shaking under acceleration - need help. s1 rb25det

[Rb.250sx]

My car started to shake and rumble whenever I step on the gas. I took the car out today and it drove great all day long prior to this problem, The shaking is very noticeable when I'm on the gas, but the problem seems to go away when I don't put it in gear/let it idle. I've recently changed my sparkplugs and gapped them so I'm sure it's not that. I'm sure or hope it's something simple, but need to narrow it down before I take a look at it tomorrow. If anyone has any sugguestions or know what it might be, let me know.

s13 s1 rb25det stock turbo running at 11psirecirculated stock bovfmicwalbro fuel pump3"inch downpipe + 3" exhaust

Oh also, sound SEEMS like it was coming from the rear near the muffler.

[Shocker]

id bet its the shear pins on your driveshaft that connect to your diff.. most likely loose. If not transmission mounts... motor mounts... check that stuff...

[Chaos the Xile]

i'm gonna have to say drivshaft tooo I had the same issue

[Darius]

Try your lug nuts too because mine loosened up after taking a couple of corners sideways and made a weird rumbling noise that didn't sound like it would be coming from the lugs.

If you think the noise and jerking is engine-related, I'd first check out your MAF connections and then check for boost leaks.