MS6 overboost fuel cut

[ihcj9]

Hey guys, bit of a stumper so looking for some insight.

Mods:
COBB Accessport, COBB turbo inlet, COBB Intake
Egr delete. JBR ECBS. HPFP.
Full race downpipe and race pipe. Stock exhaust after that.
Freaktune custom tune.

Was tuning great with Justin. Had a HP fuel line crack so replaced that, and while. I was in there, replaced a leaky header to turbo gasket.

Fired back up and it's overboosting to 23+. Ok so maybe I cracked the stock EBCS. So I ordered a James Barone 3 port and installed it in 2 port mode. Checked or replaced all the lines. Still overboosting and cutting fuel.

Bypass the ECBS, and it's hitting 19 psi...on just the WGA spring. And there is some creaking sound when the wastegate actuates that I can here in the car, that started the second I bypassed the ecbs

Now I believe it should hit 15 or so on just the spring.

So what am I missing?

[MSMS3]

Stock turbo with stock wg actuator setting should be only 8-10 psi on spring pressure.

Makes me wonder if your wastegate is binding or stuck.

[ihcj9]

Thanks for the info!

I know the vast majority of overboost issues are stupid little issues causing. But when I'm hitting 19 on the wga alone, threw me for a loop.

[Jeff23spl]

Just hook compressed air with a regulator on the WG with a T with your boost gage and slowly increase pressure and make sure the arm is going all way out while checking at which pressure this happen....There is also some DP issue where it bloc the WG flap to move properly....
I didn't measured it but i would say the travel is about half an inch.

On the turbo boost port, there is a pill to restrict air flow in order to make the 2 ports mode working. make sure it isn't plugged by dirt or oil+dirt.
I got the pill plugged on my 6 and i ended up using aftermarket ebcs in 3 port intterup mode with boost taken from somewhere else....this need some tuning adjustments but worked well.

At some point, if you got your tune during summer it may overboost with colder temp. You didn't mention if the tuning process was over or still in progress, it may not have any load control yet for winter weather....in both case, you may not see 19 with EBCS port disabled by capping both hose. (if you just by-passed it with a hose from the venting port back into the TIH, for sure it will overboost as it is like 100% wg duty...)