I was wondering if the Vortech superchargers always carry boost even at idel? I have mine on the way and just thought about this.

 

Yeah. Its not as much as under full throttle, but the belt is still moving

Edit : Unless your Madd Max and have a switch for your blower.

 

No

 

All the Vortech Superchargers I know of are centrifugal like my S-Trim in my 91Z. They do not build boost at idle even though the belt is spinning. And watching my boost guage I can still see it in the vacuum portion of the guage at idle (measured in Hg), even slight/moderate throttle. When you go WOT then it will build boost past a certain RPM, dont remember exactly what it is on my car (its been down for months w/ blown tranny).

 

Boost? Your supercharger is moving air at idle. As long as its spinning its moving air. But its not spinning fast enough to build excess pressure ie boost.

 

No.

Just becuase the impeller is spinning doesn't mean it's moving any air. Centrifugal compressors "stall" at low RPMs and/or low airflows. Yes, if you slam the throttle shut at high RPMs you'll get a pressure spike in the piping between the blower and the throttle. And at modest RPM you won't have any meaningful pressure even between the blower and the throttle.

 

YES. Of course they are always producing pressure, just not enough to offset/change things at low throttle/vacuum..

They provide positive boost once they overcome the vacuum and thats when they pressurize your intake=boost PSI you feel under your butt.. lol

Whoever says they don't, needs to go and look at a real supercharger and actually start the engine.. STALL at low RPMS.. BAHAHAHAH....That's a funny one..

 

If they do have boost at idle? then does the runner length matter? I was told once that a forced induction doesn't care abour runner length so I was thinking if this is true then I could make a custom intake and not worry about the design. Thought?

 

If you know what you are doing, then go for it. Holley, Accel, etc put hundreds of thousands of hours of testing into a manifold so they know what they are doing.

 

Ok you pull the pipe going to the tb while the car is idleing and see if air is being pushed. On my buddies stock mustang with a ati kit we found air leaks at idle.

 

I had that same problem.. I popped a pipe off the intercooler, crawled underneath there at idle and it is pushing air.. albeit, not enough to creat BOOST at idle but enough to compensate for the vacuum that the motor creates... When I unhook the procharger at idle my vacuum gauge reads more vacuum than when it is hooked up.. not much but some...

 

thats why all larger blowers have bypass valves