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No. While C5 brakes are newer in years on the planet, they are not better than C3 brakes. A four or six piston fixed caliper is a much better design than a floating caliper. When disc brakes started showing up on American passenger cars, they were mostly of the fixed caliper design. Once they became more common in the later '60s and early '70s, manufacturers went to floating calipers due to lower cost and ease of manufacture.
No. While C5 brakes are newer in years on the planet, they are not better than C3 brakes. A four or six piston fixed caliper is a much better design than a floating caliper. When disc brakes started showing up on American passenger cars, they were mostly of the fixed caliper design. Once they became more common in the later '60s and early '70s, manufacturers went to floating calipers due to lower cost and ease of manufacture.
Agreed, C3 brakes were ahead of their time when they came out in 1965 on the C2's. Think about having 4 wheel 4 piston disc brakes on a car in 1965. 99% of cars those days had 4 wheel drum brakes. They hold their own even today. In my stable of cars my '71 Vette stops the best and I don't even have power brakes.
Absolutely not!...the C4/C5 brakes are an inferior design to the C3 4 Piston fixed racing style caliper, at each wheel, front and rear, with 12 inch (11.75 inch to be exact) VENTED rotors at each wheel, front and rear. GM did not significantly improve the corvette brakes from the C3 design until the C6 Z06/ZR1/GS with a 6 piston fixed racing style front caliper and rear 4 piston fixed racing style caliper with a 14 inch drilled vented front rotor and a 13 inch rear drilled vented rotor. C3 brakes when operating correctly are simply state of the art from 65-82 and with proper ultra high performance summer only 17/18 inch tires are superior to most cars on the road today, except high end sports sedans and sports cars. I would not waste your time and money trying to improve a great system on a C3..the C3 brakes along with the transverse leaf spring independent rear suspension (even better with a monospring upgrade and heim joint strut rods) are the defining elements that made a C3 corvette light years ahead of most other cars at the time.
The weakness of the C3 brake design is the heavy weight of the cast iron calipers really for racing purposes, not so much for street driving at all, and the OEM design of the caliper piston bores being cast iron, not stainless steel polished like the aftermarket corrected starting in the 80's with rebuilt OEM 4 piston calipers.....all the OEM calipers will eventually rust and leak, if not rebuilt, with SS bores.
The simplest way to upgrade the C3 brakes for shorter stopping distances if the OEM system is operating correctly is Stainless steel braided brake hoses which will give you a harder firmer pedal for more linear brake control with high performance brake pads (IE Hawk HPS or Performance Friction carbon metallic- I have these now for abut 15 years), along with ultra high performance tires (17/18's). My car can stop on a dime with no drama.
The only way to improve the braking beyond the stock system and the comments above is the Wilwood 4 piston caliper or better the front 6 piston caliper which is aluminum for weight savings along with 13/14 front rotors. The wilwood 4 piston calipers on stock 12 inch OEM rotors will NOT brake better than the OEM system...it may feel different but the brake distances are determined by physics which will not improve with this change only.
Lastly, one correction above: The early brake calipers particularly from GM on cars EXCEPT the corvette were NOT fixed calipers. GM used exclusively front floating single piston calipers on all their cars starting in the mid 60's almost to the mid 2000's...fixed racing style brake calipers did not appear again on GM products until the C6Z06 and cars like the CTS-V until after the millennium.....tells you something about the how far advanced the C3 system was in 1965..............
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Lastly, one correction above: The early brake calipers particularly from GM on cars EXCEPT the corvette were NOT fixed calipers. GM used exclusively front floating single piston calipers on all their cars starting in the mid 60's almost to the mid 2000's...fixed racing style brake calipers did not appear again on GM products until the C6Z06 and cars like the CTS-V until after the millennium.....tells you something about the how far advanced the C3 system was in 1965..............
If you look at the calipers installed by OEMs in the '60s, GM, Ford, Mopar and even AMC, you will find fixed four-piston calipers. Kelsey-Hayes calipers on Mustang in '66, Thunderbirds, Galaxie, and on and on. My '67 Fairlane has factory discs with fixed four-piston KH calipers. Don't believe me? Go to rockauto and look up the OEMs around 1967 and gaze at the photos of those four-piston fixed calipers used on a '67 Caprice, or a '67 Pontiac Catalina. Floating calipers were far more common across the OEMs in the late '60s and early '70s, with the exception of the Corvette and certain 1st gen Camaros.
If you look at the calipers installed by OEMs in the '60s, GM, Ford, Mopar and even AMC, you will find fixed four-piston calipers. Kelsey-Hayes calipers on Mustang in '66, Thunderbirds, Galaxie, and on and on. My '67 Fairlane has factory discs with fixed four-piston KH calipers. Don't believe me? Go to rockauto and look up the OEMs around 1967 and gaze at the photos of those four-piston fixed calipers used on a '67 Caprice, or a '67 Pontiac Catalina. Floating calipers were far more common across the OEMs in the late '60s and early '70s, with the exception of the Corvette and certain 1st gen Camaros.
You are correct! Seems GM did use 4 piston calipers on the fronts only of some select vehicles, but abandoned them by the late 60's and certainly through most of the 80/90's as well. I am assuming that those vehicles with the front 4 piston fixed calipers used drum rear brakes? My mom's 72 Caprice with the 400 V8 had a single piston floating front caliper......
Absolutely not!...the C4/C5 brakes are an inferior design to the C3 4 Piston fixed racing style caliper, at each wheel, front and rear, with 12 inch (11.75 inch to be exact) VENTED rotors at each wheel, front and rear. GM did not significantly improve the corvette brakes from the C3 design until the C6 Z06/ZR1/GS with a 6 piston fixed racing style front caliper and rear 4 piston fixed racing style caliper with a 14 inch drilled vented front rotor and a 13 inch rear drilled vented rotor. C3 brakes when operating correctly are simply state of the art from 65-82 and with proper ultra high performance summer only 17/18 inch tires are superior to most cars on the road today, except high end sports sedans and sports cars. I would not waste your time and money trying to improve a great system on a C3..the C3 brakes along with the transverse leaf spring independent rear suspension (even better with a monospring upgrade and heim joint strut rods) are the defining elements that made a C3 corvette light years ahead of most other cars at the time.
The weakness of the C3 brake design is the heavy weight of the cast iron calipers really for racing purposes, not so much for street driving at all, and the OEM design of the caliper piston bores being cast iron, not stainless steel polished like the aftermarket corrected starting in the 80's with rebuilt OEM 4 piston calipers.....all the OEM calipers will eventually rust and leak, if not rebuilt, with SS bores.
The simplest way to upgrade the C3 brakes for shorter stopping distances if the OEM system is operating correctly is Stainless steel braided brake hoses which will give you a harder firmer pedal for more linear brake control with high performance brake pads (IE Hawk HPS or Performance Friction carbon metallic- I have these now for abut 15 years), along with ultra high performance tires (17/18's). My car can stop on a dime with no drama.
The only way to improve the braking beyond the stock system and the comments above is the Wilwood 4 piston caliper or better the front 6 piston caliper which is aluminum for weight savings along with 13/14 front rotors. The wilwood 4 piston calipers on stock 12 inch OEM rotors will NOT brake better than the OEM system...it may feel different but the brake distances are determined by physics which will not improve with this change only.
Lastly, one correction above: The early brake calipers particularly from GM on cars EXCEPT the corvette were NOT fixed calipers. GM used exclusively front floating single piston calipers on all their cars starting in the mid 60's almost to the mid 2000's...fixed racing style brake calipers did not appear again on GM products until the C6Z06 and cars like the CTS-V until after the millennium.....tells you something about the how far advanced the C3 system was in 1965..............
Very well put.
Bolded, that was the biggest "seat of the pants feel" improvement made to my brake system. Not sure if it was just the crappy, dry-rotted rubber lines I replaced but it sure made a huge difference.
Think about it. With whatever hydraulic pressure the system is running at through rubber lines the rubber is going to expand (even by a small amount) and you'll lose some pedal firmness. With braided steel lines they cannot expand so all the pressure is exerted on the pistons.
Thanks to all for the advice, I should have mentioned that she has VB front/rear susp ,SS brake lines & Hawk pads.
Any suggestions on brake fluid for auto x ? 5-6 times a year ?
Originally Posted by theandies
Very well put.
Bolded, that was the biggest "seat of the pants feel" improvement made to my brake system. Not sure if it was just the crappy, dry-rotted rubber lines I replaced but it sure made a huge difference.
Think about it. With whatever hydraulic pressure the system is running at through rubber lines the rubber is going to expand (even by a small amount) and you'll lose some pedal firmness. With braided steel lines they cannot expand so all the pressure is exerted on the pistons.
Last edited by 1972.5; Oct 9, 2017 at 10:32 PM.
Reason: premature send
Either one will be fine on the street, but the DOT4 Racing fluid has a much higher WET boiling point which will prevent boiling fluid at high temps and extreme use. When looking at fluids, be sure to look at WET boiling point. Lots of fluids have high dry boiling points, but brake fluid likes to absorb water. As soon as you open a bottle it starts absorbing water from the air. A fluid with a higher WET boiling point will be more effective.
Either one will be fine on the street, but the DOT4 Racing fluid has a much higher WET boiling point which will prevent boiling fluid at high temps and extreme use. When looking at fluids, be sure to look at WET boiling point. Lots of fluids have high dry boiling points, but brake fluid likes to absorb water. As soon as you open a bottle it starts absorbing water from the air. A fluid with a higher WET boiling point will be more effective.
Or you can use DOT 5 silicone that is hydrophobic. That's what I use. Works great and has good boiling point performance. Plus it won't eat your paint if you happen to spill a little.
Dry boiling point Wet boiling point
DOT 3 205 °C (401 °F) 140 °C (284 °F)
DOT 4 230 °C (446 °F) 155 °C (311 °F)
DOT 5 260 °C (500 °F) 180 °C (356 °F)
DOT 5.1 260 °C (500 °F) 180 °C (356 °F)
Absolutely not!...the C4/C5 brakes are an inferior design to the C3 4 Piston fixed racing style caliper, at each wheel, front and rear, with 12 inch (11.75 inch to be exact) VENTED rotors at each wheel, front and rear. GM did not significantly improve the corvette brakes from the C3 design until the C6 Z06/ZR1/GS with a 6 piston fixed racing style front caliper and rear 4 piston fixed racing style caliper with a 14 inch drilled vented front rotor and a 13 inch rear drilled vented rotor. C3 brakes when operating correctly are simply state of the art from 65-82 and with proper ultra high performance summer only 17/18 inch tires are superior to most cars on the road today, except high end sports sedans and sports cars. I would not waste your time and money trying to improve a great system on a C3..the C3 brakes along with the transverse leaf spring independent rear suspension (even better with a monospring upgrade and heim joint strut rods) are the defining elements that made a C3 corvette light years ahead of most other cars at the time.
The weakness of the C3 brake design is the heavy weight of the cast iron calipers really for racing purposes, not so much for street driving at all, and the OEM design of the caliper piston bores being cast iron, not stainless steel polished like the aftermarket corrected starting in the 80's with rebuilt OEM 4 piston calipers.....all the OEM calipers will eventually rust and leak, if not rebuilt, with SS bores.
The simplest way to upgrade the C3 brakes for shorter stopping distances if the OEM system is operating correctly is Stainless steel braided brake hoses which will give you a harder firmer pedal for more linear brake control with high performance brake pads (IE Hawk HPS or Performance Friction carbon metallic- I have these now for abut 15 years), along with ultra high performance tires (17/18's). My car can stop on a dime with no drama.
The only way to improve the braking beyond the stock system and the comments above is the Wilwood 4 piston caliper or better the front 6 piston caliper which is aluminum for weight savings along with 13/14 front rotors. The wilwood 4 piston calipers on stock 12 inch OEM rotors will NOT brake better than the OEM system...it may feel different but the brake distances are determined by physics which will not improve with this change only.
Lastly, one correction above: The early brake calipers particularly from GM on cars EXCEPT the corvette were NOT fixed calipers. GM used exclusively front floating single piston calipers on all their cars starting in the mid 60's almost to the mid 2000's...fixed racing style brake calipers did not appear again on GM products until the C6Z06 and cars like the CTS-V until after the millennium.....tells you something about the how far advanced the C3 system was in 1965..............
I know your reply is a little over a year old, thanks for the enlightenment regarding C3 brakes/system.
Once you get to the point of locking up the brakes, you don't need bigger brakes. They will only lock up the brakes faster. Without ABS that is not desirable. The only good effect bigger brakes have is because of the larger rotor, it will take longer to overheat them.
I can consistently lock up my brakes with my stock system on my 76 while auto crossing. That is even with running Hoosier A7s.
If you look at some of the vintage racers, they use the stock brake calipers (they're most likely regulated to these by the sanctioning body). However, they install a spacer between the two halves to widen them. That way, they can run thicker pads and rotors to keep the heat dissipated.
On the street, you will not notice any better system than the stock one. It's not until you go racing that upgrading some things will make a difference. For the most part, big brake kits are just propaganda to get people to buy them.
Once you get to the point of locking up the brakes, you don't need bigger brakes. They will only lock up the brakes faster. Without ABS that is not desirable. The only good effect bigger brakes have is because of the larger rotor, it will take longer to overheat them.
I can consistently lock up my brakes with my stock system on my 76 while auto crossing. That is even with running Hoosier A7s.
If you look at some of the vintage racers, they use the stock brake calipers (they're most likely regulated to these by the sanctioning body). However, they install a spacer between the two halves to widen them. That way, they can run thicker pads and rotors to keep the heat dissipated.
On the street, you will not notice any better system than the stock one. It's not until you go racing that upgrading some things will make a difference. For the most part, big brake kits are just propaganda to get people to buy them.
This comes up often is simply not true that having bigger rotors only advantage is to keep the brakes cooler longer...yes that is true BUT all the major sportcars today use BIGGER rotors and multi-piston calipers because BOTH increase clamping force AND brake torque reducing stopping distances. There always seems to be a lot of confusion around this issue so I will post what I have written about this brake issue now many times:
There is not much to debate on this issue since it all comes down to physics.............................
There are 4 ways to increase the brake torque of a C3, reduce the stopping distance, besides better tires:
1. Increased coefficient of friction of the brake pads
2. Increased rotor diameter-increased brake torque
3. Increased caliper piston area-increased clamping force
4. Brake line pressure in PSI
Clamping force: The clamping force of a caliper is the force exerted on the disc by the caliper pistons. Measured in pounds clamping force, it is the product of brake line pressure, in psi, multiplied by the total piston area of the caliper in square inches. This is true whether the caliper is of fixed or floating design. Increasing the pad area will not increase the clamping force.
Braking torque: When we are talking about results in the braking department we are actually talking about braking torque - not line pressure, not clamping force and certainly not fluid displacement or fluid displacement ratio. Braking torque in pounds-feet on a single wheel is the effective disc radius in inches times clamping force times the coefficient of friction of the pad against the disc all divided by 12. The maximum braking torque on a single front wheel normally exceeds the entire torque output of a typical engine.
Clamping force is brake line pressure X total piston area of caliper in square inches
Brake Torque (The Holy Grail)= DISC RADIUS (half the diameter of the rotor) x Clamping force X the coefficient of friction of the brake pad.
The brake torque number can be increased with a larger diameter rotor which is why high performance cars today have 14/15/16 inch rotors usually with a LARGER caliper of 4/6 pistons (more piston area with more clamping force) versus the standard size caliper for that car.
I did larger rotors and increased piston number per caliper on 2 of my cars to increase the brake torque and the change was monumental:
2008 Chrysler 300 Limited: Went from single piston floating front caliper with a 12 inch rotor to Hemi Dual piston front caliper with 2 BIG pistons versus 1 piston and 14 inch front rotor...Holy Smokes did this change increase the brake torque! Car stops like a sports car now and it is HEAVY, no less.
1994 Mustang GT-Went from single piston floating front caliper with 11 inch rotor, changed to Cobra dual Piston front caliper with 13 inch rotors AND changed the GT master Cylinder to a Cobra MC for more line pressure. BIG DIFFERENCE in brake torque
Last edited by jb78L-82; Feb 28, 2018 at 01:58 PM.
JB78L-82 - you certainly have a good grip (excusing the pun) on C3 brakes. I like the tech!
I've yet to see anyone so far who is using larger rotors and calipers who has been able to demonstrate improved braking performance other than by personal opinion - so no measured stopping distances - no measured skid marks etc - just personal accounts of how good their brakes are. I am alone in not wishing to lay out serious bucks (in my case quids) for a big brake kit without knowing whether or not my 18" wheeled C3 is going to stop better?
Last edited by roscobbc; Feb 28, 2018 at 04:40 PM.
JB78L-82 - you certainly have a good grip (excusing the pun) on C3 brakes. I like the tech!
I've yet to see anyone so far who is using larger rotors and calipers who has been able to demonstrate improved braking performance other than by personal opinion - so no measured stopping distances - no measured skid marks etc - just personal accounts of how good their brakes are. I am alone in not wishing to lay out serious bucks (in my case quids) for a big brake kit without knowing whether or not my 18" wheeled C3 is going to stop better?
Funny!
I don't have numbers but can tell you on the 2 others cars that I have done caliper upgrades and larger rotors (2008 Chrysler 300 now with hemi brakes and 94 Mustang GT now with cobra Rotors, Calipers and MC), there is zero doubt in my mind that both cars can stop not only faster, without any lockup, but with less drama. I also did a rotor only upgrade (11 to 12 inch rotors only) on my 2001 Pontiac Grand Prix and the difference in non lockup braking is noticeable.
On My C3, I run stock rotors and calipers with Performance Friction pads and braided Stainless Steel brake lines...no other changes so cannot personally comment since I have not done the upgrade.
What little I know about brakes has come from my dad. He was a brake technician at the Bosch (Bendix and Allied Signal before that) proving grounds for nearly 30 years. He tested everything from jeeps, mustangs, corvettes, all the way up to semis. He has told me on numerous occasions that once you get to the point of locking up the brakes at will, there is no need for bigger brakes except for the heat dissipation. Having said that, ABS system cars can benefit more from the bigger brakes because the ABS can cycle the brakes faster. Our non ABS cars really can't benefit. The best option is brake pads.
I run stock brake setup with stainless lines and Hawk HPS pads. I can lockup the tires whenever I want to and I have to modulate the brake pedal to keep from doing so while racing. I autocross the car and am very competitive with it. Have won several overall FTDs on courses that don't require horsepower, beating C5s and C6s.
You can put bigger brakes on a car and then reduce the pad fiction to keep from locking up, but why? There wouldn't be any gain.
If you look at the calipers installed by OEMs in the '60s, GM, Ford, Mopar and even AMC, you will find fixed four-piston calipers. Kelsey-Hayes calipers on Mustang in '66, Thunderbirds, Galaxie, and on and on. My '67 Fairlane has factory discs with fixed four-piston KH calipers. Don't believe me? Go to rockauto and look up the OEMs around 1967 and gaze at the photos of those four-piston fixed calipers used on a '67 Caprice, or a '67 Pontiac Catalina. Floating calipers were far more common across the OEMs in the late '60s and early '70s, with the exception of the Corvette and certain 1st gen Camaros.
My father bought a brand new Camaro, in 1967, and he ordered the disc brake option. Part of this option was the "rally" wheel, whose center was specially shaped to clear the wide calipers, the same as the Corvette's.
So, just for the hell of it I'll ask. Where did the idea originate that the rotor should be within 4" of the wheel size, 18" wheel and a 14" Rotor, 17" & 13" Rotor ?
Is this just BS & style points, or does it have any merit for the common guy who thinks he pushes the envelope on occasion ?
