Contour Enthusiasts Group Archives Forums Modifications Brakes stock rotors vs aftermarket

i'll be needing to change the front rotors and pads on my 98.5 svt. i'm considering kvr drilled with kvr or mintex af pads. since i don't go on the track is there really much benefit. or should i stick with stock rotors and change pads to mintex af. advice is much appeciated.

I would definitely go with full faced rotors & good pads. (I'd pick Mintex between the 2 you listed)

demon, u wouldn't recommend slotted rotors?

Ditto. Slotted/drilled pads are more bling than anything unless you plan to spend hours at the threshold of braking performance on the track. And they have a tendancy to crack where they were machined (stress concentration). I run the Mintex A/F and they are just as good as OEM (which are pretty good as far as OEM brakes go). You can get a cheap 4 wheel package with the A/F and 4 new rotors from BAT.

I have spoken to a few "Brake Experts" that say the slotted rotors are a real waste of time. They chew the pads much faster and create a hell of alot of brake dust. I don't need any more of that! I challenge anyone out there to prove (documented tests on the Contour) any real brake improvement from the slotted (or even cross-drilled for that matter) rotors. I am sure that the larger kits (Baer/Brembo/Wilwood) will show improvement, but that is another playing field all together. I like my stock wheels (call me kooky) and don't want to give them up just yet.

I used Mintex pads on my SE and it did give the car better braking. I would say the pads had a higher coeffecient of friction than the pads they replaced and thus increased braking power. Cheaper pads have a lot more problems than can be addressed here, but suffice it to say that mintex pads are a cheap way to get more braking performance.

I'm not sure you understand everything at sake here..

Drilled rotors sprang up in motorsports to cure the problem of pads "floating" over the discs as a layer of gas was created between the two, effectively preventing the pad to completely contact the disc. The holes gave the gas enough room to expand, allowing the pad to touch the rotor everywhere. Advancements in pad material have fortunately cured this problem, even for street cars occasionnaly driven at the track. Race brakes (BTCC, F1, CART, etc..) don't have that problem either any more, but they use rotor and pad combinations that would be undriveable on the street.. Zero friction unless you put a lof of heat in them.

Note that when Porsche or Mercedes delivers a car with OEM drilled rotors, they have the holes cast in, not drilled afterwards.. This minimizes the cracking problem.

Since most drilled rotors were experiencing hairline cracks though, manufacturers started slotting them. Slotting is pretty good at expelling gas, but it also proves helpful in "deglazing" the pads. On a certain rotor/pad combo, certain conditions can cause a "glaze" to appear on the pad contact area. The glaze is like cooked metal and is very slippery, reducing the brake performance. Slots help scrape the glaze away to reveal fresh pad material.

Slots angled "backward" send dust, gas and debris towards the outside edge of the rotor. This can cause an imbalance over time as junk builds up at the outer edge.. because of that, most slots are now angled "forward", expelling the dust and gas toward the hub, helping minimize imbalance problems.

Bottom line, for street use, autocross and light track duty, solid rotors with a good pad material will give the best performance. Leave the rotor options out (drilled / slotted) unless you're into the show aspect, as they do look great..

All of these factors have nothing to do with larger kits, they apply to all rotors.

Pascal,
A couple things about what you said. New brake pad technology has pretty much reduced braking gas to a nominal amount. Slots were used to release gas and X-Drilled holes reduce weight! This is the knowledge I've gathered form this and other forums over the years.

-Andy

Andy, if you re-read my post, in the 2nd paragraph I say just that.. We're making the same point here.

Hmm, I'm not sure about that weight reduction thing.. Rotor mass is great for absorbing heat, which is MUCH more detrimental to the whole system than rotational inertia.

I maintain that holes were drilled in rotors to provide an "escape route" where gas build-up could vent and keep pads in contact with the rotor.

The stots do just the same (as stated in my original post), and they also help deglazing the pads. Which is not needed either on a well matched rotor / pad material combination.

Bottom line, the fancy stuff is now mostly 'fo sho... It does look very good!

Don't forget about removing water off the discs... drilled rotors do that quite well. At least they do on my bike: both the mountain bike and the motorcycle have drilled discs.

--JamesT