All I really know is that Digis are harder to tune and to get the best performance out of it you will need to put in some modifications to the ECU sensors. The Digis tend to run pretty bad at higher RPMs.
One good side though is that the intake doesn't have any 90 degree turns so it flows better.
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1998 VW Jetta GLX
Past Away - 1986 VW Jetta GL