For those with test pipes/catless exhaust..

[MikeE92M3]

I noticed something interesting yesterday. I had my Turner Test pipes installed at my muffler shop that I have gone to for years for work done on my cars. The test pipes installed without a hitch, the cuts were made in the correct spots, etc, and clamped on tightly with an impact wrench.

We checked for clearance and nothing was touching anything, the heatshield was reinstalled the way it was, and all the bolts were screwed back in, as well.


However, I notice when I give it some "load" or heavy throttle (flooring it, giving it gas while making a turn) I feel like an "acoustic" vibration in the gas pedal? Has anyone else on this forum noticed something like that? It is only when the car is given a moderate to full amount of throttle. Is this because of the increase/loudness of the flow of exhaust gases in that area under the footwell/pedals where the test pipes were installed? Just wanted to see your thoughts before I freak out too much and bring it back in to have them double check it.

Mind you, I was under the car the entire time while the guy did it (good friends of my family), and EVERYTHING was bolted in tightly (header bolts, clamps).

Is this something I have to worry about it or should I let it "break in" a bit more?


Oh, but the extra power is AWESOME, too!!!

[MikeE92M3]

No input from anybody?

[p-streets]

I have a catless xpipe and I to feel it I have a buddy with same set up says he has that also i noticed about a day or two after install so I just figured it was normal he had it also he has diffrent xpipe and exhaust also not same exact set up as me

[paradocs98]

Not sure about a vibration right under the floor, but I do notice on cold start (left it intact with the software) that my rear parcel shelf/rear glass rattles for a minute or so now that I have the Dinan midpipe.

[MikeE92M3]

Originally Posted by p-streets

I have a catless xpipe and I to feel it I have a buddy with same set up says he has that also i noticed about a day or two after install so I just figured it was normal he had it also he has diffrent xpipe and exhaust also not same exact set up as me

That's good to know. I had a good friend of mine come over tonight and we put the car on ramps and listened under the car. There was definitely no leak coming from the connections between the headers and the test pipes. There was no leak from the clamps either, however, we noticed a small leak coming from the new resonators I put on in the location where the secondary cats were. We used some 2000 degree exhaust putty on the location we felt it coming from and will let the car sit overnight for it to cure.


We also noticed one of the 02 sensors looked like it was touching the heatshield, possibly increased when the car is under load, so we bent in the section of the heatshield to make sure it cleared the area. After further driving, I think it's safe to say it's just the "extra" air blowing into the pipes and the overall harmonics just being louder in the footwell area from the restrictions being gone. My friend said he is certain that's just from the nature of the test pipes (he's an engineering/mechanical engineering student) and that's just how it is. He said it sounded awesome, too

[MikeE92M3]

Originally Posted by paradocs98

Not sure about a vibration right under the floor, but I do notice on cold start (left it intact with the software) that my rear parcel shelf/rear glass rattles for a minute or so now that I have the Dinan midpipe.

Yeah, I too noticed that my "whole" car seems to rumble a lot more, especially when it is started cold. When it is warmed up and idling, I can't tell a difference from when it still had the cats on.

[paradocs98]

Originally Posted by MikeE92M3

Yeah, I too noticed that my "whole" car seems to rumble a lot more, especially when it is started cold. When it is warmed up and idling, I can't tell a difference from when it still had the cats on.

That's the great thing about it--not significantly louder at idle or light throttle when warm, but when you start opening those throttles, Yowza!

[Munit]

Ya I had that too despite thinking everything was good and clear underneath. I ended up finding that the O2 sensors were actually touching part of the heat shield underneath and a couple places of the heat shield were really close to the pipe. I used a rubber mallet to bend the heat shield and give more clearence in any close areas and made sure each O2 sensor and attached wiring were not brushing on metal.

Don't think this is a problem with test pipes but with a full x-pipe the black cross member brace was also vibrating and had to slightly modify that with a couple washers to give a bit more clearence.

But go under and pound the heat shield to give more room everywhere. Once you have it correct there is NO vibration.

The vibration really took the fun out of hte mod for me. It was super annoying and felt like crap whereas now without it I love the mod.

[M3amigos]

I had a similar experience on my previous car after I removed the cats, I had a metallic rattling sound/vibration at low rpm, but I couldn't find any leaks or loose shields, see video below. It actually went away after a little while, I think it could be just the resonance/harmonics of the new piping close to the engine, mine seemed to go away after a few months after breaking it in.

[Munit]

its not going to go away by itself. Its metal on metal vibration. You need to get under and give more clearence in the tight spots. keep in mind at 8400 rpms the movement in the piping is pretty significant and what looks like enough clearence at rest, is probably not enough at high rpm runs

[MikeE92M3]

Fixed it. Turns out one of the clamps looked a little too close to the heatshield and it was decided that it would definitely come into contact under load or heavy turns. I ended up pushing back the heatshield about a half an inch and theres no way it will touch it now!