N75 Valve upgrade????

[B5Crazy]

Hallo, Ich habe z.Z. einen 1999 1.8T mit manuellen Schaltgetriebe, mit GIAC Chip und einem nachgerüsteten K04 Lader. Ich habe, daß das 1.8T N75 Ventil zum wastegate zu den "J" oder "H, Rennen" Versionen verbessert werden kann entweder gehört. Werden Sie diese Arbeit in meinem Auto? Kann ich eine größere Verbesserung in der Triebwerkleistung vorwegnehmen? Dank, Tom

Hello,

I currently have a 1999 1.8T manual, with GIAC chip, and K04 conversion. I have heard that the 1.8T N75 valve to the wastegate can be upgraded to either the "J" or "H, race" versions. Will this work in my car? Can I anticipate a larger improvement in engine performance?

Thanks,

Tom

http://forums.audiworld.com/s4/msgs/1046677.phtml

 

[Scatha]

Hello,

you are right, the N75 valve can be upgraded for a bit of a performance boost. Wether the gain in performance is barely noticeable or undeniable seems to depend on a lot of factors nearly anybody who upgraded the N75 is happy with it.

Regarding the types of valves, most people on this forum use either the J or K versions, with the K version pleasing giving a slightly earlier pressure buildup from the turbo and holding the pressure a bit longer.

The difference between J and K ist noticeable but not major.

Regards,
Morton

 

[cruiser]

@B5Crazy

referring to Scatha the N75H is the "RACE"-Version of ECS and many other US-tuner. It's really cheaper to buy this (if you want it) at your local VW dealer.

The N75J has the part no. 058 906 283 J and the N75K the part no. 034 906 283 K.

Marco

 

[Scatha]

@B5Crazy

Just to complete the part numbers, the N75H is 034 906 283H and costs approx. $60 (45 EUR). It is normally used on Audi 100/A6/S6 cars.

Regards,
Morton

 

[B5Crazy]

Marco/Morton, Dank für Ihre Antworten. Ich entschuldige mich für Sein nicht fließend auf Deutsch. Die C, H und J Ventile sind in den US vorhanden, aber ich habe nie von das K Ventil gehört. Von welchem Auto das K Ventil kommen? Ich lehne mich in Richtung zum J Ventil, da es weniger konkurrenzfähig ist, als das H. In den US ist die Teilnummer für das H Ventil dieselbe wie Deutschland. Jedoch ist das J Ventil 034.906.283J anstelle von 058.906.283J. Sie sind beide ungefähr $75 US. Ich betrachte diese Änderung, weil das K04 Turbo langsam ist, oben zu spulen, wenn die U/min zwischen 2K und 3K U/min ist. Alle mögliche anderen Vorschläge würden willkommen sein. Beifall, Tom

Marco / Morton,

Thanks for your replies. I apologize for not being fluent in German.

The C, H, and J valves are available in the US but I have never heard of the K valve. Which car does the K valve come from? I am leaning towards the J valve since it is less aggressive than the H.

In the US the part number for the H valve is the same as Germany. However, the J valve is 034.906.283J instead of 058.906.283J. They are both about $75 US.

I am considering this modification because the K04 turbo is slow to spool up when the rpm is between 2K and 3K rpm. Any other suggestions would be welcome. Cheers,

Tom

 

[Scatha]

Hi Tom,

the N75K was used in the following cars:

- Audi Avant quattro, coupe quattro : 1992-1996 2.20 l, 230HP engine ABY;
- Audi RS2 : 1994-1996 2.20 l, 316HP engine ADU

Its supposed to be giving boost up quicker while having a smoother curve compared to the C/F/H/J valves. And it helped some people who were having surging problems with the H Valves.

The exchange of the valves might help you with your lag, it should at least give you a noticeable improvement. You haven't said how many miles your car has, but there have been reports of the N75 valve showing signs of "wear" after as few as 15000 miles.

Also a bigger turbo always means more turbo lag because it needs more air to spool up.

Regards,
Morton

 

[cruiser]

@B5Crazy

the K-version was built in the good old RS2 from Audi. This car has 315hp and a K24/26 was the reactor .

the K04 is too big for a quick spool under 2K U/min. Either you have to reprogramming your software and/or controll your A/F ratio.

Has you check your A/F ?? Is it too lean in this area??

The K-version is really agressive in the lower and higher rpm. In the middle rpm it's more weakly than the J. The J is better in the higher rpm and the H is more agressive in the middle rpm but really weakly in the higher.

The most drivers in this forum can better handle with the J, any other with the K.

Marco