a1sensei

I have been toying with the idea of a blower. The centrifugal supercharger kits I've seen say "for Holley 4150 or BG Demon". I talked to a tech at either Procharger or Vortech (I can't remember) and he was no help, just told me what the web site said (Holley or Demon). I love my Quadrajet and want to keep it. Are there any issues with using the Q-jet? What superchargers or turbochargers are you guys using? God bless, Sensei

Guru_4_hire

www.turbomustangs.com

If you look in the blow through section you might find instructions on a q-jet.

Holleys are pretty easy to modify for blow through.

Z-man

If you want to stick with a non-blower carb, you'll need one of those setups with a pressure box that goes around the carb (so that pressure is equal internally and externally). They're pretty common...

FB007

I would ask over at Vettemod.com. Alot of guys over there use blowers.

1981Z06Vette

The only issue I can think of with a Quadrajet in a blow through application would be the floats...aren't Q-Jet floats made of brass, like the old Holley ones? If so, under boost they can crush like a beer can. Blowthrough carbs need to have nitrophyl floats, so they won't crush. Whether or not they are available for a Q-jet I don't know, but I'll second checking at turbomustangs.com. Awesome site with tons of info on this kind of stuff.

murraybs

Yep, the Niehoff replacement floats for QJs are Nitrophyl, they're available at Kragen/Checker/Schucks.

V-Twin

draw through? blow through?

Z-man

Draw through - blower below the carb - draws mixture through the carb. Blow through - blower in front of the carb connected via tube (usually a centrifugal blower) - pushes air into the carb.

V-Twin

I was asking him if he wanted a draw or blow through application. See, it kinda depends on what you have to do or can do with your carb. For blow through you need to pressure reference it for one, with draw though you just have to fatten up the mixture.

BigBlockk

You boost referance a draw through system. This is so the power system will function properly.

BigBlockk

Later.....

V-Twin

What you mean is PV referencing to manifold vac. instead of blower (above rotor), this is not pressure referencing like w/ a blow through carb The carb is not under "boosted" conditions at all, the carb just "sees" a bigger engine than there really is.

BigBlockk

Correct. You need to boost reference the power valve or power piston in a draw through system because the vacuum that the blower pulls on the carburetor can hold the power piston/valve closed just when the engine needs the extra fuel the most.

In a blow through system the boost referencing is on the fuel pressure regulator so the fuel pump can keep fuel flowing to the carburetor.

BigBlockk

Later.....

hugie82

I picked up a book called Maximum Boost by Bell. It tells you all the basics of a turbo charged engine. When your finish reading it you will be able to design and build a turbo charged engine.