Instable boost

[whathits14]

I have EVO III ported w/ big flapper, lightly ported o2 housing, 3" turboback, K&N FIPK with a dave brode hard pipe. HRC super sidemount with Dejon tool LICP and david brode UICP with a 1g bov. Also have a wally 190. MBC set at 15.

In first and second, the turbo will boost all the way to 15. In 3rd+ it will go to 15 and then level out to 10-12, depending on the gear. No boost leaks at all. Anyone think they know why it's doing this? Fuel tuning via safc and larger injectors is on the way BTW.

Thanks for any help.

 

[Burnett03]

I have EVO III ported w/ big flapper, lightly ported o2 housing, 3" turboback, K&N FIPK with a dave brode hard pipe. HRC super sidemount with Dejon tool LICP and david brode UICP with a 1g bov. Also have a wally 190. MBC set at 15.

In first and second, the turbo will boost all the way to 15. In 3rd+ it will go to 15 and then level out to 10-12, depending on the gear. No boost leaks at all. Anyone think they know why it's doing this? Fuel tuning via safc and larger injectors is on the way BTW.

Thanks for any help.

where is the MBC tapped into?

 

[Ronin17]

Is the wastegate arm adjustable? This could be a problem with the preload on the wastegate, flapper could be blowing open.

 

[mastadogg2]

Where the wastegate connects to the turbo housing, the 2 bolts that hold the wastegate actuator on just add washers in between the turbo housing and wastegate and it will extend the rod and make it a tighter close.