why my car wont rev past 5.5

[leet5r]

does any 1 have any ideas why my car will not rev past 5.5 . i have done a complete stage 1 and had the head gasket and all the belts done , it pissing me rite off cos am after some cams , which will be no good if the car will not rev to the cams limit

[Dangerous Dave]

Mightywolf had a similar problem recently

http://www.vpcuk.org/forums/showthread.php?t=26483

Though his was the wastegate, it still could be any number of things, but its worth checking it.