Xdrive problem? staggered set up

[Mperformanc3]

I recently upgraded to a 2012 2.0i Xdrive Msport in Le Mans blue and I love every bit of it. Coming from the 2010 1.8i sdrive with some luxury options like panoramic roof, heated seats, the Msport is just amazing.

The Problem:
When accelerating from a dead stop on a straight path, she stater just before shifting into the second gear. It feels like hitting the brakes 3 - 4 times or going on a consecutive small speed bumps. Sometimes you can feel it sometimes not. I also noticed when I'm turning either left or right from a dead stop, the issue is not there.

19" Stance SC5 Concave Wheels (on car)
19x8.5F - 235/35/19
19x9.5R - 265/30/19
I believe this is 1% off? However, someone is running with this set up without issues.

Stock wheels M double spoke 355
18x8F - 225/45/19 (new)
18x9r - 255/40/19 (2mm left)
the issue is very minimal to none. is this because of the 2 new tyres?

I've read that the overall diameter from the stock must not exceed 1%. What are the tyres spec you are currently running for your x drive and not having any issues.

Any inputs will be greatly appreciated.

[GameWatcher]

That's almost exactly why I came to these forums. I have 2011 sDrive 18d and I get pretty noticeable vibrations/shaking on start. So 1st gear while just accelerating off from dead stop. Happens every few times. First car that did that...

[Spectralus]

Im running 245/35 + 295/30 R19 with 0.8% tire diameter difference which is same difference like your R19 setup. No problems here.