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Old 10-19-2013, 07:36 PM   #31
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Originally Posted by m998dna View Post
You need to change your driving style owning a Jeep... I came out of a Porsche straight to a Jeep, so I know a little about the withdrawals you're going through. The brakes on my JK are light years ahead of my 1991 Cherokee... my Porsche could stop on a dime. You have two choices.. adapt or sell it for another STi. Just a friendly suggestion. .
I agree. I drive a 99 caravan to and from work and the braking sucks. New brakes too.
The jeep with 35's is a lot better.

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Old 10-19-2013, 08:15 PM   #32
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Yeah I guess replacing the rotor and caliper bracket with OEM parts os replacing everything. I also missed where I replaced a bunch of stuff and opened a can of worms. Thanks for your input.
OK.. I'll take the "ALL" back... but that's it.

You're funny Doc.. I enjoy reading your threads... have fun with the can of worms.



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Old 10-20-2013, 01:48 AM   #33
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Spot on for what? Getting rid of the soft pedal feel? If that then yep.

I am looking for stronger brakes to provide the same stopping distances I was achieving prior to 35's without having to push harder on the pedal regardless of how firm or little delay or "modulation" I might be able to get out of lines.

Theoretically my pedal feel would be better with lines and I am not arguing that. I know it will. If this thread was about my mushy pedal I wouldn't have even written it because I would have just added lines. I want to push the same sustained firmness on the brake and the Jeep stop as quick as it used to. I'm not talking emergency, avoid grandma, hardcore slide down some gnarly rock face in Moab, tow the space shuttle, etc... I am simply looking put more brake torque in my system to stop a heavier object without having to push harder. Lazy, spoiled, stupid, I don't really care what that makes me. Larger rotors makes more brake torque, period. I'm looking for more brake torque. There is far more inertia in a heavy E rated 35" tire then in a 32" E rated tire and I want more mechanical advantage in stopping that.

Magnesium bespoke wheels would do the trick also... lessening the rotating mass but I'm not trying to mod my Cuda with 15" wheels. I am simply noting that bigger rotating mass x 4 feels like I have to sustain higher pedal pressures to stop the Jeep. That's simply not lines. If I have room for larger rotors and Chrysler makes parts to add larger rotors. I'm not keeping my 10A stock and looking for tricks to make it "look" stock but perform better, as in a vintage you are trying to maintain aesthetics and history but not die when you push the skinny pedal and go really fast in a straight line after smoking your tires for 30 seconds.

Did everyone read this quote or just see lots of bold words and move on.
3) Only increasing the effective radius of the disc, the caliper piston area, the line pressure, or the coefficient of friction can increase brake torque. Increasing the pad area will decrease pad wear and improve the fade characteristics of the pads but it will not increase the brake torque.
Braided lines don't increase line pressure and they sure as hell don't increase piston area or disc radius or even the coefficient of friction so I'd say if I'm looking for increased brake torque I'm not getting "fleeced" with a BBK.
You've performed a mod (tires) that increases stopping distance more than any other. Since your brakes are still able to activate the ABS, upgrading brake power isn't going to do anything because your brakes are already more powerful than your tires.

The bold stuff you quoted is right, I already said that. Doing those mods will make your brakes stronger. But it [i]won't decrease your stopping distances.[i/] Your brakes are already powerful enough to lock up the wheels from any speed - more powerful brakes aren't going to lock the tires up more. Locked up is locked up.

Because you are tire limited, not brake limited, the only functional benefit larger brakes and better calipers is going to give you is resistance to fade, simple due to the larger surface areas involved. Increasing brake-torque isn't going to magically make your tires stickier.

Since you can activate the ABS with your stock brakes....expecting a mod that increases brake-torque to reduce stopping distances is literally the same thing as expecting shorter stopping distances from pressing harder on the pedal while the ABS is pulsing. You're increasing brake-torque in both cases...and in both cases, that ABS is still going to pulse, because you've exceeded the grip provided by your tires.

I promise you man - your StopTech quote completely ignores that stopping distances are primarily determined by tire type. They're in the business of selling things. You could rip the brakes off of a 911 GT3 porsche and put them on your Jeep and it wouldn't improve your stopping distances because your tires are the limiting factor, not your brakes. I'm trying to save you like $1500 bucks and a TON of ass pain here.
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Old 10-20-2013, 02:08 AM   #34
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Teraflex Big brake kit with the teraflex large bore master cylinder

They have a pretty good vid on YouTube.
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Old 10-20-2013, 02:10 AM   #35
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Currently i'm running 35x12.5x15 BFG A/T's at 28 psi around town and had noticed much different driving characteristics compared to stock. I do have the AEV procal and everything seems fine until you take turns or really wheel it where wheel spin is desired. Even with disabling the ESC from the button there are still a few parameters that are monitored and controlled by the computer. I hate computers.

I did this mod http://www.wranglerforum.com/f33/abs...res-87119.html and have never been happier with the performance of my Jeep off-road. Most of the time I have the "training wheels" totally disabled even driving on pavement, yeah there are a couple of lights that are illuminated on the cluster but it's nothing a piece or two of electrical tape doesn't rectify.

This probably isn't the solution for everyone but one that I thought might be relevant to this thread.
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Old 10-20-2013, 02:12 AM   #36
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the proposition here is in no uncertain terms, that adding stainless steel brake lines to the stock JK brakes makes them more then anyone would ever need...

Brake lines make the pedal feel nice but also can get you into trouble as they don't allow any expansion and therefore delay in large braking force. Not a problem for a professional driver but for your everyday Joe who may get a little brake pedal happy when they are coming around a bend in slick weather, too quick modulation of the brakes will put you in a ditch. A little delay or cushion to that amplitude change in brake fluid pressure might just give you that split second to ease up when you unpucker your rear end.

Physics isn't theoretical. Larger moment arm equals same force to slow larger rotating mass. It's math.

I want a stronger brake force to slow me down not a precision pedal feel.
Ok, that's not at all what I said.

You've got it backwards about the brake line expansion. Lack of expansion in the brake lines results in faster response, not slower. Expanding brake lines increase volume. Brakes are a closed system. Increasing area without increasing volume decreases pressure. The part where you got confused was where the quote you gave mentioned that if you do brake lines, you have to do the front and rear together. The reason is that unless both axles are running the same linearity of brake pressure, the ABS system will get confused because the brakes aren't behaving the same.

God this is frustrating. Yes, larger moment arm equals same force to slow larger rotating mass. Yes. I've said yes to that like 4 times. But it doesn't matter. Slowing of a vehicle does not happen at the brake disc. It happens where the tire meets the road. Your vehicle is not stopping as well because you changed the tires. You can clamp those brake discs harder if you want...the tire is just going to continue to skid. It won't slow you down faster. The brake kit isn't going to help.

Just...stop and think about it. The increase in brake torque will absolutely increase the stopping power of your brakes. It will allow your brakes to clamp harder. But since your stock brakes can already clamp hard enough to immediately lock up...increasing brake power wont do anything.

At any given speed, even with your new larger tires, your brakes are still able to lock up the tires yes? If you press hard on that pedal....the brakes lock up, correct? The reason the ABS starts to pulse is that your braking system has overpowered your tires. If you are already overpowering your tires...why would you expect more brake force to do anything?

Clamping harder on wheels that aren't rotating isn't going to make them rotate less. You're just going to continue to bounce off the ABS and waste like $1500 while further increasing your unsprung weight.
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Old 10-20-2013, 02:15 AM   #37
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Originally Posted by mckey73 View Post
Currently i'm running 35x12.5x15 BFG A/T's at 28 psi around town and had noticed much different driving characteristics compared to stock. I do have the AEV procal and everything seems fine until you take turns or really wheel it where wheel spin is desired. Even with disabling the ESC from the button there are still a few parameters that are monitored and controlled by the computer. I hate computers.

I did this mod http://www.wranglerforum.com/f33/abs...res-87119.html and have never been happier with the performance of my Jeep off-road. Most of the time I have the "training wheels" totally disabled even driving on pavement, yeah there are a couple of lights that are illuminated on the cluster but it's nothing a piece or two of electrical tape doesn't rectify.

This probably isn't the solution for everyone but one that I thought might be relevant to this thread.
Yeah I can see how that'd help a lot off-road. ABS doesn't function as well off-road because part of what helps you slow down off-road is a buildup of material in front of a locked-up tire. The SVT Raptor has dual-mode ABS...one setting for on-road and one for off-road that allows the tires to lock up a lot more.
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Old 10-20-2013, 02:25 AM   #38
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Yeah I can see how that'd help a lot off-road. ABS doesn't function as well off-road because part of what helps you slow down off-road is a buildup of material in front of a locked-up tire. The SVT Raptor has dual-mode ABS...one setting for on-road and one for off-road that allows the tires to lock up a lot more.
The way my brakes behave with the computer disabled is more than adequate, the only time I would want the training wheels on is in a snowy or icy situation. That's only if I do not have my chains on.
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Old 10-20-2013, 04:36 AM   #39
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So...yeah. For an off-road application, unless you've decreased the leverage of your brakes to the point of not being able to activate the ABS, switching to steel braided brake lines is going to give you the biggest braking performance upgrade, by making brake response significantly more linear and controllable with the pedal. Steel brake lines really do make a huge difference.....they eliminate the mushy pedal feel almost completely. I'd be very interested in hearing what a Jeeper who's made the switch to steel braided brake lines has to say. I know for my vehicle, it made the biggest difference in braking.
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Ok, that's not at all what I said.

You've got it backwards about the brake line expansion. Lack of expansion in the brake lines results in faster response, not slower. Expanding brake lines increase volume. Brakes are a closed system. Increasing area without increasing volume decreases pressure. The part where you got confused was where the quote you gave mentioned that if you do brake lines, you have to do the front and rear together. The reason is that unless both axles are running the same linearity of brake pressure, the ABS system will get confused because the brakes aren't behaving the same.

God this is frustrating. Yes, larger moment arm equals same force to slow larger rotating mass. Yes. I've said yes to that like 4 times. But it doesn't matter. Slowing of a vehicle does not happen at the brake disc. It happens where the tire meets the road. Your vehicle is not stopping as well because you changed the tires. You can clamp those brake discs harder if you want...the tire is just going to continue to skid. It won't slow you down faster. The brake kit isn't going to help.

Just...stop and think about it. The increase in brake torque will absolutely increase the stopping power of your brakes. It will allow your brakes to clamp harder. But since your stock brakes can already clamp hard enough to immediately lock up...increasing brake power wont do anything.

At any given speed, even with your new larger tires, your brakes are still able to lock up the tires yes? If you press hard on that pedal....the brakes lock up, correct? The reason the ABS starts to pulse is that your braking system has overpowered your tires. If you are already overpowering your tires...why would you expect more brake force to do anything?

Clamping harder on wheels that aren't rotating isn't going to make them rotate less. You're just going to continue to bounce off the ABS and waste like $1500 while further increasing your unsprung weight.
You know, the other day as I was stopping for a traffic light that turned red, across the road, I watched a Toyota pickup with stock tires slam on his brakes as he slowly rolled into the vehicle that had stopped in front of him. Back tires locked up, smoke bellowing out from the rear tires... at safe distance, the lawn worker couldn't stop in time.. BAM. Poor guy rolled into the back end of a new Honda didn't know what had just occurred.

What was different?... why couldn't he stop you ask?

He was towing a trailer with a huge lawn mower on it. Maybe he should have had brakes on that trailer and that wouldn't have happened.

Moving on...

Yes sir, the first lift I installed about 20 years ago on my Jeep didn't come with stainless steel flex lines. This is when my brake problems started and that no one could fix. I could push the pedal amost to the floor and the damn thing would barely stop. I chased this problem for years.. have all the receipts, everything was swapped out 2x over.

I searched around for stainless brake lines for my Jeep but no one made them yet... At least no one made DOT approved stainless lines. Therefore I had to live with my Jeep and once again adjust my driving style in order to be safe on the road.

This was a chronic problem for Jeepers... Many installed dual diaphram MC's from later model Jeeps.. only to find the push rod that attaches to the pedal was different - as well as the proportion valve. Installing larger tires opened a can of worms you say... Absolutely!

It wasn't until I installed my second lift, a Rubicon Express 4.5" SuperFlex lift - that came with stainless steel flex lines - my five year ordeal came to a screeching halt.

Here.. I have a pic showing the resolution to my nightmare.

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Old 10-20-2013, 04:38 AM   #40
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Very interesting thread with a lot of good information from those with actual experience. I don't have any track experience, I just grew up on the German Autobahn.

I am running steel bumpers, a winch and 35" tires on my JK Unlimited and I have been thinking a lot about upgrading the brakes lately. Actually after I had taken my JK with me to Germany a few months ago I found myself questioning the brake performance of the JK even more as roads are narrower, traffic can be at least as busy as in the USA and speeds can be higher like on the Autobahn you just feel like you start going with the flow when you go 90 mph. These might be some of the reasons why overseas JKs have the heavy duty kit since 2011. I know in Germany they have them.

Anyway I am a mechanical engineer and I absolutely understand the theory behind a big brake kit being useless as long as stock brakes were able to activate the anti lock system as reliably as any big brake. However if you read this thread again you might find that the OP is not looking to activate his anti lock system. Apparently in that case he should just stick with the stock brakes. But what if he is looking for more comfort and control like not having to press himself against that back rest of his seat in order to get the same results in brake performance? Like I said, I have no experience with brake upgrades and I am just curious as I seem to be sitting in the same boat as the OP. Are stiffer brake lines alone really going to warrant a brake system that is at least as responsive and as easy to trigger as it used to be on the stock JK?

I start looking at brake performance like I used to look at motor performance. A car with 200 hp will take me from A to B but at the end of a day I feel more releaxed if the same car was able to deliver 300 hp as you don't have to be so hard on the skinny pedal all the time. Same thing might hold good for a big brake kit as it might be more effortless to travel with it. I am not stating this as a fact but more like a question. New brake lines seem to be the right way to begin a brake upgrade with. But are big brake kits really pointless when it comes to everyday driving experience which typically should not include situations where you have to lock up your wheels?
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Old 10-20-2013, 05:14 AM   #41
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Very interesting thread with a lot of good information from those with actual experience. I don't have any track experience, I just grew up on the German Autobahn.

I am running steel bumpers, a winch and 35" tires on my JK Unlimited and I have been thinking a lot about upgrading the brakes lately. Actually after I had taken my JK with me to Germany a few months ago I found myself questioning the brake performance of the JK even more as roads are narrower, traffic can be at least as busy as in the USA and speeds can be higher like on the Autobahn you just feel like you start going with the flow when you go 90 mph. These might be some of the reasons why overseas JKs have the heavy duty kit since 2011. I know in Germany they have them.

Anyway I am a mechanical engineer and I absolutely understand the theory behind a big brake kit being useless as long as stock brakes were able to activate the anti lock system as reliably as any big brake. However if you read this thread again you might find that the OP is not looking to activate his anti lock system. Apparently in that case he should just stick with the stock brakes. But what if he is looking for more comfort and control like not having to press himself against that back rest of his seat in order to get the same results in brake performance? Like I said, I have no experience with brake upgrades and I am just curious as I seem to be sitting in the same boat as the OP. Are stiffer brake lines alone really going to warrant a brake system that is at least as responsive and as easy to trigger as it used to be on the stock JK?

I start looking at brake performance like I used to look at motor performance. A car with 200 hp will take me from A to B but at the end of a day I feel more releaxed if the same car was able to deliver 300 hp as you don't have to be so hard on the skinny pedal all the time. Same thing might hold good for a big brake kit as it might be more effortless to travel with it. I am not stating this as a fact but more like a question. New brake lines seem to be the right way to begin a brake upgrade with. But are big brake kits really pointless when it comes to everyday driving experience which typically should not include situations where you have to lock up your wheels?
Yes, the stiffer brake lines are exactly what will give him the better leverage. The stock brakes are still powerful enough. The rubber/nylon brake lines bulge, and they do so quite significantly on larger vehicles like a JKUR. With steel lines, he'll require less pedal movement and will not have to press as hard on the brakes to get the same result. If he wanted to boost the pedal/power ratio even further and make his brakes significantly more sensitive, the thing he would want to upgrade is the brake booster and possibly the master cylinder. (but I wouldn't recommend messing with those unless they go bad)

I totally understand what you mean with the horsepower/less taxed engine thing being more relaxing to drive, but the braking system on a vehicle is much much more powerful than the engine. The brakes on a vehicle are able to overwhelm the tires at literally any speed. The engine equivalent of that is being able to peel out no matter how fast you are going. In such a case, I don't think further increasing horsepower and torque would make the vehicle any easier to drive - the same is true for brakes. I'm speaking from experience here - I switched out my brakes for larger slotted ones. It didn't make me have to press the pedal less hard. The brake lines were the mod that did that. I actually upgraded my brake booster as well and left it on for less than a week before switching back to my stock one...it made the brakes so grabby and hard to modulate that I couldn't drive the vehicle smoothly anymore. (ironically, I did all of this in Germany! I was stationed there the last 3 years and enjoyed lots of autocrossing. The upgraded brakes were a result of me taking my car on the 'Ring and realizing that I couldn't even complete a full lap before they faded dangerously - they actually started to smoke)

Upgrading the brake lines is the way to go. If he wants further sensitivity from the pedal, he should look into the brake booster and master cylinder. I don't think he WILL want more sensitivity after installing the brake lines because they really do make a big difference. He's got plenty of raw braking power. If he's looking to bring his stopping distances back down to how they were stock, he's SOL. The mud tires he put on his vehicle simply will never be able to do that no matter how good the brakes are.

Frankly, I think in this case it's kind of a matter of managed expectations. No amount of brake work is going to give a Jeep on mud/snow tires the braking power of a Subaru STi on dedicated summer performance rubber. It's primarily a tire thing, not a tire diameter thing overwhelming braking ability thing. That, and he said he's only driven 2 (now 3) days on these new tires. They're not broken in, they still have mold lubricant on them.
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Old 10-20-2013, 05:23 AM   #42
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Alright, thank you. I appreciate your input and your patience!
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Old 10-20-2013, 05:27 AM   #43
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Alright, thank you. I appreciate your input and your patience!
No prob. Like I said...I went through a lot of ass-pain with brakes. Overheating, over-boosting, boiling the brake fluid and having to engine-brake to avoid crashing - all sorts of craziness. Just looking to help the OP and save him some money.

And yeah you're absolutely right about the heavy duty brake kit in germany. Pretty sure they use higher boiling-point fluid too. It's all I could ever find in the autoshops when I was there.
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Old 10-20-2013, 05:37 AM   #44
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Huge kudos for the great and accurate info in this thread. I think what most people are looking for is brake "feel", which in a non-track setting is typically how much pressure on the pedal is needed to achieve some fixed amount of deceleration. In other words, perceived brake power relates to pedal pressure.

I think the only two things that impact this (that are simple to address) are pad compound and brake lines. I run track pads on one of my street cars (and would run them on another one if it wasn't for the gnarly dust) because I like the high coefficient of friction (I like grabby, immediate braking).

Otherwise, most upgrades address fade resistance, which would seem to be mostly important in towing situations (at least as it related to JK's).
Another issue with Track pads most are not bedded in until they have several Heat cycles and cooling cycles. Something most people are not aware of is if not properly bedded in most track pads will wear a lot faster then stock street pads.

Best thing most people can do is buy QUALITY pads they do not need to be the most expensive pads on the market. ATE is a very good Brake parts supplier that offers good quality pads and rotors as stock replacement equipment. They do a lot of the factory braking parts for BMW and Mercedes as well as other high vehicles.
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Old 10-20-2013, 08:10 AM   #45
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Yes, the stiffer brake lines are exactly what will give him the better leverage. The stock brakes are still powerful enough. The rubber/nylon brake lines bulge, and they do so quite significantly on larger vehicles like a JKUR. With steel lines, he'll require less pedal movement and will not have to press as hard on the brakes to get the same result. If he wanted to boost the pedal/power ratio even further and make his brakes significantly more sensitive, the thing he would want to upgrade is the brake booster and possibly the master cylinder. (but I wouldn't recommend messing with those unless they go bad)
Good information in this thread. Here's a bit of recent experience that supports the above...

I just installed the following in my 5 month old 2013: front & rear bumpers, tires & wheels (35"), and lift. I was worried about brake feel and performance as a result of the mods. The lift (MC GC Lite) came with SS braided lines. I was pleasantly surprised to find minimal difference in brake feel from what it was before the mods.
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Old 10-20-2013, 08:46 AM   #46
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The info in this thread has been most useful.

So, just a theoretical question for my own edification. (I realize this question may have no simple answer, but just trying to get a rough idea).

Before I got the Jeep, I had a 2010 Nissan Frontier Pro-4X, and its braking distance was much better than my 2013 Jeep JK. When I compare the specs of the two vehicles, they are quite similar in many regards (besides the obvious difference in wheel base).

As for a couple parameters that I picked out, the Frontier weighed ~4500 lb (similar to the Jeep) and had almost the exact same size tires (265/75/16) as the Jeep (265/70/17).

Everything else being a wash, the biggest difference in the braking distance would be the fact the Frontier tires were ATs and not the MTs on the Jeep?
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Old 10-20-2013, 09:07 AM   #47
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The info in this thread has been most useful.

So, just a theoretical question for my own edification. (I realize this question may have no simple answer, but just trying to get a rough idea).

Before I got the Jeep, I had a 2010 Nissan Frontier Pro-4X, and its braking distance was much better than my 2013 Jeep JK. When I compare the specs of the two vehicles, they are quite similar in many regards (besides the obvious difference in wheel base).

As for a couple parameters that I picked out, the Frontier weighed ~4500 lb (similar to the Jeep) and had almost the exact same size tires (265/75/16) as the Jeep (265/70/17).

Everything else being a wash, the biggest difference in the braking distance would be the fact the Frontier tires were ATs and not the MTs on the Jeep?
That would be my guess. Another thing that would affect it is that your Nissan had independent front suspension, which would help it under braking because of the dynamic camber changes.

But yeah, the type of tire is by far the most important. Mud terrain tires have large tread blocks, which leaves a lot less rubber actually touching the road. Look at a high performance tire, or slicks, and you'll see that the tire maximizes the amount of rubber touching the road and the grooves that are there are much shallower, to keep the remaining rubber stiff enough to not deform under load. The type of rubber is also important. Tires designed for mud and real off-road conditions are made of harder rubber, because off-road tires made of the soft summer rubber would just rip off those tread blocks. So they have significantly less grip on pavement, the sacrifice for durability.

All terrain tires are kind of in between all-season and mud-terrain tires in terms of grip on asphault. I bet if you put performance rubber on a Wrangler it'd stop pretty damn well.
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Old 10-20-2013, 09:14 AM   #48
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You've got it backwards about the brake line expansion. Lack of expansion in the brake lines results in faster response, not slower. Expanding brake lines increase volume. Brakes are a closed system. Increasing area without increasing volume decreases pressure. The part where you got confused was where the quote you gave mentioned that if you do brake lines, you have to do the front and rear together. The reason is that unless both axles are running the same linearity of brake pressure, the ABS system will get confused because the brakes aren't behaving the same.
Just for the record I don't have it backwards. I did not state nor believe in any way that braided lines allow expansion and delay in a braking system. I completely understand how a brake system is closed and why all 4 are done but it's excellent info for others who may not.
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Old 10-20-2013, 09:15 AM   #49
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Just for the record I don't have it backwards. I did not state nor believe in any way that braided lines allow expansion and delay in a braking system. I completely understand how a brake system is closed and why all 4 are done but it's excellent info for others who may not.
Sorry, misinterpreted what you meant man.

I hope you're able to find a solution for your brakes that makes ya happy.
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Old 10-20-2013, 09:28 AM   #50
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However if you read this thread again you might find that the OP is not looking to activate his anti lock system. Apparently in that case he should just stick with the stock brakes. But what if he is looking for more comfort and control like not having to press himself against that back rest of his seat in order to get the same results in brake performance? Like I said, I have no experience with brake upgrades and I am just curious as I seem to be sitting in the same boat as the OP. Are stiffer brake lines alone really going to warrant a brake system that is at least as responsive and as easy to trigger as it used to be on the stock JK?
Yes, that

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He's got plenty of raw braking power. If he's looking to bring his stopping distances back down to how they were stock, he's SOL. The mud tires he put on his vehicle simply will never be able to do that no matter how good the brakes are.

Frankly, I think in this case it's kind of a matter of managed expectations. No amount of brake work is going to give a Jeep on mud/snow tires the braking power of a Subaru STi on dedicated summer performance rubber. It's primarily a tire thing, not a tire diameter thing overwhelming braking ability thing. That, and he said he's only driven 2 (now 3) days on these new tires. They're not broken in, they still have mold lubricant on them.
check the thread again, I HAD stock KM2 mud tires.... I currently have 3+" wider A/T tires on it now, so lets not begin to compare contact patch with the road... Talk about tiring! Also I'm not trying to turn a JK into an STI nor did I ever state that. I would however like the brakes to perform better then they did stock (on 31" KM2 tires) which is better then they CURRENTLY are on A/T's that have some ridiculous % more rubber touching the road surface.

How about we get more opinions from members who have changed rotor sizes or added 2 piston calipers? I think that might be helpful. I believe we are all clear on the fact that braided brake lines will make my brake pedal feel improve to better then stock.
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Old 10-20-2013, 09:31 AM   #51
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Yes, that



check the thread again, I HAD stock KM2 mud tires.... I currently have 3+" wider A/T tires on it now, so lets not begin to compare contact patch with the road... Talk about tiring! Also I'm not trying to turn a JK into an STI nor did I ever state that. I would however like the brakes to perform better then they did stock (on 31" KM2 tires) which is better then they CURRENTLY are on A/T's that have some ridiculous % more rubber touching the road surface.

How about we get more opinions from members who have changed rotor sizes or added 2 piston calipers? I think that might be helpful. I believe we are all clear on the fact that braided brake lines will make my brake pedal feel improve to better then stock.
Can you still activate your ABS?
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Old 10-20-2013, 09:46 AM   #52
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Can you still activate your ABS?
I'll tell you what I am going to go out right now and check that.
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Old 10-20-2013, 09:55 AM   #53
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I'll tell you what I am going to go out right now and check that.
Cool, lemme know if it still works. I promise I'm not tryin' to be a dick. If you are actually having difficulty getting the brakes to grab hard enough to activate the ABS then a big brake kit WOULD help.

Remember to also use a procal to set your new tire diameter. That will improve your ABS's ability to do it's job. If the vehicle's computer thinks it's still riding on stock diameter tires, there's a whole host of software settings that are no longer optimal, including the ABS.

And you can expect your braking performance to improve dramatically over the next week or so. Those new tires will take a bit of time to rub all of the mold lubricant off.
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Old 10-20-2013, 10:03 AM   #54
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Warmed the Jeep and warmed brakes up with 5-6 easy to gradual stops from 35-55mph then did about 6 bury the pedal stops from 55mph. No ABS activity or loss of traction except for one instance where my left front tire went over a small dip in the road that had a bit of gravel in it. ABS on for that split second the tire lost contact but did not continue to be active.

I flashcal'd the jeep last night and my tires are 33 15/16's from ground to level surface with top of tire. I input 34" into the flashcal as this is how the recommended you assess your tire diameter even though 34.5" is the actual inflated tire diameter according to Toyo.
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Old 10-20-2013, 10:12 AM   #55
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Warmed the Jeep and warmed brakes up with 5-6 easy to gradual stops from 35-55mph then did about 6 bury the pedal stops from 55mph. No ABS activity or loss of traction except for one instance where my left front tire went over a small dip in the road that had a bit of gravel in it. ABS on for that split second the tire lost contact but did not continue to be active.

I flashcal'd the jeep last night and my tires are 33 15/16's from ground to level surface with top of tire. I input 34" into the flashcal as this is how the recommended you assess your tire diameter even though 34.5" is the actual inflated tire diameter according to Toyo.
That's.....very very odd. That really shouldn't be happening. The mods you did....there's tons of Jeepers on this forum with wheel/tire packages the same size and their brakes are still strong enough to activate the ABS.

But, if that's the case and your brakes really aren't strong enough to activate the ABS anymore, then a big brake kit will indeed help. *shrug*

That's really weird though.
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Old 10-20-2013, 12:58 PM   #56
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Doc are you going to hook up your factory rubber flex lines to your new calipers? Just wondering..

Also, I'm praying that you don't get driveline vibes with that Mopar lift.

Some get it, some don't ... That's even more fun.

Welcome to the world of Jeepers.



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Old 10-20-2013, 01:16 PM   #57
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Doc are you going to hook up your factory rubber flex lines to your new calipers? Just wondering..

Also, I'm praying that you don't get driveline vibes with that Mopar lift.

Some get it, some don't ... That's even more fun.

Welcome to the world of Jeepers.



.
Who said anything recently about calipers. I'm going to go piece by meaningful piece. 13" rotors and brackets from BR6 HD export JK front brakes.

If I'm bleeding brakes due to caliper replacement I'm not an idiot I'll put on braided longer lines for the 3" lift
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Old 10-20-2013, 01:23 PM   #58
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Yes, the 11 inch rotor will be just as effective in stopping the vehicle as the 13 inch one will. The stock system is capable of locking the brakes up immediately upon slamming the pedal. A more powerful system is still only going to lock the brakes up, and then the ABS will activate. There will be no difference in stopping distance beyond normal statistical variation.

Larger brake discs absorb more heat over a larger volume of metal, resulting in lower average surface/internal temperature, and they have a larger surface area, which speeds cooling. Venting and slotting them further increases the surface area. Larger discs and high-heat pads with a brake fluid that has a higher boiling temperature are the best ways to reduce brake fade, along with installing brake ducts. (I have personally done all of these things for my track car)

Stiffening the brake lines reduces the required pedal travel and makes the brakes behave in a more linear manner - this will provide a small increase in panic-stop distance simply due to reaction time.

Since your stock brake system is still capable of activating the ABS, increasing brake-torque via a larger brake kit is just throwing money away. The only time you need an increase in brake-torque is when the traction created by the tires exceeds the brake system's power. In such a case, the brakes would not be able to lock the wheels up. Increasing brake torque only reduces stopping distances up to the limits of the tire's adhesion. Since all modern vehicles' brake-torque exceeds the adhesion limits of their tires, increasing brake torque further will have no effect.

A good article on this:

Why a Big Brake Kit Won't Make Your Car Stop Faster

To sum it all up....since all modern cars' stock brake systems generate significantly more force than tires have friction, increasing that force further will not do anything. The system will simply activate the ABS, or lock up the wheel. TIRES are, by far, the best way to shorten stopping distances, because stickier tires take advantage of more of the brake system's brake-torque.

StopTech is in the business of SELLING things. If brake-torque exceeds tire friction limits, your stopping distances are tire-limited, not brake limited. If you can activate your ABS, then your brake-torque already exceeds your tire friction limit. Your Jeep is tire limited.

Just trying to save you money here. Unless you can't get your ABS to activate, then a big brake kit will do nothing besides increase unsprung weight and decrease wallet weight. Make sure your Jeep's ABS system is calibrated to your new tire diameter using a tuner, switch to steel-braided brake lines for increased responsiveness, and remember that until you have a few hundred miles on your tires, they're still partially covered in lubricant from the factory and will not stop as hard as normal.
Agree with everything here, spot on. If you install 60" tires, but can still activate the ABS, upgrading brakes will do absolutely nothing. As stated above, larger rotors etc will be less prone to heat, etc, but that stuff matters on sports cars where you are constantly slamming the brakes. How many times in a row are you doing panic stops in the jeep? Heat is not an issue on jeeps. The truck is simply too heavy and requires more distance to stop. It will never have brakes like a sports car, even if you put 8 pistons with 15" rotors on it. Save your money, and drive carefully.
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Old 10-20-2013, 01:39 PM   #59
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Who said anything recently about calipers. I'm going to go piece by meaningful piece. 13" rotors and brackets from BR6 HD export JK front brakes.

If I'm bleeding brakes due to caliper replacement I'm not an idiot I'll put on braided longer lines for the 3" lift
Oh.. Here's an idea! Install those braided lines first on your factory stock components and see how they work. You know, Mopar forgot that most other companies provide a heavy duty adjustable track bar and braided SS brakes lines with their kits.

You bought a Teraflex Monster TB.. why not the braided stainless steel lines to complete the package?

I don't think you're an idiot, I actually think you're pretty smart - I believe this is an orientation issue.



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Old 10-20-2013, 03:07 PM   #60
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Oh.. Here's an idea! Install those braided lines first on your factory stock components and see how they work. You know, Mopar forgot that most other companies provide a heavy duty adjustable track bar and braided SS brakes lines with their kits.

You bought a Teraflex Monster TB.. why not the braided stainless steel lines to complete the package?

I don't think you're an idiot, I actually think you're pretty smart - I believe this is an orientation issue.



.
Yeah, I doubt Mopar is putting out a kit that will some how damage my vehicle without braided lines or front track bar. AEV doesn't use one for 2.5" lift which ends up being around 3" unless you have armor or heavy bumpers. The 1/4" off center front axle was going to bother me so I did it. That was vanity more then performance. I highly doubt performance would suffer much from a 1/4" off front axle.

I'm guessing if Mopar's kit includes limit straps and doesn't include brake lines it's because the engineers that put it together wanted to make sure all of the critical items were included. I don't see many if any other kits include limit straps and have read plenty of threads of people whining about how a coil fell out. I'm also not sure they needed to include the 2.0 reservoir shocks but each piece is in the kit for a reason. Brake lines and front track bar are nice add-ons that they figure people may upgrade to at a later time.

Maybe Teraflex can comment on their testing and as to why they offer not only a performance rotor kit but also a performance brake kit. Few people would likely believe them and just rave about how they are all about the Benjamin's and trying to rape the Jeepers.

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