Vibration under acceleration

[needforspeed6]

I am getting vibration in the front floor of the car (by my feet) after shifting into second gear and under medium throttle between 3k to 4k rpms. I just replaced my rear motor mount and I still have the vibration, just not as bad as it was. Any ideas where the vibration is coming from? Could it be that my tires are out of balance or that I need an alignment? Any help would be appreciated. Thanks!

 

[MATX]

could be the tranny mount its on that side

 

[needforspeed6]

Good idea, but passenger says they can feel it too

 

[Pipatec]

I have the same problem, I was feel it like it begins in the back of the car so I have the SURE dreadnaught installed and I will buy the Juggernaught because my cousin notice that when the car accelerate the rear tires gets a noticeable negative camber and the rear diff. gets low. So I guess that the stock part is damaged. Put someone else to drive the car on a hill and you get outside to watch the rear to see if that is your problem.

 

[Mistersix]

Pop your hood and get in the car. Fire it up. Engage your e-brake very strong. Look beneath the hood and the cowl and you'll be able to see the engine from the drivers seat. Put it in first and partially engage the engine in order to get it to move. You'll be able to see if there's a lot of movement and what direction by doing this. If your getting a lot of movement, it could be another mount.

There's nothing scientific about this. Just a guess on my part.