Hi-performance brakes

[DirectConnection]

Quote:

Originally Posted by Hemi-K Sure, I'll settle that he's wrong about it being a marketing ploy for ricers.....

OK, you proved your point in that they were used in alot of different forms of racing, and that Polygon was initially referring to race cars, then now street cars. Ok. But he is right (in my opinion) that the slotted rotors are a marketing ploy for the most part...now. Admit, some of the companies offering these drilled and slotted rotors are most likely using inferior castings and materials. We all know that Brembo is the cat's booty in the name of brakes, but JC Whittney selling cheap cross drilled rotors isn't a marketing ploy? So... in an essence, you both are right...kinda

[holley]

The Bremo setup on 350Zs isn't cross drilled, and I'd take that kind of performance any day!

It's interesting everyone arguing over braking efficiency, but nobody has pointed out that using DOT 5.1 fluid can be a great help (as serious road course racers do) and 5.0 (silicone) a hinderance (4 being ok and 3 being the bare minimum).

Did you know that in Cuba they use mixtures that include water and shampoo because it looks the same as real brake fluid? They don't crash all the time either ...

[Hemi-K]

Quote:

Originally Posted by Hemi-K And as someone else mentioned about brake fluid boiling before slotted/drilled rotors would have any effect, this is only partially true. With standard DOT3 fluid this would be the case, but most supercars and racers don't use DOT3, they use DOT4 or DOT5 which have a higher boiling point than standard glycol based DOT3.

I think I did mention brake fluid earlier........you must have missed it as this thread has become exceedingly long now.

[holley]

Yeah, but not 5.1, which has a higher boiling point than 4, and isn't silicone like 5.0, which is more if a PITA than it's worth

[curbman68]

What don't you like about silicone based fluid? I've used it for years without any issues. I particularly like the fact that it won't eat the paint off my car if it's spilled.

[Reaper1]

I'm backing Polygon on this, Porche reverts back to solid rotors on their race cars. Also, if you talk to a majority of those that do track days with those cars that came from the factory with cross drilled rotors...they take them off. The crossdrilling of rotors WAS for evacuating gasses caused by overheated pads...any good pad made nowdays doesn't produce those gasses (completely different materials ect.), so there's no need to evacuate something that is not there! Also, it does remove material from the rotor. This reduces its efficiency because there isn't as much material to absorb heat. The method of slotting a rotor is more benneficial, but still suffers from the same issue of removing material. The thing that slotting does over cross drilling is that it removes a small bit of the pad to produce a fresh face of friction material to the rotor all the time. Yes, it eats at the pads, but it also keeps an optimal face on them all the time. More consistancy. At any rate, if you want to run and beleive in cross drilled rotors, be my guest. All the ricers will think you're cool... After you have to replace them because they crack when you push them to their limits, you may open your eyes to the truth....

[holley]

Curbman - This is based on reports from people I know who work with cars in the Historic Touring Car championship (which is what I'm hoping to have a go at with the SC eventually) and the SCSA (European ASA stock car racing). Aside from the fact that it absorbs water and causes premature seal degradation (neither of which matter on racecars) the general performance wasn't as good as the glycol based stuff - admittedly it doesn't boil, but that wasn't found to be a problem with DOT 5.1 anyway.

Interestingly the disks used in all the SCSA cars and all classic tourers I've seen up close are solid.

[Hemi-K]

Quote:

Originally Posted by Reaper1 I'm backing Polygon on this, Porche reverts back to solid rotors on their race cars. Also, if you talk to a majority of those that do track days with those cars that came from the factory with cross drilled rotors...they take them off. The crossdrilling of rotors WAS for evacuating gasses caused by overheated pads...any good pad made nowdays doesn't produce those gasses (completely different materials ect.), so there's no need to evacuate something that is not there! Also, it does remove material from the rotor. This reduces its efficiency because there isn't as much material to absorb heat. The method of slotting a rotor is more benneficial, but still suffers from the same issue of removing material. The thing that slotting does over cross drilling is that it removes a small bit of the pad to produce a fresh face of friction material to the rotor all the time. Yes, it eats at the pads, but it also keeps an optimal face on them all the time. More consistancy. At any rate, if you want to run and beleive in cross drilled rotors, be my guest. All the ricers will think you're cool... After you have to replace them because they crack when you push them to their limits, you may open your eyes to the truth....

They only crack if the holes are not chamfered.




You guys can argue this and argue this but I'm still sticking with my original point. They do work, and thats as far as I'm going to continue with this.

You can spend your money on whatever you want, but me personally, If I knew I was doing extreme braking I would want the best possible brakes I could get. And to me that means larger crossdrilled/slotted rotors and better compund pads. Is it overkill? Sure. But why take chances with your life.

[Hemi-K]

Quote:

Originally Posted by holley Yeah, but not 5.1, which has a higher boiling point than 4, and isn't silicone like 5.0, which is more if a PITA than it's worth

I don't think 5.1 is even available in the US. Anyone??

[holley]

Thought it was worldwide (?) Certainly it'll be available for non-road use ...

[curbman68]

If the drilled rotors only crack if the holes aren't chamfered, how do they get in between the vented part of the rotor to chamfer the inside of the holes?

[Hemi-K]

Quote:

Originally Posted by curbman68 If the drilled rotors only crack if the holes aren't chamfered, how do they get in between the vented part of the rotor to chamfer the inside of the holes?

[Reaper1]

Wow, I wish I could find the picture of that brand new Porche rotor that was cracked all to h3ll and back. Oh, and those ARE chamfered....

They say you can lead a horse to water, but you can't make him drink...truly this is an excellent representation...The Truth is Out There!(but you have to be willing to open your eyes to see it!)

[91DSX]

Has anyone here pesonally done a back to back test themselves?
Does any manufacturer state they simply are useless?

Just wondering. . .

[Hemi-K]

Quote:

Originally Posted by 91DSX Has anyone here pesonally done a back to back test themselves? Does any manufacturer state they simply are useless? Just wondering. . .

I'm inclined to think the answer to that is no. Too many people here have done too much of this: on this subject, without any real proof to back up their opinions. I have been stating fact based opinions on the subject at hand and everyone else that has chimed in has just been stating their biased opinions with no facts to back them up.

Fact: cross drilled rotors can crack, less so if the holes are chamfered.
Fact: cross drilled rotors vent gasses easier than non-drilled rotors...hence less fade.
Fact: cross drilled rotors do as they were designed, weigh less and fade less.
Fact: cross drilled rotors are not a marketing ploy.
Fact: cross drilled rotors were designed out of necessity for racing.

And finally:
Fact: anyone who thinks that there is NO ADVANTAGE to cross drilled rotors needs to open a few textbooks and READ! The info is there people, always has been. This stuff is not new, been around for 35 years now!