I have mucho experience with supercharging on the Thunderbird SC. I won't be modifying the VX until the wife hands it over to me (probably never).

I have an M90 supercharger, soon to be magnaported, but got big gains by installing an airtight ram air system, including an ugly 4 inch round pickup right to the front of the car airflow. In general, extensive air intake mods on the SC have produced perhaps hp gains of 40% over stock. So what has been reported here as 50hp increase AFTER air mods is not unrealistic. It must be proof of the poor air intake of stock design.

Ram air systems are only just being exploited and perfected in stock offerings now...especially bikes. You've seen the "batmobile" Pontiac Firebird, well it took me extensive mods to be able to run with that devil, which can take a C5 vette on the highway no problem because of its ram air.

There is NO one I know and I've done extensive research on ram air systems...that intelligently quantifies the improvement. Most get gains which show a car running cooler on a dyno because they put an industrial fan in front of the car.

On the highway, my boost gage goes from 7 lbs stock (because of headers, it's normally 12 lb stock) to 8 lbs around 90mph, to about 12lbs at 130mph. That's all FREE hp. If you recall, the old Grand Nationals got trememdous results from running the air intake out to the front of the car through a removed front headlight. I see possibilities for the VX in terms of working something to the front (but the wife deal, drats).

My bottom line experience ....do air intake and exhaust (drop cat, especially if SC, if possible) and by god supercharging is the best. For reliabilities sake I wouldn't go much past 50% hp increase though.