Hi, my nissan r34 skyline gtt running stock boost, now when it is in low boost driving normally it sounds like a turbo should, i dont pretend to know much about turbo charged engines, but obviously as the turbine spins faster at higher revs it will make a different noise as to low boost. But for some reason my turbo is making a screaming noise which im not sure if it is normal or not as i have only had the car for a few weeks. any help would be appreciated as mechanics want to charge me $110 for a dyno. I havent had any other problems, no knocking on idle or oil leaks etc just the turbo noise, It probably is normal.