I was reading an article about an electric supercharger, it was pretty useless and overpriced but it got me thinking. How big would the compressor have to be to make a few PSI with enough flow to feed the engine at reasonable revs. This will more likely than not become an idea on the "theory in progress" pile that will never happen but anyway.

Does anyone have the figures on how much the Astron II draws at specific revs, particularly 3000 and above?

And also, does a carbi equalise the fuel pressure in relation to the air pressure automatically?Basically if I pressurise all the air going into the A/F to a few PSI, Will the fuel pressure automatically be counterracted so that it wont run really lean and blow lots of air into the engine with less fuel?

PLZ keep in mind that Im still trying to get the whole forced induction theory down-pat, still got a long way to go. lol

Yeah ive had a look at something about electric superchargers as well, the one i looked at said that it was good for 2psi.
Im not sure about the operation of the carbi though, i think that if you were to try and supercharge/turbocharge a carbi that yould most likely have to have the supercharger in a draw through setup, post carbi, (a guy i know at uni is intending to do this to his old carbi fed subaru) which is fair bit harder than just blowing more air in before the carbi.

Just my thoughts :)

i'm not clear on forced induction myself, but from my understanding of a carburettor - the more air that rushes past the venturi, the more fuel the jets put into the mixture cos theres a vacuum sucking the fuel in... if the forced air was post carby, then wouldn't this cause the motor to run lean? ie. more air than fuel...

open to corrections... i'm just going by what i know about carbys and after playing with my lawnmower's carby... yeah they are basic but they work the same way as a car's carby but only smaller

has anyone thought about the ecu in a cars set up? i wouldnt know about a carby set up but from what you say with the vacuum deal that'd be right because the compressed air is going fast and will suck a lot more fuel through too but its all got to be tuned and just wont work perfectly instantly. with an efi the computer will control the A/F, you can buy airflow guages that tell you temp and i think also psi.. but i cant remember technically what it was but i saw it at autobarn and thought how dumb it was.

With blow-through carby setups (air into turbo > optional intercooler > carby > engine) there are a number of issues. Firstly, the issue of getting fuel into the carby float chamber. Obviously your fuel pressure has to be a certain amount above the boost pressure to allow it to flow in. It can't be too high though or it will push the valve open and flood the carby. For this, you will need a fuel pressure regulator referenced to the boost pressure. A modified EFI fuel pressure reg can be used if you have the tools to do it.
Secondly, more of a comment, the carby fuel chamber is referenced to the air coming into the carby so there is no problem with boost stopping the fuel flowing through the jets in the carby.
Thirdly, and most significant with respect to tuning, is the issue of mixture strength. A carburettor's fuel flow (by volume) is proportional to the airflow, by volume. This is the problem. in NA cars, they will run richer at altitude than at sea level. In a turbo engine it means that the engine will run leaner under boost than off boost as the volume flow through the carby doesn't change with boost, only the mass flow. For a small amount of boost ( as mentioned in the above post) this effect will be minimal. For bigger boost, some compensation is necessary or the engine will run poorly. Most factory carbies designed for boost are fitted with a barometer ( a pressure measuring device) that adjusts the amount of fuel to match the amount of boost (and the altidude as well...). You can get by if you jet the carby for the correct boost mixture on the power jets but the engine will run very rich at low revs.