My 1LE is getting a better brake upgrade

[X25]

Originally Posted by Mgizzle

I am baffled by Ti shims. We have this HUGE heat sink of a caliper and no fluid boil issues, especially with the vented pistons. Aluminum too so it gives it off well too. Guess where all the heat stays? The rotor........BUT, even worst.....the pad. So we have same energy at the same track into corner after straight but a smaller heat sink. Those Ti shims sure as heck make no sense to me........unless you are boiling RACE fluid...dont use them.

CTS V caliper fits but rotor doesnt so we dont have a brake system that is compatible on 5th gen. The rotor offsets are different.

At one end of the piston is the brake pads, and at the other end the brake fluid itself. As the pad gets thinner, as Justice Pete pointed out, more of the heat out of the rotors is transferred from pads to pistons. The heat transfer via pads to pistons is a lot more than through caliper, since caliper is never directly touching, and can also cool down with air.

IIRC, Titanium transfers heat 30x slower than iron. The shim put in between pad and poison slows down the heat transfer to the fluid considerably, and reduces the max temps you hit with the fluid, reducing the chances of boiling and contamination.

[Mgizzle]

Sorry, I completely understand Ti heat transfer properties and that people sell shims as a "heat barrier" but name me one high performance OEM that uses Ti shims?

Your pad touches the caliper on top and bottom (where it slides, called abutments). It also touches the SS pins that hold the pads in the cailper as well as the tension spring. All those transfer heat to the caliper of course, however, the more heat paths OUT of the pad you have to the caliper the more you increase surface area and the "heat sink" to give away heat and store heat. You do not want heat in your pads and rotor on track applications. I am pretty certain that nobody with a 6 piston brembo system on a camaro has fluid boiling issues with $50 SRF/ENDLESS/TORQUE etc. brake fluid (way cheaper than Ti shims and improves compressibility). However, I am pretty sure that a majority of us have pad fade issues depending on what we use since most of us want a pad that is good on the street (no noise, roughness etc.) but also perfect on the track.

To be honest with you, I am blown away that nobody in the aftermarket (even brembo themselves) are not selling the caliper vents since if you look at our caliper you can see two casting features that on Ferraris are drilled out for small screwes. Here they mount an aluminum or carbon bracket that allows a small duct to be added to it and blow air right at the pads, pistons etc. This is a significant temperature drop on pads. See picture below of the bracket but the bolts on our calipers would mount on the inside. Look on top and bottom and there is about 2 quarter inch round casting features that would be drilled out and a bracket like this would mount to them. I would use the inside ones since those are way away from any hydraulic circuits and are purely in the casting, the outboard ones are way too close for comfort to the pistons and without knowing exact depths etc. you could drill into the piston hydraulic circuit.

Anyhow, long story short, Ti shims on 6 piston brembos are a waste and actually hurt the performance since a way cheaper brake fluid does the job of not boiling AND allowing us more heat transfer out of the pad/rotor area.

[Nick S]

I have been thinking along the same lines as you Mgizzle. The same amount of heat is generated for any given braking event. If the Ti shims prevent the heat from transferring out of the rear of the pad to be absorbed by the caliper and any airflow across the back side of the pad then we are trapping more heat in the pad. And since pad temp affects it effectiveness then we would reach pad fade faster since we are not allowing the heat to escape the pad as well.

[summit1le]

A little off subject, I recently rebuilt my ctvs v calipers with the racing brake kit, high temp dust boots and piston seals. I have done one track day on these, however my dtc-70 pads were on there last leg. I have then driven about 200 miles on the stock pads. While swapping my pads back to race pads, I noticed a small amount of fluid on my drivers outside caliper on the back of the pads around the pistons. This was the very reason I rebuilt in the first place, however that was present on all of the front calipers. Could this be caused due to the worn out pad?? Also it appears that I am not really losing any pressure. I am running Daytona in a week, is it safe? Please advise!!

[Dropspeed]

So I have some Ti shims for sale...Brand new, never installed, cheap!

Matt

[Hilflos]

Originally Posted by Dropspeed

So I have some Ti shims for sale...Brand new, never installed, cheap!

Matt

Lol

[Mgizzle]

Originally Posted by summit1le

A little off subject, I recently rebuilt my ctvs v calipers with the racing brake kit, high temp dust boots and piston seals. I have done one track day on these, however my dtc-70 pads were on there last leg. I have then driven about 200 miles on the stock pads. While swapping my pads back to race pads, I noticed a small amount of fluid on my drivers outside caliper on the back of the pads around the pistons. This was the very reason I rebuilt in the first place, however that was present on all of the front calipers. Could this be caused due to the worn out pad?? Also it appears that I am not really losing any pressure. I am running Daytona in a week, is it safe? Please advise!!

Well, this is a tough one. You could ve not seated the seals right or maybe cut one of them during piston install. If you lubbed them up with brakefluid prior to installation you are probably OK. My recommendation would be to put a 2 x 4 against a very hard pedal after a spirited drive and jam it up against ur seat. Let it sit overnight and if ur 2 x 4 is on the ground it means u were leaking and loosing pressure. Either way dissasemble pads and check again.

Even better way would be to pressurize that caliper and look overnight if you loose pressure.

[X25]

Originally Posted by Dropspeed

It is so you can adjust camber while the wheel is on. (Loosen the bolts on the knuckle and turn that bolt clockwise for less camber or counter clockwise for more camber) In my case I used it to mark where the 1LE strut was. When I put the Z/28 strut in place I just backwd the bolt all the way out to get a much camber as possible before taking it in for an alignment. I was only able to get -2.0 and -2.1 out of the stock set-up.

I am running to different tracks this Friday and Saturday so I will provide a review of the Z/28 set-up after.

Matt

That's similar to what I got from mine. Even though the Z/28 shocks are shorter, they don't provide more camber than what 1LE shocks would. Cons of working with OEM components : )

[X25]

Originally Posted by Nick S

I have been thinking along the same lines as you Mgizzle. The same amount of heat is generated for any given braking event. If the Ti shims prevent the heat from transferring out of the rear of the pad to be absorbed by the caliper and any airflow across the back side of the pad then we are trapping more heat in the pad. And since pad temp affects it effectiveness then we would reach pad fade faster since we are not allowing the heat to escape the pad as well.

Limited heat transfer to caliper is actually OK, since it helps dissipate the heat with its much larger surface area. That said, the heat transfer directly to the piston and the seals (and fluid) is both meaningless, and dangerous.

• Meaningless: The fluid is actually not very good at transferring the heat, so the heat transferred to the fluid will stay right at the tip by the piston. This is the reason why you only need to bleed very little fluid, and after just a few milliliters bled, the fluid's color changes back to new ones' (though you should always bleed up to the goose-neck at the line).
• Dangerous: These days, even a good street pad is good up to 1300 degrees F (check out StopTech performance street pads). The track pads are also good up to 1300 degrees F and even more, with much higher bite and much better consistency at high temps. That said, even the best brake fluid cannot do much more than 600s! Simply put, the fluid is the component with the lowest tolerance to high temps in the system, and should be isolated from high temps. More importantly, pad fade is usually safer to recover from, but brake pedal to the metal can easily create catastrophic consequences.

Regarding OEM use, shims are actually used by many OEMs, but as far as I see, for cutting noise, not for temp control. However, many OEMs use upgraded pistons to do what shims would do. Virtually all brake manufacturers provide various kinds of pistons for this purpose.


A quick research reveals the information site for Wilwood's Thermolock pistons:
http://www.wilwood.com/Pdf/Flyers/fl77.pdf

....Thermlock® Pistons provide the most effective thermal
barrier available for minimizing heat transfer from the brake pads to the
caliper body, seals, and fluid. This innovative multi-part design incorporates
a stainless steel shield and coated aluminum shell configuration that
effectively retards heat transfer by 25% and more. Lower operating
temperatures translate to the elimination of seal crystallization, the
elimination of localized fluid boiling, and longer service life through
decreased distortion in the caliper body and piston bores.

[AG1LE]

Originally Posted by Dropspeed

Mmmmm vented pistons. These are good for about a 86f reduction in temp.

Are these aluminum or stainless steel pistons?

[White_SS/RS]

Originally Posted by AG1LE

Are these aluminum or stainless steel pistons?

Stainless. Aluminum transfers heat much too quickly to be used for brake pistons.

[Synner]

What are the vented piston with seal rebuild kit part numbers for ZL1? I thought it was in this thread but now can't find them. I don't need complete calipers.

[AG1LE]

Originally Posted by White_SS/RS

Stainless. Aluminum transfers heat much too quickly to be used for brake pistons.

I've heard from multiple sources that our pistons are aluminum, and stainless steel pistons are a good upgrade from OEM. Here's an example of the stainless upgrade from OEM.

http://www.racingbrake.com/CTS-V-Com...p/bc-61bsp.htm

It would be great if these vented pistons are stainless, but I'm assuming aluminum unless someone has info (not a guess) to the contrary.

[White_SS/RS]

Bump for the Z06 piston and seal kit rebuild part number. Anyone know?