According to Jake Raby at Aircooled Tecnology, the Empi twin tip is the worst performing system they have dyno'ed. Even worse than the original stock system, which he rates very detrimental overall. A 4-2-1 system was best for these engines, but what's the current knowledge and experience in this forum of this subject? Who has had what made, or bought, by whom, for what of type4, and for what purpose was the overall combination designed for? [a daily driver, a mild street, for touring, towing, climbing hills? etc]
what these you meanhttp://cgi.ebay.com.au/ws/eBayISAPI.dll?ViewItem&Item=110291024029&Category=42605&_trksid=p3907.m29
Come to Warwick and have a look at the system i got made at CES. Mandrel bent tuned length primaries for torque and it don't sound like a VW.