters:
APR 93 oct
VTDA, **** + 4bar FPR, BM (turned off)
Samco hoses (intake, IC)
TCarbon FMIC
42DD down pipe/test pipe
GReddy oil catch can

Please let me know what your boost was if you've tried running with the N75 unplugged. Thanks!!

roadyTT

Have you disconnected your BM as opposed to turning it off?

maaliish

How did you unplug the N75? Did you pull the wastegate line?

bushido

Just unplugged the electrical connector

bushido

Yup tried it, even tried switching out the **** and 4bar FPR

Russ Scott

possible: leak in the hose between the N75 and waste gate...

TTschwing

Seeems most everything else has been tried. A sticking Actuator could behave as you've described earlier. Pretty rare actually, but possible.

maaliish

the boost. Make sure you have a good boost gauge. By disconnecting this line, you're allowing the turbo to spool without ECU's control so you'll see maximum possible boost. Don't go crazy or you might blow your turbo, but I think you're ECU will cut in fairly quickly and put you into limp before you cause any damage.

I would disconnect the line and try to go WOT from about 4KRPM and see if the boost gets higher then what you've noticed before.

Post back!

maaliish

No such problems in a vett eh? :-) Is there a procedure to test it?

bushido

Pressure tested that hose, so I'm pretty sure it's not leaking.