The Peterson R4 pump that I'm currently running will pull 10" of vacuum at idle. It will pull 5 or 6" o vacuum just spinning it by hand with a speed wrench. I used to run an older 3 stage setup with the old school spur gears and it would not pull any pan vacuum so it all depends on how good the suction stages are designed. I do not run a vacuum pump with my R4 setup.

I have not used a new style Peterson pump. IMO vacuum is a good thing and if you cannot get to 17-20 you need a vacuum pump..Just my .02

We have the newer style Peterson 5 stage. We only pull from the pan. Ours makes vacuum but not enough for me. We also run a Star Machine vacuum pump

hmmm, i've set my current vac pump @ 10" with my wet sump, should i be sucking more?

This article on the Hot Rod website has a lot of pictures of my dry sump setup. You just need to select the option to look at all of the pictures and then scroll thru them: http://www.hotrod.com/articles/modify-carburetor-run-oxygenated-race-gas/

My current Moroso only pulls 9" on its own so we run a vacuum pump as well. Will be replacing it with a Daily eventually. IMO 10" is not enough. We run a 4 vane and no regulator to pull 18"

thanks Al.

I'm still wondering about the Missile pump. are they still around & are they any good?

IMO not sure your reason for wanting to change but I don't think you will find any power there at all over a good wet sump system at all.

my current wet sump has had its share of knocks from some hard wheelstands. after our current season i was looking to replace it. i built the pan i'm using now & it holds 10 quarts but i was thinking if i build a new one, i might as well go dry. my line of thought was i could possibly lower the engine a little as the carbon shield really is crushed hard into the stock floor pan. i run an accumulator so dont have any oil issues but i'm always wanting to improve on my set up thats all.