Has anyone experienced this?

2.5 sti spec d, mods are full decat 3" revo exhaust, walbro, no 7 plugs, simota panel filter and re-map 1500k ago

When going up hill on full throttle in 5th or 6th and on boost I experience vibration through the car (seams to come through the floor low down as if the engine is labouring in to a high gear) as the revs go past through around 3000 revs and then go's as the revs rise.

Has not happened before with car as standard or previous mods with ppp exhaust and re-map

Any ideas as to what is happening

 

Should have mentioned going up a moderate incline not a steep hill

 

mine did the same on 3000 rpm but everygear and was the clutch. was a 3 paddle on its last legs.

 

+1 to that statement!