What Brian said is dead on !!
I switch to vacuum pump last season and wont run without it again. You'll be amazed the stuff that comes out of the motor sometimes :shock: Both my motors seen a 20hp gain on the dyno.
Here is my rating on vacuum pump's
1. Star best by far but pricey
2. Moroso 3 vane I run wide open 4 vane needs a relief falve
3. Aerospace .. downfall to aerospace the mandrel is 1.5" instead of 1" like the rest.
4. GZ the best priced and works well, just heavy and ugly.