Draw-through or blow-through carb?The advantage of stepping up and spending three grand on an injection setup is that there is zero fiddling and zero doubt about the tune when you are done. Getting the fuel curve right on is just a matter of reading the O2 sensor output and adjusting it accordingly-that's if the injection system itself didn't actually do it for you. Going the carbureted route can save between $1,000 and $2,000, but you will almost certainly need to do at least a little fine-tuning. If the blower is a Roots-style unit, then the most obvious and convenient place to put carburetion is on top of the blower. This is the classic draw-through mode of operation. Apart from referencing the power valve to the intake manifold boost, the carb pretty much operates normally. But with some installations, building a draw-through system is not quite as easy. Centrifugal superchargers sort of fall into this category. Here, it is more convenient to have a blow-through system. Unless you have a carb built by a company knowledgeable in this mode of operation, be aware that on a scale of zero to 10, your carb calibration problems could easily be five or more, when what you need are zero problems. As for what you may give away in terms of power, the chances are the small deficit might actually help hook up the potentially large number of lb-ft the engine will inevitably make if done right. View Related Article
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