BLow thru trubo ?'s

[monte_383]

Anyone build a blow through carbed engine before. Was wondering how to enrich the fuel under boost. I have figured how to boost reference the pump so fuel pressure goes up proportional to boost, just can't figure out extra fuel for the boost. Or do you really need it? Seen couple of engines done with a single injector for supplemental fuel under boost but can't figure out how to hook one up. TIA, Chuck.

 

[turbojolie]

i am going that route eventually and i plan on using a cold start injector hooked up to a boost pressure switch.
you also have to have a variable boost pressure sensetive fuel regulator and fuel pump that will put out more fuel pressure than the maximum boost.

 

[b4black]

Another way is by simply using a progressive carburetor. Most driveing is done using only the primary barrels, but WOT/Boost happens with the secondaries open. The primaries and secondaries can be jetted differently. The Quadrajet used on the GM draw-thru works this way.

The additional fuel injector is very similar to the water injection system, which also supresses detonation. Fuel enrichment isn't the only option.


Turbochargers by Hugh MacInnes is a great book for what you are looking for.