I won a pair of these in a raffle years ago and drove around with them for a couple of weeks. Ultimately I didn't like the added vibration and sold them.

I decided to give them another try, now that the rest of my drive line is poly. You can feel every little movement of the motor when you cold start it, but the really objectionable vibration for me was reving the motor or letting off the gas after reving. you can feel the revs coming down. I thought what I was feeling was an out of balance flywheel/clutch, but I'm pretty sure it's actually the cats that cause the vibration.

Reading taco bill's write up, he mentions his friends car with cats had much more vibration. I'm thinking it's time for an off road H or X pipe.

I didn't get a video of a cold start, the whole car twists on a cold start.

http://www.youtube.com/watch?v=vdIB2...ature=youtu.be

 

Even without cats, the prothanes added more noticeable NVH than any other mod I've done.

 

i am very happy with the prothanes, never plan on going back to stock mounts. the off road H is gonna be loud.

 

I installed the prothane mounts when I did the v8 swap, I developed an exhaust leak recently and finally decided to tackle that replacement. All I can say is I'm glad it happened the bottom bushing/aluminum bracket and allen screw backed themselves out and fell down into the crossmember. So I have no clue how long that has been like that however I'm glad I did before I strap the DOB blower on this.

 

Just wait till you get that solid axle housing bushing in!

I found an old post of mine about the prothane motor mounts.

It's very strange, accelerating hard I don't notice much difference in vibration, but just revving the motor there is a noticeable vibration at low rpms that I can feel in the seat. I'm keeping them in this time, because this car is going to become my track toy. I'm looking at new 5.0's for my daily driver.

A/C delete will be next on my list, followed by some skinnies for the front. I literally never use my AC. It helps that I work in a refrigerated room and I'm skinny, so don't sweat much.

 

I have the poly mounts, does not bother me but I do feel more of whats going on. If your going to add H or X pipe and ditch the cats, I see your running a SC, I would think you are going to need a new tune too.

 

If I do it, I'll get the pipe from brenspeed and have them email me a new tune.

 

I have seen many people do this. Never gave it much thought, does the X or H pipe come with the needed OS2 sensor bongs welded on? I know the passenger side needs two. On my 08 one is in the cat and the down stream one is after the cat.

 

I'm pretty sure they all have bungs. My rear o2's are turned off and I run a lc1 wideband in the drivers side rear o2 location, after the cat.

 

I need to get me a set of those, that motor isn't flexing at all!