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Slotted Rotors

man that is one question that i want to know too, i was looking at ones off ebay, but i've herd bad things from stuff off ebay, i'ma keep in contact with this post, like i said i'd like to know this also
 
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This much I do know. I installed drilled & slotted rotors on my Cobra and MAN was there a difference in braking. Would not have believed it otherwise. They work better because the rotors disipate heat & gasses better keeping them cooler and pads in full contact. Thus improving braking! Heat+brakes= fade and that is dangerous! I am planning on buying the kit offered through Quadratec soon! :cheers: :NAXJA:
 
It would seem that "common" sense would tell you that Slotted rotors would do you good in any application. Reasons being explained by ColoradoRaptor. I would "assume" that any mud would be "burned" away from the heat of the rotors when the brakes are applied. Just like when you paint the calipers when they are near the rotors still. The overspray that is on the rotors is burned off. Sure its something you want to avoid, but its not going to do any "major" harm. I also personally doubt that you could get rocks stuck in the holes unless you stuck them in yourself.
 
Slotted rotors would help if you're working in high-speed applications, or you're doing a lot of braking under heavy weight (like with towing, or a good deal of downhill driving.)

The increased surface area and airflow over the rotor will help keep the thing cool, which also reduces "outgassing" by the pads. Also, the slots or holes passing under the pad surface will also allow any gas that the pads emit to depart, rather than "floating" the pads.

Will they help you? Probably. Are they something you should dig deeper for? Depends. How do you use your rig? How do you plan to use your rig?

I'd also be inclined to think that the grooves might collect mud - I'd be loath to use them on a rig that sees a lot of mud time. You'd "boil off" the water in the mud, making it into "dirt", and it could end up clogging up the slots (and you'd have to clear it out manually.) But, I've no direct experience with them in mud at the moment (I've usually used them on "road warriors" and bracket racers.)

If you want to get them anyhow - I'm just presenting what I think here, but your experience may be different - the single largest detail to watch out for is no sharp edges! You can find drilled/slotted rotors that have the edges rounded over where the machining is done, which is a Good Thing (tm). Sharp edges are heat and stress risers - the increase in local heat at the sharp edge can lead to excessive heat checking, thermal stresses that lead to cracking (and potential failure,) and it's possible that a sharp edge hasn't been deburred - meaning you end up gouging out the pads (I've seen it. It's rare, but it can happen. Check - because I didn't the first time I ran across it...)
 
I run the powerslot hawk pad combo and they are better than stock. Its not like you are gonna put them on and gonna stop on a dime if you couldn't before, but I like them and have never had a issue with mud clogging the slots in the rotors or anything like that. I got the whole kit for around $170.00 so I thought it was worth a try
 
krelja said:
I run the powerslot hawk pad combo and they are better than stock. Its not like you are gonna put them on and gonna stop on a dime if you couldn't before, but I like them and have never had a issue with mud clogging the slots in the rotors or anything like that. I got the whole kit for around $170.00 so I thought it was worth a try
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That's a lot of cash for front brakes on a rig that operates effectively at 5 mph on a trail. Even if you're daily driving, you're not going to see a performance gain that's worth the money driving around at 55 mph and stopping at stoplights.

Get yourself a good set of pads, the cheapest rotors you can find and run it.
 
I run cross drilled rotors with my WJ converted front end, and have wheeled it in every terrain. I've had no problems with mud, dirt or rocks getting in them.

I did however have my rear drum brakes fail on me this last weekend, and will do slotted or drilled rotors in the rear when I convert it - which is now high on the list.
 
I had a set of drilled and slotted rotors on my last car and the brake shop that I took them to to get turned said that they wouldn't turn the drilled rotors beacuse then all of the holes would have to be re-chamfered and that would take more time and cost in labor so they just told me to use them and buy new ones when they got wavey. they will turn the slotted rotors however, this is just my personal experience with drilled rotors. I loved the performance though, there's no doub't it's a major improvement over stock rotors.
 
Hrm. When i take my drilled rotors in to be turned, they just ask "Hey Cal, how's your dad?" and turn them.

Maybe try a different shop.
 
i used to road race bmws and i ran slotted and they were great coupled witha 4 piston caliper. as far as cross drilled there is a huge misconception about these, they supposedly run cooler because air circulates. but if you logically think about it there is less metal there.that means you have the same friction but less metal for it to be contained in but you have a little better cooling so the best we have figured is that you kinda break even. as far as using slotted offroad i would not think that would be such a good idea. another tip: people put so much emphasis on the rotors but a stock oem rotor with a quality pad is plenty imo. my e36 ran a 5 series 4 piston caliper from baer, slotted rotor and mintex pads it was seriously overkill if i had it to do over again i would have simply upgraded to the pads alone
 
jeep/bronco said:
i used to road race bmws and i ran slotted and they were great coupled witha 4 piston caliper. as far as cross drilled there is a huge misconception about these, they supposedly run cooler because air circulates. but if you logically think about it there is less metal there.that means you have the same friction but less metal for it to be contained in but you have a little better cooling so the best we have figured is that you kinda break even. as far as using slotted offroad i would not think that would be such a good idea. another tip: people put so much emphasis on the rotors but a stock oem rotor with a quality pad is plenty imo. my e36 ran a 5 series 4 piston caliper from baer, slotted rotor and mintex pads it was seriously overkill if i had it to do over again i would have simply upgraded to the pads alone
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Less metal either way - but it's the increase in surface area that allows them to dissipate head. Think of a heat sink in electronics - the greater surface area of all the fins allows for more heat dissipation. Increasing the amount of material increases the heat capacity (amount of heat energy required for an overall increase in temperature,) but not necessarily an increase in heat dissipation (which is what we're really after here.)

Make some sense now?
 
cal said:
Hrm. When i take my drilled rotors in to be turned, they just ask "Hey Cal, how's your dad?" and turn them.

Maybe try a different shop.
Click to expand...

That's good to know, I haven't bought drilled rotors for my XJ because I thought they couldn't be machined. I will be purchasing a set know, Thanks cal!
 
pierceME311 said:
That's good to know, I haven't bought drilled rotors for my XJ because I thought they couldn't be machined. I will be purchasing a set know, Thanks cal!
Click to expand...

There's no reason at all why they couldn't be. Granted, if they were getting uppity about their carbide lathe bits, it's possible that the chamfer may not be enough to preserve them (compared to high-speed steel, carbide can be brittle. Just don't cut as deeply...) and they're worried that the bits will shatter. Meaning? Take two or three smaller passes, instead of trying to do it all at once. Any competent machinist will know that offhand.

Considering that they likely need a "cleanup pass" after being drilled and/or slotted, anyone who tells you they can't machine them doesn't really know what they're about.
 
i agree to some extent but if you decrease capacity and at the same time you increase dissipation your not really accomplishing anything are you? hypothetically if you lose 10% capacity but gain 10% dissipation doesnt the rotor stay the same temp? with a slotted rotor you do lose some surface area but you gain more bite so to speak they still get hot not sure if they dissapate heat much better but the pads actually bite the rotors harder which in turn also eats up your pads quicker but you gain function and lose longevity
 
jeep/bronco said:
i used to road race bmws and i ran slotted and they were great coupled witha 4 piston caliper. as far as cross drilled there is a huge misconception about these, they supposedly run cooler because air circulates. but if you logically think about it there is less metal there.that means you have the same friction but less metal for it to be contained in but you have a little better cooling so the best we have figured is that you kinda break even. as far as using slotted offroad i would not think that would be such a good idea. another tip: people put so much emphasis on the rotors but a stock oem rotor with a quality pad is plenty imo. my e36 ran a 5 series 4 piston caliper from baer, slotted rotor and mintex pads it was seriously overkill if i had it to do over again i would have simply upgraded to the pads alone
Click to expand...

The holes are there simply to evacuate gasses produced by the pads as they heat up, Not for air flow purposes!! Cooling is done with ramair ducting to the brake asembly! So, logically if the gasses produced by agressive braking are dissipated by the holes, slots or both then you have BETTER braking!! Brake fade can be a bitch!! Try going down a long grade with your normal brake rotors being used all the way down. Bet you have to push harder and harder to get the same braking response!! Then try it with the high performance rotors and FEEL the difference!:peace:
 
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