wastegate actuator

[evildky]

my car is running a stock junkyard L28ET swap, no I/C no fancy downpipe just stock with the addition boost controller AFPR of a pallnet fuel rail and MSnS

 

while running the stock managment in Gainesville I decided to up the boost a 1/4 turn of the Turbo XS I was already at 10 psi and was running 110 octane so I figured and extra half a Lb of boost might get me into the 12's (ran 13.010) well that resulted in 15 psi! and yeah it was pinging like crazy! my car was trailers due to electrical issues

 

I put the MSnS back on the car with the bigger injectors and moby's newer maps and turned the boost controller down a turn and a half and it's still hitting 15psi and not pinging (it would appear the engine can handle over 10psi but the stock managment doesn't allow for enbough timing retard) and it made a wierd sound kinda like a bov but I don't have a bov and the stock boost safty valve has been plugged

 

so now to the point, i hooked up a vac/boost pump to the actuator and it doesn't start to move till about 7.5 psi and doesn't reach full swing till 10 psi, I checked another I had on the shelf and it started moving at about 6 psi but still not full open till about 10 psi ? is it possible the the pressure inside the turbo helps to push the wastegate open sooner than the static measurement on the actuator? trying to figure out if i should worry

[proxlamus©]

that sound.. that sounded like a blow off valve.. and you don't have one.. is BAD..

 

that's the sound of the compressed air being forced back into the turbo.. which could result in stalling or even breaking the fins/blades on the compressor!!

 

If your POV was not plugged up you could haev prevented it...

 

but be careful... that forced air slamming into a closed throttle butterfly, will jump back down the intake and into the turbine... which is a no no