break rotors

[Ground hawg]

I have a judder on the rear passenger break rotor and unever weare. question is are front and rear rotors on H1 the same? Is there any advantage with changing to sloted? and what about cross drilled?????

any and all info greatfully recieved

Ground hawg 99 H1 wagon

[Beastmaster]

Here's a post that I did that summarized thoughts about slotted vs. drilled vs. normal.
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Darrick Dong; Director of Motorsports at Performance Friction: "Anyone that
tells you that drilling makes the disc run cooler is smoking crack."

Power Slot: "At one time the conventional wisdom in racing circles was to cross-drill brake rotors to aid cooling and eliminate the gas emitted by brake pads. However, today's elite teams in open wheel, Indy and Trans Am racing are moving away from crack prone, cross-drilled brake rotors in favor of rotors modified with a fatigue resistant slotting process."

Stop Tech: "StopTech provides rotors slotted, drilled or plain. For most performance applications slotted is the preferred choice. Slotting helps wipe away debris from between the pad and rotor as well as increasing the "bite" characteristics of the pad. A drilled rotor provides the same type of benefit, but is more susceptible to cracking under severe usage. Many customers prefer the look of a drilled rotor and for street and occasional light duty track use they will work fine. For more severe applications, we recommend slotted rotors." (Note that even though Stop Tech sells both drilled and slotted rotors they do not recommend drilled rotors for severe applications.)

Wilwood: "Q: Why are some rotors drilled or slotted?
A: Rotors are drilled to reduce rotating weight, an issue near and dear to racers searching for ways to minimize unsprung weight. Drilling diminishes a rotor's durability and cooling capacity."

From Waren Gilliand: (Warren Gilliland is a well-known brake engineer in the racing industry and has more than 32 years experience in custom designing brake systems ...he became the main source for improving the brake systems on a variety of different race vehicles from midgets to Nascar Winston Cup cars.) "If you cross drill one of these vented rotors, you are creating a stress riser that will encourage the rotor to crack right through the hole. Many of the rotors available in the aftermarket are nothing more than inexpensive offshore manufactured stock replacement rotors, cross drilled to appeal to the performance market. They are not performance rotors and will have a corresponding high failure rate"
From Baer: "What are the benefits to Crossdrilling, Slotting, and Zinc-Washing my rotors? In years past, crossdrilling and/or Slotting the rotor for racing purposes was beneficial by providing a way to expel the gasses created when the bonding agents employed to manufacture the pads...However, with today's race pad technology, 'outgassing' is no longer much of a concern...Slotted surfaces are what Baer recommends for track only use. Slotted only rotors are offered as an option for any of Baer's offerings."

Grassroots Motorsports: "Crossdrilling your rotors might look neat, but what is it really doing for you? Well, unless your car is using brake pads from the '40s and 50s, not a whole lot. Rotors were first drilled because early brake pad materials gave off gasses when heated to racing temperatures, a process known as "gassing out." ...It was an effective solution, but today's friction materials do not exhibit the some gassing out phenomenon as the early pads. Contrary to popular belief, they don't lower temperatures. (In fact, by removing weight from the rotor, they can actually cause
temperatures to increase a little.) These holes create stress risers that allow the rotor to crack sooner, and make a mess of brake pads--sort of like a cheese grater rubbing against them at every stop. Want more evidence? Look at NASCAR or F1. You would think that if drilling holes in the rotor was the hot ticket, these teams would be doing it...Slotting rotors, on the other hand, might be a consideration if your sanctioning body allows for it. Cutting thin slots across the face of the rotor can actually help to clean
the face of the brake pads over time, helping to reduce the glazing often found during high-speed use which can lower the coefficient of friction. While there may still be a small concern over creating stress risers in the face of the rotor, if the slots are shallow and cut properly, the trade-off appears to be worth the risk. (Have you looked at a NASCAR rotor lately?)

AP Racing: "Grooves improve 'cleaning' of the pad surfaces and result in a more consistent brake performance. Grooved discs have a longer life than cross-drilled discs."

[Beastmaster]

And - a killer article on brake components.

http://www.flashoffroad.com/Maintena...kes/brakes.pdf

[Alan06SUT]

Keep it stock. No need for speacial rotors on an H1. I dont see you heating up the brakes on the twisties or a road course! But, you may be talking about BREAKS I cant tell.... In that case, I recommend the north shore HI, just dont wipe out and get stuck in one of those shallow underwater coral caverns, and dont drop in on any locals.

[ssgharkness020147]

I'm getting to the point where I will need a break job as well, espcially after the rears locked up for a mile or two. I have always advised people to stay away from slotted/crossdrilled rotors. However, this next time I'm going to give the powerslots a shot on the front of my truck.

Steve, I'm sure you have read what HMV8R has written about them on the HML. He swears that his truck stops alot better then it did with standard rotors. With all the added weight of my acc's on my truck I figure I may as well give them a whirl. Hopefully I'll get better breaking after they are installed, if not the hydroboost will be coming out to be sent out and ported.

[Beastmaster]

Actually, slotted is fine. Slotted + drilled is bad.

I might do the PowerSlot ones myself. I get bad glazing sometimes on my fronts.

[ssgharkness020147]

Are you just going to put the power slots on the front, or are looking to go front and rear? As much as I would like to put them on all four corners, the cost is a bit high and with how little your rear breaks contribute to your overall stopping power I just cant jusitfy it. On another note, do you think that vented rotors would help prevent brake lockup Steve?

Originally Posted by Beastmaster

Actually, slotted is fine. Slotted + drilled is bad.

I might do the PowerSlot ones myself. I get bad glazing sometimes on my fronts.

[galifardo]

Hello iam new in the post, i am looking for your experience, iam in the proces of buying a 1998 H1 hard top, i dorve it and is very slow and also to brake it a have to puysh the pedal an d takes almost 4 meters to stop, is it correct, i have to check something, i so some time guys with h1 tath stop in once but this one take a lot to stop, many thanks

[Jaquelyn Marilynn]

Brake judder, also known as "brake shimmy," is the feedback through the steering wheel and suspension when you apply the brakes at certain speeds and pressures. The steering wheel can shake back and forth, ranging from a faint, barely noticeable vibration to a violent shudder that feels like it could rip itself from your hands...