ZL1 / CTS-V Brakes

[JusticePete]

The OE or Pedders Camaro SS lines will work with the 2010 CTS-V calipers. When we ordered our CTS-V parts we did need to order the pins and clips separately. That may have changed, but the OE SS lines will work with the CTS-V calipers.

[radz28]

Have you guys gotten where you wanted to with regard to balance between the front and rear pads? (I'm thinking about the comments from the shootout if I remember correctly.)

[JusticePete]

Originally Posted by radz28

Have you guys gotten where you wanted to with regard to balance between the front and rear pads? (I'm thinking about the comments from the shootout if I remember correctly.)

The OE CTS-V pads have perfect bias. We have the same perfect bias with Cobalt Friction XR1 pads front and XR2 pads rear. We found the XR3 to be too mild for the rear so the switch to XR2 rear got us back to perfect.

[radz28]

Originally Posted by JusticePete

The OE CTS-V pads have perfect bias. We have the same perfect bias with Cobalt Friction XR1 pads front and XR2 pads rear. We found the XR3 to be too mild for the rear so the switch to XR2 rear got us back to perfect.

SWEET!!! I'm going to make sure to take notes!!!

[Beauwulf]

Originally Posted by JusticePete

You're right about needing acess to a GM service center at times. That is why I really appreciate the access I have at Witt, especially when doing GM based R & D. The master cyclinders are different on a six. Full retail on a new master is ONLY $123.81 so we are not talking big bucks. If there is a six owner looking to upgrade we would like to do it here at Witt. Then we can post the results here.

Hey Pete... any way to find out the MC's piston dia and stroke for the SS master? I'll do my V6 master and compare the ratios next week when I do the SS Brembos.

[JusticePete]

Originally Posted by Beauwulf

Hey Pete... any way to find out the MC's piston dia and stroke for the SS master? I'll do my V6 master and compare the ratios next week when I do the SS Brembos.

Sure, I'll ask.

[Beauwulf]

Thanks M8!

[JusticePete]

Originally Posted by Beauwulf

Thanks M8!

Nothing yet. Sorry.

Btw, you are all invited to visit with us during PRI at booth 5755!

[Chris_B]

Originally Posted by Beauwulf

any way to find out the MC's piston dia and stroke for the SS master? I'll do my V6 master and compare the ratios next week when I do the SS Brembos.

V8: 1-1/16"
V6: 1"

These are the easily measurable bores. Tandem bores are often used, meaning the front and rear circuits have different effective areas. I haven't had either of these apart yet to check, so be careful in any calculations you might use these numbers for.

Also, stroke is irrelevant when looking at brake bias or other hydraulic calculations. It only needs to have enough to prevent bottoming out.

[Beauwulf]

Originally Posted by Chris_B

V8: 1-1/16"
V6: 1"

These are the easily measurable bores. Tandem bores are often used, meaning the front and rear circuits have different effective areas. I haven't had either of these apart yet to check, so be careful in any calculations you might use these numbers for.

Also, stroke is irrelevant when looking at brake bias or other hydraulic calculations. It only needs to have enough to prevent bottoming out.

So you have, in effect, 6% more effort to generate the same brake force with the V6 master. Total volumn of fluid does matter (stroke) in the total pedal travel, which will
be longer with the V6 master than with the SS master.

[Chris_B]

Originally Posted by Beauwulf

So you have, in effect, 6% more effort to generate the same brake force with the V6 master. Total volumn of fluid does matter (stroke) in the total pedal travel, which will
be longer with the V6 master than with the SS master.

The V6 M/C will generate more line pressure (10.1%, not 6%) with the same pedal effort as compared to the V8, not the other way around. The pedal stroke will increase (by the same 10.1%) for the same amount of fluid displacement, yes, but the maximum stroke allowed by the master cylinder should not come into play unless there is air in the system somewhere.

Bottom line: When using the V6 M/C, the pedal effort will be less to get wheel lockup (or engage the ABS), but also will have a longer pedal. This statement assumes the same brake equipment is being used at the corners and only the M/C's are being compared. The V8 M/C will feel a little firmer (less pedal travel), but require additional pedal effort to get into the ABS. If 10% is no big deal to the driver, then a change would not be necessary. For drivers with more braking finesse, it's 10% in the wrong direction.

[Beauwulf]

Originally Posted by Chris_B

The V6 M/C will generate more line pressure (10.1%, not 6%) with the same pedal effort as compared to the V8, not the other way around. The pedal stroke will increase (by the same 10.1%) for the same amount of fluid displacement, yes, but the maximum stroke allowed by the master cylinder should not come into play unless there is air in the system somewhere.

Bottom line: When using the V6 M/C, the pedal effort will be less to get wheel lockup (or engage the ABS), but also will have a longer pedal. This statement assumes the same brake equipment is being used at the corners and only the M/C's are being compared. The V8 M/C will feel a little firmer (less pedal travel), but require additional pedal effort to get into the ABS. If 10% is no big deal to the driver, then a change would not be necessary. For drivers with more braking finesse, it's 10% in the wrong direction.

OK, I think I get the difference in pressure smaller piston at the master Vs the SS but the caliper total surface will be more (4 live pistons vs 1 albait larger piston) at the calipers right? So won't it still require more force to get the same brake pressure?

I don't get the 10% figure though. The difference in piston diameter is 1/16" which is a shade over 6% if my math is still valid. How do you get 10%?

Maybe we thinking of different things here. I'm saying that if you change out the V6 calipers for the SS, it will require more force at the pedal by 6% VS using the SS master on the same caliper. I'm also saying the pedal travel with the V6 master will be longer than the SS (and easier to modulate) both using the SS calipers. You agree?

I haven't measured the difference in piston surface between the V6 and SS calipers yet so I can't say what the displacement diff will be.

[Chris_B]

Originally Posted by Beauwulf

OK, I think I get the difference in pressure smaller piston at the master Vs the SS but the caliper total surface will be more (4 live pistons vs 1 albait larger piston) at the calipers right? So won't it still require more force to get the same brake pressure?

I don't get the 10% figure though. The difference in piston diameter is 1/16" which is a shade over 6% if my math is still valid. How do you get 10%?

Maybe we thinking of different things here. I'm saying that if you change out the V6 calipers for the SS, it will require more force at the pedal by 6% VS using the SS master. I'm also saying the pedal travel with the V6 master will be longer than the SS (and easier to modulate) both using the SS calipers. You agree?

The sliding calipers on the V-6 actually have slightly more piston surface area (F: 1 x 60mm / R: 1 x 45mm) than the fixed Brembos on the SS (F: 44mm/40mm / R: 32mm/28mm). The number of pistons is only part of the equation. As a result, the SS calipers require slightly more line pressure for the same clamping load, but those calipers are also squeezing down on larger discs. I don't have time to run all the math right now, but I can see just by looking that the disc diameter difference will outweigh the small piston area differences. In total, it's probably not that much different than the V6.

6% is the difference in M/C diameter. 10.1% is the difference in piston surface area, which is what creates fluid pressure and flow (Area = pi * radius^2). The larger the M/C, the less line pressure for a given pedal effort, but the more fluid it moves per unit of piston travel.

If using the setup you described (SS calipers with V6 M/C), it will require 10% less pedal effort, but also 10% more pedal travel than if using the SS M/C. Of course, this assumes that the caliper deflection is equal. I haven't measured it, but I would hazard a guess that the OE Brembos (not the stiffest ones in their stable) are still stiffer than the V6 sliders, as those are on rubber bushings. Consequently, some unknown (by me) portion of that 10% loss in pedal travel is probably gained back. The stiffer calipers will have no effect on pedal effort.

Is this clear or am I mucking the explanation all up?

[Beauwulf]

Originally Posted by Chris_B

The sliding calipers on the V-6 actually have slightly more piston surface area (F: 1 x 60mm / R: 1 x 45mm) than the fixed Brembos on the SS (F: 44mm/40mm / R: 32mm/28mm). The number of pistons is only part of the equation. As a result, the SS calipers require slightly more line pressure for the same clamping load, but those calipers are also squeezing down on larger discs. I don't have time to run all the math right now, but I can see just by looking that the disc diameter difference will outweigh the small piston area differences. In total, it's probably not that much different than the V6.

6% is the difference in M/C diameter. 10.1% is the difference in piston surface area, which is what creates fluid pressure and flow (Area = pi * radius^2). The larger the M/C, the less line pressure for a given pedal effort, but the more fluid it moves per unit of piston travel.

If using the setup you described (SS calipers with V6 M/C), it will require 10% less pedal effort, but also 10% more pedal travel than if using the SS M/C. Of course, this assumes that the caliper deflection is equal. I haven't measured it, but I would hazard a guess that the OE Brembos (not the stiffest ones in their stable) are still stiffer than the V6 sliders, as those are on rubber bushings. Consequently, some unknown (by me) portion of that 10% loss in pedal travel is probably gained back. The stiffer calipers will have no effect on pedal effort.

Is this clear or am I mucking the explanation all up?

No, I got it this time. I'm just trying to justify the $150 for the SS MC.

I assume a small amount of travel from the OEM setup will be reduced by adding the braided lines. Maybe 2%?

I'd still like to do the CTS-V clampers... or Lockheeds if I could find a good price, then I guess the SS MC would be better. It sucks being poor! LOL!

Guess I'll just have to work more OT and spring for the SS MC.

Thanks for the info... I appreciate it.