Thumbnail Filmstrip of Block Off Plugs Big and Ugly BAU Butterfly Block Images
If you are flowing too much air and want to re balance your system down to suit your engine size this is for you . These work great on Mechanical, but for EFI we recommend retro fitting the Progressive linkage .
When using a 5-9/16" on a lesser engine you can use 1 of these or two for mechanical injection on engines under 550 cu in or with light blower boost.
Our BAU injector blanks are inserted from behind the butterfly and secure with a bolt and sealer. 5 minute job if the injector is not on the blower
For engines not requiring so much air flow, blanking off 1 or 2 butterflies and using a filter in the operating butterfly, helps throttle control.
You can use as many as you wish.
When the butterflies are closed they are not visible.
Also available in3-11/16", 4-3/8" (BAU3), 5"(BAU2)