N75 valve - how does it work

[S4TAN]

I will pop out at lunchtime and get the number of the new one I put in, and get the number off the older one that I took out tonight ... certainly fixed my problem!

Thanks - i'm intrigued by this; as far as i'm aware there's only one version of the N75 for the B5 S4 so will be very interesting to see what version you've got (where'd you get it from by the way?)

[viperbl]

I got it years ago, I think I got it from some VW specialist in Edinburgh! (mail order) but never used it because the problem I had then was not the N75 valve, so it sat in my toolbox...

Let me go and check the car now ... ok, I have Q34906283H. What do you have on at the moment??

Now, here is an interesting topic to read

[S4TAN]

ok, I have Q34906283H. What do you have on at the moment??

Hmmmm ... the thick plottens! I have 078906283B (part number written below 'VWAudi - made in monaco EATON') - i've got a nice collection of N75s (all with various degrees of "screw-turn") and they ALL have this part number. I'm always buggering about with them and swapping them around to see what results i get ...

Got any photos of this Q valve?? My curiosity is seriously piqued by this!

Also: it may have been the RS2 valve that i was told about - looking at the VWvortex forum i think it's the K version ...

[viperbl]

Got any photos of this Q valve?? My curiosity is seriously piqued by this!

Why? Do you think I am winding you up

I will get a picture later, and I will find out what valve I had in before (I have a funny feeling the number is quite different!!!, not just the letter at the end, but I could be dreaming again ...)

[dodgydave]

okay, H valve will make 0.3 more boost but the connector is 90 degrees turned compared to the B and you'll get a deviation error if you don't clamp your MAP.

[S4TAN]

Why? Do you think I am winding you up

hahaha - no! I just have a "thing" about N75s! I'm always on the hunt for the 'perfect' valve ... !

[viperbl]

hahaha - no! I just have a "thing" about N75s! I'm always on the hunt for the 'perfect' valve ... !

Thats like the quest for the perfect woman, it will never end, you'll always want to try another!

[S4TAN]

if you don't clamp your MAP

How do you clamp the MAP? I've seen the H version and know the connector socket is rotated but i reckon i've got enough slack in the lead to still plug in ...

[viperbl]

okay, H valve will make 0.3 more boost but the connector is 90 degrees turned compared to the B and you'll get a deviation error if you don't clamp your MAP.

Deviation if I don't clamp the MAP??

I am not sure what you mean?

[S4TAN]

Thats like the quest for the perfect woman, it will never end, you'll always want to try another!

I'm always trying another! So many women ... so little time ....

[S4TAN]

ok - just done a bit of research; from what i can make out clamping the MAP seems to be voltage related - i.e. clamp the voltage at a certain value so the MAP doesn't register boost beyond a certain level (and doesn't make the ecu sense an 'overboost' condition) - the boost measured by the MAP stays at this level even though there is actually more boost being produced in reality (but the MAP can't register it)

This is for voltage-based MAPs - so 2 questions: 1. what voltage should the MAP be clamped at? 2. How do you do it? (solder in a diode somewhere in the MAP cct?)

[ChipHazzard]

could it be one of the fleabay special cheap chips ????

[MarkB]

Why bother with this. Just ask your friendly mapper to set your car to run more boost. You may need to sign a disclaimer first though

Whoooosh POP!

[oliew]

N75s only cost a few 'squid'

tweak it haha

[S4TAN]

N75s only cost a few 'squid'

tweak it haha

That's the spirit!