Interesting thing is we've been using a new turbo builder (godsend) for a while and our turbos don't smoke at all. Mind you we are paying more and EVERY wearing part is new, but we just aren't dealing with smoking issues anymore. Like JWT turbos some of our old turbos were smoking every once in a while (obviously even more so when running striaght exhaust) which doesn't appear to be really affecting the life or potential of them, but they just puff a little. I've found that its more of an annoyance than a real problem. And working with our new turbo builder I know what causes them to do that and I know how to stop it.
Russell Floyd
Z1 Motorsports www.300zx.com 1990+ Nissan Z specialists
Used Parts, New parts, Service/Repair and Performance
2877 Carrollton Villa Rica Hwy Carrollton, Ga 30116