Vacuum pumps almost always add some power. You CAN lose some when you overdrive the pump too much depending on which model it is and how much seal your engine is good for. The same pump will not pull the same vacuum on all engines. It depends on the sealing and power of the engine the pump is on and how fast or slow you drive it.

I actually do dyno stuff and we have never seen lower on anything but we have seen lower gains at the school often. Other times with dedicated setups you can see 30+ with the right stuff.

 

does anyone have the weight of the caddy or SSBC pumps? just a curiosity thing. we arer going to be putting the SSBC pump on our procharged 3rd gen.

 

I purchased the SSBC system from Ram Chargers. Not installed yet though.