help! cobra has no power at WOT

[4.6mustang5.0]

I was just driving around downtown houston this last weekend and i had a new genesis pull up to me and he gave a little rev at me when he passed so i took the bate and followed him to I-10 so we could run them, there is no traffic so we slow down we go on 3 and i give him the initial hit and i took off, as my car gets around 4500 i hear a huge squeal and power pretty much stops i instantly get off of it.......so long story short, whenever my car is wot it squeals from one of the pulleys and power goes out the door, but when in neutral it revs past 4500 flawless, but when under a load it squeals


anyone ever had this happen? is it the tensioner pulley giving out?

any ideas before i take it to a shop and get bullshitted about whats wrong with it

 

[fastlane65]

belt slip

 

[4.6mustang5.0]

so new belt should fix it?

 

[Termi Mo]

Do you have an additional idler by the s/c. It will increase the belt wrap to prevent the slippage?

 

[fink46]

Sounds like belt slip I would check the belt for signs of slippage. Good indicators would be a glaze surface on the top of the belt and black dust around the snout of the supercharger. I had same problem before I got a snub idler.