[s-cars] Stromung in the rain

[Postupack, Jeff]

Hi:

I waited for most of the posts to review this morning. I also have
experienced the increased noise (vibration) and the louder turbo sounds
while driving the Stromung Gen #4 in the rain.

My current theory is the center pipe contacts the cross member located
midpoint of the C4 chassis. By visual inspection you can see even a
cooled pipe is pretty close as it threads thru the space. (Look under
the passenger seat area).

 I think the system expands when hot and contracts with a water splash
makes contact Stromung owner told me stainless has a high coefficient of
expansion.  I  think the contacting pipe causes the louder noise because
the exhaust is now modulating the chassis member to some degree. Simply
vibrating or buzzing away.

My solution to this is to add fender washers between the chassis and the
cross member to add clearance. 4 bolt location, so double up the washers
2 per location.

I have know idea why the turbo spool sounds louder, as Chad Clark
explained earlier.  Traveling this weekend prevents a test.. But I'll
welcome any ideas on this topic.

Jeff