Brakes Revisited

[cloud9]

Looks great Steve. I am guessing this is something I will want given the fact that the rotors have been a limiting factor for me at this point. More mass has to be a good thing. I will be very anxious to see how they work for you.

 

[VoodooBoss]

Wow those pads are a lot larger. I sure hope Enkei PF01's fit over those brakes. Once my current rotors are used up I'll be upgrading.

 

[06mach1]

The size of the pad is one thing, but you still need brake fluid volume and pressure via the master cylinder. Without that, it does not matter how big the pads are. Sure would be nice to have the hydro boost system.

 

[PeteInCT]

The larger brakes on the 302S (still a 4 piston caliper) uses a higher pressure master cylinder.

 

[KNS Brakes]

The size of the pad is one thing, but you still need brake fluid volume and pressure via the master cylinder. Without that, it does not matter how big the pads are. Sure would be nice to have the hydro boost system.

If the piston area is more than pedal travel will increase because the force multiplication changes (area of MC/area of caliper) but the larger rotor increases the effective radius and thus brake torque.

That matters - but the primary gain is mass and surface area to manage heat better. The brake pad is the fuel and the rotor and caliper are the radiator. All of it got bigger.

 

[Sesshomurai]

If the piston area is more than pedal travel will increase because the force multiplication changes (area of MC/area of caliper) but the larger rotor increases the effective radius and thus brake torque.

That matters - but the primary gain is mass and surface area to manage heat better. The brake pad is the fuel and the rotor and caliper are the radiator. All of it got bigger.

Thank you. I've been trying to convince folks of this for a long while!

 

[KNS Brakes]

This one is pretty close.

 

[PeteInCT]

That is the correct pad. Pagid has these available in RS-19 and RS-14 compounds. If anyone is interested please PM me.

 

[steveespo]

This one is pretty close.

Thanks Ken, That is from the Brembo Catalog right? Do you know what Carbotech charges to reline plates, As much as I would hate to do it I would buy another set of pads and have it done if the cost was close. As far as the HB 616/WVA08355 shapes they do look like they would fit just expensive. I have no intention of going cheap at this point but if I commit to something I want to be sure it will work,

Pete I have to measure and see if 16.4 mm pads will fit and not bind up or drag as the stock thickness is 15mm. Really appreciate the searching and will be making a decision on which direction to go in the next week or so.
Thanks
Steve

 

[KNS Brakes]

This one is pretty close.

Hawk's catalog!

You can tell by the gframmer/aspelling........

 

[steveespo]

Update; I just mocked up the caliper/pad/rotor assembly and tried it inside my 18" SVE Drift wheels, No go even with caliper pushed down onto the rotor the setup wouldn't clear. Looks like I will be running Boss 302S 19"x9" up front. I guess I can run my 18" rears, will call my car "FrankenBaus" with that configuration.
Steve

 

[PeteInCT]

Sure you want to raise the front 1/2 in compared to the rear?

 

[2012YellowBoss]

If the piston area is more than pedal travel will increase because the force multiplication changes (area of MC/area of caliper) but the larger rotor increases the effective radius and thus brake torque.

That matters - but the primary gain is mass and surface area to manage heat better. The brake pad is the fuel and the rotor and caliper are the radiator. All of it got bigger.

The rear brake rotors on the 13 Shelby are bigger of course but the pads are the same. I got this from a CTSCC team, they are running the 13 setup with 1082 PFC pads. They tried to explain to me that even if the pads and calipers are the same the larger rotor makes a big difference in stopping power. I understand the heat part with the larger rotors but not the rest, do you agree with this?

They also told me I may have a problem with brake bias and it may also have a negative effect on the ABS if I only swap the rear and not the front (due to rims). I can understand them saying this but they are also looking at hundreds of a second lap times and have a professional setup on every aspect of the car. For my purposes just running track days I wonder if I will see any major negative effects. Thoughts?

 

[KNS Brakes]

It will change bias.

Brake torque at the wheel is proportional to the effective radius of the pad/rotor. If you increase rotor diamter - you increase the lever arm of the pad area thus increasing brake torque.

It's a stroked version of your brakes.

So you will be front biased some.

Not sure about the ABS thing as much unless there is a brake force distribution circuit in the car as that would be mapped to some extent to react to wheel speed inputs.

 

[2012YellowBoss]

It will change bias.

Brake torque at the wheel is proportional to the effective radius of the pad/rotor. If you increase rotor diamter - you increase the lever arm of the pad area thus increasing brake torque.

It's a stroked version of your brakes.

So you will be front biased some.

Not sure about the ABS thing as much unless there is a brake force distribution circuit in the car as that would be mapped to some extent to react to wheel speed inputs.

Thanks, so you think it is a bad idea just to slap on the bigger rear rotors and brackets without any other changes?

 

[steveespo]

Sure you want to raise the front 1/2 in compared to the rear?

Pete I have tires in both 26 and 27" diameters, both front and rear. I can mix and match to tune gear ratio and rake. You are right though I wouldnt want to run the front tires 680mm and the rears 660mm.

It will change bias.

Brake torque at the wheel is proportional to the effective radius of the pad/rotor. If you increase rotor diamter - you increase the lever arm of the pad area thus increasing brake torque.

It's a stroked version of your brakes.

So you will be front biased some.

Not sure about the ABS thing as much unless there is a brake force distribution circuit in the car as that would be mapped to some extent to react to wheel speed inputs.

Been here too, I run the 14" Baer rears with their relocation bracket and stock calipers. Don't really know how much it helps but they fill out the wheels better and I haven't had any strange ABS intervention on street or on track.
Steve

 

[2012YellowBoss]

Been here too, I run the 14" Baer rears with their relocation bracket and stock calipers. Don't really know how much it helps but they fill out the wheels better and I haven't had any strange ABS intervention on street or on track.
Steve

It is something I would like to try, just don't want to do anything stupid and end up in a tire wall. If it does not work I am not out that much for a set of rotors and a bracket but the potential gains are big and worth the risk (in cost not tire walls).

 

[VoodooBoss]

Update; I just mocked up the caliper/pad/rotor assembly and tried it inside my 18" SVE Drift wheels, No go even with caliper pushed down onto the rotor the setup wouldn't clear. Looks like I will be running Boss 302S 19"x9" up front. I guess I can run my 18" rears, will call my car "FrankenBaus" with that configuration.
Steve

Mark posted in the other thread that the BBS 302R/S wheels fit over those brakes. So you could still run 18" wheels.

Post #25

https://trackmustangsonline.com/index.php?topic=3723.0

 

[KNS Brakes]

Thanks, so you think it is a bad idea just to slap on the bigger rear rotors and brackets without any other changes?

Adding some rear bias is usually fine. passenger cars are generally over front biased for safety. plow rather than spin

But too much rear bias reduces control when trail braking - and if you can't trail brake into the apex......

 

[2012YellowBoss]

Anyone know what the difference is between the Motul RBF 600 and 660? Looks to me like it is the same fluid but the 600 has nitrogen filled bottles from the factory.