Extractor Part 1


Of all the after-market tuning products that money can buy, exhaust extractors are on the top of the list amongst the most cost-effective power improvement solutions. It’s no wonder that almost every new car is immediately fitted with an extractor kit the moment is hits the road. But what type and make of extractors that are available in our local market actually make a difference? Here, we are going to find out what features, design factors, build quality, etc. that we should look out for in order to be assured of a product that actually works.

    Incidentally, the word extractor means to pull out. In fluid dynamics jargon it means the siphoning effect that draws out the exhaust gases. Without this crucial effect, the exhaust gases have to be pumped out by the piston on its exhaust stroke. Of course, a lot of power is lost this way, by what is known as pumping losses. Extractors are as known as headers in America.

    Basically, there two distinct types of extractors. Four into one (4-1) and four into two, into one (4-2-1). Without going into a detailed discussion, it is sufficient to say that the 4-1 design is mainly suited to engines that spend most of their lives revving at high RPM in track circuits. The 4-2-1 design is more suitable for road use, giving a good usable power band across a wider RPM range.

(Get the full story in Extremekars July 2007 issue)