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bolt-on
11-19-2002, 10:50 AM
I know that the topic of brake rotors has been visited before, but with another season of open track experience, I was wondering what recommendations other members may have. Our 1997 Cobra is nearing the end of the usefull life of it's rotors (1999 Cobra Brembo's on the front and stock Varga's on the rear). What experiences, good and bad, have you had with your rotors? What recommendations do you have for rotors (we will stay with 17 X 9 wheels)?

Larry

98banana
11-19-2002, 11:35 AM
Originally posted by bolt-on
I know that the topic of brake rotors has been visited before, but with another season of open track experience, I was wondering what recommendations other members may have. Our 1997 Cobra is nearing the end of the usefull life of it's rotors (1999 Cobra Brembo's on the front and stock Varga's on the rear). What experiences, good and bad, have you had with your rotors? What recommendations do you have for rotors (we will stay with 17 X 9 wheels)?

Larry

I'm not going to recommend, but I'll share my experiences. I tried Power Slot rotors because I was running Hawk Blue pads up front and I was informed that gas-slotted rotors were needed. Now I get mixed advice about needing slotted rotors.

Anyway, I went through 3 sets of power slot rotors up front and 2 in the back and the last set cracked before the useful thickness was gone. When the last set cracked, John Pearson gave me a set of Brembo rotors that are still on the car.

One interesting thing is that I changed to CarboTech 1108 pads and they virtually stopped wearing the rotors while stopping just as well as the Hawk Blues. The Blues really ate the rotors.

If I have enough money when I build the new banana, I'm going with the Griggs/Sierra brake setup. (I'm still researching that one though.) If the money's tight, I'm going with the stock Cobra setup from the original banana. I'll definately stick with the CarboTech pads and hopefully the 1109's will be out by then.

Dean95CobraR
11-19-2002, 12:03 PM
Originally posted by bolt-on
I know that the topic of brake rotors has been visited before, but with another season of open track experience, I was wondering what recommendations other members may have. Our 1997 Cobra is nearing the end of the usefull life of it's rotors (1999 Cobra Brembo's on the front and stock Varga's on the rear). What experiences, good and bad, have you had with your rotors? What recommendations do you have for rotors (we will stay with 17 X 9 wheels)?

Larry

Hi Larry.... I hope everything is going great for you and the misses.:)

I had the same experience as Tom did on the Powerslot rotors. Luckly the crack didn't happen on the track but during the cool down lap.

Since then, the only thing that I had used was the solid Brembos. They sell them at a decent price and they hold up really well. I would recommend them to anyone.

(BTW - I have an extra set if you are interested. They are Cad plated solid Brembos. Current setup can not use them)

Dean95CobraR
11-19-2002, 12:04 PM
Originally posted by 98banana
If I have enough money when I build the new banana, I'm going with the Griggs/Sierra brake setup. (I'm still researching that one though.) If the money's tight, I'm going with the stock Cobra setup from the original banana.

I am interested in this setup also but I have not been able to find any information. I would appreciate any info you could provide.

98banana
11-19-2002, 12:33 PM
Originally posted by Dean95CobraR
I am interested in this setup also but I have not been able to find any information. I would appreciate any info you could provide.

That's why I'm still researching. There's not much on them. I did a search on cc.com and all I could find is one guy in a Baer or Brembo conversation saying "well, if you want a real nice setup, then get Sierra" then the subject changed back to the other system.

I did find their web site and it the parts look impressive, but I'm still trying to find somebody that's using them. http://www.sierraracing.com

Eric at Griggs told me that all of their cars use them, of course.

sn8kbit
11-19-2002, 03:29 PM
i gotta chime in on this, of course. while overkill, the solid eradispeed fronts were darn impressive at RA with the blues. we figured the set of blues i was using had only that weekend left in them, and i was wurprised to see hardly any wear after 2 days of track (regardless of how slow i was ;) ). i obviously generated a ton of heat, the black centers turned purple on me, but i didn't burn off the dustboots of the calipers either. combined with the cooling, these are probably the best things i've put on the car.
drawback is price only. these rotors now have 20k miles on them, and 3 events (not including auto-x's) and other than the grooves the blues naturally ran in the rotors, they still seem (bad choice of word?) to be in the same state as when installed. i'm not planning on having to change rotors till possibly next winter, and that's only if necessary.

edit: removed some double statements. i was holding the baby while typing ;)

98banana
11-19-2002, 03:39 PM
Originally posted by sn8kbit
i gotta chime in on this, of course. while overkill, the solid eradispeed fronts were darn impressive at RA with the blues. we figured the set of blues i was using had only that weekend left in them, and i was wurprised to see hardly any wear after 2 days of track (regardless of how slow i was ;) ). i obviously generated a ton of heat, the black centers turned purple on me, but i didn't burn off the dustboots of the calipers either. combined with the cooling, these are probably the best things i've put on the car.
drawback is price only. these rotors now have 20k miles on them, and 3 events (not including auto-x's) and other than the grooves the blues naturally ran in the rotors, they still seem (bad choice of word?) to be in the same state as when installed. i'm not planning on having to change rotors till possibly next winter, and that's only if necessary.

edit: removed some double statements. i was holding the baby while typing ;)

You know, that's a good point. I can't say how the Blues affect any rotors other than the Powerslots. I never ran them on anything else. It very well could be that the Blues won't affect other rotors as bad.

And I've HEARD great things about the Eradispeed too. Eric at Griggs was trying to sell me a set of those last year.

kevin
11-19-2002, 03:48 PM
if steve can "chime in" then i will too.

i use the brembo 2-piece rotors on the front. rotors and hawk blues (my first time using them) were put on in april of this year. there is virtually no wear on the rotors (look good for another season) and the pads (altho i haven't measured them yet) still have plenty of thickness (as guaged by the wear slots).

however, i will be going to performance friction pads when it's time to change again (i use the 01 compound on my other car and like them a lot)

sn8kbit
11-19-2002, 04:47 PM
tom, if you decide to stick with the PBR setup, the eradispeed are the way to go. i can't stress that enough. i will be going to the Carbotech pads, simply because the "grooving" the blues do. according to "shuggextrodinaire" the carbotech pads tend to clean that mess up, and groove less.
also, on the way to RA, i stopped in indy at gasoline alley (no, not KB). place called RacerWholesale. these guys do mostly Alcon stuff (you should see that 12 piston caliper....OMG!) while asking him about cooling hose for the ducts, he walked out and looked at the setup. immediately started bragging on the rotors. mentioned that he has a customer that's had them on the car since they were first introduced, runs the blues, 6 events a year and IRP whenever he can get in, hasn't changed the outer discs yet. that's gotta say something......
understand tho, only the PBR calipers will clear the hat on these. if you choose to upgrade to a Brembo 4 pot, Wilwood 6/4 pot, or Alcon 6/4 pot, the rotors will have to go. not to mention it's not a "bushed" rotor like the Brembo or Baer Extreme offerings, which you'd need to go with using a fixed position caliper, vs. floating.
i'm just waiting for baer to do the Eradispeed +1 rears in a solid disc....

fastoldman
11-19-2002, 09:27 PM
We spend so much time trying to get more power,and we don't spend enough time on stopping. The weight of the Cobra necessitates some modifications for those who get serious on the track. Check out www.thebrakeman.com if you want to look at a phenomenal big brake upgrade. More importantly his pads are spectacular and have no where the near of Hawk blues,plus they are progressive - ABS or not,as smooth feeling pad that stays static throughout a run session is superb. Alot of companies like StopTech and Brakeman , also make quality slotted rotors,and will not have the problems you have witha Powerslot - essentially nothing more than an OEM rotor with slots. These two racing rotors will give you alot more life, and with a high temp fluid will keep your brakes under you until you go fast enough to require ducting. Ducting is a great investment with the Cobra, as it will keep those rotors and pads more consistent, and your wear usually increase 2 fold, at the same time you can dive deeper into the corners.

thomasmoran1
11-19-2002, 11:27 PM
Tom, we are running hawk blue's with slotted brembo rotors and they are working great. The pads seem to last about three track events which is good for us (remember I'm the one who actually started a grass fire in Road atlanta:D ) and the rotors about twice that. On another note I have to agree with Steve that if you keep the Cobra stock setup you should go with a two piece rotor because of the un-sprung weight alone.

Just my 2 cents

Thomas

COBRA #17
11-20-2002, 10:17 AM
Well I agree & disagree!!!

I don't think you can just say soenso's rotors are the best or soenso's pads are the best !!! It comes down to the combination and how well they are used!!!

Shugg and I ran the same pads most of the year. He went through 2 or 3 sets of pads by mid season and I was still on my 1st set. Of coarse he called me a liar but I proved it to him. Not saying he is rough on the brakes but it boils down to use and abuse! :thumbsup: Different people use there brakes differently so find a set up that works for you and don't be affraid to try new stuff.
It is a proven fact the Hawk's are hard on rotors. I'm also surprised to see no one has mentioned the cryoed stuff. Deversifed Cryogenics is going to sponsor AI next year and they have a great product!! www.frozenrotors.com ( I believe)


AI EAST ASST DIRECTOR
COBRA #17 (1 fasthillbilly):flash:

b_tone
11-20-2002, 10:42 AM
What make the eradispeed rotor better than the Ford OEM Brembo rotor?

Personally I have been using the Ford Brembo rotor (cryogenically treated) for nearly 7 years and I have never had a problem with warping, or extreme rotor wear. I have tried nearly every pad compound from Hawk, PF, Porterfield and I am now playing with the carbotech compounds.

I support Frozen rotors (actually I turned them onto AI) and I would recommend them to everyone. They will last longer and are less prone to warping than a non treated rotor.

Just my opinion

Brian

fastoldman
11-20-2002, 11:03 AM
Pad wear can be very different from driver to driver based on numerous variables:

1. Do both cars have ducting?
2. Does one driver trailbrake ,while another does not?
3. Is one driver a few seconds faster?

Amazingly, many friends assume that one guy is harder on brakes than another, and the first comment you sometimes hear is, " Heck , he is only 2 seconds faster than me." At Road America in 2000, I was turning 2:37's in a stock Viper with stock Michelin tires. In 2001, in the same car, with the same set-up I turned a 2:34 --- but I also fried a set of pads and destroyed my front rotors in one 30 minute session. This is a perfect illustration of how speed will affect pad wear, as speed equals heat. I have since gone to a tested brake ducting system, better fluids, and my pad wear has increased 4 fold. The reason I have brought this up , is that pad wear is often different among fellow participants, and in analysing what works best, it is important to go into types of rotors, pads, fluids, along with driver style.Keep in mind, that what worked last year , may not work this year, as track time ( seat time) often equals greater speed,hence more wear.


Bill Pemberton
Trophy Placing at Solo II Nationals in 97 Cobra
National Champion , Super Stock , Viper Days
Track Record Holder - Spec Miata , SCCA
Instructor for - Viper Days, Porsche Club, Corvette Club, SCCA, and had the distinct pleasure to help some great drivers including El Head Honcho , Tony, at your last SVT Cobra Track Event.

COBRA #17
11-20-2002, 11:29 AM
Well that's funny our situation was different!
I was consistantly 1 or 2 seconds faster than SHUGG and easier on pads TOO!! ( HMMM HOW"S THAT !!) His luck was just a little better than mine!!!:thumbsup: ( PUNK )
We both had ducts as far as I know ! Maybe it's that extra 50lbs of gut !!:rotf: :thumbsup:

I'll leave it at that !!!
:rotf: :rotf: :rotf:
:rotf: :rotf: :rotf:

AI EAST ASST DIECTOR
COBRA #17

fastoldman
11-20-2002, 12:14 PM
Then we are in agreement,as those are just some of the criteria, since we both are discussing driver differences can affect pad life, etc. This is only one area a driver can improve,and obviously you have some skill and one can not give a generic answer that will satisfy all drivers --- just giving some areas to ponder and nothing more.

cobrabitn
11-20-2002, 12:17 PM
You tell them Bill! ;)

I wish you were coming to our driving school in the Spring. I really learned a lot from you and I am sure others will too. Out of all the events I have been to, I learned more from you in one session then I did in three years.

Besides, you're a nice guy too! :)

b_tone
11-20-2002, 12:37 PM
I have run near 1500 laps at Road America and I would simply be amazed that a stock viper could turn a 2:34 on stock tires. I have driven with vipers there and if you look at the results from this years event at Road America the fastest stock viper there was running right around 3 minutes.

look here for the results (http://www.viperdays.com/elkhart2002.html)

I did find your results here (http://www.viperdays.com/elkhart2000.html) and it looks like you ran Bill Pemberton 2:37.984.

That is fast at road america I will give you that. Is that a flying lap? With the ford group we get timed from standing start so it's a bit different. One last note, it seems to me that you really were hard on pads if you burned a set up in 30 minutes unless they were stock pads. If the were a good performance/race pad then you did something strange with the middle pedal.

Brian

sn8kbit
11-20-2002, 03:12 PM
well, i'm not saying one is better than the other. maybe i worded it wrong. there are some benefits however to the eradispeed (solid) than the stock brembo. while i agree proper cooling and driving style do affect braking, i think that rotor design can also affect how the rotor cools. my understanding of braking (and i might be wrong, please correct me if i am) depends on how well the rotor absorbs, then dissipates that heat. more mass would then equal more surface area for the metal to dissipate that heat (yes, no, maybe?). attached shots show the difference in mass of the eradispeed vs. the stock brembo. since i don't quite know enough about the different kinds of iron/metals used in the brembo or eradispeed, i would also venture to say that a thicker rotor would be less prone to cracking. (again, yes, no maybe?) not to mention unsprung weight as thomas mentioned earlier
i've heard of some folks going thru the stock brembo rotors about every 3 events (these are guys doing several events a year versus my 3-4, if i'm lucky). i'd really like to see a set on someone's car that actually gets to 'threshold braking' just to see what the life of these rotors really are. regardless of what the guy in indy told me (i already had them, so he wasn't trying to sell me a set), i'd really like to know. if true, it'd save a bit of money also.
side note--2.30's is flyin around RA, not that i'll ever see that. i'll be lucky to break 3:00 next time on a fast lap! LOL

sn8kbit
11-20-2002, 03:13 PM
another (i'll leave the 'pimpy' shots out of it....;) )

98banana
11-20-2002, 03:34 PM
Originally posted by sn8kbit
another (i'll leave the 'pimpy' shots out of it....;) )

Those Eradispeeds have got to suck the heat out of the pads better than stock. No doubt in my mind.

The Brembos on my car, which came from Brian Groth, lasted one day at CMP (hard on brakes), 2 wet days at Road Atlanta with the SCMC (we won't even count those) and 2 more hard, and I mean HARD, sessions at Road Atlanta (1:39 - 1:40 with a worn out trackloc (depending on who was holding the watch)). I know, that's not a lot of track time, but there was virtually no wear on the rotors. I did go through a set of CarboTech 1108's in that time frame though.

tgentry
11-20-2002, 04:50 PM
Tom, I went through a set of Carbotech Panther XP (1108) pads in a day and a half at MAM. I loved the feel but not the pad life.

Maybe we need to have a discussion on braking technique. I must be doing something very wrong.

sn8kbit
11-20-2002, 04:53 PM
Maybe we need to have a discussion on braking technique

i agree, i for one know i'm way early on the brakes simply due to lack of knowledge.......

one of these days i'll learn.....

tgentry
11-20-2002, 05:12 PM
Bill might have a point that applies to me. I've been working hard to get everything I can out of the Fairmont suspension. Could be that suspension upgrades will make brakes last longer by letting me carry more speed through the turns.

How's that for justification of expenses?:rotf:

98banana
11-20-2002, 05:12 PM
Originally posted by tgentry
Tom, I went through a set of Carbotech Panther XP (1108) pads in a day and a half at MAM. I loved the feel but not the pad life.

Maybe we need to have a discussion on braking technique. I must be doing something very wrong.

Yeah, I went through the carbotechs as fast as the blues, but the difference was on the rotor side of it.

Braking technique wouldn't be a bad topic to start. Here's my technique: Wait as long as I can and then stomp on them until they are just about to lock up. Then pray that it wasn't too late.If it was, then do a little accidental trail braking into the corner and hope that the next lap is better. :D

In other words, I use my brake pedal like an on-off switch that has a little knowledge of lockup position. Is there any time that soft braking is advantageous. I've even heard that hard/late braking is better than soft/early braking when it comes to heat buildup. Not sure if I believe that one or not, but I don't know for sure.

Anyway, maybe this is good for another thread...

Dean95CobraR
11-20-2002, 05:17 PM
Originally posted by 98banana
I've even heard that hard/late braking is better than soft/early braking when it comes to heat buildup. Not sure if I believe that one or not, but I don't know for sure.

Anyway, maybe this is good for another thread...


I can believe this statement. I've always heard that the early/long braker will generate more heat than the hard/short braker. I see a lot of people practically coasting with the brake on and I believe this kills pad life.

I hear all this talk about Blues being bad on rotors and getting very short life. My lasted a very long time and I didn't have any brake cooling. Using a set of brake pads in one open tracking weekend just doesn't seem feasible. :eek:

tgentry
11-20-2002, 05:21 PM
Originally posted by 98banana
Here's my technique: Wait as long as I can and then stomp on them until they are just about to lock up. Then pray that it wasn't too late.If it was, then do a little accidental trail braking into the corner and hope that the next lap is better. :D

That sounds a lot like mine. I figure the later the better, and find that I gain ground on a lot of people in the braking zones.

Have also heard that short/hard braking is actually easier on equipment than long/soft braking. I would think it would be better for the fluid, and possibly for the pads.

tgentry
11-20-2002, 05:25 PM
Originally posted by Dean95CobraR
Using a set of brake pads in one open tracking weekend just doesn't seem feasible. :eek:

Unless they're PF "Z" pads from Autozone! :thumbsup:

I think I might try the PF 01 pads. I've heard excellent things about pad/rotor wear and performance.

sn8kbit
11-20-2002, 05:38 PM
I see a lot of people practically coasting with the brake on

i'll just go on and raise my hand at that one. being a novice and Road america being my first dry track, the speed alone at my skill level makes early braking an unconscious reaction. (for me anyway) it's almost like when i see the 5 brake marker it acts as a switch. by the end of the day sunday, i was trying to brake later, but this was also one of the reasons i was so surprised that those blues still had quite a bit of pad left.

fastoldman
11-20-2002, 05:55 PM
b tone,

Please check the following year ( 2001 ) , and you will see I ran a 2:34.9. This is only to illustrate that I was doing okay in 2000 at 2:37, but the 3 extra seconds I found were enough to fry the fluid, and destroy the rotors and pads. I was using the same pads that the full blown race group was using, but the extra speed was too much for the stock rotors and a quality Dot 4 fluid. I put ducting on the car, and ran the same pads for an entire weekend at Mid Ohio with no concerns - I actually got another day at another track out of them. Keep in mind this is just a personal example to attempt to illustrate, what will happen as we all go faster. My Cobra's were the same ,in that they also were heavy cars that are faster than Trans Am cars of 20 years ago. The ducting and other items are just observations to help other track addicts, as we all have the same disease. And yes, the time of 2:34 was on Michelin MXX3's, as you will note in the rules Matrix, only street tires are allowed - and they must be Michelins.

Check out the General Discussion and come run with us, and I will buy you a beer. We are even better bench racers, and the guys are from 19-72, so you really get some interesting perspectives.

kevin
11-20-2002, 07:38 PM
well it seems no one chenaged threads so it's a two topic thread now:D

i tend to brake late and hard, then off (like tom's example of the on/off switch). some of you have riden with me and can correct me if i'm misreading what i'm doing (and don't use the first couple laps as those are car and driver warmups)

the two-piece rotors are wearing great and the hawk blues look like they may have another full season on them. this, on the 00r, 14 track days after subtracting for the weathermen effects.

but like i've said b4, i'll be switching to pf 01 after these blues are gone

thomasmoran1
11-20-2002, 09:34 PM
I'm like tom, hard as you can and then trail brake into the corner. My favorite for that is Road Atlanta. Coming down the hill into 11a I'm standing on the brake pedal as har as I can. In fact just thinking about how much fun that is makes me want to get out there right now.


Thomas

thomasmoran1
11-20-2002, 09:43 PM
Originally posted by Dean95CobraR
I can believe this statement. I've always heard that the early/long braker will generate more heat than the hard/short braker. I see a lot of people practically coasting with the brake on and I believe this kills pad life.



Dean, I have to disagree with you on this one. If you ever watch any long distance racing like Le Mans you will see that some teams will make there drivers take it easy in the brake zones to get the brakes to last to the end of the race. In fact I've even seen it happen in F1 on tracks like the old Hockenheim and Montreal where in the dying laps of the race a car will fall a couple of seconds off the pace because they need to make the brakes last till the end.

Thomas

Dean95CobraR
11-21-2002, 07:30 AM
Originally posted by thomasmoran1
Dean, I have to disagree with you on this one. If you ever watch any long distance racing like Le Mans you will see that some teams will make there drivers take it easy in the brake zones to get the brakes to last to the end of the race. In fact I've even seen it happen in F1 on tracks like the old Hockenheim and Montreal where in the dying laps of the race a car will fall a couple of seconds off the pace because they need to make the brakes last till the end.

Thomas

You may have a point but I'm not sure that their situation relates to our relatively feable braking systems and hardware. They are totally in a different league. They could actually be coasting more without the brakes applied also. JMHO ;)

thomasmoran1
11-21-2002, 12:43 PM
Dean, those brakes are much better than anything on our cars but they are still doing the same thing. Turning Kentic energy into heat. When we were in MAM and I was instructing Denis, he was telling me how he was having brake fade and wear problems with his 03 (He was out on the track the day before most of us got there). For the record he was running a stock setup with hawk blue pads and some ducting. When he told me this I told him to back off in the brake zones and they will last. For example I had him braking at the 41/2 marker on the front straight. In the first day Denis was there he destoryed a set of rotors and I think pads (Denis can you please chim in). On the second day with the two of us in the car for most of the day (car would have been over 4000 pounds) we made the brakes last the whole day and there was much less wear on the rotors.

Thomas

b_tone
11-21-2002, 12:47 PM
Coming down the hill into 11a

you mean 10a right?

. I've always heard that the early/long braker will generate more heat than the hard/short braker. I see a lot of people practically coasting with the brake on and I believe this kills pad life.

If you are going 150 and brake to 50 mph you have the same amount of energy to dissapate. Pe=1/2mV^2 is the governing equation relaying potential energy to velocity. You will have the same amount of energy being converted into heat and the shorter amount of time that is is done in (i.e. the harder the brakes are used) the shorter the time you allow this heat to dissapate. The heat is then built up and retained in the system so immedietly following your banzi braking style you may have a reduced braking force in the next corner.

basically you will not generate more heat (from a systems perspective), you just a spike in the temp of the rotor in a shorter period of time and this will require a longer cooling period.

Does this make any sense or did I just muddy the waters?

thomasmoran1
11-21-2002, 12:57 PM
Originally posted by b_tone
you mean 10a right?


Your right. I just went the Road Atlanta web site and they actually have no turn 11 listed. I just assumed that the chicane was the last set of turns before 12 which is the last turn on the track. I guess they count the up hill going into 12 also. Thanks for pointing that out.

Thomas

Dean95CobraR
11-21-2002, 01:00 PM
Originally posted by b_tone
basically you will not generate more heat (from a systems perspective), you just a spike in the temp of the rotor in a shorter period of time and this will require a longer cooling period.

Does this make any sense or did I just muddy the waters?

A little mirky. ;)

Are you saying that if the end temp of the rotors equal 700F, the amount of time it takes to cool off is related to how the heat was generated - long/soft vs short/hard? :confused:

98banana
11-21-2002, 01:02 PM
Originally posted by thomasmoran1
Your right. I just went the Road Atlanta web site and they actually have no turn 11 listed. I just assumed that the chicane was the last set of turns before 12 which is the last turn on the track. I guess they count the up hill going into 12 also. Thanks for pointing that out.

Thomas

I think turn 11 is uder the bridge. The 2 turns before that are 10a and 10b.

When I was chasing down the Porsche before my fender-bender, I would make up a lot of ground under braking coming into 10a. And no matter how late I braked, I could have braked later.

Now as far as turn 12, I have never heard of that one. :D

Dean95CobraR
11-21-2002, 01:02 PM
Originally posted by thomasmoran1
Dean, those brakes are much better than anything on our cars but they are still doing the same thing. Turning Kentic energy into heat. When we were in MAM and I was instructing Denis, he was telling me how he was having brake fade and wear problems with his 03 (He was out on the track the day before most of us got there). For the record he was running a stock setup with hawk blue pads and some ducting. When he told me this I told him to back off in the brake zones and they will last. For example I had him braking at the 41/2 marker on the front straight. In the first day Denis was there he destoryed a set of rotors and I think pads (Denis can you please chim in). On the second day with the two of us in the car for most of the day (car would have been over 4000 pounds) we made the brakes last the whole day and there was much less wear on the rotors.

Thomas


Yep, I forgot about that. I didn't realize that Dennis was using Hawk Blues the first day. :o

98banana
11-21-2002, 01:05 PM
Originally posted by Dean95CobraR
A little mirky. ;)

Are you saying that if the end temp of the rotors equal 700F, the amount of time it takes to cool off is related to how the heat was generated - long/soft vs short/hard? :confused:

I was thinking that too, but what tone says actually makes a little sense because the brakes start dissapating heat as soon as the braking starts. That means earlier braking starts cooling earlier. If that's not correct, then I still think that harder braking is easier on the brakes...

And I didn't even stay at a Holiday Inn Express last night.

Dean95CobraR
11-21-2002, 01:08 PM
Originally posted by 98banana
And I didn't even stay at a Holiday Inn Express last night.


But did you drive by one on your long trip to work? ;)

thomasmoran1
11-21-2002, 01:17 PM
Originally posted by 98banana
I was thinking that too, but what tone says actually makes a little sense because the brakes start dissapating heat as soon as the braking starts. That means earlier braking starts cooling earlier. If that's not correct, then I still think that harder braking is easier on the brakes...

And I didn't even stay at a Holiday Inn Express last night.


Tom, think of when your at the track and think of how when someone is out there for their first time they can get away with a stock setup in most cases because they are not braking hard enough to generate more heat then the stock setup can handle. But then as they start getting faster they need to upgrade their brakes to cope with the extra heat which increases wear.

Thomas

Dean95CobraR
11-21-2002, 01:35 PM
Originally posted by thomasmoran1
Tom, think of when your at the track and think of how when someone is out there for their first time they can get away with a stock setup in most cases because they are not braking hard enough to generate more heat then the stock setup can handle. But then as they start getting faster they need to upgrade their brakes to cope with the extra heat which increases wear.

Thomas

That analogy really doesn't relate to the discussion about braking technique though. Everyone agrees that more speed will generate more heat.

svt_coupe
11-21-2002, 01:36 PM
I haven't finished reading this thread but wanted to toss out a couple of things.

In the first part of the year, I was running my ducting in a funky way. Found out that only about 20% (rough guess) of the air was getting to where it needed to be. After re-routing the ducting, brake wear got better.

Then I got a torque arm. The wear rate of the front pads was improved dramatically. I started using more rear pads, but that's because I was no longer trying to launch the rear of the car over the top of the car underbraking. The rears actually started working. Also, I don't have a bias adjuster so the rears still aren't contributing like they should be. And, I trail brake.

Since the torque arm, my braking has improved (literally, the actually braking power of the car) and I'm on the same set of front pads that I installed for Lowes. 6 races and I still have pads left...

I did, however, get through the season on 1 set of Toyo's... :D :D

sn8kbit
11-21-2002, 01:52 PM
ok, i think i see what tone's sayin.

from 150-50 regardless of when you brake, it takes the same amount of energy, thus generates the same amount of heat. starting the braking earlier gets the rotors in the cooling process sooner. 700 degrees at a spike, versus 700 degrees on metal already cooling would equal cooler brakes going to the next corner. of course, i probably just screwed it up even worse...LOL

also, i think you've got a point there on that TA shugg. my car with the IRS is going to brake completely different than your stick axle car since the two setups are completely different. i wonder how you'd try to reduce brake dive with an IRS...

ya'll keep goin, i think i might actually be learning something here...

thomasmoran1
11-21-2002, 01:55 PM
Originally posted by Dean95CobraR
That analogy really doesn't relate to the discussion about braking technique though. Everyone agrees that more speed will generate more heat.

Sorry Dean for not being clear. The point I was trying to make was that the extra heat generated by hard braking is what wears pads and rotors out. Not costing them into the brake zone which I believe increase’s brake life.

Thomas

b_tone
11-21-2002, 01:56 PM
Are you saying that if the end temp of the rotors equal 700F, the amount of time it takes to cool off is related to how the heat was generated - long/soft vs short/hard?

not really. If you take 500ft to stop from 150 your rotor temp will be much less than if you do it in 300ft. You still generate the same amount of energy based on the Kinetic Energy (i misspoke before it's not PE, it's KE) equation but you allow some of that heat to dissapated into the air rather than being retained in the rotor.

The heat generated is the byproduct of the work done on the rotor (force x distance = work). When braking over a long distance vs a short distance you will do the same amount of work, you will just have to have higher or lower force to do the same amount of work.

Doing that work over a short distance is what caused the high temperature spike and this is what hurts the rotors.

Is this any better?

Personally I tend not to come into a corner and wait until that last minute, I tend to brake just under limit for a little longer. This keeps the heat down and usually keeps me under control coming into the corner. I don't know about you guys but I never enter a corner perfect enough to wait until the last second to brake. I always need a bit of a cushion.

EDIT: if you want to reduce brake dive in an IRS you should really start at the front of the car with the geometery(sp?) because it's easier than changin it in the back. a poor mans way is to increase the spring rate in front as well, but this has other effects.

I am also saying that the temp will not be as high when you brake froma greater distance vs a shorter one.

Shugg did you get my email?
Tom Lewis, shoot me an email: btone@ford.com

tgentry
11-21-2002, 02:58 PM
I've been giving this a lot of thought and here are the factoids that I've come up with. I'm comparing late, hard braking to earlier, lighter braking. Feel free to poke holes in any or all of them.

Early braking allows a greater percentage of the braking to be done by other factors than the brakes. Engine drag, rolling resistance, aero resistance all become larger (if only slightly) factors in the energy dissipation calculation. This obviously can lead to lower brake temps.

Early braking means less time spent accelerating, and therefore less braking is necessary. The simple fact is, if I brake 100ft earlier, I'm NOT going as fast. Again, obvious implications to the brake temperatures.

Early braking allows more time for rotor heat to soak into the pads/calipers/fluid. Boiling fluid is a bad thing! This may even mean that while rotor temps are lower, pad/caliper/fluid temps are as high or higher for the early braker.

Early braking means more rotor surface area contacting the pads. The rotor will turn more revolutions during the braking process. Again, I'm not sure what effect this has, but it's something no one has mentioned.

To keep it on topic, does anyone have a recommendation for where to get rotor on hat rotors for the stock PBR setup? I'm interested in going that route if the replacement rotors are reasonable in price.

sn8kbit
11-21-2002, 03:16 PM
tom, back up a couple of pages. (i thought you saw mine at RA this year) replacements for mine are right at 140 each, solid disc.


looking at the late/early braking, there's a lot of things i think that come into play also. (thanks tom for turning that light on for me, pads, fluid etc...) tires, level of experience ect, but i think the basic pad/rotor life pretty much rests on how soon/late you brake. also, i think there should be some basic techniques everyone should be able to do, then there would be what i call a braking style, which is how different drivers use those basics.
i've ridden with Dean, Kevin, and the illustrious mr Groth ;),(next RA, i'm gonna try to con tone into a ride...;) ) and all three of them approach a corner completely different (which has helped immensley in adapting my own approach) how soon or how late comes with experience, what i'd like to know is what the "fundamentals" would be i guess is what i'm asking....

hopefully i'm going in the right direction with the frontend. i'm avoiding coil-overs for the moment to improve my driving first. the H&R race springs should help. i'm still trying to work up a urethane bushing setup for the rear....

98banana
11-21-2002, 03:18 PM
Originally posted by thomasmoran1
Tom, think of when your at the track and think of how when someone is out there for their first time they can get away with a stock setup in most cases because they are not braking hard enough to generate more heat then the stock setup can handle. But then as they start getting faster they need to upgrade their brakes to cope with the extra heat which increases wear.

Thomas

But, that's the key, "they're getting faster". I'm not arguing with you though because I'm starting to agree. It's just that the newbie won't wear brakes as much because he or she is driving slower which means less energy from braking.

Good conversation here... :thumbsup:

Dean95CobraR
11-21-2002, 03:36 PM
Originally posted by 98banana
But, that's the key, "they're getting faster". I'm not arguing with you though because I'm starting to agree. It's just that the newbie won't wear brakes as much because he or she is driving slower which means less energy from braking.

Good conversation here... :thumbsup:


Maybe that's why I didn't have a wear problem - I brake like a girl!! :eek: :rotf: :rotf: :rotf:

tgentry
11-21-2002, 03:37 PM
Originally posted by sn8kbit
tom, back up a couple of pages. (i thought you saw mine at RA this year) replacements for mine are right at 140 each, solid disc.


Steve, am I mis-remembering? I thought you had the one piece Eradispeeds, not rotor and hat. If I am, forgive me, it's the sometimers setting in again.

If those are rotor on hat, what is the weight difference from the stock one piece rotors?

At $140 each, that's over twice what I pay now. You really think I'll get over double the life? I was thinking that rotor on hat would be a big initial investment but that the rotor part would be less expensive in the long run (in addition to any performance/reliability/wear gains). And don't rule out the pimp factor :thumbsup:

tgentry
11-21-2002, 03:40 PM
Originally posted by Dean95CobraR
Maybe that's why I didn't have a wear problem - I brake like a girl!! :eek: :rotf: :rotf: :rotf:

That's understandable, kart brakes look a little wimpy! Thinking of joining GGR?
:rotf: :rotf: :rotf:

sn8kbit
11-21-2002, 04:21 PM
Originally posted by tgentry
Steve, am I mis-remembering? I thought you had the one piece Eradispeeds, not rotor and hat. If I am, forgive me, it's the sometimers setting in again.
If those are rotor on hat, what is the weight difference from the stock one piece rotors?
At $140 each, that's over twice what I pay now. You really think I'll get over double the life? I was thinking that rotor on hat would be a big initial investment but that the rotor part would be less expensive in the long run

i can't testify to life yet. you're much quicker than i am on track. i do however have right at 20k miles on them, with no problems as yet. i didn't think to weigh them when i put them on, unsprung weight in this particular area was new to me. the only thing i can say is there is a difference. (wow, real tech huh?)
the 140 each replacement price was for the zinc washed, i'm shying away from that due to some things i've heard about it reduces the ability of the rotor to absorb heat as it should. key word being heard. if you paying 70 a rotor, are you using the brembo or the KH style? (that is durn cheap)
now that i officially have a business license, i'm looking into a way to reduce that price some. if anything results from that, you guys'll be the first to know.

(ok, here's a pimpy shot...;) )

b_tone
11-21-2002, 05:04 PM
Early braking allows more time for rotor heat to soak into the pads/calipers/fluid. Boiling fluid is a bad thing! This may even mean that while rotor temps are lower, pad/caliper/fluid temps are as high or higher for the early braker.

Why do you think this?

Don't forget that for every second you are accelerating you are adding the energy not in a linear fashion but as a square of the velocity. this means that if you are on the gas until the very last second you have that much more speed to scrub off. speed through the corner and the exit speed is more important than your ultimate velocity on the straight. They are directly connected and a function of eachother but I am willing to give up 100ft of on throttle at the end of the straight for a nice clean corner entry/exit allowing me to accelerate at a greater rate than if I muff the entry.

Boil it down to seat time and figure out what makes your car fast and how to drive it fast. Doing that will benefit you more than listening to the slowpokes like me.

Brian

tgentry
11-21-2002, 06:25 PM
Steve, very pimpy indeed! I still can't understand why the rotor, without hat, should cost so much.

I've been using Bendix rotors in the directional style. Word way back in '98 was that the Bendix rotors were a bit better than the actual KH ones. I tried Brembos and didn't feel there was any real benefit over my tried and true Bendix rotors. YMMV.

BTW, I also tried the Bendix non-directional and have decided that the directionals are worth a few extra dollars.

Tone, I'm basing that theory on the fact that the rotors and pads are in contact for a longer period. It's my belief that the rotor temps won't vary enough to make up for the duration. Am I making sense?

Your technique sounds like a good way to save brakes, tires, and gas. In our universe you might even be right, nailing the corner is probably more important than that last 100 ft of acceleration. Even so, I'd be willing to bet that if you're name was Schumaker you'd be standing on the gas until you saw God and STILL nailing the turn.

sn8kbit
11-21-2002, 10:05 PM
these were prices quoted last year, when i first picked them up. i have no clue if they've gone up or down, since i've noticed they have more options now. one piece, and the +1 kits which are new brackets and rotors 1 inch larger than stock. i may give em a ring tomorrow while not doing anything and find out....

97whitevert
11-21-2002, 10:32 PM
Originally posted by 98banana


Good conversation here... :thumbsup:

very good!! i am reading, thinking and hopefully learning!!:thumbsup: :thumbsup:

97whitevert
11-21-2002, 10:34 PM
Originally posted by Dean95CobraR
Maybe that's why I didn't have a wear problem - I brake like a girl!! :eek: :rotf: :rotf: :rotf:

DEAN!!!!!!!!

that was uncalled for!!!!!!:mad: :mad: :mad: ;)

Dean95CobraR
11-22-2002, 06:36 AM
Originally posted by tgentry
That's understandable, kart brakes look a little wimpy! Thinking of joining GGR?
:rotf: :rotf: :rotf:


Sorry, but there doesn't seem to be any chance of advancement in your club since your senior officers have a life time membership. :D

Dean95CobraR
11-22-2002, 06:37 AM
Originally posted by 97whitevert
DEAN!!!!!!!!

that was uncalled for!!!!!!:mad: :mad: :mad: ;)


:rotf: :rotf: :rotf: :rotf: :rotf: :rotf:

I was wonderin how long it would take.:D

fastoldman
11-22-2002, 10:23 AM
This is a very interesting thresd, and alot of thought has been brought to the table by alot of folks. The two ideas that are being brought out,in my humble opinion are not mutually compatible. Some are talking wear, while others are talking speed. Stock rotors, regardless of the vehicle are not a race set-up, and therefore as we go faster, the upgrade to an Eradispeed ( kind of a beginner race set-up ) will help with stopping distances and faster laps, but .......this is where we have to think about wear. Wear is all about heat, and if you are going faster, you will generate more heat. This is the old conumdrum that racers run into ---- " My stuff is wearing out faster!!" Of course, if we are going faster, then this is part of the equation. Braking earlier may extend brake pad and rotor life,but this has to be the drivers choice. If just having fun and going 8/10ths is the concern, then this is probably okay, but if speed is the concern, you will learn to brake late, and you will master trailbraking. This was my personal problem , and finally after 2 Panoz schools I realized I was getting the hang of it - effective trailbraking is an art and it takes time .Now after 2 more years I have realized , it is an arcane art, and it will make the underpowered car as fast or faster than the guy/gal with the built motor. When you get to a point where the brakes , with ducting, and high temp fluid ( Motol 600, Brakeman, AP 600 ) aren't working, it is probably a simple sign we all ignore ( because it involves money ) that you are overdriving your brakes. It is pretty humorous that when we finally get alot faster, we don't want to take the simple cues that we have reached a new plateau, and it is time to upgrade. At this point you can move efficiently to a better fluid ( Castrol SRF or Brakeman Xtreme 6 ), better rotors ( Eradispeed or StopTechs), etc.
These changes will make a big differences until the day, when you are running maybe 3 seconds faster than you have ever run on your favorite track before, and hopefully this time the light goes on and you realize....." Damn , I am at a new level ." This is where the Big Brake kits, ( Brakeman, StopTech, Baer ), High quality fluid, full race pads, etc. will come in and you will continue your quest for speed, by having alot smaller brake patch than your competitors.


PS - Long ago you should have gone to stainless steel lines to decrease flex, and moisture absorption ----remember brake fluid has an attraction to water.

b_tone
11-22-2002, 10:41 AM
How does the increased thickness of the baer rotors play in with the stock thickness pads in the PBR? In what direction is the rotor wider? To clear that question---there is very litttle room to move to the center of the vehicle due to the toe link so is the increased thickness put on the outside of the rotor. My worry is that the rotor may not be not centered on the caliper thus providing the pad a higher drag on the rotor when not in use.

I agree with you on the trail braking aspect but I think you are taking my 'early braking' strategty a little too extreme, i.e. at road america coming into T5 I can brake at the 3 marker (with a terminal velocity around 160) but I usually brake at the 3.5-4 marker for that added little cushion.

I don't think that the speed gained in that 100 feet is what is going to make your lap faster, it's the controlled entry into the corner at the maximum lateral g's your car can sustain (this is where trail braking comes into play). keeping with the road america thought, if you exit T3 150rpm higher in a give gear you will be going much faster into 5 than if you had not. This is not based on braking at 10/10ths every corner it's based onthe corner speed you can carry.

Does this make any sense to anyone but me?

tgentry
11-22-2002, 11:11 AM
Originally posted by b_tone
at road america coming into T5 I can brake at the 3 marker (with a terminal velocity around 160) but I usually brake at the 3.5-4 marker for that added little cushion.

Brian, look at this way: If you brake at the 5 marker instead of 4, will your lap times go up? BTW, turn 5 is scary enough at 130+, 160 must be a pretty wild ride! :eek:

Think of this hypothetical situation: Two identical cars and drivers, with identical corner lines and speeds. Car A brakes at the 4 marker, while car B stays in the throttle until the 3 marker. Who is going to be gaining there? Since we're discussing braking here I don't think it's fair to assume that car B will execute the corner any worse than car A.

In the real world, sure, we sometimes brake TOO late and end up blowing the corner, but in the real world we sometimes blow the corner for other reasons too. I think what makes this sport so challenging is the goal is to do everything perfect, every time. Some of us come closer than others, and go drive F1 cars.

b_tone
11-22-2002, 12:50 PM
I have think that I will pass from this planet way before I will every run a perfect lap. hell, I don't think that I have ever run a perfect corner.

to each his own, just get the seat time and that will pay off in spades..

Dean95CobraR
11-22-2002, 01:29 PM
Originally posted by b_tone
How does the increased thickness of the baer rotors play in with the stock thickness pads in the PBR? In what direction is the rotor wider? To clear that question---there is very litttle room to move to the center of the vehicle due to the toe link so is the increased thickness put on the outside of the rotor. My worry is that the rotor may not be not centered on the caliper thus providing the pad a higher drag on the rotor when not in use.


I believe the airgap between the rotor surfaces is narrower.

sn8kbit
11-22-2002, 02:08 PM
wow, 160? now i know i'm braking early......LOL (and i'm slow LMAO) i notice the car "unsettling" depending on where i started my braking on T5 (hehe, this is gonna turn into how to attack RA...LOL) i was at maybe, MAYBE 120 (LOL) and at the top of that rise, i'd let about about half throttle and start braking at oh, say, 4.5. i'd also be dropping a couple of gears to try and set up the "hill climb" to T6. i see where you're coming from tone, and i agree. i'd like to concentrate more on speed thru the turn without having to add more to the equation, espcially at my level right now.
tone, it's the airgap between surfaces that makes the rotor thicker on the eradispeed. it's a curved vane designed rotor.

b_tone
11-22-2002, 02:10 PM
I believe the airgap between the rotor surfaces is narrower.

if this is the case I don't see that as being any better. Sure the rotor can take more heat but will it be able to dissipate that heat with the reduced air flow through the center?

Whey you go to the 1.25" thick rotor (ala. baer, sierra, brembo, alcon) you also keep the gap to allow adequate airflow to transfer some of the heat to the surrounding atmosphere.

This is going in the direction more towards a solid rotor and you know the problem with those.

fastoldman
11-22-2002, 03:30 PM
I absolutely felt 100% like you did Tone, as I was for years the King of Brake Pads and Rotors --- mine lasted alot longer than all my friend's equipment did. You answered your own question almost verbatim to what happened to me about 5 years ago. Did I think that the extra 100 ft of speed I gained made that much difference in the lap time-no. I also talked about the safety factor and a cushion, and I felt supreme smoothness made me quicker. After running aroung Road Atlanta ( Panoz School ) with some pretty salty drivers, I found I could waste the entire class , except these 3 guys, and I also began to understand that their cajones were bigger than mine in the braking dept. What I learned was their braking was more controlled and more polished, and therefore they were annihilating me in the corners. In answer to your comment on Road America ( you have one fast Stang cuz, I could only hit 160 in the Viper going into turn 5 )is whether any of us thought that extra 100 ft made that much difference and the answer 5 years ago , is heck no! The answer today is, 14 turns times 100ft is 1400 ft, heck yes it is a huge difference. Learning to trailbrake efficiently took quantum amounts of time off my laps there, and it is one reason I believe this arcane science is often the secret to going faster. Once at Derek Daly , the lead instructor discussed the winner of their racing challenge ( the winner at that time got to run a Toyota Atlantic for Team Green during the next season ) was able to trailbrake into two corners that no one else could master, and he ended up 5/10ths faster than all the rest - this was huge on a 1.1 mile road course. I am convinced that alot can be accomplished if you brake late and in control, as trailbraking you actually will exit quicker --fast in, fast out. Tough technique and it took me forever to acquire ( I still don't consider myself a master ) , but an area that will allow you to conquer your foes, even when they have more power.