Our man on the ground in Vegas was able to snap these today during setup for the show.
BorgWarner kp39 and some bv39 are prone to fail due to construction flaws.
On engines equipped with these turbos I wouldn't even consider a standard stage 1 tune.
If tuned they turn into a ticking time bomb, they are one of the most common failed units I get from customers in my workshop, and most of my customers drive completely stock cars, no tune or something like that.
Those turbos are made for quick spool, lightweight and therefore weak rotating assembly with super thin shaft, small bearings axial and radial, undersized in every point of view plus an fail constructed compressor wheel, weakened exactly at the point of highest load/centrifugal forces. ( see picture of JFettig, that's an typical failure - compressor wheel burst.. )
Tune them, use the extra power - wait for boooom. It's just a matter of time....
For some application there is even an OEM Garrett replacement available since the failing of the BorgWarner units is a well known and common issue.
yes i was bothered by that since i plann(ed) to get the cobb unit. if you dig a bit, you find that there are immediate replacements for that turbo for the vw folks that produced better tuning results and that are more robust. one had a slightly larger coldside. these were garret turbos. and they are direct replacements. which means that the same turbos can be adapted for use on the fiesta being of the same physical size as the stock turbo. it just takes market interest. this is what happened with subaru WRXs. popular tuner car so turbo aftermarket started making bolt on replacements that fit in the same location, bolt pattern and hookups as the stock turbo for existing turbos that were used on other cars.Well that's always nice to hear. :/
my experience with other cars is the aftermarket will take a turbo like above and machine it to fit. not garret. and im not sure what the difference is between incremental and significant. thats in the eyes of the beholder. i went from a car with 220 hp at the crank on a 2.0l to a one with 390 or therabouts at the crank on e85. this is what i what i describe as incremental. a similar upgrade to the fiesta st would exceed 300 at the crank. my guess is that around 250 many folks would be satisfied and i suspect that turbo above or something similar would produce such gains.That doesn't look like it will fit a Fiesta.
If you have to wait for Garret to tool up for a drop in replacement, it may be a long wait.
I haven't seen anything suggesting that Garret has or is planning on making something like that. On the other hand I wasn't looking specifically for that because I wouldn't want an incremental improvement from a replacement turbo, I would want a significant improvement.