Pad Question: HT-10s Front / Stock Rears

[BMW M Power Mexico]

Hi,

I am going out on Saturday and just found out that the HT-10s I got don't fit (just the rears). I am installing the HT-10s on the front only (I have no choice as anything here is mail order and would take at least a week).

This is my first time out on a square R-Comps setup after about 12 track days and a couple of HPDE schools.

Is there any concern with running the stocks in the rear? I have no choice so I will go out like that (except maybe getting new stock rears - worth it?). Anything to look out for? The rears have more than half of their life left.

[TUNEDM3]

THe rear will get very light under heavy braking, especially since you are running r comps. It really depends how hard you push it, but be especially careful as the car will not feel very settled.

[BMW M Power Mexico]

Originally Posted by TUNEDM3

THe rear will get very light under heavy braking, especially since you are running r comps. It really depends how hard you push it, but be especially careful as the car will not feel very settled.

Thank you. I will be extra careful since its my firs time on R-Comps. I plan to leave MDM on all the time - no DSC off this time.

[earlyapex]

I don't think you'll have a big issue. I found the stock pads faded very quickly, so you'll get fade fairly fast (although it will all be coming from the rear).

It will be interesting to see just how much relative work the front brakes are doing (we all know it's most of the braking).

[lucid]

I assume the stock pads deliver less friction and therefore less braking torque, and that means you will alter your brake bias if you run them just in the rear, which will result in more relative brake torque up front and your front rotors will heat up more than they would if you were running the HT-10s on all corners (I don't know if that will make the HT-10s up front fade or not as that depends on how hard you will be braking). The rear rotor temps run significantly lower than the fronts, so I don't think you will run into fade issues there even with the stock pads unless you are really beating up on the car.

[BMW M Power Mexico]

Originally Posted by lucid

I assume the stock pads deliver less friction and therefore less braking torque, and that means you will alter your brake bias if you run them just in the rear, which will result in more relative brake torque up front and your front rotors will heat up more than they would if you were running the HT-10s on all corners (I don't know if that will make the HT-10s up front fade or not as that depends on how hard you will be braking). The rear rotor temps run significantly lower than the fronts, so I don't think you will run into fade issues there even with the stock pads unless you are really beating up on the car.

I don't know if they are different in friction or just fade resistance.

In any case I'll be careful. Thank you for your comments.

[lucid]

Originally Posted by BMW M Power Mexico

I don't know if they are different in friction or just fade resistance.

In any case I'll be careful. Thank you for your comments.

The coefficient of friction associated with the pads are temperature dependant. The stock pads might have higher CoF at lower temps, but as temp increases the track pads should offer higher CoF. CoF eventually peaks at a certain temperature and then starts to decrease. That peak point is when your brakes "start to fade". I haven't seen temp vs CoF data on the stock pads either.