Best rotors for KJ ?

[teeje]

Cross drilled rotors are actually worse for braking performance,less metal ='s less braking.



The only reason drilled rotors came to be is from drag racing were every ounce counted in weight reduction.That is it,they drilled holes in the rotors to save weight.There is no other benefits period.The import idiots adopted them because they "look cool".



Slotted rotors can have a effect but unless your racing you also don't need them.Good way to trash pads on a daily driver.

Holes and slots reduce wear, slots increase brake grip,holes and slots eject water and can reduce hydro planing. Wearing the pads out sooner can be possible if you use cheap brake pads. Holes also expel the "gas" from the brake pads to stop them from wearing faster. Multiple sources all say the same thing. They work great. Unfortunately I did not break in my first set. I noticed a big difference when I switched to them the first time. Yes they can wear the pads down faster if you're going fast but if you're driving normal, they actually have a ton of benefits. Technology has changed and while cross drilling may not be necessary anymore, it still helps
While stock rotors have more surface area and while the cross and slotted has less because of the slots and holes, more is not always better.

 

[u2slow]

The mopar dealer had a fresh front brake job done when we got it in spring 2012. I just changed the pads this spring, only the inboard one worn. 60,000km from them. I put on cheap pads. The rotors will probably rust out before the cheap pads are done.

It is a 6spd, and we both downshift as primary braking... so probably speaks to the good lifespan.

 

[profdlp]

Proper break in of your brakes is the key, sadly very few people actually know how nor do shops take the time to explain to customers.

I'll be doing mine before too long and have no idea how to break them in. Just drive like a wuss for a while to get 'em used to it?

(That is a serious question, by the way.)

 

[TheBlueKJ]

Holes and slots reduce wear, slots increase brake grip,holes and slots eject water and can reduce hydro planing. Wearing the pads out sooner can be possible if you use cheap brake pads. Holes also expel the "gas" from the brake pads to stop them from wearing faster. Multiple sources all say the same thing. They work great. Unfortunately I did not break in my first set. I noticed a big difference when I switched to them the first time. Yes they can wear the pads down faster if you're going fast but if you're driving normal, they actually have a ton of benefits. Technology has changed and while cross drilling may not be necessary anymore, it still helps
While stock rotors have more surface area and while the cross and slotted has less because of the slots and holes, more is not always better.

More is not always better? You sir do not understand how brakes operate then. You need surface area to absorb heat. Once the rotors can't absorb anymore because they are heat saturated you get brake fade which means they won't be working very well. The pads transfer the kinetic enrgy of the moving vehicle to the rotors in the form of friction and heat to stop the vehicle.

Modern brake pads also do not have gas build up on them since we no longer use asbestos based pads.


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[tommudd]

Holes and slots reduce wear, slots increase brake grip,holes and slots eject water and can reduce hydro planing. Wearing the pads out sooner can be possible if you use cheap brake pads. Holes also expel the "gas" from the brake pads to stop them from wearing faster. Multiple sources all say the same thing. They work great. Unfortunately I did not break in my first set. I noticed a big difference when I switched to them the first time. Yes they can wear the pads down faster if you're going fast but if you're driving normal, they actually have a ton of benefits. Technology has changed and while cross drilling may not be necessary anymore, it still helps
While stock rotors have more surface area and while the cross and slotted has less because of the slots and holes, more is not always better.

Hydro planning ? Brakes do not cause that
And they just don't work as well on street cars/ whatever sorry
Have done a ton of brake jobs over the years, started life as a brake and suspension mechanic ( before the word Tech was the cool word ) :happy175:

 

[tommudd]

I'll be doing mine before too long and have no idea how to break them in. Just drive like a wuss for a while to get 'em used to it?

(That is a serious question, by the way.)

I'll send ya a pm
but pretty simple really

 

[teeje]

More is not always better? You sir do not understand how brakes operate then. You need surface area to absorb heat. Once the rotors can't absorb anymore because they are heat saturated you get brake fade which means they won't be working very well. The pads transfer the kinetic enrgy of the moving vehicle to the rotors in the form of friction and heat to stop the vehicle.

Modern brake pads also do not have gas build up on them since we no longer use asbestos based pads.


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Multiple sources say the same thing for the most part.

http://www.sp-performance.com/advantages_drilled_slotted.htm


Read up on it.

 

[tommudd]

Rotor Warping

As your car rolls freely or without the brakes applied, the pads constantly drag the rotors. They are never completely pulled away from the rotor surface. This means that when you park your car, your rotors do not cool evenly. They stay hotter where the pad is still applied to the rotor surface. If the rest of the rotor is allowed to quickly cool this can allow for rotor warping. There is another down-side to removing rotor material: as you remove rotor material you are taking away from the surface area. This means less surface area to absorb and radiate heat. Cross drilled and slotted rotors should only be used on a rotor with a large enough diameter to retain heating and dissipation requirements.

if you look at any serious professional race car today, you wouldn't find any with cross-drilling. They used to use them, no longer .

The reason why rotors were drilled in the first place was to relieve the gas that was created when the pad material started to breakdown (burn). on a race car. Since modern pads don’t gas off any significant amount, this is simply not a concern.

 

[tjkj2002]

Holes and slots reduce wear, slots increase brake grip,holes and slots eject water and can reduce hydro planing. Wearing the pads out sooner can be possible if you use cheap brake pads. Holes also expel the "gas" from the brake pads to stop them from wearing faster. Multiple sources all say the same thing. They work great. Unfortunately I did not break in my first set. I noticed a big difference when I switched to them the first time. Yes they can wear the pads down faster if you're going fast but if you're driving normal, they actually have a ton of benefits. Technology has changed and while cross drilling may not be necessary anymore, it still helps
While stock rotors have more surface area and while the cross and slotted has less because of the slots and holes, more is not always better.

It's not the '60's anymore with asbestos's brake pads that outgas,no "gas" is made by brake pads in the last 30+ years,even the super cheap organic pads.

Your also not going to "hydroplane" your brake pads,simply appling the brakes will evaporate the water fast.

Brakes are friction based. What does friction create? yep heat. Less material ='s less ability to absorb heat.Those holes do nothing for cooling,it's the veins in the rotor that do that and thicker solid rotors do even better.

For brakes more is always better.There is never a such thing as to much brakes in any vehicle.

 

[teeje]

Rotor Warping



As your car rolls freely or without the brakes applied, the pads constantly drag the rotors. They are never completely pulled away from the rotor surface. This means that when you park your car, your rotors do not cool evenly. They stay hotter where the pad is still applied to the rotor surface. If the rest of the rotor is allowed to quickly cool this can allow for rotor warping. There is another down-side to removing rotor material: as you remove rotor material you are taking away from the surface area. This means less surface area to absorb and radiate heat. Cross drilled and slotted rotors should only be used on a rotor with a large enough diameter to retain heating and dissipation requirements.



if you look at any serious professional race car today, you wouldn't find any with cross-drilling. They used to use them, no longer .



The reason why rotors were drilled in the first place was to relieve the gas that was created when the pad material started to breakdown (burn). on a race car. Since modern pads don’t gas off any significant amount, this is simply not a concern.

Direct copy and paste. I read that as well. I already know the advantages of them and what's not needed anymore. They work great and that's all that matters to me

 

[tjkj2002]

Multiple sources say the same thing for the most part.

Advantages of Cross Drilling or Slotting Rotors


Read up on it.

What do you think a place that caters to imports and such will say?

 

[teeje]

What do you think a place that caters to imports and such will say?

I don't care what anyone says quite frankly. If it works for me and I think it's good that's all I care about. I build my jeep with myself in mind, no one else. I see, I FEEL a difference as well.

 

[TheBlueKJ]

You probably feel a difference because the old pads and rotors were worn out of spec


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[tjkj2002]

You probably feel a difference because the old pads and rotors were worn out of spec


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The 1 thing that made the biggest difference for my KJ was not even related to pads or rotors,stainless braided brake lines made the brakes feel 100% better without changing the rotors or pads.

 

[Jim McClain]

We're driving Jeeps, not street cars. The real main reason most cross drilled rotors are sold is for looks, not performance. Most of those buyers won't admit it though. Slotted rotors are better than cross drilled because they do help minimize the dust and gasses that build up under hard breaking. Yes, asbestos brake pads are no longer being made, but all brake pads wear out. The part that wears out doesn't just disappear into thin air, it is slowly ground off the pads by the friction of the rotors - the fine dust. Under extreme conditions, the dust might be so fine as to be almost a vapor - the "gas." Under these conditions, slotted rotors might be a good choice, but certainly not cross drilled. Race cars don't even use cross drilled rotors anymore. The only people who use cross drilled rotors are those who have been misinformed and those who just want their vehicles to look cool.

Slotted rotors help dissipate the dust and gas, giving your pads a better bite on the rotors. But again, this is more important on race or performance cars than on Jeeps. Many slotted rotors have sharp edges around those slots, which causes the pads to wear quicker. The pad will bite better too, but this is only necessary under extreme conditions - speed racing. If you are speed racing in a Jeep, you don't need a Jeep.

One thing that isn't mentioned too often though: It is much easier for trail debris - mud, small rocks, sticks - to get stuck in those slots and cross drilled rotors. This will cause damage and premature wear on the best of pads. A solid surfaced rotor and centrifugal force will expel that debris better than any slotted or drilled rotor.

If you don't spend much time off road and are more interested in stylin' at the mall than being rough and ready, then maybe slotted and cross drilled rotors will work better for you. If you live in steep mountain terrain with relatively gentle dirt roads that require you to ride the brakes more than average, slotted rotors might also be an advantage over smooth surface rotors. But if you like your dirt, mud, rock and desert trails and can't wait to slip it into 4WD, then it would be just plain foolish to use slotted rotors and ridiculous to add cross drilled to the mix.

Just my (highly researched) opinion.

Jim

 

[LibertyFever]

I must admit I agree with Jim.
The slotted & drilled brake rotors look and work best on cars and possibly are sold for their looks only.
And I feel strongly that debris, i.e.: rocks & mud, would get caught in them.

So this discussion has me asking which is more important?
Good quality brake rotors or pads?

And why have we stopped turning down the brake rotors?
Why have we become a throw away society???
This has me wondering how I can resurface my own brake rotors.


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[u2slow]

This has me wondering how I can resurface my own brake rotors.

Funny you should say that.... I put an old unit bearing in my vise, rotor on top, and spin the rotor with my left hand and angle grinder in my right hand. Not a resurface by any means... just a little cleanup. :gr_grin:

 

[TheBlueKJ]

Well to answer your question as to why we dont turn them anymore is that now a days most manufacturers make their rotors thinner to reduce weight to improve mpgs. It pretty much means you can only get maybe one resurface or throw em away


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[CalcityRenegade]

With the cost of turning rotors compared to new rotors you might as well do it right and replace them instead of prolonging an issue. Worked fine back in the day but not as much now with modern designs and materials. That being said I might have my rotors turned on my Titan. Just replaced the front & rear pads with Wagner Ceramic pads and they are incredible. I suspect very minor runout. The $100 rotors like Dura have not proved well with the Titan's due to weight and towing usage. The Wagner rotors are also $150-200/Rotor. That's a lot of money for rotors and my current rotors and massive so can spare a sliver of material. At least my KJ was reasonable for such parts.

 

[teeje]

I don't go off roading as much. I like to keep my jeep clean. However I am going to lift it and put bigger tires on it. I need those rotors for the places I drive to. Lots of hills and they don't warp as fast as my old ones did. They work for me.


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