Rotor choice for dirt road driving

So I'm a newbie to the forum and I get to post now instead of lurking around! In my lurking I have read quite a few opinions on brake rotors, specifically the desirability or lack thereof of slotted/drilled rotors. I have so far not seen any post referring to my situation.

 

My 97 GT Sedan that I bought a couple of months ago is showing pretty deep grooves on the rear rotors, and spongy pedal feel. I'm thinking of what to do with the rotors and pads. I live in Alaska, and on a dirt road. During the winter months the paved roads get a lot of sand as well. So the brakes and rotors live in a dirty environment pretty much all the time. I'm thinking I might benefit from slotted rotors as a means of keeping the pads surfaces cleaner and maybe saving the rotors from getting grooved out. Specifically I was considering EBC 3GD series with the Green Stuff pads. The car is a daily driver. Stock engine with 4EAT for now, although I will probably do intake/exhaust and a mild cam.

 

By the way, I plan to do all four brakes along with new fluid and maybe braided lines for the pedal feel.

 

Anyone have thoughts on this?

Well, nobody seems to have much knowledge to share or much of an opinion on this issue, so I will close it out by posting some information I got from EBC on the issue. This post is an E-mail I sent to them along with imbedded reply information regarding my questions. Take it for what you will. Comment if you like.

 

As Follows:

 

Question about brake pad/rotor choice for my driving condition: I live

in Alaska, and drive my Subaru Legacy in a dirty and cold environment.

Lots of sanded roads and dirt roads up here. The car is a daily driver,

and not driven particularly aggressively or rallied. My stock rear

brake rotors are pretty badly grooved, and in choosing a replacement I

am considering whether I would benefit from a slotted rotor. I am

considering the 3GD series along with the Green Stuff pads front and

rear. I have 2 questions:

 

1. Does a slotted rotor like the 3gd provide benefit in keeping road

dirt and grit cleaned off the rotor and pad, or is it primarily

effective in dissipation of hot gasses and brake dust?

The slots & dimples in the 3GD rotor actually do quite a lot. They de-gas the pads, circulate cool air in the system to promote even pad wear, and remove dirt/debris/water from the brake system.

 

2. Are the green stuff pads optimum for performance when cold and/or

wet? Is there another pad choice that would be better?

Greenstuff have an amazing cold bite, although not the best out of all of our pads. Slotted rotors actually clear water from the pad surface area right before it makes contact with the rotors so water isn’t too much of an issue. If you are interested our Yellowstuff High Performance range pad actually has the best cold bite out of the general street pads we offer.

There is no more gassing of pads anymore. That is a myth from back in the pre-80s days when the pads were made of different material and needed the slots and drilled to de-gas.

 

Get a set of inexpensive generic branded non-slotted, non-drilled rotors and call it a day. We use smooth rotors on our race cars and track oriented cars. From our testing, drilled/slotted/expensive rotors lasted 10% longer than generic ones and cost 50% more.

 

-mike

 

http://www.pbase.com/paisan/image/91072632.jpg

AIM: AZP Installs | E-mail: paisan@azpinstalls.com | 725 Fairfield Ave | Kenilworth, NJ 07033

"Race Tested, Enthusiast Approved!"

We suggest Centric Rotors or Mountain Rotors w/Hawk HPS Pads as a stock to slight upgrade.

 

-mike

 

http://www.pbase.com/paisan/image/91072632.jpg

AIM: AZP Installs | E-mail: paisan@azpinstalls.com | 725 Fairfield Ave | Kenilworth, NJ 07033

"Race Tested, Enthusiast Approved!"

Hey Mike thanks for the thoughts. The direct comparison on your race cars in interesting. You didn't say what type of racing your cars do, but if it's on the pavement it would be interesting to have a similar comparison from someone who does off road oriented rally type driving. It's the dirt and grime aspect of the rotor performance that is my specific interest.

 

At any rate, I know I can put standard rotors on the car with some decent pads and maybe some stainless lines and be perfectly happy. It may come down to price in the end, but the analytical engineering side of me is sucked into considering the options and how well suited they are for how I drive my car.

I rallycross on blank rotors and have had no issues. And that includes dirt, fine dust, and mud the consistency of chocolate pudding. For a dirty/dusty environment, the above recomendation of blanks and good pads is fine.

 

Oh, and the Subaru Group-N rotors that are used on the Group-N rally cars are blanks.

We use ours on the road course and the street. As Draco said, blanks are really the way to go in terms of price/performance. If you want the bling factor, then go for the slotted/drilled ones.

 

-mike

 

http://www.pbase.com/paisan/image/91072632.jpg

AIM: AZP Installs | E-mail: paisan@azpinstalls.com | 725 Fairfield Ave | Kenilworth, NJ 07033

"Race Tested, Enthusiast Approved!"

There is no more gassing of pads anymore. That is a myth from back in the pre-80s days when the pads were made of different material and needed the slots and drilled to de-gas.

 

Truth. There is simply no advantage to cross drilled rotors at all. I like the cheese grater idea of slots though, to clear away the smear layer of water, mud, whatever...plus it looks nice.

I liked the cleaning concept as well. My fronts are still smooth but the rear rotors are really grooved. I was thinking the road grunge may be a contributing factor to that and that the slots, at least theoretically, could help minimize that. No desire for cross drilling here. The EBC are dimpled but not drilled through. If I can find em cheap enough on line I may go that route. If not, blanks.