When I first bought this car about a year and a half ago the ad I had read said it was “chip tuned”. I drove from Vegas about 4 hours to California. Learning more about the car, I found it wasn’t this guys car but a friend he was selling it for who had moved across the country. So he was unaware of exactly what tune was done. It hit 20lbs of boost at this time with the k03s. And just a couple months ago it starting spiking really high. Anywhere between 25-29 lbs. Even with me not driving it hard the constant ~20 lbs blew the turbo bearings and some of the blades where messed up. I replaced it with a k04 recently and since then the spikes are even higher. I slowly got on the throttle more and more until it reached 22 lbs and stopped from there. It had a lot more pedal to go. I’m assuming it would peak more than 30 lbs. How would I go about diagnosing this? I’ve checked all hoses going to n75, and really every turbo related hose and all seem to be fine. The car doesnt have a cat, and 3 inch straight pipe, I don’t know if that has anything to do with the pressure it’s getting. I can hear the wastegate opening as well.

 

It may be a faulty n75, have you scanned the car to see what codes come up? Definitely don’t drive the car under wot as that much psi may blow your engine unless you have the mods to support it. If it has a k03 tune and you run a k04 then it will spike regardless even if everything is working fine however you said it was spiking when it had the k03 on which suggests something is up.

I would look for a proper k04 tune to suit the setup

 

N75 and/or Waste-gate. DO NOT **** around with it.I blew two engines back to back - even after I replaced the N75 valve, because I had a problem with the waste-gate.....the N75 valve was the wrong one (they all look the same but there are many different kinds, for many different applications).