Slotted & drilled rotors - worth it?

[ntsqd]

Modern pad formulas actually transfer an invisible layer to the rotor surface. I'm guessing Goodtimes & a few others know this, but I don't think that it's common knowledge.

I think whether you'd have trouble or not would depend on how similar the two compounds are. You wouldn't need to re-bed them at every swap, but there may be a delay while the new transfer layer is happening and potentially frequent changes could result in an uneven build-up (see Stoptech's page on "The Warped Rotor Myth").

 

[R_Lefebvre]

Just curious, do you have any problems switching between pads for track days, other than needing to bed them in each time? I have heard some people claim they have problems if they don't turn the rotors (resurface them) when they change...and others say they have no problems. I don't spend time on the track, so I don't change pads until they are worn out.

Not really.

Seems worse when I go from the Q to the E than it is going the other way. When I start a trackday, I tend to have some shudder at first, but it goes away shortly after the first time they get hot. When I put the Q back on, IIRC, they don't grab the best at first, but that also goes away.

In any case, it hasn't been a big enough deal that I really even notice. I haven't noticed any long term effect. Any time I get shudder, on any car, I just go out and get the brakes hot and that always straightens things out. In fact I had a 2006 Focus with all factory brakes that got "warped rotor syndrome" But after towing a utility trailer with a dirtbike on it for a while, the problem goes away. Just goes to show...