Wierd... Sounds Like turbo!!

[svxjoe]

When I accelerate real hard (pedal to floor) the car takes off like usual..... but if I let off (all the way) after about 2 seconds of hard acceleration the car will make a quick *whisp* slipping sound. There's no lunging or un-smooth shifting.... it just makes this wierd noise.... kinda like a turbo's blow-off valve, but more like something is slipping with no physical feeling. AND, it does not do this in between gears.

Does anyone have any idea what this could be?

Or maybe somebody has secretly installed a turbo on my SVX!?!?