It is difficult to describe this mod without pictures however here it goes. At the factory were the Viper engine was assembelled, the intake and throttle bodies were Manufactured by different companies at different times. When the intake is bored and tapped to accept the throttle bodies the intake hole is bored slighly smaller than size of the opening of the throttle body. Additionally, with small varience allowed in the manufacturing specifications of both the intake and throttle bodies components, the allignment of these components is not guaranteed. In the case of my 1994 the right throttle body was off of center about 1/4 inch and the left throttle body was off of center even more. I was told by the machinest at the Speed shop this condition is not uncomon, not only to Viper motors but to most mass produced engines. Unfortuantly, there is no easy way to determine if this condition is present in your car without removing the throttle bodies from the intake and measuring exact dead center (up and down and left and right) of the square throttle body base. At the shop they used a metal ruler to determine the true dead center of the throttle body. Then they scribed small lines on the throttle body base as a refrence. Then they matched the throttle bodies center to the intake opening dead center. Each throttle body is attached to the intake by four bolts. The correct way to correct throttle body misalignment would be to re tap the intake. However, the small distances that the throttle bodies are off would make this an overly expensive mod. The solution is to increase the size of factory opening in the intake. My intake now has larger slightly oval openings instaed of factory bored round openings. This misalignment issue goes unnoticed because the throttle body blade is actuated within the throttle body base and the throttle body blade never comes into contact with the intake face. I belive this is the reason that some Viper repond well to smooth tubes and filters while some do not. Additionally, a while back there was much discussion whether increasing the bored diameter of the throttle bodies increased HP. Cars that had proper TB alignment perhapse would respond favorably, but cars with mis alignment issues could actually increase the mismatch and make more turbulent airflow and decrase HP.
