Brake rotor questions

[Corbusa]

I didn't want to hijack xFires thread so I'm asking here. I looked on eBay just to see what is out there and I'm sure you get what you pay for . But just in general will the slotted rotors do a lot better job than stock ones?

I found sets starting at $135.00 and up...
I do know the extra piston and size of the zo6 should make a huge difference , but as I slowly progress , I'm just curious if the factory size rotors being drilled and slotted will be worth the efforts?

[Paul Workman]

I've a friend that drives the road course circuit, and I asked him pretty much the same thing. He showed me a couple stock, cast iron rotors off his car that were cracked, and blue/black from heat. His point was unless you go really big (read:really exotic and expensive) the cast iron is best sans drilled (especially) - slots OK, but not worth the cost, far as braking improvement goes.

From a bling point of view, cheap might be OK, long as you don't road course...is what I took from that. Road course abuse seems to be the dividing line, from what those that do say.

Twould be interesting to see what uther roadies have to recommend.

P.

[XfireZ51]

To do "cross drilled" rotors properly, the holes should be cast into the rotor and the holes chamfered as done by Porsche. Simply drilling rotors results in the cracking Paul points out. Also the drilling can weaken the rotor if the drill through the inner vanes.

[A26B]

For an entry level upgrade to brakes for the ZR-1, I suggest the following;


Rotors: about $400 for 4 wheel set http://www.powerslot.com/
PowerSlot rotors, you can choose from std to cryo treated. Slots offer de-gassing & cleaning benefits of the drilled rotors, but without the stress cracks prevelant in all but the most expensive rotors

I have owned them and never incurred any "hot warpage." Most other entry level, slotted or drilled rotors I've owned have ultimately developed rotor warp when used moderately. OK when cool but pulsating pedal when hot.

Brake Pads, abt $200 for 4 wheel set
Performance Friction: This a top shelf manufacturer. They make a variety of pad compounds and are used in professional motorsports. I recommend the carbon-metallic, Performance Friction-Z pads.

Link to Performance Friction
http://www.performancefriction.com/aftermarket/aftermarket-brake-pads.aspx

Link to O'Reilly's Auto Parts: Distributor
http://www.oreillyauto.com/site/c/detail/PFC2/041220/03351.oap?year=1991&make=Chevrolet&model=Corvette&vi=1041297&ck=Search_C0068_1041297_178&pt=C0068&ppt=C0009

Calipers, abt $300.00 (optional)
The first shortcoming of the stock calipers is the lack of heat dissipation. For drag racing or street driving, not a problem. The first level of upgrade would be to 96 Grand Sport calipers. Look good, and aluminum dissipates heat faster. My recommendation for entry level.

Brake Lines, abt $100
Switch to a good quality, braided stainless steel line, for firmer pedal. If yours are original, they are old and probably deteriorated.

Brake fluid, abt $8.00Valvoline Dot 3/4 Synthetic
http://www.napaonline.com/Catalog/CatalogItemDetail.aspx?R=VAR601458_0337002502

Switch to synthetic. Lots of tech data out there. Wet & dry boiling point is a principal factor for me. Valvoline meets the standard very well and is affordable & readily available. Pressure bleed/flush complete system with new fluid until clean.


This will get you in to a very good system for about $1,000.

For a 4 piston Brembo, aluminum hat rotor system, be prepared to spend $5,000 plus. Lots of good selection both below and above this level. I would venture to say that most brake upgrades are done for the bling factor rather than outdriving the stock system's capability.

[Corbusa]

Thanks Bro, Thats a load if info... When ever you guys write stuff like this up I print it out for future use, and put it in a folder.
I'll be talking to you soon.. :)

[Paul in SC]

I just added the GS Calipers, Powerslot Slotted rotors and Hawk HPS pads. I haven't pushed the envelope with them yet but they are a big improvement over what was on it before. Drilled originals (Baer) were cracking in several places; stock pads. The car had only 32,000 at the changed and I don't know how long it had this setup.

I am especially very pleased with the lack of dust from the Hawks. Helps protects the Fikses.

Overall, good first level improvement. Also went with the DRM bias spring...nice change as well.

I have a very good friend that drives SCCA pro and he goes with custom everything (Coleman Rotors). His recommendation and what most racers use is solid or slotted rotors. Drilled are a no-no.

Good luck and have fun. It's exciting to feel the difference when you make the move up...even better if you go for broke. Maybe next time.

Paul

[mike100]

http://www.summitracing.com/parts/EBC-USR7010/

I'm real happy with these EBC rotors (I have the C5 brake conversion). semi-slotted- EBC claims quieter operation over full slotted and it has proven to be much more heat tolerant over my previous chinese parts store rotor and ceramic pad combo. I'm using Hawk HPS semi-metallics this time around.

http://i29.photobucket.com/albums/c265/mschrameck/Cars/EBCrotors_sm.jpg

http://i29.photobucket.com/albums/c265/mschrameck/Cars/EBCdiscs_sm.jpg

[Corbusa]

Do they make or are these the same size as the original rotors? The set up looks great - price isnt bad, pretty close to the powerslots Jerry listed .. I would just want to get the best brakes I can without having to change rims, tires , bla bla bla.
where's the best place to get stainless lines?

[Corbusa]

After careful reading it seems the Powerslots are a Factory replacement ( answered my own question ) :) also cryo.

[Paul Workman]

This article is one I can attest to for accuracy by its applicaton to my brakes in several different cars/brake jobs now over several years (since this article came out).

A good read. Check out the article regarding warped rotors and other myths. I've never had a "warped rotor" since studying this article, and neither has my wife since coaching her on braking on especially hard stops.

http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths

P.

[A26B]

This article is one I can attest to for accuracy by its applicaton to my brakes in several different cars/brake jobs now over several years (since this article came out).

A good read. Check out the article regarding warped rotors and other myths. I've never had a "warped rotor" since studying this article, and neither has my wife since coaching her on braking on especially hard stops.

http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths

P.

Admittedly, I am not a brake expert and do not profess to be, but do have some questions about the article. Understandably, the author probably was never able to check the run-out of a hot rotor, i.e. one that was causing pedal pulsation just moments before.

I agree completely with his reference to hot spots and have no arguement with the causes. And, as he states, hot spots do occur for whatever reason. When uneven temperature (hot spots) occurs, thermal expansion/growth will be greater in the hotest areas, which will result in a change in thickness and waviness or irregularity in the flatness of the rotor. Depending on the metalurgy and a host of other characteristics I am unaware of, the irregularity may not be noticable when the rotor cools down, and can be inspected.

I know of no other reason that would cause brakes to work fine, with no pulsation in normal driving, but does occur & progresses as the brakes are used more agressivly, i.e. get hotter. The transference of material and the molecular alteration described in the article is well known, but does not go away when it cools down. If such "buildup is the cause of the pulsating pedal, then I would think it would still be present when much cooler under normal driving conditions.

So, for lack of my complete understanding of the subject or a better term, I call the phenomena "hot warpage," because I think that is what it is. BTW, I do break in according to instructions.

As always, I remain open minded and receptive to productive discussion.

[batchman]

I have a very good friend that drives SCCA pro and he goes with custom everything (Coleman Rotors).

I would love to figure out the recipe for Coleman rotors on stock c4 setup. Looking through their catalog once it looked like the stuff was there and not unreasonable, but I've never had a fresh GM rotor to get the measurements off of.

Too bad I just can't afford to buy them from the houses that do know the measurements...

Cheers,
- Jeff

[scottfab]

.... snip.....
When uneven temperature (hot spots) occurs, thermal expansion/growth will be greater in the hotest areas, which will result in a change in thickness and waviness or irregularity in the flatness of the rotor.

In the article he says this is not a warped disk. Interesting. I sure would call it warped.


Depending on the metalurgy and a host of other characteristics I am unaware of, the irregularity may not be noticable when the rotor cools down, and can be inspected.

I know of no other reason that would cause brakes to work fine, with no pulsation in normal driving, but does occur & progresses as the brakes are used more agressivly, i.e. get hotter. The transference of material and the molecular alteration described in the article is well known, but does not go away when it cools down. If such "buildup is the cause of the pulsating pedal, then I would think it would still be present when much cooler under normal driving conditions.

I know this is counter intuitive but I've experienced it. That is no pulsation after cool down. Upon continued driving after the first say half dozen heating/cooling events the pulsating was permanent. Not sure why the pulsating went away the firs few times.

So, for lack of my complete understanding of the subject or a better term, I call the phenomena "hot warpage," because I think that is what it is. BTW, I do break in according to instructions.

As always, I remain open minded and receptive to productive discussion.

I have tried the break in process recommended in the article with mixed results. On my C4 it worked. On a friends Toyota Avalon it failed, not just once but twice with new pads and disks. The solution was to dump the ceramic pads.

In the article it is stated
"Regardless of pad composition, if both disc and pad are not properly broken in, material transfer between the two materials can take place in a random fashion - resulting is uneven deposits and vibration under braking."

Note he states "can take place" not "will take place".
From what I learned on the Toyota when using OEM pads there is NO "material transfer" sufficient enough to cause any pulsation even if no break in process is used.

[4CAM LT5]

This article is one I can attest to for accuracy by its applicaton to my brakes in several different cars/brake jobs now over several years (since this article came out).

A good read. Check out the article regarding warped rotors and other myths. I've never had a "warped rotor" since studying this article, and neither has my wife since coaching her on braking on especially hard stops.

http://www.stoptech.com/technical-support/technical-white-papers/-warped-brake-disc-and-other-myths

P.

Good info....all around. Thanks...!!!