991Chris

I just got the FabSpeed Center Muffler Bypass X-Pipe installed on my 3.4 Carrera and I've been driving round with them for 2 days already and I notice that when I'm park at a light (W/Sport Off) the cars starts to shake like the seats start to shake and you can feel it pretty good, that's around 500-600 RPMs. Then when its in sport the RPMs go to 700-800 when idling and it goes away. Just want to know if this is normal or should I get it checked out for a leak or something i don't like that little shaking. I'm usually in sport mode or PDK but occasionally I do ride in normal when I'm in traffic.

991Chris

991Chris

No one has anything to say?

Justin N

I had a different brand x pipe installed on my C2 and had the same issue with a low rpm rough idle. I don't have a solid answer as to why but some suspect it has something to do with reduced backpressure on the low end.

I returned the xpipe and got an almost brand exhaust take off from a C2S. for half the price of the x pipe. sounds great, looks great and no idle issues. S

dhud

I had an X-pipe on my 997 C4S and got vibrations at idle. I crawled underneath, loosened all bolts, and went as far as taking a feeler gauge to make sure there was no contact with any other components. I did think an exhaust pipe and the X-pipe were mighty close and possibly touching. Once I was convinced with adjustment nothing was touching, I tightened up all bolts again. The vibration was gone. Hope that helps.

991Chris

Yeah i was think of changing the stock filters to see if that helps. maybe it will go away with some extra air intake. Or if i can find a c2s but haven't had any luck with lol

satoru

Don't think filters would have anything to do with the vibes, if it was there after x-pipe install then it might be the pipe. I have an x-pipe from another company and have heard of others that have the vibe from that particular brand but on my 3.4, no vibe on mine

991Chris

Its I'm guessing it's because of the back pressure I'm going to have it checked it anyway. What Xpipe did you get?

satoru

Sharkwerks. Heard of some with vibrations but I guess I got a good one. I noticed that on your install they have a couple of band clamps installed. What is the extra piece between the x-pipe and oem mount that the clamps are attached to? Maybe that might be your problem. Mine does not have any clamps that attach to engine side.

RobC4sX51

Chris, I had a SharkWerks center muffler delete (similar to an X pipe) on my 997.2. SWs said that w PDK some cars would experience a "vibration" while stopped (brake on and in gear), which I did have after install. The remedy (and they had approved and tested it) was an ECU mod from Evomsit. One of the things it did was raise the idle rpm about 60-80 (650 to 710-730). It fixed the problem.

I now have a SharkWerks side muffler delete (aka Race exhaust) on my 9914S w PDK. No vibration issue but when backing up my driveway I do notice a small "harmonic" echo under the car. Not bad, just different. Hope this helps.

991Chris

Those Clamps are on a plate that the OEM contemplate was attached to they where in the box i figured they where for that. I put them on there because there was a little gap between the plate and the pipe so it wouldn't make a rattling noise. It only when its not on Sport I haven't had a chance to check it out i have to change my oil in 4k miles so il probably just wait for that .

whiteflashe90

I have the same set up and have been running it for about a month. I have the vibrations initially, then tightened the band clamps which seemed to do the trick. It's got a better sound outside the car, and slightly better inside. I had the side muffler deletes on for a day, the sound was amazing, however, the drone and volume was completely unbearable. Interested in what you think as I'm considering other options, which include Fabspeed side mufflers.

Thoughts anyone?

Olcha911

I have a complete Fabspeed Exhaust on my 3.4 Carrera- Headers w/cats, X-pipe, and Sport Mufflers. Sounds great, no vibration, no drone. Careful installation helps.

Maxhouse97

I have the same problem as RobC4SX51. I think it has to do with idle speed. When my engine is cold, after the fabspeed x-pipe was installed, my car idles at 640 rpm. This then causes the vibration. When the car is warm, idle raises closer to 800 rpm, and the vibration goes away.

So again I think it's not related to clamps or mounting. Lower back pressure and ecu tuning seems to make sense. Either that or the stock ECU adjusting for it eventually.

Code

This seems to be a common occurrence for a good amount of folks running X-pipes. Some resolved/reduced it by re-torquing all the bolts, including myself.