Brakes
#1
#3
i recently installed powerslot slotted rotors, and they are performing absolutely great, along with the hawk pads i installed with them. if you can afford it, i'd suggest purchasing the cryo-treated powerslots. theyre much much more resistant to heat, and in turn, warping. the regular powerslots are about 130 each, and the cryos are about 170 each.
#5
#6
I would just buy some good slotted rotors and maybe some Axxis or Hawk pads. The pads will help the most, as these are the actual friction material, but the slotted rotors will help reduce brake fade. Cross-drilled is complete overkill IMO unless you race a lot, and I'm not talking about drag racing. Cross-drilled rotors have also even been known to crack where they drilled the holes...
My personal plan for a brake setup is Axxis Metal Masters or Hawk pads, with probably some Powerslot Slotted Rotors, and some stainless steel brake lines. Add some new fluid and bleed the brakes and you're done. You've got plenty of upgraded stopping power for MOST of our applications and you haven't spent an arm and a leg...
My personal plan for a brake setup is Axxis Metal Masters or Hawk pads, with probably some Powerslot Slotted Rotors, and some stainless steel brake lines. Add some new fluid and bleed the brakes and you're done. You've got plenty of upgraded stopping power for MOST of our applications and you haven't spent an arm and a leg...
#8
Originally Posted by Redneckstone
we dont own mustangs here!
plus i'll be getting new 18" wheels soon, so the rotor/pad upgrade was a preemptive move for the new wheels. (had to replace the old rotors/pads anyways as the pads were gone and my rotors were both out of spec)
but it is true that slotted rotors wouldnt be as good if you'll be using your truck offroad a lot. ive heard dirt/mud can get stuck in the slots under heavy offroading and cause some annoying braking vibrations. i don't offroad, so it isnt an issue for me.
#9
#11
Join Date: Oct 2004
Location: Coal Region, MTC to be exact...heart of the coal region.
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Without getting into a huge arguement here, slotted/cross drilled rotors do not yield any benefiet. they hurt ur braking performance. modern pads to not gas 1/100th of older pads and do not need the extra slots/holes to vent. a solid rotor disappeates (sp) heat better and will last longer. torque ur lug nuts evenly and keep an eye on the brakes and they shouldnt warp. on extended braking sessions use the transmission to slow urself down, it wont hurt anything...thats why u have the ability to downshift.
now for my suggestion on parts. Bendix OEM replacement rotors and Bendix Titinimetllic pads work wonders. if u do not want the little bit more dusting opt for a set of ceramic pads. Napa also sells some good parts under the Wagner name.
please whatever u do, dont buy the cheapest thing u can find. the rotors are made of junk and wear down in no time. also the pads are excessivly cheap and wear own like hot butter.
oh and switching to stainless steel lines is a nice idea. FYI, if u dont race ur truck u wont need DOT-4 brake fluid.
now for my suggestion on parts. Bendix OEM replacement rotors and Bendix Titinimetllic pads work wonders. if u do not want the little bit more dusting opt for a set of ceramic pads. Napa also sells some good parts under the Wagner name.
please whatever u do, dont buy the cheapest thing u can find. the rotors are made of junk and wear down in no time. also the pads are excessivly cheap and wear own like hot butter.
oh and switching to stainless steel lines is a nice idea. FYI, if u dont race ur truck u wont need DOT-4 brake fluid.
#12
Originally Posted by optikal illushun
they hurt ur braking performance.
I wouldnt mind some good reading though, if you'd like to point us in the direction of a website or something that elaborates on the inferiority of slotted rotors versus blanks.
blanks will most likely last longer though, as they can be machined back into spec when/if they warp. slotted/drilled rotors cannot.
#13
Join Date: Oct 2004
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well, heres a quote from wilwoods FAQ page:
i think thats more than enough proof. but heres some more, heres a quote from an Anti-lock brake engineer for the Robert Bosch co
heres some more:
references (some i posted on as well)
http://www.automotivearticles.com/Br...Practice.shtml
http://fullsizebronco.com/forum/show...3&page=2&pp=20
http://fullsizebronco.com/forum/show...slotted+rotors
http://fullsizebronco.com/forum/show....asp#question7
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.
Slots or grooves in rotor faces are partly a carryover from the days of asbestos pads. Asbestos and other organic pads were prone to "glazing" and the slots tended to help "scrape or de-glaze" them. Drilling and slotting rotors has become popular in street applications for their pure aesthetic value. Wilwood has a large selection of drilled and slotted rotors for a wide range of applications.
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.
Slots or grooves in rotor faces are partly a carryover from the days of asbestos pads. Asbestos and other organic pads were prone to "glazing" and the slots tended to help "scrape or de-glaze" them. Drilling and slotting rotors has become popular in street applications for their pure aesthetic value. Wilwood has a large selection of drilled and slotted rotors for a wide range of applications.
Let's look at some common rotor "modification" and "performance" upgrades that you may have been exposed to. We'll try to separate the marketing from the engineering:
Bigger rotors will make your friends think you are cool, bigger rotors look ***y, but bigger rotors do not stop the car. What a bigger rotor will do is lower the overall operating temperature of the brakes - which is a GREAT idea IF your temperatures are causing problems with other parts of the braking system.
Take for example, a Formula 500 racer, a small 800-pound, single-seat formula car. While the brakes are certainly much smaller than those found on a 3200-pound GT1 Camaro, that does not necessarily mean that they need to be made larger. In fact, installing a GT1 brake package onto our formula car would probably do more harm than good. That's a lot of steel hanging on the wheel that needs to accelerate each time the gas pedal is pushed. So the moto of this story is bigger is better until your temperatures are under control. After that point, you are doing more harm than good, unless you really like the look. (And hey, some of us do.)
Crossdrilling your rotors might look neat, but what is it really doing for you? Well, unless your car is using brake pads from the 40's and 50's, 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." These gasses then formed a thin layer between the brake pad face and the rotor, acting as a lubricant and effectively lowering the coefficient of friction. The holes were implemented to give the gasses somewhere to go. It was an effective solution, but today's friction materials do not exhibit the same gassing out phenomenon as the early pads.
For this reason, the holes have carried over more as a design feature than a performance feature. 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 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, then these teams would be doing it.
The one glaring exception here is in the rare situation where rotors are so oversized that they need to be drilled like Swiss cheese. (Look at any performance motorcycle or lighter formula car. for an example.) While the issues of stress risers and brake pad wear are still present, drilling is used to reduce the mass of the parts in spite of these concerns. Remember that nothing comes for free. If these teams switched to non-drilled rotors, they would see lower operating temperatures and longer brake pad life, at the expense of higher weight. It's all about tradeoffs.
Slotting rotors, on the other hand, might be a consideration if your sanctioning body allows for it. Cutting thin slots accross 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 risks. (Have you looked at a NASCAR rotor lately?)
Bigger rotors will make your friends think you are cool, bigger rotors look ***y, but bigger rotors do not stop the car. What a bigger rotor will do is lower the overall operating temperature of the brakes - which is a GREAT idea IF your temperatures are causing problems with other parts of the braking system.
Take for example, a Formula 500 racer, a small 800-pound, single-seat formula car. While the brakes are certainly much smaller than those found on a 3200-pound GT1 Camaro, that does not necessarily mean that they need to be made larger. In fact, installing a GT1 brake package onto our formula car would probably do more harm than good. That's a lot of steel hanging on the wheel that needs to accelerate each time the gas pedal is pushed. So the moto of this story is bigger is better until your temperatures are under control. After that point, you are doing more harm than good, unless you really like the look. (And hey, some of us do.)
Crossdrilling your rotors might look neat, but what is it really doing for you? Well, unless your car is using brake pads from the 40's and 50's, 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." These gasses then formed a thin layer between the brake pad face and the rotor, acting as a lubricant and effectively lowering the coefficient of friction. The holes were implemented to give the gasses somewhere to go. It was an effective solution, but today's friction materials do not exhibit the same gassing out phenomenon as the early pads.
For this reason, the holes have carried over more as a design feature than a performance feature. 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 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, then these teams would be doing it.
The one glaring exception here is in the rare situation where rotors are so oversized that they need to be drilled like Swiss cheese. (Look at any performance motorcycle or lighter formula car. for an example.) While the issues of stress risers and brake pad wear are still present, drilling is used to reduce the mass of the parts in spite of these concerns. Remember that nothing comes for free. If these teams switched to non-drilled rotors, they would see lower operating temperatures and longer brake pad life, at the expense of higher weight. It's all about tradeoffs.
Slotting rotors, on the other hand, might be a consideration if your sanctioning body allows for it. Cutting thin slots accross 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 risks. (Have you looked at a NASCAR rotor lately?)
lets not forget those racers have special ducting to help cool the rotors, stainless steel brake lines and multiple pistion calipers.
truth be told, D/S rotors have less surface area. this means they will heat up quicker, espically with larger tires. we dont have the ducting to help cool them like a race car so they cant effectively transfer the heat.
Quote from (http://www.automotivearticles.com/Br...Practice.shtml)
So what cross drilled rotors do is reduce suface area decrease co-efficient of friction and are more prone to thermal shock, and cracking unless, you have a specialized braking system using, special brake fluid, stainless steel brake lines, venting all the necessary items to aid in convection
truth be told, D/S rotors have less surface area. this means they will heat up quicker, espically with larger tires. we dont have the ducting to help cool them like a race car so they cant effectively transfer the heat.
Quote from (http://www.automotivearticles.com/Br...Practice.shtml)
So what cross drilled rotors do is reduce suface area decrease co-efficient of friction and are more prone to thermal shock, and cracking unless, you have a specialized braking system using, special brake fluid, stainless steel brake lines, venting all the necessary items to aid in convection
http://www.automotivearticles.com/Br...Practice.shtml
http://fullsizebronco.com/forum/show...3&page=2&pp=20
http://fullsizebronco.com/forum/show...slotted+rotors
http://fullsizebronco.com/forum/show....asp#question7
#14
thats actually pretty interesting stuff.
i agree that drilled rotors (or a combination of the two) may indeed be inferior. i'd even say drilled rotors are more for looks these days (which is why some companies offer 'dimpled' rotors) as drilled rotors are notorious for cracking at the drill points, especially in high temperature situations.
i was more specifically talking about slotted rotors. Slotted rotors (assuming theyre done properly) DO cool better. Since some surface area is removed in the slotting, i guess its feasible that the reduction in surface area would result in less pad-to-rotor contact, and therefore, increased brake time. I'm not sure how dramatic the effect would be, but i'm thinking basically nothing (or next to nothing).
In performance/heavy braking/sustained braking conditions, slotted rotors outperform blanks, as the balance between lesser surface area cooler temperature/gassing/reduced glaze shifts. one of your own sources even briefly touches on one of the advantages (specifically refering to slotted only rotors):
i agree that drilled rotors (or a combination of the two) may indeed be inferior. i'd even say drilled rotors are more for looks these days (which is why some companies offer 'dimpled' rotors) as drilled rotors are notorious for cracking at the drill points, especially in high temperature situations.
i was more specifically talking about slotted rotors. Slotted rotors (assuming theyre done properly) DO cool better. Since some surface area is removed in the slotting, i guess its feasible that the reduction in surface area would result in less pad-to-rotor contact, and therefore, increased brake time. I'm not sure how dramatic the effect would be, but i'm thinking basically nothing (or next to nothing).
In performance/heavy braking/sustained braking conditions, slotted rotors outperform blanks, as the balance between lesser surface area cooler temperature/gassing/reduced glaze shifts. one of your own sources even briefly touches on one of the advantages (specifically refering to slotted only rotors):
Originally Posted by optikal illushun
Cutting thin slots accross 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... ...if the slots are shallow and cut properly, the trade-off appears to be worth the risks.
Last edited by barrman; 07-01-2005 at 12:18 PM.
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