Hello I currently have rebuild my BTR trans for my turbo eb and running it with deleted s3 and s4 solenoids , but im having trouble finding some good info on modifying the BAR circuit as I understand from my drawings the bar spring is located behind the S4 solenoid?  1) do people just shim the spring and by how much to get increased pressure has any got some good pictures of the BAR mod 2) when I select low manually with shifter I get a slight hydraulic buzzing noise if I go out of low