Forgive me if this is stupid. But on a EFi turbo. There are two ways of increasing your fuel flow. You can get larger injectors. Or you can increase the presure in your rail.

Now Im looking at my carb setup as if it was an injector. Because the carb is no longer working under presure. Rather the float bowl area and the jets are typically seeing 20-30 PSI.

Now using the jet numbers, BHP, air flow I can work out a jet size that will work.
But how do I factor in pressure. How much a 200 jet will flow we can work out.
But how much a 200 will flow under presure of say 20 PSI we dont know.
Can anybody help with an equation. Here.
Or is the best way to chk it just hook up the jet to pressure and see how much she flows at diffirent pressure points like 10 PSI / 15 PSI etc.

 

It's a fluid dynamics problem (a class I haven't had for some years). I think the equation you need to use is the Bernoulli equation?? I'm not 100% sure though. Once you have the right equation its not hard to figure out.

 

I hope your not using the stock fuel pump. Most carb pumps fill around 7psig to atmosphere. If its 30psig in your carb air will be forced down your fuel lines and pressurize your fuel tank.

Sizing should be more of a trial and error rather then a calculation. The fuel is pulled and atomized through the venturi because there is a local pressure drop when the air has to speed up in the reduced cross section. Its really carb specific. I would try to get the bowl to boost pressure and then start out with the same jetting as NA based on your predicted turboed BHP.

 

55 PSI Pump.
Homemade FMU
Stock Jets not working out.
Stock carbs flow due to vacum signal.
Boosted setup there is no vacum.
Fuel flows becuase the presure in the float bowl chamber is allways 10 PSI more than boost pressure.
So in effects its no longer a carb but an FI.