Red_Bean_Bun
Well-Known Member
Today was asked by a bro on the forum which brake pad is a good match for his ride. His ride is a F30 and though the sensor hasn’t hit the threshold, we thought it’s a good idea to get it changed next week.
So I dug up my old notes from way back to have a look at a couple of major factors to consider when choosing brake pads – Friction co efficient and temperature before fade. There is another factor which is initial bite (which is not big on my mind) but this is the factor that illustrates the behavior of the at its initial contact when the braking begins. So when the initial bite rating is higher than the average friction co efficient – Expect some jerking action and a “sudden” deceleration before it gradually stops. Most OEM pads have a higher initial bite.
So before you choose a pad you need to understand how this works. SAE has a standard for rating the friction co efficiency of these pad materials. It looks like this -
Friction Coefficient Code
View attachment 58324
The friction co efficient D has the least braking power while H has the highest braking power. However, before you going out to buy the pad with the highest rated co efficient you need to understand the tradeoffs –
- The higher the code, the higher the wear acceleration on your rotors
- The higher the code the higher the operating temperature. These pads can go up to a very high temperature
before it fades. This also means that it needs to go up to a higher temperature before it become efficient.
- While the pads are cold, it makes a heck of a lot of noise till it warms up
- And it won’t be as bite as well while its cold as well
And that is why you need to drive fast to get these G rated pads and above to work well – Like on a track.
Here’s some data of what the characteristics of the pads are –
OEM
- examples: Mintex, Textar
- cF=0.30-0.40
- max temp before fade: 315-370 Celsius
Street Performance
- examples: Hawk HPS, EBC Greenstuff, EBC Redstuff, Porterfield R4-S, Axxis Ultimate
- cF=0.41-0.45
- max temp before fade: 370-537 celsius
Light Track Pad
- examples: Hawk HP+, Ferodo DS-2000, EBC Yellowstuff
- cF=0.46-0.49
- max temp before fade: 482-593 celsius
Track Pad
- examples: Ferodo DS-2500
- cF=0.50-0.55
- max temp before fade: 593-704
Race Pad
- examples: Ferodo DS-3000, Hawk Blue 9012, Hawk Black, EBC Bluestuff, Porterfield R4
- cF=0.56-0.68 (depends on specific race application)
- max temp before fade: 704+ celsius (depends on specific race application)
Brembo have a cF between 0.4 (340 celsius) to 0.63 (390 celsius)
Some interesting information –
- Pads that can go up to 1648 celsius will start to glow. These are typically Carbon brake pads
- All Pads will have a print at the edge to give you the rating. This is especially so for SAE DOT compliant pads
- 100% Steel on Steel rotors have a cF of 0.25
- So some E rated pads have a marginal level of stopping power more than using a piece of Steel as a brake pad.
- F rated pads are the minimum to be considered a Performance Brake Pad
View attachment 58323
So based on what he was driving (F30) and driving style - He chose the EBC Greenstuff.
So I dug up my old notes from way back to have a look at a couple of major factors to consider when choosing brake pads – Friction co efficient and temperature before fade. There is another factor which is initial bite (which is not big on my mind) but this is the factor that illustrates the behavior of the at its initial contact when the braking begins. So when the initial bite rating is higher than the average friction co efficient – Expect some jerking action and a “sudden” deceleration before it gradually stops. Most OEM pads have a higher initial bite.
So before you choose a pad you need to understand how this works. SAE has a standard for rating the friction co efficiency of these pad materials. It looks like this -
Friction Coefficient Code
View attachment 58324
The friction co efficient D has the least braking power while H has the highest braking power. However, before you going out to buy the pad with the highest rated co efficient you need to understand the tradeoffs –
- The higher the code, the higher the wear acceleration on your rotors
- The higher the code the higher the operating temperature. These pads can go up to a very high temperature
before it fades. This also means that it needs to go up to a higher temperature before it become efficient.
- While the pads are cold, it makes a heck of a lot of noise till it warms up
- And it won’t be as bite as well while its cold as well
And that is why you need to drive fast to get these G rated pads and above to work well – Like on a track.
Here’s some data of what the characteristics of the pads are –
OEM
- examples: Mintex, Textar
- cF=0.30-0.40
- max temp before fade: 315-370 Celsius
Street Performance
- examples: Hawk HPS, EBC Greenstuff, EBC Redstuff, Porterfield R4-S, Axxis Ultimate
- cF=0.41-0.45
- max temp before fade: 370-537 celsius
Light Track Pad
- examples: Hawk HP+, Ferodo DS-2000, EBC Yellowstuff
- cF=0.46-0.49
- max temp before fade: 482-593 celsius
Track Pad
- examples: Ferodo DS-2500
- cF=0.50-0.55
- max temp before fade: 593-704
Race Pad
- examples: Ferodo DS-3000, Hawk Blue 9012, Hawk Black, EBC Bluestuff, Porterfield R4
- cF=0.56-0.68 (depends on specific race application)
- max temp before fade: 704+ celsius (depends on specific race application)
Brembo have a cF between 0.4 (340 celsius) to 0.63 (390 celsius)
Some interesting information –
- Pads that can go up to 1648 celsius will start to glow. These are typically Carbon brake pads
- All Pads will have a print at the edge to give you the rating. This is especially so for SAE DOT compliant pads
- 100% Steel on Steel rotors have a cF of 0.25
- So some E rated pads have a marginal level of stopping power more than using a piece of Steel as a brake pad.
- F rated pads are the minimum to be considered a Performance Brake Pad
View attachment 58323
So based on what he was driving (F30) and driving style - He chose the EBC Greenstuff.
