inside a turbo theres a valve that controls the amount of exhaust gas that flows over the turbine. this is called the wastegate valve. the more the valve is open, the more boost can be generated. this valve is operated by an actuator that is driven pneumatically by the N75 valve (or the "wastegate bypass regualtor valve" to give it its technical name).
so basically, an uprated N75 will change the way that the wastegate bypass reacts to the signals from your ECU. some people change their N75 for one that reacts more slowly to the ECU signals and therfore creates a smoother boost curve!
hope this helps!
dan
so basically, an uprated N75 will change the way that the wastegate bypass reacts to the signals from your ECU. some people change their N75 for one that reacts more slowly to the ECU signals and therfore creates a smoother boost curve!
hope this helps!
dan
changing it for an uprated one can APPARENTLY give you around a 10bhp increase but i have not done any tuning on a 1.8T before so i dont know if this is true or not. and sorry i dont know who does them either. try bill @ badger5 maybe?
one of the 1.8T owners on here may be able to give you an answer on whether its worth doing or not.
i don't know whether if you're doing a re-map then you may be able to have the correct value in the eprom look-up modified so that the standard N75F performs just as well as an uprated one on a standard map? but that depends on the maximum flow that the standard N75F will allow and i'm afraid i dont know the answer to that sorry mate.
if anyone can give some more info on the standard N75 and whether its worth upgrading then i'd also be interested!
one of the 1.8T owners on here may be able to give you an answer on whether its worth doing or not.
i don't know whether if you're doing a re-map then you may be able to have the correct value in the eprom look-up modified so that the standard N75F performs just as well as an uprated one on a standard map? but that depends on the maximum flow that the standard N75F will allow and i'm afraid i dont know the answer to that sorry mate.
if anyone can give some more info on the standard N75 and whether its worth upgrading then i'd also be interested!
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oh yeh forgot to say....
there are some different types of N75 too. F, J, and H. The F is the stock valve. The H and J allow more boost and for a longer period. the H valve is the best of the two
there are some different types of N75 too. F, J, and H. The F is the stock valve. The H and J allow more boost and for a longer period. the H valve is the best of the two
here you go mate. just found you this which should help a bit.....
http://www.seatcupra.net/forums/showthread.php?t=49098
http://www.seatcupra.net/forums/showthread.php?t=49098
ive never seen conclusive proof that changing the n75 offers any benefit, in fact on sunday one lad had to have his changed back to the standard one to stop throwing an error code.
i hear of more people switching back to standard N75's after their 'J' or 'H' valve has caused their problem
not worth it IMO
i hear of more people switching back to standard N75's after their 'J' or 'H' valve has caused their problem
not worth it IMO
a lot of companies who produce them sell them with the understanding that they can give you an "up to 10bhp increase". notice the word "can". if you look around then you will see this.
as i said in my original paragraph explaining the N75 valve, it can "APPARENTLY" give you a 10bhp gain. this is, as with many tuning mods, a manufacturers figure. as we all know, manufacturers figures often tell a different story to independent testing.
as i said in my original paragraph explaining the N75 valve, it can "APPARENTLY" give you a 10bhp gain. this is, as with many tuning mods, a manufacturers figure. as we all know, manufacturers figures often tell a different story to independent testing.
So not worth changing the valve to either J or the H valve then, coz i have been thinkin of doin this.
from the sound of it mate, i would say it depends on your current set up. its certainly something to try, but don't expect it to give the gains that the manufacturers claim. and remember you may even end up changing back to your standard F valve
There was a thread trying to answer this
http://www.seatcupra.net/forums/showthread.php?t=49098
But it's dead for sometime.
Would be nice to have some updates on this issue.
http://www.seatcupra.net/forums/showthread.php?t=49098
But it's dead for sometime.
Would be nice to have some updates on this issue.
mk4polo said:
you are quite pedantic arent you!!!
if you actually look at the market then you will see that companies sell "uprated" N75 valves. they are still made by vw/audi though. for example, the "uprated" N75 valve that ECS sell as a "race valve" is just the vag N75H
so
danregs said:you are quite pedantic arent you!!!
if you actually look at the market then you will see that companies sell "uprated" N75 valves. they are still made by vw/audi though. for example, the "uprated" N75 valve that ECS sell as a "race valve" is just the vag N75H
so
thats you told mk4polo.
blade said:thats you told mk4polo.
blimey! thats an old thread!
and the old N75 debate is still as unsolved as ever!
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