Hey everyone,

I have a 97 a4 1.8tm that is only running about 4-5psi of boost. I have check for leaks and have found none. I unplugged the N75 valve today and took it for a drive and it drives the exact same, same boost levels and low end power is terrible. Are these a sign of a bad N75 valve?

Thanks for the help.

Also, if it is the N75. What is everyones opinion on the N75 Race valve ECSTuning offers.

 

You can test the N75 with a multimeter


Specified value should be 25-35ohm accross the terminals.

If that checks out, you may want to check or replace your dv. If the spring is worn out or the diphragm is leaking then that is like an internal boost leak.

The N75 "race" valve is good. It gives a constant slightly delayed response to the wastegate which ends up smoothing out and stabilizing boost delivery. The stock n75 gives maybe a more rapid boost response, but not near as smooth as the race valve. I've had it beofre.. Until I broke it by dropping it at some point for whatever reason.... I noticed that there is a slight increase in lag, but where it saves breath down low- it gains on top-meaning the turbo is still efficient around 5k or + and why they claim a small hp increase and call it the "race" valve.

I didn't have any issues with it, but it may be a problem for some DBW engines with map sensors. A different n75 or any mbc for that matter can cause too much deviation between requested and actual boost levels and put you in limp mode.