Vid of noise. Pitch is lower in cabin that recorded (probably poor low end mic roll off). Imagine it with a lower pitch and quieter and that's what it's like.
Bit of ambient hiss as gain was turned up to record it with decent volume.
Hmm. Found a link on Vortex - seems like people have had issues with the HPA SHS. Perhaps those on Vortex are a bit dramatic but it does show that the shocks are not infallible.
http://forums.vwvortex.com/showthread.php?4807583-HPA-SHS-Clunk-Noise-Issue-Ongoing
Vid of noise. Pitch is lower in cabin that recorded (probably poor low end mic roll off). Imagine it with a lower pitch and quieter and that's what it's like.
Bit of ambient hiss as gain was turned up to record it with decent volume.
To our HPA/SHS customers,
We wish to report back on the various questions posed both here in the public forum and directly to our team. After a detailed review from a small handful of SHS owners, and the posts in this thread, our group has investigated and identified two potential happenings in reference to noises encountered with the MK5 SHS application
CLUNKING NOISE
Diagnosing any suspension noise is a challenge as there are so many elements at play. The natural wear tendency of control arm bushings, upper strut steering bearings, etc all can result in clunking-like noises.
Furthermore, it has come to our attention that the ride height being set by installers with our SHS applications may be incorrect. The threaded housings optically offer a broad adjustment range which cannot be supported by either the spring or the damper. Each application has a specific window in which the spring seat can be positioned, and going higher or lower will cause the spring bind and the dampers to bottom in either their rebound stroke or compression stroke.
Clunking in reverse would indicate that the damper might be over extended and striking an internal rebound limiter under throttle input. In addition, if the spring seat is too high, the dust boot will have no path to travel and will strike the housing and become damaged.
By mid next week, we will circulate to our existing SHS owners a more detailed instruction on how to capture the ride height range to be sure that the car is not too low or too high.
WHOOSHING NOISE
A key advantage to the SHS and KW offerings is that each damper is 100% dyno tested and serialized. This is a major benefit when situations such as this arise as we can look over statistics and identify production batches etc.
In this case, the serialized dampers allowed us to quickly identify an isolated production batch where the occasional front damper generated a whooshing noise of sorts. The KW factory identified the raw material batch involved and test results realized this week confirm there to have been a defect on the surface of some of the piston rods; creating a frictional harmonic resulting in the whoosh noise.
A small number of SHS dampers fall under this production batch and those will be handled through a damper exchange program we are coordinating with the KW factory in Germany.
* * * * * * * * * * * * * *
Nik and team will update our website mid next week with the lowering ranges specific to the MK5 based platforms and issue clear instructions on how to verify you are within the accepted min and max. We are confident this should address the majority of any clunk complaints. For the few that had the whoosh report, your serial # has been used to identify the concern and Nik will follow up accordingly to insure that your dampers are exchanged.
Thank you for the support while we dug through this concern. As with any thread, one noise complaint opens up multiple levels of interpretation. From our side, we need to take each individual case and review the possibilities. I am happy with the findings of the team as we now have a clear action plan to carry out over the next two weeks.
Kind regards,
- Marcel Horn
Nik Brkich
T: 604-598-8520 x103 E: sales@hpamotorsport.com
HPA Motorsports
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Eugene - don't forget that erWin specifies a +/-10mm tolerance from Factory. So, if your ride height wasn't actually measured BEFORE fitting of the HPA kit there's no guarantee you're within HPA's specification for max/min travel on the shocks.
That might have been luck, it might also have been that my installers made a point of measuring the height to match exactly the drop i asked them to do - 10mm from "OEM" as measured.
HPA Dirtections said:*The remaining thread measurement is approximate and only intended as a general guide. Actual results may vary due to various axle weights.