Braking perfomance with oe rotors over vented

Cantslowdown

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Jun 20, 2004
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Is there a big need for vented rotors i was thinking about going with decla rotors for the front and oe in the back but would my money be better spent just to get some oe rotors form like autozone are somewhere and put the money in mods?
 
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vented rotors are nice when it comes to repeatablity of the stop. they cool better.

equally sized rottors on one panic stop you proabaly won't notice much.

now when you get into the baer decelra rotors they are also cross drilled and stuff like that. that is not ever nessesary. they are kind of spendy too. I think they may be plated though so they will look pretty longer.

I would look for a cheaper solution than the decelera rotors. something that is just a plain, vented, and plated rotor is someone makes it.
 
Just buy then now

http://www.buyfordracing.com/shop/product_info.php?products_id=594

Mach 1 13" brakes for $310.

My local AZ has the decela rotors for $2XX. Add a set of pads and you might as well just buy the 13" upgrade kit.

And yes, plain faced rotors do perform better than crossdrilled because there is more heat absorbtion due to the mass. Crossdrilled rotors are for venting gas given off by race-spec pads, not for cooling the rotor. There is actually very poor airflow in recesses perpendicular to laminar airflow. Street car pads do not vent gas, so the crossdrilled holes do nothing for you.
 
DTNODYA said:
What does that mean? :(:shrug:


Flowing air can't turn 90 degree corners that well, so airflow through the crossdrilled holes is actually very poor.


This of it as if it's a very windy day with the wind blowing down the street and you duck into a small alley between two buildings. It would be calm in the alley.
 
Cantslowdown said:
So its really just for show and looks...


On everyday normal street cars like our Mustangs yes.


It does have function in race cars or high end exotics with massive 14" pads and aggressive pads, but that's a whole different discussion.
 
All front Mustang rotors are vented. Vented is not the same as slotted or cross drilled. No one driving on the street needs anything but stock rotors. If you are craving up tight mountain roads for extended periods of time and getting very high rotor temps. then you might think of slotted rotors and better quality brake parts. You can't get the stock Ford brakes overheated even in aggressive street driving unless you are severally abusing the posted laws.
 
Mustang5L5 said:
Flowing air can't turn 90 degree corners that well, so airflow through the crossdrilled holes is actually very poor.


This of it as if it's a very windy day with the wind blowing down the street and you duck into a small alley between two buildings. It would be calm in the alley.

Gotcha :flag:

So would they function better if you routed some hose/tubing ... so that a air would be forced onto the brakes (like the rear on cars with the functional side scoops)?
 
DTNODYA said:
Gotcha :flag:

So would they function better if you routed some hose/tubing ... so that a air would be forced onto the brakes (like the rear on cars with the functional side scoops)?


Yes and no.

If you are referring to venting air onto the crossdrilled rotor than no it will not help. Venting air to the rotor does help, but the airflow must be directed at the center open area.

The rotor acts as a centrifigal pump. In other words when it spins, it slings whatever is in the middle outwards through the center vents outwards. To help this process, you can rout a hose to direct air at the center "hat" area of the rotor on the backside. This will feed nice cool air to the rotor so it can "pump" it through the vents in the center.

This is why solid rotors perform well. There is more mass to absorb and distribute the heat and more surface area to contact the air rushing outwards through the cooling vanes.

crossdrilled holes are for race pads which expel gases during braking. The holes give the gas a place to escape toso they don't build up under the pad and push it away reducing braking. That is their only function. They do nothing for cooling at all.

They do look good though and i don't fault people for running them. It's just that a lot of people are misinformed about their function and routinely claim to feel a difference. The truth is when you switch from stock WORN out brakes and pads to new rotors and pads, you will feel a difference even if running crappy Autozone $20 rotors and $10 pads. New stuff always has good bite. They won't last long of course, but my point is people are comparing their buttmeters with the new crossdrilled parts to their old worn-in setup.

With that said i run crossdrilled rotors :)
 
Mustang5L5 said:
Yes and no.

If you are referring to venting air onto the crossdrilled rotor than no it will not help. Venting air to the rotor does help, but the airflow must be directed at the center open area.

The rotor acts as a centrifigal pump. In other words when it spins, it slings whatever is in the middle outwards through the center vents outwards. To help this process, you can rout a hose to direct air at the center "hat" area of the rotor on the backside. This will feed nice cool air to the rotor so it can "pump" it through the vents in the center.

This is why solid rotors perform well. There is more mass to absorb and distribute the heat and more surface area to contact the air rushing outwards through the cooling vanes.

crossdrilled holes are for race pads which expel gases during braking. The holes give the gas a place to escape toso they don't build up under the pad and push it away reducing braking. That is their only function. They do nothing for cooling at all.

They do look good though and i don't fault people for running them. It's just that a lot of people are misinformed about their function and routinely claim to feel a difference. The truth is when you switch from stock WORN out brakes and pads to new rotors and pads, you will feel a difference even if running crappy Autozone $20 rotors and $10 pads. New stuff always has good bite. They won't last long of course, but my point is people are comparing their buttmeters with the new crossdrilled parts to their old worn-in setup.

With that said i run crossdrilled rotors :)

Informative, thanks for the lesson on rotors. :nice:

"With that said i run crossdrilled rotors" ... made me :rlaugh: I'm with ya tho. :)
 
i think crossdrilled is over rated as it allows the rotor to crack WAY easier and also eats away at your braking surface... the slots vent enough gas for 90% of racers even and it also kinda cuts a clean edge on the pad so it always bites... drilling is useless unless you are doing something like running a carbon rotor w/ carbon pads like on the Carrera GT or a F1 car...

i will never buy Crossdrilled rotors unless they come w/ a kit from brembo or something of the like..