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Better Brakes???
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=1&t=2957		 Page 1 of 2
Author:  KJKev [ Mon Oct 24, 2005 1:27 pm ]
Post subject:  Better Brakes???
Since I've added bigger tires and now seem to have less rolling resistance, the stock brakes just don't seem as strong as they once were.

I'd like hear to what set ups other than OEM any of you are running.

I know better pads and some slotted and drilled rotors will improve my stopping performance a bit, but what I'm interested in as some BIG rotors and pads.
Nothing King Kong like, but something with more stopping power that won't bankrupt me in the process.

Any and all help is appreciated.

KJKev
Author:  sleeve84028 [ Tue Oct 25, 2005 11:06 am ]
Post subject: 
I don't know if there are any brake upgrades out there for the Jeep (I haven't looked to be honest) but here is what I think about brakes:

The best way to increase your stopping power is to help dissipate the heat that is generated by the brake system when it's called upon to slow your Liberty down. All brake systems function by using friction to slow a vehicle down. The by-product of friction is heat. The generated heat reduces the coeffecient of friction between the brake pad and rotor and thus, your loss of brake performance. So the only real way to increase the amount of heat dissipation is by increasing the diameter of your rotor (larger swept area = greater heat dissipation.) or adding cooling ducts at the front of your vehicle. increasing rotor size is where things get expensive, because you have to change the caliper mounting points, then buy new rotors and possibly the calipers to fit over the rotors....

The only thing you can do to improve the brakes without spending tons of money:

1.) Change the pads from OEM style materials to ceramic (better heat resistance = less brake fade = repeatable stopping)


Some people think that slotted / drilled rotors will help decrease the stopping distance, but this is a common misconception. A slotted rotor only gives brake dust a place to accumulate but doesn't increase the cooling performance or increase the swept area of the rotor thus no change in brake performance. A drilled rotor does give heat a place to go, but at the same time reduces the amount of swept area on the rotor which typically negates any benefits that you could realize from the drilled rotors. I personally think drilled / slotted rotors are mostly for bling....


Now, on to calipers. A brake calipers only job is to apply the clamping force (pressure) on the pad and rotor. Most cars come from the factory with enough clamping power to lock up the tires. If you can already lock up your tires in a panic stop, why would you need anymore clamping force? [Think about that for a second] Most aftermarket calipers go from a sliding single piston to a fixed 2, 3, 4, etc. piston calipers. The benefit of this type of caliper over an OEM one is again, consistance over time. We all know that the slide pins can become un-lubed and cause uneven pad wear after months, years of use. When you switch to a fixed aftermarket caliper, this issue is resolved. Allowing you to have consistant pressure application no matter what. But an aftermarket caliper doesn't help reduce your brake distances.
Author:  KJKev [ Tue Oct 25, 2005 12:00 pm ]
Post subject:  Thanks for the info
wow, you just reminded me of the 20+ years I spent in auto garages explaining the very same thing....lol.
Deja vu...all over again.

Yeah, I guess I am looking for an upgrade of the brake system.

I'm not worried about heat since 90% of my driving is on the highway.
And at low speeds, such as when I'm wheeling, the brakes work fine.
But I'd just like to have more piece of mind that an upgrade would give me for when those idiots in town think they're more nimble and quicker than my Liberty.

Thanks again.
KJKev
Author:  sleeve84028 [ Tue Oct 25, 2005 1:24 pm ]
Post subject: 
Yeah.... I get those questions a lot. People are always asking why their slotted rotors didn't improve the stopping distance on their car. I hope my speach didn't sound too rehearsed, I try to break down the descriptions so anyone can understand what actually helps the brake system perform better....

On a side note: I just spent 10 minutes looking on the internet and I couldn't find any aftermarket kits for the Liberty... I'll keep looking but I am shocked that for such a heavy vehicle there aren't "big brake" kits out there yet.
Author:  MikeD0106 [ Tue Oct 25, 2005 6:46 pm ]
Post subject: 
I've read that drilled rotors are actually weaker because of the holes and have a tendancy to warp when a large amount of pressure is placed on them. I was going to purchase some for my last vehicle and changed my mind after reading that. This was a few years ago and I can't remember where I read that information at. At the same time, however, couldn't you go with a larger rotor (drilled or not) and caliper in order to increase the braking surface?
Author:  Eddo [ Tue Oct 25, 2005 9:45 pm ]
Post subject: 
I always though the stock breakes where pretty darn good. They had no real problems stoping my KJ and a trailer.
Author:  sleeve84028 [ Tue Oct 25, 2005 10:13 pm ]
Post subject: 
MikeD0106 wrote:
I've read that drilled rotors are actually weaker because of the holes and have a tendancy to warp when a large amount of pressure is placed on them. I was going to purchase some for my last vehicle and changed my mind after reading that. This was a few years ago and I can't remember where I read that information at. At the same time, however, couldn't you go with a larger rotor (drilled or not) and caliper in order to increase the braking surface?


What you read was correct. The drilled holes can actually weaken the rotor and cause premature warping or even cracking in extreme cases.

Yes, a larger rotor will increase your brake performance... That was what I was saying in my original post.


Eddo wrote:
I always though the stock breakes where pretty darn good. They had no real problems stoping my KJ and a trailer.


I too have been impressed with my brakes. My Jeep (39xxx miles on it now) just had it's first brake job. I switched to some ceramic pads and I am even more impressed. My Liberty pulls a 18' sail boat most of the summer and also a 6'x12' trailer very well and stops good too.
Author:  FreedomKJ [ Tue Oct 25, 2005 11:28 pm ]
Post subject: 
I'll second the plug for ceramic pads. I switched over at 25k miles and I'll never use another type of brake pad again. They feel better, seem to help stop faster, are quieter, produce less brake dust and the dust they do produce is light in color so it doesn't show up (especially on my graphite wheels.)

Oh, and alays remember to follow the manufacturer's bedding in procedure or you'll wear out your pads and rotors faster and reduce their effectiveness at the same time.
Author:  USPLibby [ Wed Oct 26, 2005 3:12 am ]
Post subject: 
I also thought that the Libertys brakes needed some upgrading, I almost bought the rear disc conversion kit but then I got new tires, Revos, and my stopping distance is awesome. The stock POS goodyears did not grab the ground too well = bad braking power.
Author:  Guyute1210 [ Wed Oct 26, 2005 11:01 am ]
Post subject: 
FreedomKJ wrote:
Oh, and alays remember to follow the manufacturer's bedding in procedure or you'll wear out your pads and rotors faster and reduce their effectiveness at the same time.

Can you elaborate on this please?
Author:  FreedomKJ [ Wed Oct 26, 2005 4:53 pm ]
Post subject: 
Guyute1210 wrote:
FreedomKJ wrote:
Oh, and alays remember to follow the manufacturer's bedding in procedure or you'll wear out your pads and rotors faster and reduce their effectiveness at the same time.

Can you elaborate on this please?


I'd explain, but StopTech (performance brake manufacturer) does a much better job: http://www.stoptech.com/tech_info/wp_bedintheory.shtml

At the end of the article they give you a general procedure for bedding in your brakes, but when you buy new pads the box should have specific instructions from the manufacturer.
Author:  MikeD0106 [ Wed Oct 26, 2005 10:59 pm ]
Post subject: 
sleeve84028 wrote:
What you read was correct. The drilled holes can actually weaken the rotor and cause premature warping or even cracking in extreme cases.

Yes, a larger rotor will increase your brake performance... That was what I was saying in my original post.


Thanks for the info...

Sorry, what I meant to ask was if you do go with a drilled rotor would it be better to go with a larger rotor in order to kind of prevent the warping or would it even matter?
Author:  sleeve84028 [ Thu Oct 27, 2005 8:54 am ]
Post subject: 
MikeD0106 wrote:
Thanks for the info...

Sorry, what I meant to ask was if you do go with a drilled rotor would it be better to go with a larger rotor in order to kind of prevent the warping or would it even matter?


Ah... Sorry about that, I misinturperated your last post. (Anyway, back to brakes) By increasing the diameter of any given rotor [say from 11" to 13"] and using the same size and number of drill holes in the two rotors; you reduce the chance for cracking / warpage because you have increased the surface area by going to the larger rotor. This extra area (metal) helps with added cooling and thus less warpage.
Author:  roadrunner [ Fri Oct 28, 2005 1:47 am ]
Post subject: 
Sleeve84028,

Very informative write-up. Thanks!! :D
Author:  Jeepjeepster [ Mon Jan 30, 2006 3:47 pm ]
Post subject: 
Ive always heard that ceramic pads make more heat and warp the rotors faster, is this true? Ive always wanted drilled rotors, guess I do not now?
Author:  sleeve84028 [ Mon Jan 30, 2006 4:00 pm ]
Post subject: 
No, in fact it's just the opposite. The reason that a Cermaic pad has better 'bite' is because they reject heat better than identical metal compound pads. Think of it like a ceramic tile on the space shuttle. Very good insulating properties. I run ceramic pads and solid rotors and am very happy with them.
Author:  Jeepjeepster [ Mon Jan 30, 2006 6:22 pm ]
Post subject: 
Where do you get your rotors sleeve84028? Some people say napa is the best, are they all the same? Im still on stock everything and it going good.
Author:  kickit_in4wheel [ Tue Jan 31, 2006 2:20 am ]
Post subject: 
My question is this: If slotted and cross-drilled rotors offer no benefits, than why do the high performance brake companies make them? Baer, Brembo, Wilwood, check their websites, they all make rotors with these features. Wilwood had something interesting to say about cross drilling:

Quote:
Caution on drilled rotors: There is a common mis-perception that rotors are drilled to improve cooling. The reduced mass of a drilled rotor will dissipate its retained heat quicker, but it also builds up heat at a much faster rate. The decision to use drilled rotors should be solely based on the merits of the lower rotating and unsprung weight, and not for improved cooling. It is not wise to use drilled rotors in sustained high heat on hard braking tracks unless the team budget affords a high frequency of rotor and brake pad replacement."


However, the same Wilwood discusses rotors with vanes on another page, and said that vanes DO help with cooling. Cross drilled, slotted, vaned, whatever, these are original equipment on some very nice and very functional sports cars. Not just a weekend racer or bracket race dragster, cars that road race or participate in endurance racing. I agree that the recent "bling" factor types have embraced the large, drilled and slotted rotors as glamorous go fast pieces, but surely they must offer some performance benefits that off-roaders (especially vehicles that do double duty as the off-road and daily driver) can benefit from.
Author:  0311_DoC [ Tue Jan 31, 2006 2:53 am ]
Post subject: 
I had the powerslots with the hawk pads on my truck and I noticed a major difference. my .02 I loved em
Author:  Taz [ Tue Jan 31, 2006 8:33 am ]
Post subject: 
A couple of things.

1. What breaks do you guys have that you think are weak? Front disk/Rear drum? The breaks in my 2005 are pretty good for a 4000+ lb vehicle, but they are 4 wheel disk, with rear proportioning. Anyone thought of doing a swap to rear disks on a KJ with rear drums? Also are there different size rotors in the different years of the KJ or different models?

2. One of the reasons that high performance break rotors are better is that they are made out of better materials. These materials resist warping better and are stronger. Most good crossdrilled rotors are designed with crossdriling in mind so the holes are not in the vanes and do not weaken the rotors like the old ones that were just regular rotors that were drilled, these tended to crack out around the holes.

3. Crossdrilling was done primarily for removing the gasses that are given off by the pads when they heat up. If the gas is trapped between the pad and rotor is reduces the stopping power greatly. The new premium pads do not offgas like the old ones. Cheap pads still will offgas but in normal driving the offgassing should be minimal, towing might be a different story. If the pads offgas and the braking performance is degraded.


So here is the question that I have that I can't seem to find is why are ceramic pads not recommended for towing?
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