I have a 058806283f (N 75) cut off valve on my '01 1.8 L Turbo Beetle.

I've seen all kinds of information on the 'H" and "J" versions of this valve. Even information on the 'C' version.

Does anyone have any idea how the 'F" compares to the "H" and "J"??

And, any ideas if changing to an "H" or "J" would improve performance on a stock turbo engine?

Thanks in advance!

I fiited a J to my RS....allowed the turbo to spin up quicker and increased boost by a little.....it was fitted on top of a remap so was not taken into consideration.....I could hit boost limit as I could hear the turbo whistle "pulsing".

Had it remap with the N75....was aweful...very rough...so ditched it.

Quite popular with the Seat guys.....you'll probably get a better description of what it does and how it does it over at Seat Cupra Net or Seat Enthusiasts.

J valve is the same for an Audi S2.

Thanks Skodi!!!! I'll look up those sites. Sorry you had so much trouble with the N75. I'm not chipped, so I'm keeping my fingers crossed that the updated valves (N-710 and N75n) will put a little more spunk in Ziggy.

I've just added a vented fender liner and it does make a noticible difference. Now air really gets thru the intercooler and the power is a lot smoother and the engine freer reving at mid RPM.

Cheers!