Does anyone have any braking questions. - Page 87 - CorvetteForum - Chevrolet Corvette Forum Discussion

Notices
Autocrossing & Roadracing Suspension Setup for Track Corvettes, Camber/Caster Adjustments, R-Compound Tires, Race Slicks, Tips on Driving Technique, Events, Results
Sponsored by:
Sponsored by:

Does anyone have any braking questions.

Old 10-17-2018, 02:54 AM
  #1721  
fatbillybob
CF Senior Member
 
fatbillybob's Avatar
 
Member Since: Dec 2004
Posts: 2,893
Thanked 102 Times in 77 Posts
Default

Discounting wheel sizes are c5 big brake kits ok to move to c6 cars? The uprights are the same. What about master cylinder diameters or part numbets the same?
fatbillybob is offline  
Old 10-17-2018, 05:35 AM
  #1722  
Todd TCE
Supporting Vendor
 
Todd TCE's Avatar
 
Member Since: Jun 2008
Location: tempe Arizona
Posts: 1,980
Thanked 64 Times in 59 Posts
Default

Only difference are the flare fittings on the hard lines.
Todd TCE is offline  
Old 10-17-2018, 09:15 AM
  #1723  
[email protected]
Supporting Vendor
 
JRitt@essex's Avatar
 
Member Since: Oct 2009
Location: Charlotte NC
Posts: 1,186
Thanked 160 Times in 115 Posts
Default

Originally Posted by hemmerman View Post
Johnnie C:: im having issues with CC brakes. I get a warning message every start up saying "warn brakes" Chevy dealer here in middle TN is baffled. Im a GM employee and know some folks in Corvette quality. I wrote to one manager in Corvette brand quality in Warren MI. he tells me its probably one of the front pad sencers. Also another issue something is rubbing the wheel weights off the inside of the wheel about two inches in from the inside. . thanks for any help
I agree with everything Bill Dearborn said above. Listen to the man! It's something to do with the pad wear sensor, and the wheel weight is likely making contact with the caliper body. Check the caliper for witness marks. They shouldn't be making contact if you're on stock wheels, but if the adhesive fails and they start to sag, they could easily grab the caliper. Put a nice piece of Gorilla Tape over the wheel weights to make sure they don't drop down and hit the caliper.
JRitt@essex is offline  
Old 10-17-2018, 09:17 AM
  #1724  
[email protected]
Supporting Vendor
 
JRitt@essex's Avatar
 
Member Since: Oct 2009
Location: Charlotte NC
Posts: 1,186
Thanked 160 Times in 115 Posts
Default

Originally Posted by fatbillybob View Post
Discounting wheel sizes are c5 big brake kits ok to move to c6 cars? The uprights are the same. What about master cylinder diameters or part numbets the same?
C5 and C6 share master cylinders across the range and trim levels. With our Essex Designed AP Racing Brake Kits, the difference comes down to the brake lines. One chassis has a convex brake line fitting at the hard line attachment point, the other has a concave fitting. That's the reason for the different part numbers. Otherwise our C5 and C6 kits are the same. That may be different for other manufacturers though, so make sure you check with the specific manufacturer before swapping to a new chassis.
JRitt@essex is offline  
Old 10-17-2018, 11:23 AM
  #1725  
KNSBrakes
Supporting Vendor
 
KNSBrakes's Avatar
 
Member Since: Jul 2007
Location: Raleigh NC
Posts: 15,457
Thanked 78 Times in 72 Posts
Default

Stoptech kits have different piston sizes between base and Z06 on C5/C6 base cars and they observe the brake line difference as well.
KNSBrakes is online now  
Old 10-17-2018, 01:26 PM
  #1726  
mr.beachcomber
CF Senior Member
 
mr.beachcomber's Avatar
 
Member Since: Jan 2003
Location: Roswell Georgia
Posts: 711
Thanked 22 Times in 16 Posts
Default

If you are using the correct master cylinder for your '68, you should have two bleeder screws - one to bleed the front and the back reservoirs. When I was racing my '72 B Production Vette, I found that there would be a little air within the master cylinder even if I bench bled the unit first before installing. You might try re-bleeding the master cylinder as installed. (Double check that you haven't installed a master cylinder for power brakes on your manual system. The difference between the two is the internal bore size for the piston. The one for power brakes is larger and will give a mushy pedal on a manual system.)

You mentioned that you've gone through two quarts of brake fluid. I'm guessing this is from constant bleeding to get a firm pedal. It wouldn't hurt to check and see if you're weeping brake fluid around any of the fittings for the new calipers/master cylinder. It wouldn't hurt to check the rest of the steel/rubber lines/fittings also.

Hope this helps!

Last edited by mr.beachcomber; 10-17-2018 at 01:28 PM. Reason: Clarifying that the bore size referred to is "internal"
mr.beachcomber is offline  
Old 11-10-2018, 05:17 PM
  #1727  
rad63
Junior Member
 
Member Since: May 2016
Posts: 14
Thanks: 0
Thanked 0 Times in 0 Posts
Default Ice mode?

I am have 2008 C6 Z51, and I autocross it extensively. I run SCCA A street class, so car is basically stock.

I believe I experience "ice mode" from time to time, but not really sure: my brake pedal becomes rock hard and car doesn't stop. It is not consistent and never happens on the street, so no real way to reproduce.

Another theory is that after a lot of steering front wheels overheat together with brakes.

On my last run I failed to stop at straight line after finish, so I think that something is definitely not right.

I have stock Z51 rotors (probably original from 2008, 35k miles on them)
Stock Z51 brake pads (all changed 6 months ago)
Endless RF-650 brake fluid (changed 3 month ago)
Bridgestone RE71 tires (new)
rad63 is offline  
Old 11-10-2018, 06:06 PM
  #1728  
urslooow
CF Senior Member
 
urslooow's Avatar
 
Member Since: Feb 2002
Location: Miami Fl
Posts: 2,444
Thanks: 0
Thanked 2 Times in 2 Posts
Default ICE mode

if pedal remains hard u may have an issue w the brake booster. When it is starting to go u get a hard pedal that doesn’t stop the car
urslooow is offline  
Old 11-10-2018, 06:24 PM
  #1729  
tony 63 vette
CF Senior Member
 
Member Since: Dec 2005
Posts: 165
Thanks: 0
Thanked 0 Times in 0 Posts
Default chatter

Hello my name is Tony I have a c7 Z51 10k miles built 10/15 chatter comes and goes daily basis most noticible @ 40 mph light pedal any ideas???
tony 63 vette is offline  
Old 11-10-2018, 07:15 PM
  #1730  
rad63
Junior Member
 
Member Since: May 2016
Posts: 14
Thanks: 0
Thanked 0 Times in 0 Posts
Default

Originally Posted by urslooow View Post
if pedal remains hard u may have an issue w the brake booster. When it is starting to go u get a hard pedal that doesn’t stop the car
I *think* I also feel ABS kicking in when this happens. And never experience hard pedal on highway. So is it possible that brake booster only misbehaves at autocross?
rad63 is offline  
Old 11-11-2018, 12:48 AM
  #1731  
urslooow
CF Senior Member
 
urslooow's Avatar
 
Member Since: Feb 2002
Location: Miami Fl
Posts: 2,444
Thanks: 0
Thanked 2 Times in 2 Posts
Default

Originally Posted by tony 63 vette View Post
Hello my name is Tony I have a c7 Z51 10k miles built 10/15 chatter comes and goes daily basis most noticible @ 40 mph light pedal any ideas???
try bedding in the brake pads to the rotor. Do 10 consecutive 60-10 mph hard braking near-stops w/o invoking abs then let brakes cool over night. U should smell brakes when u park.

Last edited by urslooow; 11-11-2018 at 12:49 AM.
urslooow is offline  
Old 11-12-2018, 06:21 PM
  #1732  
Poor-sha
Track Rat
Support Corvetteforum!
 
Poor-sha's Avatar
 
Member Since: Oct 2006
Posts: 5,207
Thanked 2,032 Times in 828 Posts
Default

Originally Posted by rad63 View Post
I am have 2008 C6 Z51, and I autocross it extensively. I run SCCA A street class, so car is basically stock.

I believe I experience "ice mode" from time to time, but not really sure: my brake pedal becomes rock hard and car doesn't stop. It is not consistent and never happens on the street, so no real way to reproduce.

Another theory is that after a lot of steering front wheels overheat together with brakes.

On my last run I failed to stop at straight line after finish, so I think that something is definitely not right.

I have stock Z51 rotors (probably original from 2008, 35k miles on them)
Stock Z51 brake pads (all changed 6 months ago)
Endless RF-650 brake fluid (changed 3 month ago)
Bridgestone RE71 tires (new)
That could also be the pads overheating. Do you see any splotchs or what looks like smearing of pad material on the rotors? You should see an even layer of pad material.
Poor-sha is offline  
Old 11-28-2018, 09:12 PM
  #1733  
romandian
CF Senior Member
 
Member Since: Nov 2014
Location: Switzerland
Posts: 1,020
Thanked 34 Times in 34 Posts
Default

so i have been thinking, why are there no titanium pistons (or are threre)? ti is less conductive than stainless and stronger than aluminum. also i have come accross phenolic pistons. how good of an idea is that and why are they not more popular? phenolic is one of the hardest plastics but with todays abs i wouldnt trust it.
romandian is offline  
Old 11-28-2018, 09:18 PM
  #1734  
badhabit_wb
CF Senior Member
 
Member Since: Sep 2014
Location: in the country North Carolina
Posts: 2,021
Thanked 187 Times in 166 Posts
Default

badhabit_wb is offline  
Old 11-28-2018, 09:28 PM
  #1735  
Todd TCE
Supporting Vendor
 
Todd TCE's Avatar
 
Member Since: Jun 2008
Location: tempe Arizona
Posts: 1,980
Thanked 64 Times in 59 Posts
Default

Ti heat shields would seem to be equally effective for far less money. Given they go on the back of the pad plate the insulation value runs the length of the entire pad.

I stock them for all the Wilwood calipers and have them for the rear of the C5/6 now just have not done fronts.

Last edited by Todd TCE; 11-28-2018 at 09:28 PM.
Todd TCE is offline  
Old 11-29-2018, 08:32 AM
  #1736  
[email protected]
Supporting Vendor
 
JRitt@essex's Avatar
 
Member Since: Oct 2009
Location: Charlotte NC
Posts: 1,186
Thanked 160 Times in 115 Posts
Default

Originally Posted by romandian View Post
so i have been thinking, why are there no titanium pistons (or are threre)? ti is less conductive than stainless and stronger than aluminum. also i have come accross phenolic pistons. how good of an idea is that and why are they not more popular? phenolic is one of the hardest plastics but with todays abs i wouldnt trust it.
romandian,
Your conclusion is a logical one!

The current batch of elite-level racing calipers all have titanium pistons. Below are some shots of the AP Racing Radi-CAL calipers that just won the season championship in NASCAR Sprint Cup, along with some F1 calipers. As you noted, titanium does an excellent job of keeping heat out of fluid. At the highest level, weight savings is what makes titanium so desirable. It is incredibly lightweight, and the clear choice when cost is not a concern.

That said, it's also really expensive! Stainless steel is almost as good as titanium at keeping heat out of the fluid, except at a much lower cost. Stainless steel pistons were used in the Radi-CAL calipers that have won Le Mans on the Porsche 911 RSR and on the Corvette C7R, and we use stainless pistons on all of our Radi-CAL calipers that are available for corvettes. Phenolic pistons have been used in many places of the years, but haven't proven as effective, durable, etc under race conditions as stainless or titanium.

Below are some images of the titanium pistons found in AP Racing Radi-CAL calipers used in Formula 1, a NASCAR Cup, and GT3.

Formula 1



Sportscar Caliper




NASCAR Cup rear...yes, that caliper weighs 2.5 lbs., partially due to the titanium!



In my palm...tiny little guy...



When I was digging through my files I found this pic...obviously I was telling someone what I thought about aluminum pistons for track use along the way. Friends don't let friends track aluminum pistons! :p




Here are the ventilated stainless steel pistons we use in all of our Essex Designed AP Racing Radi-CAL Competition Brake Kits for Corvettes. They are incredibly effective at preventing brake fluid from boiling.



Here's what they look like on the back side. They have a domed back to add stiffness, and an anti-knockback spring attached.



Hopefully that gives you an idea of some other solutions that are being employed. If you want to see more pics of the Radi-CALs (they are automotive sculpture), check out our recent post about SEMA 2018 on the Essex Blog.
JRitt@essex is offline  
Old 11-29-2018, 03:58 PM
  #1737  
KNSBrakes
Supporting Vendor
 
KNSBrakes's Avatar
 
Member Since: Jul 2007
Location: Raleigh NC
Posts: 15,457
Thanked 78 Times in 72 Posts
Default

When you have all the moneys - you get titanium!
KNSBrakes is online now  
Old 11-29-2018, 04:41 PM
  #1738  
romandian
CF Senior Member
 
Member Since: Nov 2014
Location: Switzerland
Posts: 1,020
Thanked 34 Times in 34 Posts
Default

thanks folks. i was not avare of titanium pistons actually being used. that vid is interesting (i almost died watching it) but the conclusion is wrong imo. you would not make the titanium piston like the phenolic, there is no need for that "puck" type construction. a titanium piston of regular shape obviously has a smaller cross section and will conduct less heat.
romandian is offline  


Thread Tools
Search this Thread
Quick Reply: Does anyone have any braking questions.


Sponsored Ads
Vendor Directory

Contact Us About Us Archive Advertising Cookie Policy Privacy Statement Terms of Service

© 2018 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: