Factory wastegate crack pressure

[KnappAttack]

How much increased performance are you experiencing after adding washers…

Adding 2 washers got him back to the stock 9 lbs of boost. Adding washers is like tightening up the wastegate on say a garret turbo, each turn was about a pound of boost, but because the ECU controls the boost cut if you set it up much more that the tune is set for you could likely hit the boost cut. The boost cut is there for safety. When you hit the boost cut, the machine will shut off and come back on once the boost get back under that boost cut. Most all the tunes are designed for 9 lbs. of wastegate crack pressure unless you have the bigger wastegate.

He did this as his tunes were down on boost.

 

[Simplespeed]

Adding 2 washers got him back to the stock 9 lbs of boost. Adding washers is like tightening up the wastegate on say a garret turbo, each turn was about a pound of boost, but because the ECU controls the boost cut if you set it up much more that the tune is set for you could likely hit the boost cut. The boost cut is there for safety. When you hit the boost cut, the machine will shut off and come back on once the boost get back under that boost cut. Most all the tunes are designed for 9 lbs. of wastegate crack pressure unless you have the bigger wastegate.

He did this as his tunes were down on boost.

I assume he was experiencing a loss of performance based on lower boost numbers with all tunes… Thank you for the reply…

 

[KnappAttack]

I assume he was experiencing a loss of performance based on lower boost numbers with all tunes… Thank you for the reply…

That would be correct. His boost number was down from where it should have been so he checked the crack pressure and found it low. My guess is the spring may have broke internally in the actuator or somehow went bad like that.

 

[Turboflash]

FYI - I had my turbo off so I checked my crack pressure just because. My sled had been running great, no issues.
Well, crack pressure was only 6.5 psi! Whatever - obviously ECU was able to deal with that and still achieve target boost per tune table. If ECU could not achieve table boost, it would set a code.
It took .115" shim to get crack pressure up to 9. Sled has 9000 miles on it. Stage 4 PEFI. The actuator spring must get tired after a while so crack pressure goes down. My spring is Not broke.
P.S. My sled was just at Ulmer Racing track dyno and there were no boost issues even at that crack pressure. Again, apparently, the ECU must be able to manage that crack pressure. And, sled acheives target boost.