Dum Dum Head

Since the rear brakes heat up considerably more than the fronts, what affect would having say, Porterfield R-4s up front with stock pads in the rear? Wouldn't this make the fronts brakes work harder and therefore decrease the amount of stress put on the rear brakes?

marcucci

Not sure exactly what you're talking about. You feel your rear brakes get too hot?

It's not uncommon to run race pads in front and stock in back. Primarily, it's cheaper. Front brakes do most of the work, too, and having a more agressive pad in front will help more than stickier pads in back.

I can't speak from experience on the S2k how it will affect the brake balance, but I ran race pads up front in my Prelude with slotted rotors, and was all stock in back. No problems, had much improved braking.

You will likely not reduce the braking effort in rear, only improve it in front- I don't think you will succeed in reducing the temp of the rear brakes, though you will certainly heat up the fronts more (race pads result in higher temps).

pfb

I was actually thinking of a permutation on this idea...

I'm currently running R4S's front and rear. They are perhaps 2/3's gone.

Based on an earlier thread, I'm thinking of changing out the fronts only to Panther Plus's, mostly to give the panthers a try and increase the pad thickness, thereby reducing head transfer to the piston and fluid.

yogi

read: http://www.turnfast.com/tech_brakes/brakes...balancing.lasso

dwb1

I agree with the information that's supplied at Turn Fast . The reason that I tested car at the track was to check balance of car . On our big brake kit we are taking the rotor diameter from 11.98 to 12.19 not a huge difference . The improvement in rotor design is used to remove heat . Caliper design gives quicker response and better clamping ability . The whole assembly reduces weight to improve handling . One of the things that I was trying to do at the track was brake very late and deep in the corners to see if balance of car had been changed, there were no signs of pushing the front end or the rear coming around . Also another sign of balance being greatly shifted would be ABS kicking in during panic or threshold braking .
The biggest factors in changing braking components is the ability to sustain high level braking over an extended period of time . . I also don't think that there is huge difference in friction between stock pads and #3 pad that I was running . I feel that the problems that the S-2000 has is the front brakes overheat ( can't handle continued abuse over long period of time ) then the rear brakes over load . You want to talk about changing the balance of the car put 50% of your braking on the rear of the car !!!!!!! The reason that I did not start producing kits the minute that we got calipers and rotors to fit, was putting miles on the system to determine problems that might come up before people started purchasing them . (I'm the ginnie pig ) . The calipers on my car have 1.75" pistons , this same caliper is also available with 1.5" pistons . The 1.5" piston calipers have the same clamping force as the stock calipers , Warren at the Brake Man recommended the 1.75 pistons on our cars because of total weight of car and front to rear weight distribution . ( 50/50) . He has a lot of braking history with Vett's and Viper's besides all the racing cars that they work on .
If balance becomes a problem with a braking system , you can change piston sizes in the caliper , change pad material or make changes to other end of car that has not been modified. If you modify the brakes to better handle the abuse that you are going to put them through this does not effect handling . If the brakes on your car start to fail ( fade) the entire system will be effected , and not at the same time or the same way . A stock system with stock pads may effect handling differently than a stock system with racing pads . If you can keep system from failing ( by upgrading) the effects on handling will be a given over entire range of driving.
Our goal was make kit that fit stock wheel .
Reduce weight of components
Improve mechanical properties of calipers ( less flex and caliper movement)
Increase rotor diameter ( in available space)
Increase heat rejection of rotor and caliper
Increase selection of pads available for car
Easy to work on
I feel that the new rear rotor will cool better than the stock rotor and the reduction in weight will be a performance enhancement ( it also looks cool)
In my post Trying Hawk HPS pads, I was not trying to condone installing racing pads on the front and stock pads on the rear . My car is that way because rear pads aren't done yet . The #3 racing pad from the Brake Man is a very forgiving pad it does not bite like a high friction brake pad . You can drive with this pad cold or very hot and it stays the same through out its temperature range . I feel that the greatest difference between the stock setup and the Big Brake kit is the ability to modulate the brakes while braking at threshold . You have the ability to push right to the limit with out loosing control to the ABS. In a panic situation " balls to the wall" or limited traction under a single tire or tires, ABS sill works just the same as on stock car.
My car will be at Rick event . You will see how kit holds up ( by then I will have close to 9,000 miles on it ) and be able to feel difference between stock and modified system. When more people start to use this kit and push it to the limit, with different drivers at different tracks the true abilities of what it is capable of will be known.
I can tell you with my driving experience I don't feel that the balance of the car has changed for the worse .

brad

Ps
You might be able to tell that the caliper does respond faster that stock . At slow speeds that might be the answer or the reason they seem more responsive than stock.

dwb1

I also wanted to remark at the amount of research that the people on this board do . It seems like most car groups just accept what the norm is and don't ask questions or look for answers . On this board most of the true in-depth discussions , I always feel that I get some more information or some thing is posted that makes me look for a answer to a new question . I am definitely impressed.

Brad

Ps
All the flaming replies are not included in the above statement . ( they are a waste of the band width they are posted on)

Mikey

I'd recommend that if you go with race pads in the front, use them in the rear as well.

Positives of stock pads:

Stock pads are cheaper, about 1/2 to 1/3 the cost of race pads. But rears are cheaper than fronts, so you actually save less than 1/2 of that.

You may not need the extra braking power as most of the braking is done by the fronts.

The rears will not run as hot as they would if you had race pads back there. But with race pads on the fronts, I think the rears will still run hotter than normal.

Negatives of stock pads.

If you're using more aggressive compounds pads on the front, you will have the ability to brake later than you normally would. Most people tend to take advantage of the better braking ability and brake later. Braking later means the same amount of speed (energy) must be bled off in a shorter time. This means more heat will be generated and transferred to the braking system. And even though the fronts will be doing much of the work, the rears will be braking later as well. My feeling is that this will heat them up more than if you only had stock pads all around.

Which leads into the fact that the stock pads are not up to extreme heat. The adhesive that holds the pad compound to the backing tends to burn up. Race pads have either very high temperature adhesive or rivets or both.

I've seen a set a stock rears worn down form nearly new to nothing in only 3 1/2 hour sessions! Heat kills them.

You can go through the stocks so quickly that there is no cost advantage. Savings for your suggested combination are probably less than $30-$50 per set. Race pads can last 2 to 3 times as long, even though you're using them harder. An added advantage is that you only have to be MR. Mechanic and change race pads half as often.

Allan Haggai

Hi Mikey. With out the luxury of an adjustable proportioning valve, running different compounds at each end of the car can be helpful, even with ABS. Let's say you put real aggressive pads at both ends and put sticky track tires on. Due to all of that extra bite at the front, the forward weight transfer under braking will be greater, weight on the rears will be lighter and more likely to lock or engage ABS. The car will wiggle under braking if the rears are pumping and the fronts are not. Some guys run a less aggressive pad at the rear to prevent this and it is easier than putting in a valve. But like you said, put a real whimpy pad in the rear of an S2K and you'll probably fry them. Something like Hawk Blues up front with Hawk Blacks or Carb Panthers in the rear MIGHT be the hot set up.

Later!

Mikey

Hey Allan

Good point. I've heard that the S2000 4 channel ABS is actually robust enough to handle different grip levels at each wheel. So mixing race pads may be a good option.

The stock pads though, just can't hold the heat.

I'm installing the Carbotech Panther Plus next week and I'm going to try them out as street pads. But if I get the constant squealing you did, I may just drop in my set of stock pads for awhile.

dwb1

The ABS on our cars is 4 channel , ABS can be applied to only one wheel if required. It uses a sensor at each wheel that detects the wheels not turning or turning at a different rate with the brakes on . When it detects a wheel sliding it shuts off petal pressure from master cylinder and reduces pressure to wheel that's not turning, as soon as wheel starts to turn ABS pump pulses pressure to that same wheel to keep wheel from locking up , but still braking car . At some point computer decides that problem is over and ABS kicks off.


brad