Looking to upgrade calipers and rotors for my 82. I will be upgrading to 18" wheels. Are C5 or C6 calipers an option for me? Trying not to spend what Wilwood wants for an upgrade if I could find some good used C5 or C6 red calipers. Thanks all!

 

you could just upgrade your brake pads....The good ceramics will put you through the windshield if thats what your looking for. I upgraded my stock calipers to O rings with a CSBBinc kit and used VHT caliper paint to paint them red

 

Unless you plan to race the car, the stock 4 piston fixed racing style OEM calipers, front AND rear with 12 inch vented rotors, front AND rear, are pretty darn good, even today, and were state of the art brakes from 1963-1982. Try and find any mass market car with fixed 4 piston calipers in the both the front and rear of most modern cars...they hardly exist except on very high end performance sedans and sportscars....

Forget the C5 caliper and brake system except the C5Z06 and just maybe..it is not an upgrade over the C3 system. The C6Z06/GS/ZR1 with a 6 piston massive front fixed caliper with a 14 inch drilled rotor and 4 piston fixed rear caliper with a 13 inch drilled rotor is a BIG upgrade but requires works to retrofit and bigger wheels.

I would do what I have for brakes on my C3, many years ago:

1. Flush your brake fluid every 3-5 years with new fluid
2. High Performance brake pads-Performance Friction Carbon Metallics or Hawk HPS...even standard semi metallics work extremely well. I would stay away from ceramic pads which are more for standard street driving with minimal rotor wear, less brake dust, and average stopping distances, secondary.
3. Ultra High performance summer only 17/18 inch tires-This change alone will greatly decrease your stopping distances under threshold braking.
4. Stainless Steel braided brake hoses, front and rear, will greatly increase brake pedal firmness, reduces brake hose expansion under extreme brake application for more consistent linear brake modulation with the brake pedal.

Do this ^^^^ and you will be surprised at the outcome, assuming your current brake system is in top shape.

 

I’ve had to emergency a few times already this summer with idiots merging into the street or highway incorrectly causing me to panic stop to avoid swerving into the other lanes. I wish I had videos of these idiots, it’s like classic cars are magnets to these *** clowns. Well anyhow I easily stopped the wheels from turning and had to start pumping the brakes to avoid a long skid. Bigger brakes are going to do the same thing. Bigger brakes will cool faster if your racing but other than that, not having an ABS system you may just Be wasting money. If you want less effort upgrade to power brakes. That alone drastically improved my mess then the Hawk ceramics put them over the top

 

Not to digress, but bigger brakes do provide better cooling for the brake system and longer repeatedly high speed braking without fade but also bigger rotors with bigger multi piston calipers with a bigger brake pads, most importantly, allow for much bigger brake TQ at the wheel/tire which is what slows a high performance car faster, short of lock up, than a lesser brake system.

i can assure you that my 73 Nova I had in college with 4 wheel power drum brakes could easily lock all 4 wheels BUT the braking distances that occurred short of that lockup were MUCH longer in 99% of braking events in real world driving...no question. The brake distances were dangerously long, short of locking all 4 wheels in a panic stop (and the loss of control with that braking event).

Bigger brake systems will slow any car much quicker in 99.9% of driving NOT involved in total brake wheel/tire lockup. No one drives/brakes with all 4 wheels locked......Not only does that type of driving lead to dangerous loss of control but you would need new tires every week.....

When I switched the Mustang GT brakes to the cobra front brakes about 15 years ago, there was a HUGH difference in brake TQ in everyday driving....not debatable...with the exact same tire before and after.the brake swap.....

There seems to be a LOT of confusion that any brake system that can lock the tires amounts to equivalent brake events (not about cooling) but equal brake distances......not so simple as just wheel lockup....

 

If you are just doing a pad swap, my personal experience with ceramics was uneven braking and having to stand on the pedal until they heated up (autocross). Hawk's web site has a nice graph that shows the coefficient of friction vs temperature for various materials. Worth a look to get some idea of what's best for you.

 

If you're not doing track days, I'd probably just get this kit from Vansteel - new vented rotors and Hawk brake pads for $600. This with some good fresh brake fluid should stop you quick on the street.
https://www.vansteel.com/index.cfm?f...p=3111&ID=2888



I have a heavily modified stock configuration brake system (stock size rotors & calipers) with cooling ducts, and can just about throw you thru the windshield repeatably on high performance tires without locking up the tires. I've lightened my system with alot of aluminum parts and cool it better than stock, but a factory system is very good for panic stocks on the street.

Here is an example of what I mean. Data taken from a track event showing I'm pulling over 1G while braking lap after lap (see first column). I was pulling so hard on my factory seat belts I fatigued the re-tracker and broke the seat belt mechanism so the belts wouldn't tighten up or retract anymore - had to send them in for a rebuild. After that I quit using the factory seat belts on the track and switched to a harness. The factory configuration when in good working order is pretty darn great - you don't have to totally swap out brakes, just get yours working like they should and you'll probably be amazed.

 

Jason: How are you collecting this data? Max brake g's could be illusory as stopping distance is what really matters. Hitting a high instantaneous longitudinal number is OK, but not enough for me. I have similar numbers from Harry's Lap timer for my Wilwoods but I'd like a little more insight.

I've been fooling around with some electronics to calculate stopping distance from say 70 to 0, just to compare with published numbers on other cars. Does your on board computer do anything like that?

Oh and good recommendations on part replacement. I've gotten good performance out of the Hawk pads.

 

Regretfully I haven't taken a 70-0 stopping distance measurement like during a panic stop because all my data is recorded from open track day events. I record it on a Traqmate data system. I plotted some data in a couple of the turns just to share some info.

Someday, I would love to do a 70-0 test comparing modern high performance 17"+ tires and say some BFG's just to see the difference, but I don't have any BFG's anymore. Do like 10 stops each and see how they compare initially and how fast they fade upon repeated stops.

Here is some data from ~120 to 80 mph. Over Segment 2, the average brake deceleration rate ranged from .83-.91 G's over a 2 second time period compared to pk G's of 1.01-1.06 in the same turn. Due to the elevated speed the distance traveled was about 318 feet.




Here is data from ~90-70 mph. Over Segment 4 the average brake deceleration rate ranged from .87-.95 G's over a 1 second time period compared to pk G's of 1.03-1.09 in the same turn. Distance traveled was about 136 feet.

 

Thanks for taking the time to post this Jason, appreciate it. Your deceleration numbers look really good for our brakes. I would guess you are right on the edge to hold those numbers at those speeds.

I calculate stopping from 70 MPH to zero is about 160 ft if you can maintain 1G. That is just kinematics. The benchmark for the average supercar, including C7's, seems to be about 135 ft.

I did a lot of work on my brakes but it is still essentially GM tech from the 60's with better pads and calipers. I have a plan and some cheap electronics to boot, nothing fancy but it's been a low priority. And the other issue is where to do this. Needs to be somewhere straight flat and safe and with some reasonably sticky tires. And where I won't get arrested.

Not expecting to get anywhere near these cars but I would hope to be considerably better than the road test reports on C3's from their introduction in the 60's and 70's.

 

Ignatz, FWIW, in 1978, in the Road and Track road test summaries for all cars tested that year by the magazine, the 1978 C3 corvette with stock brakes and OEM GM pads stopped from 80 MPH-0 in 244 ft. There were only 2 cars that year that were better than the 1978 corvette in braking from 80 MPH to zero of all the cars sold in the USA, the 1978 Porsche 930 Turbo and the 1978 Ferrari Berlinetta Boxer, at 239ft and 241 ft, respectively, a difference of 5 ft and 3 ft.....from 80 MPH. Thought you might be interested in this data....The C3 brakes were still state of the art all the way through 1982 and compared to the C4 brakes, as well.

 

jb: Thanks for looking that up. I have a R&T publication on just C3's, all years, all mentions, that shows 60-0 as 155' and 80-0 as 265' for a 77 and 150' and 254' for a 1981. That comparison also included a 944 at 149'. These are their classic standard reviews from that era with all the parameters. They also posted deceleration numbers for a small block at 0.84 and a big block at 0.74.

There are some pictures that show a bicycle wheel attached to the rear of the car with some sort of Heuer elex., so it is not just some guy with a stop watch and tape measure.

No 70-0 numbers so if I want to compare that, it will have to be the modern era cars.

Side note: I had a GTO with drum brakes that couldn't come to a complete stop once you got above 80 MPH. It was criminal to sell cars like that.

 

Ignatz,

The 78 C3 braking number from 80-0 MPH @ 244 ft is pretty typical for C2/C3's with the 4 wheel disc brakes and the reference of the Porsche 930 Turbo and Ferrari Boxer all with brake numbers within the margin of error are great comparators of how good the C3 brakes were in 1978 versus the best cars in the world at that time.

I do know that the 244 ft number from 80 MPH in 1978 was with the optional Gymkhana suspension AND the 255/60/15 Eagle GT tires. I would be curious to know if the 77 C3 and 81 C3 brake numbers you quoted were vettes with the optional 255/60/15 tires or the standard 225/60/15 tires? Obviously, the 255 tires will brake shorter...........the base 225 tires would produce significantly longer brake distances. I would bet the C3 77 number @265 was with base 225 polyglass tires...

FWIW-My 78 with 255/45/17 ultra high performance summer only tires with SS braided brake lines and Performance Friction pads heated up could smash that 244 ft brake number easily...no contest....

 

Here are all the cars tested, including tires and weights. Had to go back and forth a lot I think I got this right

A 1973 (178/314) had Firestone GR70-15's (3815#'s). This was an LT-1 and it doesn't say why it was so heavy, R&T complained about the Firestones
A 1977 (155/265) had Firestone Steel Radial 500 GR70-15's (3540#'s)
A 1980 (130/268) had Goodyear Eagle GT's P255/60 R-15's (3590#'s)
A 1981 (130/268) had Goodyear Eagle GT's P225/60 R-15's (3430#'s)
A 1982 (150/254) had Goodyear Eagle GT's P255/60 R-15's (3505#'s) I had the wrong year for this car in my first post

A modified 454 weighing over two tons was also test with Michelins. Stopping from 80 was 310'. They did not like the car's performance at all but it was comfy cruising

I have no doubt you (or I) can beat these numbers

 

Thanks..not surprised the 77 brake numbers are with the skinny 225 tire! The 80/81, one with the 225 tire the other with the 255 having the EXACT numbers from 80 MPH and 60 mph for 2 different years with 2 different size tires looks very suspicious............Highly unlikely....something not right there....

 

Agreed but that's what's there in print. .

I didn't read the text maybe there's an explanation but I didn't care to dig that far.