hey guys im goin to be putting a weiand 142 roots style supercharger on my camaro over the winter and i need to know if a supercharger carburetor is necessary only because i just picked up a quick fuel 750 carb that does not have any vacuum ports on the carb at all.and i would like to continue to use this carburetor........it is a drag race setup carb. any help is appreciated thanks

 

anyone?

 

You need to reference the power valve to manifold pressure. I don't know what else you need to do, though.

Let's try the Power Adder forum instead of the Carburetor forum.

 

thanks for moving it for me five7kid.......... i thought since it was a carb question i would put it in the carburetor section.

on another note i have heard of a power valve block off plug... im just concerned i wont be able to use the nice carb i have sittin on my 355

 

Use your current N2O fuel solenoid for the boost fuel. Turn the solenoid on with a Hobbs switch. Do the power valve mod. so you don't blow it out.

Boost reference your fuel pump.

 

Boost reference your power valve to your intake to be more streetable. That would mean adding a vacuum port in your base plate. I'm in the process of doing this with mine. See my post on the Carb board. I posted 2 ways to do it, Holley's way and another way I found on another board.

For strictly 1/4 mile, which sounds like your carb is meant for (with no vacuum ports)- you really don't need to. Just plug both power valve ports, get a straight mechanical distributor, richen the jet sizes and go!

No need to boost reference your fuel pump unless you go with a centrifugal supercharger (aka BLOW-THROUGH application). Only exception might be as junkcltr said - if you're running N2O in your intake runners - maybe you do need to boost reference the pump in that case....don't know myself.

Remember - you're using this carb in a DRAW THROUGH application. Just like carbs were designed to be. You're not forcing air through the top, so aside from referencing the PV to the intake - it works just like a NA engine -You just need to richen the jets for the extra cubes being created by forcing more air in - under the carb.

There's a better resource on this board when it comes to Weiand 142's - Damon. He's played with them for awhile now, and has helped me quite a bit! And just as a disclaimer - I'm still learning myself, but I've done mega searches...good luck with it!!

 

interesting...................ive been tryin go find any info about this subject................i planned to fatten up the jets if i didnt use a boost referenced power valve setup.........i run 72 primary and 80 secondary jets............i figured id run a 80 primary and a 88 secondary jet setup to make up for it