sorry about the delayed response. I had the flu last week and this was the last thing on my mind.
We take our customer service very seriously. We want to do the right thing by all our customers, but if there's something wrong with the car that's caused a brand new, genuine OEM turbo to fail so quickly, then why would we send out another without asking a few questions first? We have hundreds of these turbo's out in the field working to their full potential.
When we tried to delve further to find the potential cause for the failure we were greeted with the following response: "I'm an engineer, I know what I'm doing, just send me a turbo or else" and escalating threats. We try to go out of our way to take care of our customers, but if they can't supply us with the information we need to make an educated decision on the cause the the failure it becomes difficult for us to take the added measures of insuring the best possible customer experience. I never spoke with him or e-mailed him personally, but the way it all happened was very uncomfortable from the start.
As far as a correct recommendation at the time of the sale, we have to rely on our customers knowledge of their vehicle to make an informed recommendation. We can only go with what we are told.
First it's RC3 with stock map sensor. That's normally 18 psi, no problem. But we say the turbo won't be able to use it's full potential unless there's a 3bar AND MATCHING TUNE (this tune is something we emphasize but somehow got disregarded by the customer, but it is a very key point). He gets the 3 bar, and later we learn (in a forum post) he decided to ditch the boost valve for some reason (which we didn't know about or we would have said to keep it if he had a RC tune). And no matching update to the tune.
Then when I reminded him of this error on the forums, all of a sudden it's RC5, not RC3 after all. With a stock map sensor that would also be ~18 psi, but apparently the vnt17 was pushing 23 psi (boost valve limited) which would DEFINITELY be overboosting for that tune and map sensor combo. So something's not right there's either.
We can only work with the info we are given. Second-guessing on the forums and retroactive info doesn't help.
So there's some miscommunication there, and at least missed opportunity to identify a preexisting problem. Maybe if we had better info we would have made a different recommendation, or even had an opportunity to make a stronger caution to "fix what's wrong with the car first". Maybe some of this could have been communicated to us before the sale, and not only on the forums much later?
I don't know if this was brought up when he spoke to Chris initially, but also consider the old turbo is pushing oil past the blown piston ring seal at an alarming rate- this does not "just happen". The normal "wearing out" mode for those turbos is the thrust bearing wearing to the point where the compressor makes contact with the housing. It grinds away to where it's just not efficient anymore because of excessive compressor/housing clearance. Then it spins faster and faster trying to keep up with requested boost and eventually bang. (or sometimes they just howl louder and louder until the just stop making boost in a less dramatic demise)
My point being, the usual failure mode on a vnt17 is not the oil seals. From what I've seen, when oils seals fail on those, it's from high crankcase pressure, which impedes oil return flow. They can also fail from high oil supply pressure or some other cause like a kinked oil return line or an incorrectly oriented return line (seen in some uh, "custom" installations.) So in other words, this car has an oiling problem. The failure diagnosis (performed by an independent third party individual with 40 years of experience building custom turbos) did say it was a problem with the oil, along with overspeed (tuning/installation issue).
So what causes high crankcase pressure? blocked puck on top of the cam cover obviously, or else worn/sticking rings creating excessive blowby. Rings can stick like that when a car sits for a while without running (like this car did). If you are an old timer you may recall some of the forum discussions back in the day about "higher stage" tunes and crankcase pressure, dual puck setups, and so forth.
Then we see posted (first time I heard of it was a post) that it's not responding as quickly as the old vnt17? That's contrary to everything we know from our personal experience with the S7. It responds lighting fast, faster than any other turbo we've seen for those cars, even faster than the stock turbos. This tells me there was a problem with the installation like a boost leak or something like that. Even it's detractors (buzzken for example) claim "it's a spiky little b*tch". Not slow response. Never ever a "slow response" complaint. So that alone tells me something was not right with the installation. (removing the boost valve would only make it respond faster, not slower as Viesel guesses).
So is the problem that it's just an "inherently fragile" turbo? (as the detractors would like you to believe). I don't think so.
At one extreme. we have one customer in WI running this turbo at 45 psi with nitrous running 12 sec 1/4 miles in his Mk4 ALH. Not an exaggeration. (Not my recommendation, either) And when he's not at the track with slicks, he drives it every day AFAIK, for nearly a year now. The salesman who sold him this turbo has one in his own car and beats on it regularly. It works so well in our experience for many ALH/BEW applications that it will remain our "go-to" turbo in many cases. There are well over a hundred of them sold this year alone, so why is this one "not so lucky?" I would sure like to know for certain. We have a credible evaluation from an experienced expert that says this is not a manufacturing defect, so it's not a warranty issue as far as we are concerned.
It's not fair to us to be expected to just eat it, especially without any questions asked at all. At the tight margins these things get we aren't going to just keep throwing free turbos at it until someone figures out what's wrong with the car. We already offered various options that did not include a completely free new turbo. We came up with so more that included free tunes and so forth (with contingencies to help fix the car) but did not have a chance to present them before the latest damning post. Hope it gets sorted, but we are pretty much done with this one at this point.
