So I finally got an N75J valve to replace my old rusty N75C and was stoked to put it in. So after it was all said and done I took it for a test drive. The car is wayyy faster than before and boost rises very quickly and holds pretty well to redline but from about 3-5th gear i have horrible, horrible, surging, its like a wild horse bucking when i left off the gas, and sometimes it will backfire through the intake if im going up the a hill in the wrong gear. The car is a 99.5tqm AEB(I think) with a hyperboost DV, also did the beer mod intake. Mind you it was about 30 degrees out tonight so I'm thinking that didn't help either. Any thoughts?

 

what does the temps being 30 degrees have to do with anything? Are you sure you plugged the wiring harness back into the n75?? Are you sure you put it in the right way and it looks like the old one did before you took it out? Are you sure you didnt rip a hose when taking out the old one? You should notice a good difference in how you build boost, but I wouldnt say it is WAY faster. If your waste gate is stuck open, that will cause the symptoms you are talking about which means you didnt hook it up right.

 

Pull the pos side of the battery for 15 min then hook it back up. After that turn the key as far as it will go without starting it, leave it like that for a few more minutes. Once you have done all that come back on here and let us know if it helped.........

 

k, i'll give it a try, thanks

 

Yup, that seemed to do the trick for now at least, thanks!

 

It still surged a lot tonight, I feel like the ambient temperature makes a big difference, at 45 degrees it didn't do any surging but later tonight at around 28 it would go nutso