[Archived Account 7]

I had a look at my N75 the other day. The number on it has an F on the end. I have problems with surging and was wondering if swapping it for one with a C on the end of the model number would help. Don't know where, one of the VW forums, I heard this mentioned?

Anyone know how much an N75 would cost?

Pete

 

[mosser]

In 90% of the cases a C version has fixed the surging, they cost around £70 and if you cant get one then try VW delaers for a passat part instead, the ECS race N75 cures the surging in about 40% of cases and can add a little more boost but is more expensive and there's currently a waiting list for them!!

 

[Archived Account 7]

Tell me about it, there's a waiting list for their BOV kit too... But it should be here soon...

Pete

 

[.:matt:.]

Any idea what cuases the actual surging??? I take it the valve is for some reason going into 100% duty cycle mode and diverting everything to the DV then dropping out and cutting back in again?

In an undampened spring kinda way??

m

 

[mosser]

It appears to be either a lower gauss magnetic field being generated in the solenoid that controls the solenoid valve, or a weaker spring that is resulting in a delay in the response time, there is a restriction in the input to the unit but its exactly the same for the 'c'and 'f' versions at 1.8mm,

No fix has been suggested by anyone for the 'f' version that works and the only solution at the moment seems to be replacing it with a 'c' version

 

[.:matt:.]

sounds like a bad design of control system to me... as that should be compensated for....

I reckon it maybe worth looking for a industrial divertor valve not nessecarily for a VAG engine or for any engine infact there has to be one out there!

Have you got a spare one mosser??? I wouldnt mind cranking one up on the bench ans measuring response times etc

I wander if it would be possible to make a small module to sit inline with the N75 to help out???

 

[mosser]

It could actually be down to a tougher seal slowing the response time of it down!,

Unfortunatly i havent got any sort of solenoid valves at all, and i wouldnt know where to start for getting one either!, I believe that is exactly what the ECS N75 is, just a heavier duty Boost bypass valve than the original, might be worth looking at other makes of cars (know anyone wth a turbo car?) to borrow one off to test though

The only N75 i have got is the 'f' version currently on my car !, maybe a modest voltage boost might up the response time of the valve?,

Another thought is that Seat might have put a resistor inline with the solenoid to prevent problems with faulty valves, maybe they suspect burnt out coils?

 

[.:matt:.]

I know a guy with a turbo volvo I will take it to bits tomorow

As you know mate I have the F version as well.. do you still reckon you have power only at the top end witht he F valve as opposed to power all the way through the range witht he C one??

If there was a series resistor it would just turn it into a potential divider and you would get a lower proportion of the 12V accross the coil and therefore the valve would pull in slower...

need to measure the impedance of the F and C versions to compare if there is any difference..

you could go over voltage and that would snap it shut quicker but at the cost of possibly changing the lifetime of the unit..

Need the spec from bosch really but they werent forthcomming when I asked them for it..

Could be an interesting project though

I'll take some piccies of the volvo tomorrow

m

 

[Archived Account 7]

OMG! what have I started...

Never mind though because I fixed mine by adding a flux capacitor... Can't seem to get above 88mph now though...

Pete