[JDougM3]

Looking for some help here. My car is a Feb '15 build with about 1900 miles currently. I'm experiencing what I can best describe as a rapid pulsing or shaking sensation in the car around 60mph, most notably doing a 3rd gear pull around 4500rpm and a 4th gear pull around 3500 rpm. I never feel it in 1st or 2nd - presumably because I don't reach 60mph in those gears. The shaking can also be felt when maintaining 60(ish)mph in any gear, but it's much more pronounced under heavy acceleration. The obvious answer is tire balance but I eliminated that variable today through road force balancing all 4 corners. Granted, the left rear was out of spec but the issue still exists. I do have spacers and lowering springs but they have been on the car since the day 3 of ownership and this issue didn't begin until a few weeks ago. Also of interest is the problem is worsened when I activate my JB4 (Map 1). The pulsing sensation is still present in the same scenarios with the JB4 off (Map 0), but not as noticeable.

The tach doesn't drop when the pulsing occurs and the car pulls strong...but I have to think something isn't normal. I should also add this isn't the shaking sensation one gets when trying to accelerate in too high a gear as I've experienced that too. Anyhow, I wanted to solicit some feedback from you good folks before I removed the JB4 and made a service appointment.

Thanks in advance-