Before I endulge in a blower I have a burning question for those with a blower that is bothering me. If a blower is pushing air into the intake, what happens to the level of vacuum? If it is very low, how did cars like the super charged thunderbird deal with vacuum accessories? Would you need a vacuum pump?

 

A car with a blower will have just as much vacumm as a car without. It is only pulling boost( which is the opposite of vacumm) when you are at WOT, and i hope your not using some of your vacumm accesories such as brakes under WOT. What i am trying to say is that your vacumm is fine with a blower and all your accesories will work just as good as they did!

 

Vacuum is related more to the cam you are running. As a rule of thumb the bigger the cam the less vacuum. If your in boost you are only in it generally for a short time so you don't notice it. I have never got an ABS light or had any vacuum issues with my stroker, It has 11 inchs vacuum at idle and about 20 cruising at 2500 rpm's.

 

Do either one of you have a blower?

 

I have a blower on my other car, A mustang, And it also has a huge cam in it, i will agree and say bigger the cam the less vacumm, but my mustang runs 10 inches of vacumm regardless of wether or not the blower belt is on or not!

 

385 with Vortech

 

As stated above, vacuum is mostly influenced by the cam. I drive a 10# Vortech setup with a vacuum/boost gauge. My 218/230/114LS CC Xtreme cam develops 17" of vacuum at idle. Boost occurs more often than just WOT, basically anytime you have throttle more than 50% and the engine's under load (hill). I've never had any vacuum related issues.