[D.O.M.D1]

how do I get the rear SS-style breaks for the LT Camaro equipped with the heavy-duty break and cooling package or Brembo style(or high performance) break pads

thank you

[protovack]

unfortunately you can't, the parking brake is integrated into the rear calipers and cannot be retro-fitted. The SS rear brakes have a different parking brake mechanism that cannot be transplanted onto an LT car. You could bolt them in and hook up the brake lines and they would work, but you would have no parking brake. Keep in mind, the rear brakes don't do that much, so replacing the rear calipers would not be a performance upgrade. Some really don't like the look of the OEM calipers in back, but you'll probably get used to it.

[D.O.M.D1]

there is always a catch, in that case, do you recommend some good rear break pads that are similar performance to the Brembo front pads

thanks

[JamesNoBrakes]

You don't want to break your camaro.

[D.O.M.D1]

I don't want to "break" as in damage the car I meant what kind brakes do you recommend that are Brembo like performance for the rear

omg

[dpevans]

I really don't think it's a good idea to only modify the rear brakes. If you want to upgrade I would do the fronts first since they do 70% of the stopping. Maybe get some better rotors and pads to start. Some good information in the Brake section in the forum.

[Whitespeed]

If you're talking about improving brake torque, upgrading the front brakes only will actually result in longer stopping distances. The torque from the rear brakes is what generates load transfer to the front wheels. Without that, your upgraded front brakes are going to more easily overcome the grip of the front tires making it harder to stop. Saying that the rear brakes don't do much is a common misunderstanding of how brake systems work. The balance between front and rear is critical for optimum braking, and that balance needs to be maintained.


Nigel

[JamesNoBrakes]

Originally Posted by Whitespeed

If you're talking about improving brake torque, upgrading the front brakes only will actually result in longer stopping distances. The torque from the rear brakes is what generates load transfer to the front wheels. Without that, your upgraded front brakes are going to more easily overcome the grip of the front tires making it harder to stop. Saying that the rear brakes don't do much is a common misunderstanding of how brake systems work. The balance between front and rear is critical for optimum braking, and that balance needs to be maintained.


Nigel

The hell? You've got to be kidding. Deceleration is what transfers weight to the front, not the rear brakes. If you only used rear brakes, you'd have very little braking and they'd lock up real easy, doing nothing. If you only used the front brakes, you'd have plenty of braking power, but your rear end would want to swap with the front during hard braking. Deceleration is caused by using either one of the brakes (front or rear).

Try this with a bike, where you can use the brakes independently, you'll see what I mean. The front most certainly does ~80% of the braking.

If you are overpowering the grip of your front tires, it's most likely because your rubber is not sufficient for the braking power. You'll most likely notice insufficient rear brakes by the rear end coming loose easier and sideways skids.

Acceleration causes the rear end to squat, transferring weight to the rear. Deceleration causes the opposite of this, transferring weight to the front.

[Whitespeed]

Originally Posted by JamesNoBrakes

The hell? You've got to be kidding. Deceleration is what transfers weight to the front, not the rear brakes. If you only used rear brakes, you'd have very little braking and they'd lock up real easy, doing nothing. If you only used the front brakes, you'd have plenty of braking power, but your rear end would want to swap with the front during hard braking. Deceleration is caused by using either one of the brakes (front or rear).

Try this with a bike, where you can use the brakes independently, you'll see what I mean. The front most certainly does ~80% of the braking.

If you are overpowering the grip of your front tires, it's most likely because your rubber is not sufficient for the braking power. You'll most likely notice insufficient rear brakes by the rear end coming loose easier and sideways skids.

Acceleration causes the rear end to squat, transferring weight to the rear. Deceleration causes the opposite of this, transferring weight to the front.

I am not kidding. Brake torque is what causes deceleration and load transfer. If you increase the brake torque on the front axle, by increasing the pad coefficient of friction, increasing the rotor diameter, and/or increasing the caliper piston area, without a proportional increase in the rear brake torque, you will have longer stopping distances. Now, I should have clarified that it's not just rear brake torque that generates load transfer to the front. It's the combination of front and rear brake torque. But without an adequate contribution of rear brake torque to the load transfer to the front axle, the front tires will have less grip under braking (less force pushing them against the road) and thereby will lock up easier, resulting in longer stopping distances.

[95 imp]

^^Cocaine is a helluva drug....

[JamesNoBrakes]

That all makes certain assumptions that you can't prove. A proportional increase in rear braking is needed, except that assumes you had the proportions and rear power perfect before you got the new front brakes, while things like wheel size, tire size and composition, airflow to the brakes, are variables that could throw it either way. In many cars, the rear calipers are kept the same between trim levels while the front brakes are increased. My BMW with optioned M-sport brakes had upgraded rear and front calipers/rotors, however, the higher trim and heavier 435 had the same front calipers and smaller rear brakes and calipers. The 1LE has bigger and more powerful front brakes than the SS, but the same rear rotor and calipers. The same brakes I had on the BMW could be optioned on the 435, but the smaller rear caliper/rotor was obviously determined to be adequate. Given similar situations and other variations of the same (manufacturers that keep the rear calipers the same and change the front brakes between trim levels) I would bet there is some decent wiggle room in there. Unless you are doing far more testing to determine the actual %, effects of heat and so on, it's probably best to upgrade the front, see what happens, and upgrade the rear if necessary. That is probably going to work well and provide better braking more than 50% of the time, but there will inevitably be situations where the rears should be upgraded too.

[Whitespeed]

Originally Posted by JamesNoBrakes

That all makes certain assumptions that you can't prove. A proportional increase in rear braking is needed, except that assumes you had the proportions and rear power perfect before you got the new front brakes, while things like wheel size, tire size and composition, airflow to the brakes, are variables that could throw it either way. In many cars, the rear calipers are kept the same between trim levels while the front brakes are increased. My BMW with optioned M-sport brakes had upgraded rear and front calipers/rotors, however, the higher trim and heavier 435 had the same front calipers and smaller rear brakes and calipers. The 1LE has bigger and more powerful front brakes than the SS, but the same rear rotor and calipers. The same brakes I had could be optioned, but the smaller rear caliper/rotor was obviously determined to be adequate. Given similar situations and other variations of the same (manufacturers that keep the rear calipers the same and change the front brakes between trim levels) I would bet there is some decent wiggle room in there. Unless you are doing far more testing to determine the actual %, effects of heat and so on, it's probably best to upgrade the front, see what happens, and upgrade the rear if necessary. That is probably going to work well and provide better braking more than 50% of the time, but there will inevitably be situations where the rears should be upgraded too.

Unfortunately, I don't have time to go into this in detail right now. But keep in mind that looks can be deceiving when it comes to brake components. Just because they look bigger doesn't mean they necessarily have greater brake torque. Case in point, I found the piston specs for the the 6 piston ZL1 caliper (Piston 1: 38mm, Piston 2: 34mm, Piston 3: 30mm) and a regular 4 piston SS caliper (Piston 1: 42mm, Piston 2: 42mm). That equates to 5540sqmm for the SS caliper, and only 5498sqmm for the "bigger" ZL1 caliper. I am pretty tired, so hopefully I got the math right?

Nigel

[JamesNoBrakes]

Originally Posted by Whitespeed

Unfortunately, I don't have time to go into this in detail right now. But keep in mind that looks can be deceiving when it comes to brake components. Just because they look bigger doesn't mean they necessarily have greater brake torque. Case in point, I found the piston specs for the the 6 piston ZL1 caliper (Piston 1: 38mm, Piston 2: 34mm, Piston 3: 30mm) and a regular 4 piston SS caliper (Piston 1: 42mm, Piston 2: 42mm). That equates to 5540sqmm for the SS caliper, and only 5498sqmm for the "bigger" ZL1 caliper. I am pretty tired, so hopefully I got the math right?

Nigel

There is far more going on than brake torque, heat dissipation for one. Pad surface, pad material, caliper rigidity, master cylinder, the ratio that actually determines the mechanical advantage, etc. More pistons, specifically different size pistons, is known to increase modulation. Modulation is what slows you, vs. locking up brakes (power/brake torque). Again, there are plenty of examples of different front brakes on cars with the same or even lesser rear brakes. It appears the manufacturers frequently upgrade the front brakes on higher trim/optioned models and do not even touch the rears or assume they are adequate without upgrading. That doesn't mean that in all situations it will work out perfectly, but the chances are probably better than 50% that upgrading the fronts will result in better braking.

[Whitespeed]

Originally Posted by JamesNoBrakes

There is far more going on than brake torque, heat dissipation for one. Pad surface, pad material, caliper rigidity, master cylinder, the ratio that actually determines the mechanical advantage, etc. More pistons, specifically different size pistons, is known to increase modulation. Modulation is what slows you, vs. locking up brakes (power/brake torque).

I agree that brake torque is not the end-all and be-all of a brake system. However, to achieve the shortest possible braking distance, which is a fundamental goal of a brake system, the maximum brake torque available at all 4 wheels for the given level of grip of the tires to the road must be applied. Without balancing the front to rear brake torque (bias) to match that of the tire grip, braking distance will go up and modulation can't compensate for a poorly balanced system.

Originally Posted by JamesNoBrakes

Again, there are plenty of examples of different front brakes on cars with the same or even lesser rear brakes. It appears the manufacturers frequently upgrade the front brakes on higher trim/optioned models and do not even touch the rears or assume they are adequate without upgrading. That doesn't mean that in all situations it will work out perfectly, but the chances are probably better than 50% that upgrading the fronts will result in better braking.

This is where you have to be careful. While it may appear that manufacturers mix and match brake components, a lot of careful engineering and testing goes into ensuring the balance of the system is optimized. Upsetting that balance (assuming it was optimized in the first place) by shifting the brake torque bias front or rear can negatively impact braking distances. "Upgrades" like larger rotors or multi-piston calipers may be made available to improve the heat capacity and dissipation, but engineers will typically size brake caliper pistons and rotor diameters and select pad compounds to maintain the same front/rear bias. Furthermore, to err on the side of caution, additional front bias will be dialed in to improve stability, even though this may be at the expense of some braking distance.

Using the Mustang as an example, the same rear caliper is used on the base Ecoboost, all the way up to the GT Performance Pack 2. However, despite going from a 2 piston floating caliper on the front of the base model, to the optional Brembo 6 piston front caliper on the GT, the Brembo front caliper only has a 5% greater piston area. Yes, the front rotor is significantly larger, but a slightly larger rear rotor is fitted as well. More importantly though, the GT is a heavier car, and it has stickier tires. Consequently, biasing more brake torque to the front makes sense.

Sure, there's some wiggle room, but deviate too far and things quickly start to go downhill...

Here's a link to an article with test results that show how increasing the diameter of the front rotor on an Audi S4 by only 7% (about a 10% increase in front brake torque), while using the same caliper, resulted in longer stopping distances...

https://www.zeckhausen.com/catalog/i...Path=6446_6565

That article also demonstrates the challenges in making improvements to a braking system.

Here's a quote from an excellent article by Stoptech on brake bias (link to the full article is below)

The most dramatic front-bias impacts are usually brought about by “big brake kits” which are not properly matched to the intended vehicle. Any time that a bigger front rotor is installed, there is a simultaneous need to decrease the effective clamping force of the caliper (installing smaller pistons is the easiest method) to offset the increased torque created by larger rotor effective radius. The objective is to maintain a constant amount of brake corner output (torque) for a given brake line pressure as Figure 6 illustrates. Unfortunately, too many upgrades do not take this factor into account, and those poor cars end up with both bigger rotors and larger pistons which serve to drastically shift the bias even more forward. While rock-solid stable under braking, stopping distances will go up dramatically.

https://www.apcautotech.com/getmedia...e_8-2018_1.pdf

Which is not to say that OEM'S always get it right either. Pre-2001 Dodge Vipers were notoriously overly front biased. They came from the factory with a 36mm piston rear caliper. After many complaints of front wheels locking up too easily, a rear piston upgrade mod to 40mm was developed for those earlier Vipers which resulted in a braking force increase from 0.8G's to 1G with no other changes. Here's a very detailed forum post from Stoptech in a Viper forum on brake bias, in response to questions about rear brake upgrade options on Vipers.

https://www.viperclub.org/vca/thread.../#post-2068464

So, dismissing rear brakes as only having a minor roll, and/or focusing only on front brake upgrades, particularly if they are going to increase brake torque, is very likely to make things worse. Even something as simple as installing front pads with a higher coefficient of friction, which is a common first step that a lot of drivers make, can negatively impact braking distance. More often than not, the homegrown front brake upgrade, whatever it may be, doesn't taken any of this into account. But the driver then marvels at how they can lock up the front brakes easier now and concludes that he's 'improved' the braking. In reality, the braking distances likely just got longer, contradicting the expectation.

With respect to the Camaro, the engineers appear to have done an excellent job with optimizing brake bias. Consequently, I'd be very cautious about making any changes to upset that, particularly given that the system will already be designed with a slight additional front bias for stability. So, for example, if you want to try a different pad compound, run the same compound on the front AND rear of the car.