MBC Racing

iTrader: (3)

I would like to buy some new rotors for my 00 M6 Z28. I can't go bigger in the front since my Front runners won't fit anymore if I did. I like the look of the cross drilled, but have heard the horror stories of cracked rotors. I will probably spend more time roadracing and autocrossing than at the drag strip this year. Should I get slotted? Crossdrilled? Combo of both ($$$$)?

I also need to get some stainless lines. Which are the best?

Thanks.

Judd

iTrader: (1)

Lou G. is getting ready to offer some bigger rotors that I think still fits inside the stock calipers. I think this is right, someone correct me if I'm wrong. From what I've read don't get the drilled or slotted replacements. These rotors need more mass, was thinking about KVR blanks untill I heard about Lou's.

Silver99Z

A rotor larger in diameter wouldn't fit into the stock caliper unless the caliper was repositioned outward with a different bracket, and a thicker rotor wouldn't fit betwen the pads.

Just buy a good quality, plain blank rotor. Before you install it, get on Baer's website http://www.baer.com and print out their instructions for seasoning rotors. New rotors are "green" and must be brought up to temp gradually and let cool properly so they season. I've worn out three sets of front rotors on track, but never had one crack or warp.
Instructions are under FAQ

[ January 20, 2002: Message edited by: Silver99Z ]</p>

99HOSS

you can try out the GMPP front rotors, they've lasted two seasons on my SS (~ 10 sessions) with some left. They are not drilled or slotted, and it's not really needed (IMHO) for the occassional romp at the track.

And the seasoning of rotors and bedding of pads are a very important step in the longevity of these items. Here's another LINK on the subject.

[ January 21, 2002: Message edited by: 99HOSS ]</p>

Silver99Z

On the subject of rotors, I'll put this up FWIW:

There are two kinds of rotor "warp".

1 - This is like when a wooden board warps. An unseasoned rotor is subjected to premature excessive heat and the casting actually warps or changes shape.

2 - There is "warp" caused by lateral runout. Here the rotor doesn't spin true, but wobbles from side to side. As the rotor spins, the shoes, always in contact with it, wear the rotor unevenly. Finally, It gets to the point where when the brakes are applied, the shoes sort of bounce across the uneven rotor surface causing vibration or pulsation.

Lateral runout can be caused by the rotor being untrue or it can originate at the hub. If the hub is at fault it should be replaced. To check for lateral runout a dial indicator is used. I bought mine from http://www.ontool.com for about $150. They come with either a magnetic base or with a vice grip which provides a more secure anchoring point.

As an example: Last year I installed a Baer Pro four piston caliper kit. Although there was no noticable hub play, I figured I'd replace them as they'd seen considerable abuse on the roadcourse. I clamped the new hubs to the top of my table saw and clamped the dial indicator there too. With the indicator's needle on the edge of the hub, I slowly turned it to check for runout. On both hubs, runout was barely recordable on the indicator.

I then installed the hubs and clamped the indicator to the upper arms and again checked runout which did not increase.

I installed the new Baer passenger side rotor and checked it's runout which was less than .001".

When I installed the driver's side rotor, I found runout to be .003". Since there are five lugs, there are five positions for the rotor. By moving the rotor (indexing it) two positions, I was able to get runout of just under .001".

I check for runout periodically because as they say, an ounce of prevention is worth a pound of cure and rotors are expensive.