While I'm here and imposing on the collective wisdom -- anyone know of a source for slotted (not drilled and slotted) rotors? Thanks!

 

did you try to do a google search?????

http://froogle.google.com/froogle?q=...oogle&ct=title

 

5 or so years ago I bought mine from carparts.com but I'm not sure if they're still available. Yes mine are just slotted, not cross drilled. I only ordered the front though... hmmm

 

How do you like them?

 

well, of course they feel just like stock rotors. No BS about how they grab so much better now! They look good, and so far they aren't rusting so the factory coating is working. They've been on the car for about 2 years.

The pads are holding out too, so I don't believe that slotted rotors eat your pads up. Also, I'm just doing normal driving; I'm not on the brakes all that much.

I need to clean up my calipers now...

 

Powerslot

My brother has them on his corrado and they've been doing great so far
They may be more expensive than the psuedo ebay rotors but I think its worth the extra money for quality and peace of mind.. especially on brake related components.

 

Don't bother with slotted rotors unless you're running your car on the track and you have a problem with debris building up on your rotor/pad surface.

The slots will do absolutely nothing to improve your stopping ability and will actually reduce the whole systems brake fade resistance by removing material from your rotor. The rotor is just a big heat-sink and when you remove material from that system, you lessen it's ability to absorb heat. This will increase the tendancy for your brake fluid to boil and your brakes to fade.

Go to Tirerack.com and buy some nice cheap Brembo solid replacment rotors and you'll be better off for it.

 

The only time cross drilling or slotting is at all beneficial is when upsizing your rotor because it will keep weight down. But a lot of aftermarket companies use aluminum hats to accomplish the same, if not better results without the need to degrade your rotor. But by removing the material with drilling or slotting you start to negate the purpose of going with a bigger rotor in the first place, which is to dissipate heat (as mentioned by l-dub).

A couple other points not made are that cross drilling can clog the vanes of vented rotors with brake dust and inhibit cooling even further. Not good. And todays pads dont usually produce enough gas to necessitate the need for gas dissipation anyways (which was the original purpose of slots and holes)

I should also point out that "solid" as used by lww shouldn't mean an actual solid rotor (atleast I hope thats not what he meant). You should always try to use vented rotors to help with heat dissipation.

 

You are correct, I was referring to vented, but not slotted or drilled rotors. Completely solid rotors are the worst as they have great heat sink capability, but little surface area to dissipate it.

 

my stock rear rotors are solid....

 

i think all ours are so dont feel bad Bleach The rear brakes on an OEM application typically do far less braking then the fronts. Not the best thing for stopping distance, but it does make the car safer and more stable under hard braking. So on top of less heat build up in the rear, I guess the OEM's figure they'd rather the rears fade then out-brake the fronts. Not to mention the lower cost of those solid rear rotors.

 

ya, not untill 1987 did the Z get rear vented rotors... another good thing about a Z31 5-lug swap (if you go with the 87-89 brakes)

 

I love all the different arguments both for and against slotted, or cross-drilled and slotted rotors. Pretty much the same number of opinions on that as there are about who killed JFK. All of you missed the SINGLE BIGGEST REASON WHY YOU NEED THEM! ....

They look REALLY FRICKIN' COOL!

Rod.

 

cant argue with that

And I killed JFK. I think I just heard my computer being bugged

 

I never said I didn't have a set, just that they don't improve anything if you do! I prefer the faux drilled and slotted rotors so they look like they're drilled and slotted, but the holes and slots don't go all the way through the rotor, just dimples and divits...

 

I got Toyota fronts on my '70 with '81 ZX discs on the rear. Vented rotors on front, drilled and slotted with full radius on the holes (not chamfered) and non vented drilled slotted on the rear. They are cad plated and made in Japan not China. The only time I get on them hard is when my radar goes off. I can reduce my speed by 20mph in a heart beat. And they look great behind my 17" Revos. I think the purpose of the holes and slots is to disipate heat gas by venting it into the holes, fanning the heat away. I would like to see actual test results.

 

The problem with the gas theory is that brake pads no longer produce that excessive gas. Back when people first started drilling rotors it was because the pad compound would cause gas to build up and the holes and/or slots would allow that gas to escape. Since that gas is no longer a problem the holes/slots are no longer needed from a functional standpoint. And pads that do tend to release excessive gas tend to have the slots in the pad so as to evacuate the gas, so again, a means of evacuation on the rotor itself is not needed.

The problem with the holes being abled to dissipate heat on drilled rotors is that the metal of the rotor is much better conductor of heat then air is. Well with that being said, the holes are just far too small to allow any significant amount of air to be able to escape the heat conductive metal. Cross drilling is used on race cars to reduce weight, not to help dissipate heat.

The only true ways to increase heat dissipation is to increase the surface area of the rotor by upgrading to a larger diameter rotor which increases the overall area that the heat has to dissipate over, to increase pad surface area becuase this distributes the heat instead of concentrating it so you have lower temps over a broader area as opposed to concentrated patches of high heat, and finally through venting the rotors. Most disc brake vehicles come with vented rotors anyways though. Pad compound can also affect heat build up.

And on a final note: On a street vehicle, even if driven reasonably hard, the brakes will likely never see the kind of abuse that would bring on the problems normally associated with cross drilled and/or slotted rotors.

 

The gas I was referring to is the super heated air between the pads and the rotor face. I was looking at the Bugatti Veyron and it doesn't have slotted/drilled rotors. With the eight piston calipers on the front and six piston on the back, it stops the car from 250 mph to 0 in less than 10 seconds. I guess if they don't need it then I don't either. maybe it's just more bling. I really don't need the 17" wheels either.

 

If you want more gripping power, then upgrade the pads. If you want to reduce fade, then upsize the rotor. Thats pretty much all there is to it. Sure there are more details, but thats the jist of it.