You shouldn't be getting any whining, but a low reading might be as Lee says, incorrect dyno process.
I've had mine at a certain reputable Essex VAG tuner (on a dyno day), and they didn't have a clue what to do with it. Firstly they couldn't work out dyno mode, then eventually when they got a good run my car was spinning up on the rollers and was trying to climb free.
My dyno graph looked like the graph on an ECG monitor, during a 98yr old girl having both an orgasm and heart attack at the same time.
Took it again to a more RWD/high performance friendly garage locally to me and seemed happy at 520hp, otherwise stock car.
Fuel can also have a lot to do with it. Are you on Super? Hopefully, but even so I've had a crap batch of Shell V-Power before which made the car feel very sluggish. I flushed it through with Momemtum 99 and it was a beast once more.