M8 Aero Boost Decrease?

[9500blizzard]

I have a 08 M8T OVS Aero 53 that i would like to turn down the boost on. Its currently at 10.5psi and i'd like to go down to 8 or 9psi. How do i go about doing this? I know about the shims behind the wastegate diaphram, do i need to remove another shim or is there a way to make small adjustments? Has anyone played with the adjustible viens? If you have what results did you have. Thanks for the answers in adavance

 

[turboless terry]

I believe the shims are for small adjustments. Depending on how far down you want to go you have to put a lighter spring in.

 

[turborev]

the veins are for back pressure which are for spool time. To adjust the boost pressure you have to do the shims.

 

[BigAir]

You most likely have an orange spring in your controller with either 2 or 3 shims. If you go to one shim it should put you right around 9 lbs. If you have an orange spring and want to go lower you will have to change the spring like Terry said.

Does anyone know what the range of adjustment is on the set screw for the veins? I just set it back exactly where it was when I change shims because I don't know how much adjustment it has.

 

[9500blizzard]

Thanks guys, i'll try going to one shim and see if it works. When i bought the sled someone had 4 shims and it was spooling to 14psi so i changed it right away. This is why i'm wondering about the viens because i'm sure he "fixed that up too". Turning the set screw in closes the viens? How much of the set screw do you have sticking out?