Weird Problem... 110km/h

[Digital360]

I went to see a 1991 Talon today, very clean and nice, its Automatic AWD Turbo. I take it on the HWY and as soon as I reach 110km/h (~70mph) the car feels like its bouncing off the rev limiter and wont go any faster. I am not saying its hitting the rev limiter (its still at like 3-4K) but the feeling is as if its a rev limiter, any ideas

Edit: the car only has 103,000km (~66,000miles)

Also the dealership where the car is, well the employees I think had no idea what car they took as a trade in last week. He has no idea about the problem, when he opened the trunk to put the X-Plate there was a subwoffer and hes was like "What the hell is this thing" The sub setup Bazooka style sub looked like it belonged (stock) did they ever come equipped with this?

 

[Digital360]

I just got a call from the dealer, Chrysler found the problem, its was a broken vavle. Because the valve was broken, it was sending to much boost to the engine