Slotted and Drilled Rotors with Hawk Pads
11-19-2007, 05:50 PM
#11
1st Gear Member
Thread Starter
Join Date: Mar 2007
Location:
Posts: 110
RE: Slotted and Drilled Rotors with Hawk Pads
ORIGINAL: onederful100
so are the 14" brembo's going on the back? how much did the front brakes cost you? i was thinking of doing brakes some time later
so are the 14" brembo's going on the back? how much did the front brakes cost you? i was thinking of doing brakes some time later
11-20-2007, 01:12 AM
#12
4th Gear Member
Join Date: Jul 2007
Location: Houston TX
Posts: 1,474
RE: Slotted and Drilled Rotors with Hawk Pads
Wow, some of you definitely need to do research before yapping your gums. I've done countless discussions on this topic on other forums and have done thorough research on it as i was looking for upgrading tips for braking in my personal track/drag conditions.
Bigger brake rotors are big for one main reason: Heat dissipation. Control of heat is the BIGGEST factor with braking ability. Heat to a certain level introduces brake fade, which drastically reduces your stopping ability. More surface area for braking? What about adding more unsprung rotation weight on the axle? Theres some physics for ya. Track pads (or even upgraded street pads) and upgraded fluid already does a fine job at controlling fade alone. Rotors are dead last in the equation. After a drag run, city driving, you will not be able to toast the brakes up enough to fully utilize the "benefits" of larger rotors. Larger rotors help cool in road racing applications, but even then, stock sized blank rotors do a FINE job at that without hurting times at all.
Drilled slotted rotors, ss lines, bigger rotors generally do not help braking ability. they are mostly for cosmetics.
-drilled/slotted-keeps pad cleaner and cools better, but CANNOT be resurfaced and reused after several pad changes. this is bad b/c deposits from old pads do not let the break-in compounds of the new pads to properly burn off on the rotors. so you'll end up replacing rotors every year or so. also, do not road race with drilled rotors.
-bigger rotors-increase surface area, BUT adds unsprung weight and counteracts benefit of bigger surface area.
-ss lines-more for pedal feel, if u're concerned with brake fade, get ATE blue brake fluid or Motul RBF600 Dot4.
if you really want added braking ability setup, you have 2 options.
-OEM blank rotors and better brake pads. SS lines and ATE/Motul fluid are extras. Hawk HPS and Axxis Ultimate pads are the best for daily. Axxis outperforms Hawk a bit but gets REAL dusty. But i havent found Axxis Ultimates for the S197 yet.
-Saleen TWO-PIECE big brake setup-bigger rotors, BUT aluminum center hat so less unsprung weight vs. weight of bigger solid rotors and even OEM rotors. 4 piston calipers, and all the benefits and cosmetics. Your regular one-piece kit adds unsprung weight, ever wonder why the 2-piece is much more expensive? The braking feel is all based on the pads/fluids/SS lines, which in the Saleen/Brembos are better pads/lines already. They DO NOT "feel better" based on rotor size.
plenty of sources to back me up:
http://www.stoptech.com/tech_info/wp...upgrades.shtml
http://www.popularhotrodding.com/tec...ms/rotors.html
search "negatives of big brake kit" on google and you'll find your answers.
Bigger brake rotors are big for one main reason: Heat dissipation. Control of heat is the BIGGEST factor with braking ability. Heat to a certain level introduces brake fade, which drastically reduces your stopping ability. More surface area for braking? What about adding more unsprung rotation weight on the axle? Theres some physics for ya. Track pads (or even upgraded street pads) and upgraded fluid already does a fine job at controlling fade alone. Rotors are dead last in the equation. After a drag run, city driving, you will not be able to toast the brakes up enough to fully utilize the "benefits" of larger rotors. Larger rotors help cool in road racing applications, but even then, stock sized blank rotors do a FINE job at that without hurting times at all.
Drilled slotted rotors, ss lines, bigger rotors generally do not help braking ability. they are mostly for cosmetics.
-drilled/slotted-keeps pad cleaner and cools better, but CANNOT be resurfaced and reused after several pad changes. this is bad b/c deposits from old pads do not let the break-in compounds of the new pads to properly burn off on the rotors. so you'll end up replacing rotors every year or so. also, do not road race with drilled rotors.
-bigger rotors-increase surface area, BUT adds unsprung weight and counteracts benefit of bigger surface area.
-ss lines-more for pedal feel, if u're concerned with brake fade, get ATE blue brake fluid or Motul RBF600 Dot4.
if you really want added braking ability setup, you have 2 options.
-OEM blank rotors and better brake pads. SS lines and ATE/Motul fluid are extras. Hawk HPS and Axxis Ultimate pads are the best for daily. Axxis outperforms Hawk a bit but gets REAL dusty. But i havent found Axxis Ultimates for the S197 yet.
-Saleen TWO-PIECE big brake setup-bigger rotors, BUT aluminum center hat so less unsprung weight vs. weight of bigger solid rotors and even OEM rotors. 4 piston calipers, and all the benefits and cosmetics. Your regular one-piece kit adds unsprung weight, ever wonder why the 2-piece is much more expensive? The braking feel is all based on the pads/fluids/SS lines, which in the Saleen/Brembos are better pads/lines already. They DO NOT "feel better" based on rotor size.
plenty of sources to back me up:
http://www.stoptech.com/tech_info/wp...upgrades.shtml
Potential Impacts of Big Front Brakes Fortunately (from a safety standpoint anyway), when most big-brake suppliers adapt a mondo rotor and caliper package to a vehicle, they end up actually increasing the FRONT bias. How? By increasing the effective caliper piston area and the rotor effective radius, these two factors work together to increase the 'mechanical gain' of the front brakes, building more torque for the same pressure, everything else being equal. So, from a bias perspective we are not pushing the vehicle toward instability, but rather just the opposite - we are underbraking the rear axle! The obvious impact would be an increase in stopping distance - probably the one thing the new owner was actually hoping to reduce. Ironic. So, say you chose to install these big brakes on the front axle but want to maintain the OEM bias. What's the answer? Well, one way would be to invest in big rear brakes too which increase the rear mechanical gain to the point that the system is balanced once again. So, What's The Harm In Doing That? Well, let's look at why we upgraded the front brakes in the first place. Contrary to popular belief, the real reason sports- and racing cars use big brakes is to deal with heat. Period. There has been a bunch of stuff published which will disclaim this, but when you look at the braking system from a design standpoint, making them 'bigger' doesn't fundamentally do anything for stopping distance. It's all about the heat. So, you upgraded the front brakes because of thermal concerns but as a hidden surprise got a shift in brake bias. As a band-aid to this condition, you now spend thousands more on a rear brake upgrade because the front system was not sized correctly in the first place. Sure, it looks great, but there is another option... Which Is? When upgrading your front brakes, it is possible to size the caliper pistons and rotor effective radius to maintain the original brake system's pressure-torque relationship. Yea, it takes more engineering know-how and you can't sell the same part to everyone anymore, but you are not altering the base brake balance from what the OEM intended. This design philosophy stands behind every brake upgrade kit STOPTECH manufactures. Now, if you sized the front brakes correctly, why would you need to change the rear brakes? Good question. If there are no thermal concerns with the rear brakes (and on a front-engine street car there rarely are) then by installing a rear big-brake kit all you are doing is (a) spending money and (b) adding unsprung weight. This is not usually viewed as favorable, unless you like driving a heavy, expensive car.
Rotors
Rotors are all about mass and heat dissipation. Think of the rotor as the radiator of the brake system. During braking, huge amounts of heat are generated by the action of slowing the car. This heat needs to be shed as quickly as possible to keep from cooking the brakes, which can lead to fade, or worse, failure. The more metal in a rotor, the more it takes to get them overheated. The venting design of the rotor's fins helps circulate air through the rotor and shed this heat. Also, we all see big rotors and think they look really great filling up that wheel, but there is an added benefit to large rotors. A larger rotor will have more mass for better heat control and the larger diameter will allow more leverage for the caliper. There is a point of diminishing return since as the rotor gets bigger it also gets heavier; lots of rotating mass robs acceleration and hinders stopping. Like all things in life, a happy medium needs to be kept.
Rotors are all about mass and heat dissipation. Think of the rotor as the radiator of the brake system. During braking, huge amounts of heat are generated by the action of slowing the car. This heat needs to be shed as quickly as possible to keep from cooking the brakes, which can lead to fade, or worse, failure. The more metal in a rotor, the more it takes to get them overheated. The venting design of the rotor's fins helps circulate air through the rotor and shed this heat. Also, we all see big rotors and think they look really great filling up that wheel, but there is an added benefit to large rotors. A larger rotor will have more mass for better heat control and the larger diameter will allow more leverage for the caliper. There is a point of diminishing return since as the rotor gets bigger it also gets heavier; lots of rotating mass robs acceleration and hinders stopping. Like all things in life, a happy medium needs to be kept.
11-20-2007, 10:01 AM
#13
5th Gear Member
Join Date: Mar 2007
Location:
Posts: 2,033
RE: Slotted and Drilled Rotors with Hawk Pads
ORIGINAL: ChiDiddy
plenty of sources to back me up:
http://www.stoptech.com/tech_info/wp...upgrades.shtml
http://www.popularhotrodding.com/tec...ms/rotors.html
search "negatives of big brake kit" on google and you'll find your answers.
plenty of sources to back me up:
http://www.stoptech.com/tech_info/wp...upgrades.shtml
Potential Impacts of Big Front Brakes Fortunately (from a safety standpoint anyway), when most big-brake suppliers adapt a mondo rotor and caliper package to a vehicle, they end up actually increasing the FRONT bias. How? By increasing the effective caliper piston area and the rotor effective radius, these two factors work together to increase the 'mechanical gain' of the front brakes, building more torque for the same pressure, everything else being equal. So, from a bias perspective we are not pushing the vehicle toward instability, but rather just the opposite - we are underbraking the rear axle! The obvious impact would be an increase in stopping distance - probably the one thing the new owner was actually hoping to reduce. Ironic. So, say you chose to install these big brakes on the front axle but want to maintain the OEM bias. What's the answer? Well, one way would be to invest in big rear brakes too which increase the rear mechanical gain to the point that the system is balanced once again. So, What's The Harm In Doing That? Well, let's look at why we upgraded the front brakes in the first place. Contrary to popular belief, the real reason sports- and racing cars use big brakes is to deal with heat. Period. There has been a bunch of stuff published which will disclaim this, but when you look at the braking system from a design standpoint, making them 'bigger' doesn't fundamentally do anything for stopping distance. It's all about the heat.So, you upgraded the front brakes because of thermal concerns but as a hidden surprise got a shift in brake bias. As a band-aid to this condition, you now spend thousands more on a rear brake upgrade because the front system was not sized correctly in the first place. Sure, it looks great, but there is another option... Which Is? When upgrading your front brakes, it is possible to size the caliper pistons and rotor effective radius to maintain the original brake system's pressure-torque relationship. Yea, it takes more engineering know-how and you can't sell the same part to everyone anymore, but you are not altering the base brake balance from what the OEM intended. This design philosophy stands behind every brake upgrade kit STOPTECH manufactures. Now, if you sized the front brakes correctly, why would you need to change the rear brakes? Good question. If there are no thermal concerns with the rear brakes (and on a front-engine street car there rarely are) then by installing a rear big-brake kit all you are doing is (a) spending money and (b) adding unsprung weight. This is not usually viewed as favorable, unless you like driving a heavy, expensive car.
Rotors
Rotors are all about mass and heat dissipation. Think of the rotor as the radiator of the brake system. During braking, huge amounts of heat are generated by the action of slowing the car. This heat needs to be shed as quickly as possible to keep from cooking the brakes, which can lead to fade, or worse, failure. The more metal in a rotor, the more it takes to get them overheated. The venting design of the rotor's fins helps circulate air through the rotor and shed this heat. Also, we all see big rotors and think they look really great filling up that wheel, but there is an added benefit to large rotors. A larger rotor will have more mass for better heat control and the larger diameter will allow more leverage for the caliper. There is a point of diminishing return since as the rotor gets bigger it also gets heavier; lots of rotating mass robs acceleration and hinders stopping. Like all things in life, a happy medium needs to be kept.
Rotors are all about mass and heat dissipation. Think of the rotor as the radiator of the brake system. During braking, huge amounts of heat are generated by the action of slowing the car. This heat needs to be shed as quickly as possible to keep from cooking the brakes, which can lead to fade, or worse, failure. The more metal in a rotor, the more it takes to get them overheated. The venting design of the rotor's fins helps circulate air through the rotor and shed this heat. Also, we all see big rotors and think they look really great filling up that wheel, but there is an added benefit to large rotors. A larger rotor will have more mass for better heat control and the larger diameter will allow more leverage for the caliper. There is a point of diminishing return since as the rotor gets bigger it also gets heavier; lots of rotating mass robs acceleration and hinders stopping. Like all things in life, a happy medium needs to be kept.
11-20-2007, 10:23 AM
#14
Retired Mod
Join Date: Jan 2007
Location: Long Island, NY
Posts: 7,658
RE: Slotted and Drilled Rotors with Hawk Pads
ChiDiddy.... you point is only partially correct in my view. yes they do dissipate heat more and that is the enemy of continued stopping power and avoiding fade. The larger size increases stopping power overall and that was what was being discussed here...not the ability of the brakes to maintain the same (or similar) stopping power with continuous use.
Even your second quote discusses it:
"the larger diameter will allow more leverage for the caliper."
http://www.buybrakes.com/brembo/faq.html#q3
"Why use larger discs?
Braking generates heat, and the more heat the disc can absorb and dissipate, the greater the fade resistance of the system. Additionally, the use of a larger disc generally results in a larger effective radius, which increases brake torque."
Two different issues in my view...so I'll continue to flap my gums with your permission.....
Even your second quote discusses it:
"the larger diameter will allow more leverage for the caliper."
http://www.buybrakes.com/brembo/faq.html#q3
"Why use larger discs?
Braking generates heat, and the more heat the disc can absorb and dissipate, the greater the fade resistance of the system. Additionally, the use of a larger disc generally results in a larger effective radius, which increases brake torque."
Two different issues in my view...so I'll continue to flap my gums with your permission.....
11-20-2007, 10:50 AM
#15
4th Gear Member
Join Date: Jun 2006
Location: CA
Posts: 1,700
RE: Slotted and Drilled Rotors with Hawk Pads
ORIGINAL: ChiDiddy
Wow, some of you definitely need to do research before yapping your gums. I've done countless discussions on this topic on other forums and have done thorough research on it as i was looking for upgrading tips for braking in my personal track/drag conditions.
Bigger brake rotors are big for one main reason: Heat dissipation. Control of heat is the BIGGEST factor with braking ability. Heat to a certain level introduces brake fade, which drastically reduces your stopping ability. More surface area for braking? What about adding more unsprung rotation weight on the axle? Theres some physics for ya. Track pads (or even upgraded street pads) and upgraded fluid already does a fine job at controlling fade alone. Rotors are dead last in the equation. After a drag run, city driving, you will not be able to toast the brakes up enough to fully utilize the "benefits" of larger rotors. Larger rotors help cool in road racing applications, but even then, stock sized blank rotors do a FINE job at that without hurting times at all.
Drilled slotted rotors, ss lines, bigger rotors generally do not help braking ability. they are mostly for cosmetics.
-drilled/slotted-keeps pad cleaner and cools better, but CANNOT be resurfaced and reused after several pad changes. this is bad b/c deposits from old pads do not let the break-in compounds of the new pads to properly burn off on the rotors. so you'll end up replacing rotors every year or so. also, do not road race with drilled rotors.
-bigger rotors-increase surface area, BUT adds unsprung weight and counteracts benefit of bigger surface area.
-ss lines-more for pedal feel, if u're concerned with brake fade, get ATE blue brake fluid or Motul RBF600 Dot4.
if you really want added braking ability setup, you have 2 options.
-OEM blank rotors and better brake pads. SS lines and ATE/Motul fluid are extras. Hawk HPS and Axxis Ultimate pads are the best for daily. Axxis outperforms Hawk a bit but gets REAL dusty. But i havent found Axxis Ultimates for the S197 yet.
-Saleen TWO-PIECE big brake setup-bigger rotors, BUT aluminum center hat so less unsprung weight vs. weight of bigger solid rotors and even OEM rotors. 4 piston calipers, and all the benefits and cosmetics. Your regular one-piece kit adds unsprung weight, ever wonder why the 2-piece is much more expensive? The braking feel is all based on the pads/fluids/SS lines, which in the Saleen/Brembos are better pads/lines already. They DO NOT "feel better" based on rotor size.
plenty of sources to back me up:
http://www.stoptech.com/tech_info/wp...upgrades.shtml
http://www.popularhotrodding.com/tec...ms/rotors.html
search "negatives of big brake kit" on google and you'll find your answers.
Wow, some of you definitely need to do research before yapping your gums. I've done countless discussions on this topic on other forums and have done thorough research on it as i was looking for upgrading tips for braking in my personal track/drag conditions.
Bigger brake rotors are big for one main reason: Heat dissipation. Control of heat is the BIGGEST factor with braking ability. Heat to a certain level introduces brake fade, which drastically reduces your stopping ability. More surface area for braking? What about adding more unsprung rotation weight on the axle? Theres some physics for ya. Track pads (or even upgraded street pads) and upgraded fluid already does a fine job at controlling fade alone. Rotors are dead last in the equation. After a drag run, city driving, you will not be able to toast the brakes up enough to fully utilize the "benefits" of larger rotors. Larger rotors help cool in road racing applications, but even then, stock sized blank rotors do a FINE job at that without hurting times at all.
Drilled slotted rotors, ss lines, bigger rotors generally do not help braking ability. they are mostly for cosmetics.
-drilled/slotted-keeps pad cleaner and cools better, but CANNOT be resurfaced and reused after several pad changes. this is bad b/c deposits from old pads do not let the break-in compounds of the new pads to properly burn off on the rotors. so you'll end up replacing rotors every year or so. also, do not road race with drilled rotors.
-bigger rotors-increase surface area, BUT adds unsprung weight and counteracts benefit of bigger surface area.
-ss lines-more for pedal feel, if u're concerned with brake fade, get ATE blue brake fluid or Motul RBF600 Dot4.
if you really want added braking ability setup, you have 2 options.
-OEM blank rotors and better brake pads. SS lines and ATE/Motul fluid are extras. Hawk HPS and Axxis Ultimate pads are the best for daily. Axxis outperforms Hawk a bit but gets REAL dusty. But i havent found Axxis Ultimates for the S197 yet.
-Saleen TWO-PIECE big brake setup-bigger rotors, BUT aluminum center hat so less unsprung weight vs. weight of bigger solid rotors and even OEM rotors. 4 piston calipers, and all the benefits and cosmetics. Your regular one-piece kit adds unsprung weight, ever wonder why the 2-piece is much more expensive? The braking feel is all based on the pads/fluids/SS lines, which in the Saleen/Brembos are better pads/lines already. They DO NOT "feel better" based on rotor size.
plenty of sources to back me up:
http://www.stoptech.com/tech_info/wp...upgrades.shtml
Potential Impacts of Big Front Brakes Fortunately (from a safety standpoint anyway), when most big-brake suppliers adapt a mondo rotor and caliper package to a vehicle, they end up actually increasing the FRONT bias. How? By increasing the effective caliper piston area and the rotor effective radius, these two factors work together to increase the 'mechanical gain' of the front brakes, building more torque for the same pressure, everything else being equal. So, from a bias perspective we are not pushing the vehicle toward instability, but rather just the opposite - we are underbraking the rear axle! The obvious impact would be an increase in stopping distance - probably the one thing the new owner was actually hoping to reduce. Ironic. So, say you chose to install these big brakes on the front axle but want to maintain the OEM bias. What's the answer? Well, one way would be to invest in big rear brakes too which increase the rear mechanical gain to the point that the system is balanced once again. So, What's The Harm In Doing That? Well, let's look at why we upgraded the front brakes in the first place. Contrary to popular belief, the real reason sports- and racing cars use big brakes is to deal with heat. Period. There has been a bunch of stuff published which will disclaim this, but when you look at the braking system from a design standpoint, making them 'bigger' doesn't fundamentally do anything for stopping distance. It's all about the heat. So, you upgraded the front brakes because of thermal concerns but as a hidden surprise got a shift in brake bias. As a band-aid to this condition, you now spend thousands more on a rear brake upgrade because the front system was not sized correctly in the first place. Sure, it looks great, but there is another option... Which Is? When upgrading your front brakes, it is possible to size the caliper pistons and rotor effective radius to maintain the original brake system's pressure-torque relationship. Yea, it takes more engineering know-how and you can't sell the same part to everyone anymore, but you are not altering the base brake balance from what the OEM intended. This design philosophy stands behind every brake upgrade kit STOPTECH manufactures. Now, if you sized the front brakes correctly, why would you need to change the rear brakes? Good question. If there are no thermal concerns with the rear brakes (and on a front-engine street car there rarely are) then by installing a rear big-brake kit all you are doing is (a) spending money and (b) adding unsprung weight. This is not usually viewed as favorable, unless you like driving a heavy, expensive car.
Rotors
Rotors are all about mass and heat dissipation. Think of the rotor as the radiator of the brake system. During braking, huge amounts of heat are generated by the action of slowing the car. This heat needs to be shed as quickly as possible to keep from cooking the brakes, which can lead to fade, or worse, failure. The more metal in a rotor, the more it takes to get them overheated. The venting design of the rotor's fins helps circulate air through the rotor and shed this heat. Also, we all see big rotors and think they look really great filling up that wheel, but there is an added benefit to large rotors. A larger rotor will have more mass for better heat control and the larger diameter will allow more leverage for the caliper. There is a point of diminishing return since as the rotor gets bigger it also gets heavier; lots of rotating mass robs acceleration and hinders stopping. Like all things in life, a happy medium needs to be kept.
Rotors are all about mass and heat dissipation. Think of the rotor as the radiator of the brake system. During braking, huge amounts of heat are generated by the action of slowing the car. This heat needs to be shed as quickly as possible to keep from cooking the brakes, which can lead to fade, or worse, failure. The more metal in a rotor, the more it takes to get them overheated. The venting design of the rotor's fins helps circulate air through the rotor and shed this heat. Also, we all see big rotors and think they look really great filling up that wheel, but there is an added benefit to large rotors. A larger rotor will have more mass for better heat control and the larger diameter will allow more leverage for the caliper. There is a point of diminishing return since as the rotor gets bigger it also gets heavier; lots of rotating mass robs acceleration and hinders stopping. Like all things in life, a happy medium needs to be kept.
I spoke to Robin Burnett at great length a couple of weeks ago. For those of you that don't know who he his he drives the red S197 sponsored by Steeda in NASA's American Iron AND SCCA's A-sedan. Guess what - he runs on STOCK calipers and rotors. He has done this for 3 full seasons.
I recently ran at Buttonwillow Raceway Park on STOCK pads because it was a last minute decision to run. My sponsor popped the motor in his car, which I was supposed to drive. I got around okay. On my Hawk blues life would have been peachy.
Too many people think they NEED big brake kits. What they NEED to do is get educated and learn how to drive. 99% of people overuse their brakes. Brakes are getting bigger because cars are getting heavier. The GT500 has bigger brakes because it weighs 500lbs more than a GT - and it's all on the front. It doesn't stop any better or faster than a GT.
If people want to blindly throw their money away i'm accepting tire donations!
11-20-2007, 12:17 PM
#16
6th Gear Member
Join Date: Feb 2007
Location: state of confusion
Posts: 7,635
RE: Slotted and Drilled Rotors with Hawk Pads
ORIGINAL: RodeoFlyer
Brakes are getting bigger because cars are getting heavier. The GT500 has bigger brakes because it weighs 500lbs more than a GT - and it's all on the front. It doesn't stop any better or faster than a GT.
Brakes are getting bigger because cars are getting heavier. The GT500 has bigger brakes because it weighs 500lbs more than a GT - and it's all on the front. It doesn't stop any better or faster than a GT.
Norm
11-20-2007, 01:03 PM
#17
4th Gear Member
Join Date: Jul 2007
Location: Houston TX
Posts: 1,474
RE: Slotted and Drilled Rotors with Hawk Pads
ORIGINAL: Stkjock
ChiDiddy.... you point is only partially correct in my view. yes they do dissipate heat more and that is the enemy of continued stopping power and avoiding fade. The larger size increases stopping power overall and that was what was being discussed here...not the ability of the brakes to maintain the same (or similar) stopping power with continuous use.
Even your second quote discusses it:
"the larger diameter will allow more leverage for the caliper."
http://www.buybrakes.com/brembo/faq.html#q3
"Why use larger discs?
Braking generates heat, and the more heat the disc can absorb and dissipate, the greater the fade resistance of the system. Additionally, the use of a larger disc generally results in a larger effective radius, which increases brake torque."
Two different issues in my view...so I'll continue to flap my gums with your permission.....
ChiDiddy.... you point is only partially correct in my view. yes they do dissipate heat more and that is the enemy of continued stopping power and avoiding fade. The larger size increases stopping power overall and that was what was being discussed here...not the ability of the brakes to maintain the same (or similar) stopping power with continuous use.
Even your second quote discusses it:
"the larger diameter will allow more leverage for the caliper."
http://www.buybrakes.com/brembo/faq.html#q3
"Why use larger discs?
Braking generates heat, and the more heat the disc can absorb and dissipate, the greater the fade resistance of the system. Additionally, the use of a larger disc generally results in a larger effective radius, which increases brake torque."
Two different issues in my view...so I'll continue to flap my gums with your permission.....
"There is a point of diminishing return since as the rotor gets bigger it also gets heavier; lots of rotating mass robs acceleration and hinders stopping."
Brake torque does NOT help overall braking distance, but merely reduce pedal effort (as stated above) and have a greater thermal capacity as you have said. With the Brembo link, when talking about BBK's, keep in mind that the benefits of reduced braking distances are with the 2-piece system, not the one piece like 14" GT500 setup.
And i say again, a properly done stock brake system will still meet or even outperform your BBK's.
11-23-2007, 09:41 PM
#18
4th Gear Member
Join Date: Oct 2007
Location: Harrisburg PA
Posts: 1,778
RE: Slotted and Drilled Rotors with Hawk Pads
HeyChiDiddyor RodeoFlyercould one of you guys give us yourstep-by-step recommendation for the most cost-effective brake upgrade. It sounds like stock rotors and calipers are fine, assuming thats true...what are the best steps to improve braking performance for agressive street/occasional track usage. I have some ideas - guide me: pads, high-performance fluid, ss brake lines, brake ducts.
11-25-2007, 08:51 PM
#19
4th Gear Member
Join Date: Mar 2005
Location: California
Posts: 1,471
RE: Slotted and Drilled Rotors with Hawk Pads
ORIGINAL: exx1976
Uhh, no. Have you ever DONE a big brake upgrade? I went from 11" to 12" in the front of my last car, and the difference was immediate and measurable.
Yes, good pads and good tires will make a difference, butregarding the first phrase of your post, I'd sure like to see some evidence to back it up..
ORIGINAL: ChiDiddy
larger brake rotors do not help, its the pads, lines, and fluid that makes u feel the difference. Its all solely on the pads, and your tires.
larger brake rotors do not help, its the pads, lines, and fluid that makes u feel the difference. Its all solely on the pads, and your tires.
Yes, good pads and good tires will make a difference, butregarding the first phrase of your post, I'd sure like to see some evidence to back it up..
Youare mistaken about how brakes work and what is going on when you press on the break pedal. Brakes DO NOTstopthe car, TIRES stop the car. Brake systems justconvert the kinetic energyof the car's massinto heat, tires are thelimiting factor for stoping distanceif you have enough clamping force which EVERY modern car from the lowest KIA to the highest performance race cars have in spades.
There are many reasons that you may have perceived improved brake performance on you old car when installing largerdiam. rotors.Air in the brake lines, fluid leaks,glazed pads, worn pads, scored rotors damaged rotors etc. all reduce braking performance. The fact is that on any modern high-performance car with ABS if you can lock up the front tires and the rear tires lock up shortly after you have more than enough brake clamping force to stop the car as fast as is possible with the given brake system, brake bias, suspension, alignment and tires on the car. No amount of "extra" brake clamping force front and/or rear will stop the car any faster than the brakes on the car because more clamping force cannot be converted to more tire grip. More brake clamping pressure is frequently interpreted by drivers as "stopping better"but braking points on the road coursetell a different story just as insturmented brake testing does.
This is a fact and you can prove it to yourself if you have a fresh set of brakes and tires on the car. All you have to do isbuy one of thepopular G-meters and a set of larger brakes of your choice. Find a nice place to do your testing and baseline the stock brakes on the car and document thetrack and air temps of the test area. Nextyou just need to spend a day or two to install and fully bed and heat cyclethe new BBK rotors and pads. Once you have 3-4 complete heat cycles on the rotors retest under the same track and air temp conditions and you will have your answer which will be the same answer as everybody else how has actually performed insturmented brake testing, bigger rotors are no advantage until the stock brakes overheat.
Ah ha you say, I told you big brakes are better. Well no, not really as the stock S197GT brakes are more than adequately sized and can lock up the tires no problem. All you need to do is installrotors that are not made of cheap materials, a set of higher pads with a more reasonable MOT, wider heat range with a slightly higher friction coefficent than stock along with racing class brake fluid like Motul RBF600 or ATE Super Blue/Gold and spindle mounted brake cooling and front mounted ducts with 3" hose and you will bestopping even BETTER than the guy who only installed a BBK and is overheating his brakes.
HTH!
