Overheating brakes

Karim E36

Karim E36

Legacy Member
I have been having brake fade issues after a few laps.

I am considering brake ducts but want to sort out the current situation first.

My brother has the same car as me with a very similar setup. The only difference is that he has slightly softer springs front and rear (440/340 vs 340/280). He does not experience brake fade as bad. We have the same brakes, same tires, same weight,...

Last monday, we did a session where I would follow him closely on the track.

I was extra careful with my braking technique, trying to brake hard but for as little time as possible.

At the end of the session I measured the surface temperature of our rotors with an IR pyrometer:

Me: front 400+ F, rear 300F
Him: front 350F, rear 325F

(this is after a cool down lap for both of us)

Question: Why are my front discs getting much hotter?

It seems counter intuitive. With the stiffer springs, I would imagine my car would experience less weight transfer to the front. The greater temperature difference between front and rear on my car seem to indicate that the front brakes are doing more work. What can be the cause of this? Problem with the bias?

Any other ideas or suggestions as to what may be the cause of this?

Thanks for the input.

Karim
 
Possible. I will work on my technique.

I am puzzled by the difference front to rear though. Any ideas?
 
Is your front brake seized in any way?

With my stock setup, after I had changed rotors, there was continuous contact between the pad and the rotor. The result was high temperatures and very quick brake fade.

I'm not saying that's your problem, but perhaps it's worth looking in to...
 
FifthGear said:
Is your front brake seized in any way?

With my stock setup, after I had changed rotors, there was continuous contact between the pad and the rotor. The result was high temperatures and very quick brake fade.

I'm not saying that's your problem, but perhaps it's worth looking in to...
Click to expand...

I rebuilt both front calipers last fall. I doubt it's that but I will have a look. Will check the rears too at the same time.
 
Identic wheels or you have different wheel setup?

Wheel could cut off some fresh air... just saying.
 
I suggest switching cars for one session. If you get the same results, it's the driver. If it's the opposite, then possibly the car.
 
Technique is probably the big contributer to the way the car cools up and cools down. Think of it this way as well... Your following him. This changes the air-flow to your vehicle and could also contribute to brake temperatures.

What KIND of brake fade are you experiencing? Are you getting a SOFT Pedal but still good bite from the pads, or a FIRM Pedal, but just no braking bite. The later comes when you over-heat your pads. If you are using something like HP+, this generally happens at well over 800 degrees. While fluid fade happens much earlier in temperature, about 400 degrees if you are using a right fluids - it takes a lot higher brake temperatures for that to actually happen!

,
 
Switching cars is a good idea.

I am getting soft fade. boiled fluid. ATE Superblue or Typ200. Brake pads handle the heat no problem (Carbotech XP10).
 
Fluid could be a bit old, or has gotten contaminated. Generally after you get brake fade once; you should bleed the fluid out of the calipers. Not a full flush, but a few pumps from each corner. I do this a few times a year, or after i've done an event where i've faded the brakes.

The other option is to just upgrade the fluid as well... PBR BF600, Motul RBF 660 or any of the GULF Competition brake fluids. It goes without saying where you can find the stuff right :) (@ Perry... duh!!)
 
Just a side note: the stiffer springs don't make your car transfer less weight to the front. Your springs/shock settings/sway bars actually have no bearing on the QUANTITY of weight transfer, but HOW the weight transfer happens. With a stiffer setup, the weight will be transfers faster than with a soft setup, which means you can get on the brakes harder, faster.

The only suspension setting(s) that will affect the amount of weight transfer would be ride height and/or front caster adjustment if adjusting the front caster changes your wheelbase.
 
Karim E36 said:
Switching cars is a good idea.

I am getting soft fade. boiled fluid. ATE Superblue or Typ200. Brake pads handle the heat no problem (Carbotech XP10).
Click to expand...

I would replace this fluid for one more suitable for track use, if soft pedal is the issue. Brake fade is something different.
 
You must log in or register to reply here.
Back
Top