N75 part number

[Eddy_s3]

Can anyone confirm that i have the right part number for the N75 valve from an audi dealer?

Part Number: 058906283C or is the C now changed for an F?

Also can anyone tell me how much they are?

 

[Paradox1]

I can check this for you tomorrow if you like.

I have a c valve for sale if you like? yours for £20

think i got mine for 40ish quid

 

[<tuffty/>]

Seems to depend... Bill had a couple in recently with a C suffix for whatever reason when he thought he had ordered F's... my AMK S3 has an F and from what I have seen on most other S3's I have worked on they are F's too

Dealer should be able to look it up on their system using you r number plate or chassis number anyway..

Not sure of the exact price but I seem to remember them being around the 50 quid mark...

Have you tried one from someone else at all to see if this is your problem? Doesn't have to be from an S3... you can nab one off a mate who has an A3, Golf, Ibiza, Leon etc...

Worth trying another to see if it fixes the problem you think you may have...

In my experience N75's either don't work at all and so you get no boost or they tend to boost spike to 26 odd psi even when the map isn't requesting it... if its either of those then prob worth changing... if you problem is something else then its unlikely to be the N75...

<tuffty/>

 

[Buzzer]

I had a H valve which was a progressive boost vs the J which is a more aggressive boost.

 

[Eddy_s3]

I 100% no its my N75 i have 2 of them and there both broke lol Been having over boost problems for about 2 weeks now, had it on Vag-Com down at DPM Performance and it brought up the maf and N75 so he reset them both and was still having the same problem but didnt have my boost gauge fitted at the time so didnt no what it was boosting at but now i fitted it i was getting up to 25psi of boost. I bypassed my N75 today with a manual boost controle and the car is running fine at 16psi, i thought i would just leave it at that for now as i sont no what boost the map is asking for as i have had this problem since i got the car 2 weeks ago. I dont no anyone with a 1.8 20v turbo local to me so am just gona go get a dealer part and hope for the best i have already fitted a new maf.
I removed the N249 aswell hoping this would sort the problem out but it didnt, made the car run a little smoother but nothing else.

 

[<tuffty/>]

When you say you have removed the N249 I assume you mean bypassed and left electrically connected? N249 needs to be still connected else adaption doesn't happen and fuelling goes mental...

<tuffty/>

 

[Eddy_s3]

I had a H valve which was a progressive boost vs the J which is a more aggressive boost.

What is the H valve? i have hurd it can give upto 3psi more than standard and is a race valve and causes alot od surge. What is the J valve what other people are talking about aswell? Would you recomend using the H or J valve over the C or F valve?

When you say you have removed the N249 I assume you mean bypassed and left electrically connected? N249 needs to be still connected else adaption doesn't happen and fuelling goes mental...

<tuffty/>

Yes its still electically connected.

 

[Buzzer]

H an C and J etc, are all N75 valve variations, as the years have gone on, different Letters have been on the valve and slight differences in how your boost comes on . J for me

 

[Eddy_s3]

How much for the H valve posted that you have and is it in good working order?

 

[<tuffty/>]

Just get an F valve mate... other valves do affect teh boost control/delivery but typically the ECU goes mental especially on more intelligent ones like the ME7's as the boost deviation can get too much and it will go into limp mode..

There is no benefit to swapping N75's for others IMO...

<tuffty/>

 

[Eddy_s3]

Is it worth swapping my n75 at all as i am running a manual boost controller anyway and have bypassed the N75 and the car is running fine, or is it worth removing the boost controle and fitting the new N75?

 

[<tuffty/>]

MBC will give iffy part throttle control if used on its own... have you tried running it in parallel? this it what I normally do to curb boost spikes....

<tuffty/>

 

[Eddy_s3]

What i have done is different yo that, i have looped the n75 boost pressure and wastgate controle round on each other so its just recurculating on its self and fitted the boost controle between the turbo housing and the wastegate so i dont have the 2 Tpieces in and the car seems to be running fine

 

[<tuffty/>]

It will do as you are just using the MBC and have bypassed the N75... using the diagram above means they run in parallel... this way prevents the initial boost spike sometimes seen on rubbish maps or tired N75's

If for example you asre getting a huge spike on spool (have seen 26psi before...) then using the MBC in parallel will cap that spike to whatever you set it too but allow the N75 to carry on working as normal...

This has the advantage of stopping the turbo from trying to spool to full boost on part throttle as the boost is still under load control from the ECU using the N75

<tuffty/>

 

[Eddy_s3]

Fitted my new N75H valve and the car runs spot on, no more over boost problem but it dont feel as quick now, boost is very smooth and peak boost is 19psi, what it was with my N75C valve. Does anyone think its worth trying a N75J valve or is it worth just putting the C valve back on with my boost controle?