Quote:
Originally Posted by bign
The upipe things scares me a little more because if any of the coating comes off it's bye bye turbo..
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This is a common concern but it really shouldn't be. Even if all of the interior coating failed in a very short order, it would blow right through the turbine without the turbo ever knowing about it. Most people don't realize the amount of crap that blows through the turbine on a regular basis as-is... mostly carbon and even chunks & flakes of carbon that break off of your exhaust parts and off of your valves/pistons/etc. Also water and oil regularly and then anything that makes it through your intake and through the combustion process, which is usually like little bits of sand and whatnot.
Anyway, if it stays suspended in the exhaust gas, it is going to blow right through the turbine without even touching the wheels. The coating essentially does not bond to itself, but only bonds to the metal. So if any fails, it turns into little more than a very fine dust (whereas a coating that bonds to itself could come off in larger chunks... which actually would also likely not be a problem as long as it's not too dense) and that is what will be in your exhaust and blowing through the turbine.
The things that are capable of damaging your turbo when they go through your exhaust are dense objects. Typically this means pieces of metal. Because of their density, they don't actually blow through the turbine. They get stuck in the cup of the turbine wheel's blades from the centripetal force and then the weight of the object affects the balance of the turbo. Usually this actually makes the
compressor blades touch the compressor housing, and they get ruined. The turbine blades are pretty thick and they're high grade steel or Inconel so it's actually not very easy to hurt the things. Plus the design of them (not much more than a plain paddle shape) allows most objects to pass right through without even touching.
In contrast, the compressor blades are significantly thinner and are aluminum, which is much softer. They're much easier to damage because of this. AND.... because of their extremely cupped design and their function of compressing the air, an object getting sucked through the intake is much more likely to get caught in the wheel and cause damage.
Yeah, we get a lot of STI and 06+ WRX owners e-mailing about our uppipes and typically I suggest they put the $$$ elsewhere in the car.... the stock uppipe is *okay* and the cost and huge hassle of swapping for an aftermarket one isn't worth it for most people. Yes, because of the significantly smoother internal design and smoother bends, it's normal to see ~5-8 whp gains on a stock turbo STI from swapping to a decent aftermarket uppipe. For me, that wouldn't be worth a couple hundred bucks + the labor to change it out. BUT.... if I were doing an upgraded turbo or wanted to get the most out of whatever my setup was, it would definitely be on the list of things to do along w/ our P&P&C manifold elbows and some great tuning and all of the little small things you can do... But obviously if the OEM uppipe has a problem (and there are a lot that crack in the flex section, and they're notorious for a rattling heat shield that tricks your knock sensor into pulling timing
) then it's time to go aftermarket.
Jeremy