What Causes Sharkwerks Bypass Vibration?
#31
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Rennlist Member
Probably the difference in interaction between an automatic (yes, I consider the PDK an automatic) and a manual transmission, automatic stays engaged, manual goes to neutral or is disengaged by depressing the clutch. Relates to the raised idle resolution.
#33
I have Sharkwerks x pipe bypass on C4S 2009 with PDK and PSE.
No vibration after installation. 12 months and 5000 miles later I hear vibration at idling and Drive position. For my ears it's an annoyance. Slightly lower vibration in Neutral. With few revs up no vibration. The x-pipes and the PSE dual outlet pipes have little space in between. May be 2-3 millimeters top. I suspect the adjustment moved or bolts not at the right torque settings or fixtures to be tighten... Thanks for sharing your experiences by the way.
No vibration after installation. 12 months and 5000 miles later I hear vibration at idling and Drive position. For my ears it's an annoyance. Slightly lower vibration in Neutral. With few revs up no vibration. The x-pipes and the PSE dual outlet pipes have little space in between. May be 2-3 millimeters top. I suspect the adjustment moved or bolts not at the right torque settings or fixtures to be tighten... Thanks for sharing your experiences by the way.
#34
I believe the PDK, since it doesn't have a torque converter, is declutched at a stop, same as a manual transmission. Otherwise engine would stall, same as a manual transmission.
#36
Got feedback from Sharkwerks. As a result I re-adjusted the 2 clamps. Other bolts are just rust-welded... Et voila nasty noise at idling is gone. I'll watch again after un-
mounting side mufflers for spark plugs exchange.
mounting side mufflers for spark plugs exchange.
#37
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Interestingly, a second or two after releasing the brakes, I hear a low volume "toot," repeatable. If anyone else tries this, lmk if you get this noise.
#38
Rennlist Member
Not so. Hadn't paid any attention to this, so, yesterday when stopped, I let off the brake. A very definite move forward was made. I believe the 991 PDK allows for moving to neutral by pulling (or pushing) both paddles.
Interestingly, a second or two after releasing the brakes, I hear a low volume "toot," repeatable. If anyone else tries this, lmk if you get this noise.
Interestingly, a second or two after releasing the brakes, I hear a low volume "toot," repeatable. If anyone else tries this, lmk if you get this noise.
A possibly interesting aside: When I recently test-drove a Tesla Model S the salesman pointed out that the car was set up by default to engage slightly and roll forward as soon as the brake was disengaged. He said that apparently most drivers found this to be the most natural behavior. In the Tesla case we could defeat this in the setup menu and the car would stay put. It causes me to wonder if Porsche is doing something similar except that there is no option to defeat it in the 997 PDKs.
#39
Seems like a fine line between not declutching and stalling at a stop. I do like the neutral option in the 991 by pulling both paddles. I tried this with mine (preparation for spinning) but no luck in the 997 I guess. Just have to keep the windshield to the front!
I've never heard a toot, but that seems like a good trick.
I've never heard a toot, but that seems like a good trick.
#40
Not so. Hadn't paid any attention to this, so, yesterday when stopped, I let off the brake. A very definite move forward was made. I believe the 991 PDK allows for moving to neutral by pulling (or pushing) both paddles.
Interestingly, a second or two after releasing the brakes, I hear a low volume "toot," repeatable. If anyone else tries this, lmk if you get this noise.
Interestingly, a second or two after releasing the brakes, I hear a low volume "toot," repeatable. If anyone else tries this, lmk if you get this noise.
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rafamrqs (12-01-2023)
#41
Further to this, the revs and motor sound stay the same with foot on brake in D at a stop or if you put it in N. I think there is a partial engagement as soon as you release the brake. If you are uphill, the hill holder is on. You can release the brake and the motor bogs a bit until you offer some gas.
#42
I have Cargraphic Super Sound side mufflers with a Sharkwerks bypass on a 2010 C2S. I noticed the vibration with the side mufflers changed when I still had the stock center muffler. The addition of the bypass didn't change the vibration for better or worse. Overall I wouldn't consider it an issue and wouldn't describe it as a vibration as much as a slight resonance. I feel like the frequencies of both exhausts align because of the deeper note and cause a bit of drone which is gone once the car is moving/RPMs raised. Personally I'd take slight resonance/vibration at idle over cruising speed any day. The overall sound of the bypass increases my enjoyment of the car so much that I wouldn't even consider driving without it regardless of the idle resonance. It is a must buy for the vehicle.
#43
Respectfully, I believe the transmission is programmed to mimic the torque converter creep of a manual and engages the clutch slightly when you take your foot off the brake to allow the car to creep forward and imitate the behavior that we are all so familiar with...