u can either see or feel grooves on ur discs, the discs r supposed to be flat on the surface. if there r "channels" on it, dat is one kinda warp. basically, discs warp is uneven surface on the disc
FYI, maximum breaking can be obtained if maximum contact between pads and discs occurs. dis doesnt mean dat if the disc seems warp, dat it doesnt bite. as long as the pads fills in every gap / channel on the discs, den u r supposed to get good grip. the thing wit warped disc is, when u change to new pads witout skimming the discs first (means, new pads coupled wit uneven disc surface, which will decrease the contact area between those two items). den, u'll have to wait for d pads to bed in wit the discs and dis may take a while to happen, usually days of driving ur car. u get me bro?
but, wit performance brake pads, such as ferodo and bendix, since they r made outta soft (softer, comparison made between oem and mentioned aftermarket pads) compound, they usually bites faster even when coupled wit a warp / worn discs. they generally worn out faster den oem pads, but consider dis.. it may take years for them to wear out. for me, dats worth all the trouble and sultans spent, as iam not gonna compromise on safety. cheers!!:cyclops: