Thumbnail Filmstrip of EFI Conversion Birdcatcher Block Off Plates- to Reduce the oversized butterflies Images
Birdcatcher Butterfly Blanks for EFI Conversion- Block offs-
Need one for most engines- Need to block off two for small block engines and very moderate Big Blocks - Requires Tig Welding
Helps prevent butterflies being sucked shut when running a blower
To help with street driving we recommend blanking off 1 or 2 of the outer butterflies. This reduces the amount of air the can flow past the butterfly and tames your engines down so its not too snappy.
These blank plates are simply tack welded into the injector and fully sealed with a fuel resistant sealer.
Bird Block off Block off Bird