Rear brakes need opinion?

[stockman1]

5341

I have a 99 steeda q400 with a bit over 400 rwhp. Brembo gran turismo 4 piston calipers on front, 13 inch disks. Rear brakes are puny stock 10 inch with hawk blue pads. I wish to upgrade rear brakes. Ford has a cobra kit with 11.65 rotors. I believe that you can't have too much bhp! I would like the bias to still be forward. Suggestions?

[mrzw70]

I wouldn't think the 11.65 rotors would over power the front 13's except maybe in an extreme panic stop. I'm assuming the car does run an abs setup as well. Worst case scenario is you have to upgrade to an adjustable proportioning valve to take a little pressure out of the rear set-up. Just my .02 , although I've been told it's only worth .011

[stockman1]

Abs is inop. Sounds like you feel the cobra brake kit is adequate?

[MikeFleming]

Just as important as rotor / pad area sizing is piston diameter, which is the ultimate decider between F/R balance, then the MC bore size dictates pedal pressure/control.

Ask the folks at Maximum Motorsports for input also. They have done all the piston/rotor size versus MC bore calculations.

[stockman1]

Just as important as rotor / pad area sizing is piston diameter, which is the ultimate decider between F/R balance, then the MC bore size dictates pedal pressure/control.

Ask the folks at Maximum Motorsports for input also. They have done all the piston/rotor size versus MC bore calculations.Hey thanks mike we are really under braked in rear and they tend to overheat more than anything. The eBay link is the kit i am considering. http://www.ebay.com/itm/110647622524?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

[MikeFleming]

Overheating is related to rotor size, wheel configuration and airflow. And dynamic weight on that axle, of course.

Maybe you need to move more braking force to the front?

[stockman1]

Overheating is related to rotor size, wheel configuration and airflow. And dynamic weight on that axle, of course.

Maybe you need to move more braking force to the front?added agent 47 ducting to front, are you suggesting more aggressive pads up front and leave rears as is?

[MikeFleming]

What is overheating in the rear?? And how are you defining "overheating"?

[stockman1]

What is overheating in the rear?? And how are you defining "overheating"?at Sebring rear brakes welded to rotors. Slides were not greased uneven wear. Haven't been back since mods made but after about 4 laps (approx 16 miles @ Sebring) brakes were exhibiting fade. At Roebling no real issues with braking with hawk blue pads in rear and greased slides, but no real heavy brake zones like Sebring. Oh fronts have hawk hp plus and ducting now. No rear ducting. Not sure if I answered your questions?

[MikeFleming]

Sounds like you need real track pads - Hawk HP pads are street compounds and will overheat easily when used on track especially if you drive like I do and use LOTS of brake.

There is always a serious trade-off between street pads: low dust, quiet, cold grip; versus track pads: high temp stability, low wear, good linearity/control and grip levels at high temperature.

Look into Raybestos ST43, Carbotech Xp12 and Xp10, maybe even Xp24's if you're really fast on track. Note that track pads don't stop well and usually wear rotors VERY fast when cold.

[SVOC]

Fluid???

[stockman1]

Fluid???i use dot 4

[MikeFleming]

Fluid??? True, needs to be addressed, but does not cause pad material to fade or overheat. We also didn't talk about titanium shims.


i use dot 4 Switch to ATE Type 200 Amber Brake Fluid, or alternately ATE Type 200 Super Blue. Or better.

ATE 200 is the only DOT 4 high-temp fluid that is rated by the mfgr for 3 years. All the other stuff, although *some* of it has a higher dry boiling point, is recommended to be changed in 6-12 months.

Then pump a few ounces out of each corner nipple after each tack event, and then again before the next one.

[stockman1]

True, needs to be addressed, but does not cause pad material to fade or overheat. We also didn't talk about titanium shims.

Switch to ATE Type 200 Amber Brake Fluid, or alternately ATE Type 200 Super Blue. Or better.

ATE 200 is the only DOT 4 high-temp fluid that is rated by the mfgr for 3 years. All the other stuff, although *some* of it has a higher dry boiling point, is recommended to be changed in 6-12 months.

Then pump a few ounces out of each corner nipple after each tack event, and then again before the next one.great advice I don't think blue is available in Florida for some reason? Tell me about titanium shims???

[MikeFleming]

ATE Super Blue has [almost] been declared illegal by DOT standards, so some states have already "banned" it and ATE is in the process of discontinuing the product (only the blue tinted version).

Reason being that all motorists are considered to be stupid, by definition. And centuries ago DOT declared that all brake fluids will be clear or amber, all auto-trans fluids will be pink or red, all PS fluid will be pink or red, etc. Usually the only under-hood fluid that is blue is windscreen washer fluid, and if someone added that to the brake fluid reservoir, well, that would be bad.

But all of those recommended fluid color rules were written back in the 50's way before everything was so clearly labeled under the hood. But rules are hard to change and often times don't keep up with reality.

So grab some Blue while you can.

Titanium shims are very popular in the Brembo brake arena. They sit between the caliper pistons and the back of the pads - the same place those anti-rattle shims sit. Titanium is a very poor heat conductor, so it helps keep calipers, pistons and fluid from getting as much heat transfer. They do nothing to prevent or reduce heat build-up between the pad and rotor though. And like most things titanium, they're pricey.

[k98dave]

This is unreal.....the nanny state police now under your hood!


ATE Super Blue has [almost] been declared illegal by DOT standards, so some states have already "banned" it and ATE is in the process of discontinuing the product (only the blue tinted version).

Reason being that all motorists are considered to be stupid, by definition. And centuries ago DOT declared that all brake fluids will be clear or amber, all auto-trans fluids will be pink or red, all PS fluid will be pink or red, etc. Usually the only under-hood fluid that is blue is windscreen washer fluid, and if someone added that to the brake fluid reservoir, well, that would be bad.

But all of those recommended fluid color rules were written back in the 50's way before everything was so clearly labeled under the hood. But rules are hard to change and often times don't keep up with reality.

So grab some Blue while you can.

[MikeFleming]

This is unreal.....the nanny state police now under your hood! Have you been in hiding for the past 70+ years? DOT has been all over the roadways and vehicles for many, many decades now. Nothing new here.

[Mike S]

You don't have a enough pad up front. Use the Hawk blues on all four corner. Most of your braking on the course needs to be on the front wheels as that is where the weight transfer provide most of the grip during braking. Just get some Motorcraft Dot 3 and be done. That is what a lot of Porsche guys use. It hasn't failed me since I switched. I change it once a year. It will save you some coin too.