air box differences??

[jamrock]

why are there two different types for the 16v?? and how do i know which i should have.





i have the later but i know i am missing a sensor of sort as i have a unplugged jack plug near the box.

one is pluged in to the diaphragm
 
thanks 

[Wayne]

Later one is KE I believe.

[jamrock]

if both are for 16v how do i know which one to use??

[tony_ack]

Pic 1 is pre-90 and pic 2 is '90 spec. Not quite sure why changes were made to the rubber boot on '90 specs, as I believe the airbox itself and meterting head are the same.

[rubjonny]

the reason rubber boot is different is because the 90spec airbox is much bigger. it sits higher so the boot was redesigned to be flatter and give the required room.  90spec 16v uses same size filter as the 8v digi, the pre-90 filter is quite a bit smaller. the unused plug, does it have a black wire and a white wire? if so thats for the throttle enrichment vac switch. doesnt really do a lot as it only works when you floor it with a cold engine, the thermoswitch for it cuts in pretty soon after engine first started

[VeeDubGTI16v]

i changed from a small box to a big box setup and felt no improvement whatsoever

[jamrock]

ok ive just tryed to offer up the waffle type early rubber boot. is there a different type of pipe that sits in between the throttle body and boot?? i have this one in currently



also, where and how do i connected up the over run valve??



which bit goes into the boot and what do i do with the other end??
like this maybe???



is it even nesesary? i have it so i might as well use it but i cant seem to work out where it goes

thanks

[rubjonny]

other way round chap, the long bit goes to the boot, the short end attaches to the rear of the airbox with a short length of rubber hose

the plastic bit is different on the later models, as on them the over-run valve connects to the bottom of the plastic bit rather than the side of the rubber bit as on the early ones. you can get away without the over-run as lonmg as all the holes are plugged up. without it if you lift off at high revs you might see the idle drops a bit too low or stalls, this is the function of the over-run it 'catches' the revs at around 2k and makes it fall slowly to idle