My last track weekend at beaverun, this is what happened...

Car: S2000 stock running S02's
Set up: Front - Cobalt Spec Vr's with GC3000 Rotors
Rear - Cobalt Gt Sports with GC3000 Rotors

In between sessions, I noticed that steam was coming up from my rear rotors. They were smoking, I saw it and got kinda scared thinking i fried or destroyed something. I did not see this on my front. When I started the weekend, both sets of pads were new. At the end of the 2 days and drive home, my GT sports were almost to the metal about 1-2mm left. My fronts still had half or lil over half of the pad. I am wondering what the deal is. Should I run better rear pads or do i need better front brakes? I was discussing this with an ITR track ***** but I know my balance is 50/50 so that makes my braking different from his car.

Also, I decided to run stock pads and rotors on the street again vs gt sports (too much squeaking). When i get on the brakes, my abs always kicks in. I was told it could be air in the lines. Could it be anything else? I will order some brake fluid from andie this week as well as SS lines. Thanks for the help!

 

I run Carbotech Panther Plus front and rear on my S2K for track days. I thought the S2K's 50/50 weight balance eliminated the need to use a pad with a lower coefficient of friction in the rear.:shrugs:

 

50/50 wieght distribution has nothing to do with wieght transfer during braking, right?

doesn't matter where the wieght is distributed it will always shift forward during braking.
So front does more braking, always.

this is why front brakes are always bigger on cars, and why front pads wear the quickest

but the proportioning valve should take away the need to run a lower coefficient pad in the rear.

If I were you I would cut off the dust shields in front and back to get more cooling to the brakes. also maybe fab some brake cooling kit. this will decrease pad wear significantly.

do those rotors have slots or crossed drilled? cuse that will also cause a greater rate of pad wear

 

Go with the Spec C's & you should be fine. Depending on the driver's level of experience we will recommend GT Sports or Spec C's for the rear. It looks like you need to move up. You are simply pushing the GT Sports beyond what they can handle.

You should be aware that it will change the brake balance but it shouldn't be anything you can't handle. Most likely, you will only notice it in trail braking situations.

It should also be noted that some people are hard on brakes & some aren't. The driver's style has a lot to do with it. eg Some customers with Civics run the Spec C & some the GT Sports in the rear. These are guys running the same class, racing against each other. The cars are set up pretty close to each other - it is just the driver.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by niterida &raquo;</TD></TR><TR><TD CLASS="quote">this is why front brakes are always bigger on cars, and why front pads wear the quickest</TD></TR></TABLE>

On FWD cars, yes. But on everything else? Not always true.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by stealthx32 &raquo;</TD></TR><TR><TD CLASS="quote">On FWD cars, yes. But on everything else? Not always true.</TD></TR></TABLE>

Sorry, but on ALL cars that drive in a forward direction. The front side brakes will always take about 70+% of the punishment.

 

Did you leave the E-brake on? ahahah......

I run carbotech XP10's in front and XP9's in the rear. The rear pads lasted pretty much all season last year and the fronts I went through 3-4 sets.

Usually your brake pedal is spongey if you have air in the lines, so I doubt that is it.

Did you "bed" the pads and let them cool for an hour or so? I had a front pad catch on fire at Beaver because I had just thrown them on and went to the track. you can hear them sizzle after a hot session..... to ensure no fires you have to heat them up then let them dry out.

it sounds like the rears are dragging for some reason... maybe a problem with your caliper?

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Nishant &raquo;</TD></TR><TR><TD CLASS="quote">My last track weekend at beaverun, this is what happened...

Car: S2000 stock running S02's
Set up: Front - Cobalt Spec Vr's with GC3000 Rotors
Rear - Cobalt Gt Sports with GC3000 Rotors

In between sessions, I noticed that steam was coming up from my rear rotors. They were smoking, I saw it and got kinda scared thinking i fried or destroyed something. I did not see this on my front. When I started the weekend, both sets of pads were new. At the end of the 2 days and drive home, my GT sports were almost to the metal about 1-2mm left. My fronts still had half or lil over half of the pad. I am wondering what the deal is. Should I run better rear pads or do i need better front brakes? I was discussing this with an ITR track ***** but I know my balance is 50/50 so that makes my braking different from his car.

Also, I decided to run stock pads and rotors on the street again vs gt sports (too much squeaking). When i get on the brakes, my abs always kicks in. I was told it could be air in the lines. Could it be anything else? I will order some brake fluid from andie this week as well as SS lines. Thanks for the help!</TD></TR></TABLE>

 

o ya.... i have never run anything but stock rotors so i have no idea if that could be an issue with your problem or not.

 

i pretty much agree with you.... but just for fun... what about a 911 that has all that weight over the rear wheels? do the front tires provide enough grip to allow 70% braking?

Just curious. I have never owned a 911 to know.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TimeRacer &raquo;</TD></TR><TR><TD CLASS="quote">

Sorry, but on ALL cars that drive in a forward direction. The front side brakes will always take about 70+% of the punishment. </TD></TR></TABLE>

 

the rotors i used are oem replacements one from cobaltfriction. they are stronger than oem and handle higher temps. my oem rotors did not hold up to the Spec Vr's hence the upgrade. the pads were bedded in per instructions from andie. bah i need to figure this crap out soon for itr expo

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Scot &raquo;</TD></TR><TR><TD CLASS="quote">i pretty much agree with you.... but just for fun... what about a 911 that has all that weight over the rear wheels? do the front tires provide enough grip to allow 70% braking? </TD></TR></TABLE>

yes, and that's about the only place where you might see a front bias that LOW. Your hondas have a front bias that's closer to 80%

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Nishant &raquo;</TD></TR><TR><TD CLASS="quote">the rotors i used are oem replacements one from cobaltfriction. they are stronger than oem and handle higher temps. my oem rotors did not hold up to the Spec Vr's hence the upgrade. </TD></TR></TABLE>

I would have to say you have a caliper issue if you did not leave the e-brake on. Pads and rotors installed correctly?

I purchased a set of the "cobalt coated rotors". I cracked them with one day of Summit main. I have since used AutoZone specials and they last many weekends.

"to each there own"

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TimeRacer &raquo;</TD></TR><TR><TD CLASS="quote">

Sorry, but on ALL cars that drive in a forward direction. The front side brakes will always take about 70+% of the punishment. </TD></TR></TABLE>

think again. The new electronic brake systems on MB's run more bias to the rear of the car to prevent nose dive and improve braking efficiency. It's contrary to what I thought but it's apparent when the rear pads dust more and wear quicker than the fronts as well as what tech's indicate a totally different brake proportioning system. And I ask, wouldn't that make you spin if you braked hard in a turn? MB tech's already solved that through the software of the system. This isn't new, F1 setups run quite a bit of rear bias.

Nishant, on almost all track setups I run a higher Mu rear brake pad. That should solve your problem.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by vapor &raquo;</TD></TR><TR><TD CLASS="quote">think again. The new electronic brake systems on MB's run more bias to the rear of the car to prevent nose dive and improve braking efficiency. It's contrary to what I thought but it's apparent when the rear pads dust more and wear quicker than the fronts as well as what tech's indicate a totally different brake proportioning system. And I ask, wouldn't that make you spin if you braked hard in a turn? MB tech's already solved that through the software of the system. This isn't new, F1 setups run quite a bit of rear bias.

Nishant, on almost all track setups I run a higher Mu rear brake pad. That should solve your problem. </TD></TR></TABLE>

WOW, this is crazy.

it doesn't matter where the engine, trans driver fuel pump, etc is.
Under hard braking or any braking weight WILL shift forward.

this will always cause a need for the front of the car to do more braking. if you were to slam on the brakes hard enough (and the tires could hold grip) the car would actually pick the rear wheels off the ground

in an extreme example, on a motor cycle when the rider slams on the brakes too hard he will go flying over the handle bars and the bike will flip over as it pick the rear wheel off the ground.

and since physics never fails, when a top fuel dragster slams on the gas the front wheels LIFT off the ground.

two very good examples of wiegth transfer.

this is also independent of the proportioning of fluid pressure to the calipers and the coefficient of kenitic friction of the brake pad to the rotor.

so ALL cars that move in a forward direction will need more braking up front. unless you are creating like 75% more downforce in the rear than the wiegth transfer up front.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by TimeRacer &raquo;</TD></TR><TR><TD CLASS="quote">Sorry, but on ALL cars that drive in a forward direction. The front side brakes will always take about 70+% of the punishment. </TD></TR></TABLE>

Is that your final answer? Check the NSX, any Z car except the latest (S30, S130, Z31, Z32), or the Exige/Elise for starters.

Most MB's now have electronic proportioners, that can alter the pressure front and rear dynamically. So chomping down on the rear hard, and then making sure it doesn't lock before the fronts is technically feasible.


Modified by stealthx32 at 4:37 AM 5/10/2005