robertbartsch

Our brakes in comparison to newer vehicles (Acura, BMW, Audi, Jeep) are tiny. This is true particularily in regards to the rear size rotors, calipers and pads.

Why are new vehicles equiped with huge brakes now? Was this another GM oversight or does this have something to do with wheel and tire development in recent years?

Sam Strano

iTrader: (41)

12" rotors all around are tiny???? Cars are getting heavier, wheels are getting bigger so brakes tend to need to get larger too. And "small" brakes don't mean the car can't stop anyway. F1 car's brakes aren't that big, they only have 278mm discs.

If you want bigger brakes, you can have them, but be prepared for all that's involved (like new wheels, tires, and more unsprung weight). And what are you trying to change that you think the brakes are too small?

robertbartsch

....just a visual observation really

I saw a Dodge SRT recently that had factory 20 inch wheels! The front and rear brake rotors where freak'n HUGE!!!!!

This car was definately on steriods.

o2camaross

iTrader: (2)

yeah and thats part of the reason why the SRT 8's are sloww.... bigger wheels and brakes = more rotational inertia which = more power and more time to move those big *** wheels.

chicane

Well... yeah. They only weigh 1323 pounds. Any more brake and they would become hyper-sensative for that chassis weight. Not to mention that they still have to fit into the rules of the FIA, concerning wheel sizes...

Most European manufacturers have been building cars for countries that have transportation routes like that of the Autobahn. Mass in motion has larger system requirement to stop it from higher speeds. The American auto industry has been behind the curve (of this specific subject) for years. But then again... we dont have an Autobahn. There is just enough brake built into the stock chassis, to do what it needs to. You modify it from that aspect... and the requirements change right along with it.

But... Sams question of: ...makes me question the same thing as he.

And I believe his answer to that... sums it up nicely. Basically it comes down to mass and inertia additions in the manufacturing of late model vehicles, specifically concerning the wheel and tire packages... and the need for the hefty luxuries that we fatass Americans adore. Total chassis weight, pad surface area, the COF of materials being used and clamping force are the big players in this equation. You can/may simply improve... just one of them... and it can/may net a world of difference.

For lack of a better lame-mans definition... its the tires that stop the chassis... not the brakes. Improve your current system, and knowledge of, before you think of dropping some major coin on something you might not need.

I kinda laugh at this. I myself am one of those with 14.5" six pot brakes... but in my own defense, I use and need them for my application. And not to argue, but to counter, Sam's idea of increasing weight and rotational inertia... my efforts were actually a wash. I went from a 11.75" (one piece hub and rotor) four pot iron caliper set up to a 14.5" (two piece) alloy hat and six pot alloy caliper and actuall lost an infinitesimal amount. The wheel and tire package was even a wash...

...but it did come with a price. Lots-o-money.

robertbartsch

..even the sweep area in the newer cars is larger. Like Suburas and Audis, weigh a ton less than our cars, have bigger rotors and the pad sweep is much wider.

Their tires are still skinny, however.

I'm not a fan of increasing un-srung weight, but I suspect this is big-brake trend will continue.

3.4camaro

iTrader: (1)

BMW M5s have an aftermarket 16" rotor. Mother of God.

z28bryan

iTrader: (7)

The damn thing is a pig. Those weigh like 4000 lbs don't they?

Xsta Z 28

iTrader: (2)

I think it's becoming asthetics vrs function . . .

Cars are getting bigger wheels, and bigger wheels look absolutely rediculous with small brakes. . . .

On my STS-V the REAR brakes are bigger than the fronts . . . . ??? Why? Front brakes do well over 50% of the braking force, so why are the rear brakes bigger? Because the rear wheels are bigger than the fronts . . . .

robertbartsch

I agree that the size of the brakes on new cars are a function of looks and not necessarily need.

The Dodge SRT had 20 inch wheels and I guess the rotors on this monster were 18 inches front and rear!

I thought the front brakes do 70% of the braking.

iansane

Because the rears probably incorporate a drum in rotor parking brake setup, the pad area is probably similar, if not smaller.

coolformula

iTrader: (21)

I would again question, what is his goals/needs of the breaking system.

Things usually get bigger, but for the dodge truck you have a 20 inch rim and a TRUCK, they weigh a good bit more than our cars.

Remember the LS1 fbody came out in 98, I don't know the lead time, but when did they get the finally specs on the brakes 96 or 97(no idea just makign a guess...maybe earlier) So your looking at 10 years old. Things some as weight distrbution etc, would play in ...in needing larger brakes.

For a daily driver, there are many cars that have worse brakes. I think wtih decent,pads,rotors,fluid its MORE than SAFE. You have a 20 inch rotor lol and still with 17 tires your not going to be able to stop in 20 foot. There still laws of physics and the amount of traction you can get wtih your current tires.

FiredUpZ28

That statement was meant as an exaggeration to prove a point right?

robertbartsch

Dodge SRTs are not trucks; these are passenger cars. They are designed to look like 70s Chargers on steriods. ...they have 20 inch wheels and HUGE brakes front and rear.

NVR_SPDS

iTrader: (39)

The Charger SRT-8 right?

All these have SRT on em:
Chrysler 300C SRT-8
Dodge Charger SRT-8
Dodge Magnum SRT-8
Dodge Ram SRT-10
Dodge Viper SRT-10

The Charger SRT-8, 300 SRT-8, and Magnum SRT-8 are all based on the same platform. Not trying to be a jerk, just posting it up.

YellowToy/A

iTrader: (1)

Can you not go out and lock your tires with the brakes on your car. If you can you have more brake than you need. If you are going 150 and need to stop quick that might not be the case(this is true). Bigger brakes disappate more heat. That is all they do.

Do you drive so fast that you have fade? Try better pads. If they still fade try running air ducts to them like cup cars on a road course. If they still fad then bigger rotors and better pads and ducts. Also most bigger rotors have the vents that will pull ait thought them.

Bigger brakes take more heat and look kool. They do not stop better.

chicane

I dont think I can believe your last statement and I'll give you and example as to why...

The example, DRM did back to back testing on a single chassis with three brake systems. The chassis was a C5 and the system components consisted of OE PBR components, Wilwood and APRacing.

The results for the given tests are as follows:

Wilwood 6 pot front, 13" rotor / stock rear... 60-0 @ 112ft

Wilwood 6 pot front, 13" rotor / stock OE PBR fronts converted to the rear, 13" rotor... 60-0 @ 108ft

Wilwood 6 pot front, 13" rotor / Wilwood 4 pot rear, 12.75" rotor... 60-0 @ 102ft

APRacing sequential 6 pot front, 14.25" rotor / APRacing 4 pot rear, 13" rotor... 60-0 @ 96ft

So your theory that they do not stop better is pretty much nixed.

robertbartsch

Yeh, I agee.

However, if I were asked to do a C5 conversion again, I would say no way; the cost is not worth the effort and the ruesults are very marginal.

On a scale of 1-to-10, I would rate the C5 brake upgarde as very moderate at 2 MAX!