EMC2

I had the SW Bypass on my 997.2 PDK 3.6l - No vibration issues at all.

Scott997

i had shark werks muffler bypass on 3 997s never any vibration. PDK and manual.

StormRune

I was originally reporting problems due to vibration, but as nwGTS suggests I ended up going back under, loosening everything that was movable, then reworking the adjustable connections trying to make sure everything was routed as well as possible.

The only real adjustable parts are how the straps connect to the bypass pipes to the carrier, the slip joints, and the tailpipes themselves. I did notice that previously the tailpipes weren't quite in the same position on both sides, now they look to be in the same place on both sides now.

No vibrations for a year now on my PDK.

Mumbles

I had to return sharkworks bypass due to vibration. 09 c2s .

I think the vibration came from the the flow from the exhaust addition, free flowing ?

Astur

Given that English with its nuances and intricacies are not my primary language, I'm not sure I understand your comment. Can you please elaborate?

upier

Think of your exhaust system like the pipes in a pipe organ. As you change the effective length you change the frequency of the sound waves. This change in frequency causes the system to vibrate differently and you hit new harmonics causing possible new rattles.

Astur

Ahhhh, makes perfect sense. Thank you!

jimjoe997

I installed the bypass in 2011. It did vibrate noticeably, but I am virtually certain it was due to over tightening during installation. I then had the PSE installed also, and it solved the problem. I assumed that the PSE install required removal or adjustment of the SW bypass, and the end result of the two installations is minimal vibration and great sound.

CT944

Most vibration issues are due to over tightening the exhaust. Just snug them and you should not have any noticeable vibration.

Astur

OK. So based on my prior comment about language, can "snug" be qualified as tighten vigorously and then back it off 1/2, 1/4 or 1/8 turns? Given something to that effect, won't the vibration eventually loosen the bolts so that they have to be re-tightened?

Mumbles

To install the bypass you have to remove the center muffler. I may be wrong but by removing the muffler and adding free flowing bypass with no restrictions I think the exhaust fumes exit at a quicker rate thus causing vibration. With the quicker flow comes the added power of 10 hp ?

When I reinstalled the center muffler back to OEM the vibration goes away.

RobC4sX51

I had the SW CM bypass installed on my previous 911 (2010 C2s Pdk) and it then had the "vibration". Per Sharky and Dan, the EVOMSit tune which did raise the idle about 50-60 rpm smoothed it out perfectly. I later installed an IPD plenum and that car was sweet. Faster than a 991S 0-60 & 70-100! I recommend these mods and talk to Alex or Dan @ Sharkwerks.

Crester

So my current understanding is that it's not just Sharkwerks but any of the bypass pipes made that cause PDK cars to vibrate. Interesting to see that raising the idle or loosening the bypass pipe connections can make the vibration disappear.

But I still haven't gotten an answer an to what is causing these bypass pipes to make the car shake?

ltcjmramos

See Upier's post #21 above.

Crester

I see that post... but why would it happen to only PDK cars? If what he said was the case... wouldn't it happen on all cars?