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Overheating brakes - driver or equipment issue?

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I'll be there in June and August with MVP Track Time. I did it with them last year for both events and had a blast!
 

dmichaels

Papa Smurf
547
30
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Some closure for anyone interested: Flushed the system with 2.5 bottles of Motul RBF600 last weekend, and also bled the clutch twice, sucking out the bled fluid (quite a bit of particulates), and replenishing with RBF.

Had the car out at Limerock yesterday for about 120 track miles and had zero brake issues all day. Did not even have to consider trying to bleed in between sessions. I was hard on the brakes and pushed the car about as far as I can as a driver and it performed flawlessly.

So my conclusion is I had not flushed the system properly before and the fluid was old. New fluid, properly bled made a nice difference. I am happy. ;D
 
Ran Motul RBF 600 last summer (also have FRPP brakes ducts and ran Pagid RST2/RS56 combo) and found I had to bleed the calipers after every weekend of use, or else I'd have this weird variability in pedal feel during an HPDE. One session it'd be rock solid, the next would be a bit mushy. Bleeding the calipers seemed to work. Going to run Castrol SRF this summer instead and see if that makes a difference.
 

dmichaels

Papa Smurf
547
30
CT
dabossinne said:
Ran Motul RBF 600 last summer (also have FRPP brakes ducts and ran Pagid RST2/RS56 combo) and found I had to bleed the calipers after every weekend of use, or else I'd have this weird variability in pedal feel during an HPDE. One session it'd be rock solid, the next would be a bit mushy. Bleeding the calipers seemed to work. Going to run Castrol SRF this summer instead and see if that makes a difference.

Also thinking I will switch to castrol soon, but was happy I had no issues yesterday for the first time!!
 
Maybe I'll bleed more often too.

I find that my pedal feel changes throughout the day... sometimes feels pretty hard, sometimes more squishy, and sometimes hard but not biting very well.
 

Bill Pemberton

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Bleed my brakes after every weekend, but have done that with everything from my Viper ACR to when I was running Spec Miatas. If you brake deeply or trailbrake, and are on reasonably fast tracks it is a great idea with the Boss. Part of the benefit is your pedal will stay harder longer, and definitly make sure you have cleared the clutch fluid out also -- have had very few issues with high rpm downshifts to second on most tracks, but the fluid is always freshened.

As you go faster you subject the system to higher temps and hotter cycles will degrade even the best fluid faster than you would believe. Motul 600 is good stuff and if changed after each weekend , it will be more than sufficient in my experience.
 
Bill, are you suggesting one needs to *bleed* or *flush* after ever weekend? (it's wasn't completely clear to me from your post).
 
Every 3 hours track time for me. Time to bleed :) Money, oil, brake fluid take your pick.

Sent from my DROID4 using Tapatalk
 
jlwdvm said:
Is there a consensus on which brake pads (front and rear) to upgrade to with stock rotors for HPDE's?

In my opinion, not at all. What will work seems to vary a bunch from person to person.

But if you're a novice driver with a Boss Mustang (or a Brembo GT)... I think you can do the first few events on your stock pads. I did, and didn't have any problems.

Whereas I'm having all sorts of problems now that I'm trying to run track pads in combo street/track situations. I tried to run Pagid RS-19/RS-56 pads full time... street and track... and was disappointed. Now I'm trying to run Carbotech XP20 (track days) / Bobcat (street) in the front and XP10 in the rear (full time). Rears are okay, but front's aren't great. Brakes are tricky.
 
I run the Stock pads on the street. And Hawk HP+ on the front with stock pads on the rears. They seem to hold up fine even after my last event at Sebring last weekend. We had temps in the mid 90's most of the day (ouch). Supporting mods include blowfish cooling ducts and Castrol SRF fluid. I might switch out to Hawk DTC-60s after the HP+ are spent.

p.s. I'm a novice/intermediate driver I have 3 tracks days in total at Sebring, and a handful of autoX.
 

JScheier

Too Hot for the Boss!
As Kyle stated above, it's all personal taste / feel.

As an example, I do not like Hawk pads. DTC60 or DTC70. Doesn't matter. I don't like the feedback they provide, nor do I like how quickly they are used up. This is based on my braking technique and my car, but since it's my dollar, I choose other pads. And since it is my dollar, be aware that Hawk is a NASA contingency / sponsor, so each time I win or place in TT, I have the opportunity to win 'Hawk Bucks' which would / could reduce my overall brake pad cost. (Note: I didn't like them on my M3 either)

I'm now running Cobalt Friction on the Boss which is what I previously ran on my M3. Andie Lin has been great to work with and coming up with compounds that fit my style of braking. I'm currently running XR1 front, XR2 rear (sometimes XR3 depending on tire selection). They are giving me great feedback, I've yet to fade them and they last easily 2x longer than the Hawks on the same car, same setup, same driver. They are also very easy on my rotors (3 years of tracking / TT and I'm on my OEM rear rotors and 2nd set of fronts). They work well for me, but I know they don't work well for at least one other member here.... and that's why brake pads are a personal taste selection :)
 

steveespo

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John is right on. I too loathe Hawk DTC pads, but Gary who is wicked fast swears by them. It's all what feels good to the driver and how they use the brakes. I am somewhere in the middle, I brake moderately late and deep into the turn in (trailing) to me Carbotech XP-24 works the best.
Steve
 
steveespo said:
John is right on. I too loathe Hawk DTC pads, but Gary who is wicked fast swears by them. It's all what feels good to the driver and how they use the brakes. I am somewhere in the middle, I brake moderately late and deep into the turn in (trailing) to me Carbotech XP-24 works the best.
Steve
There is no good universal answer. The bottom line is we have heavy high horsepower cars which means they are generating a ton of heat to deal with all the energy coming from a fast fat car into braking zones. That translates into brake issues. My braking style is to "hammer" them early in the braking zone and be off them by turn in so I can be on the "go" pedal way before apex. I was just out at Spring Mountain this March where they taught a similar braking style. The key benefits are the following:

1) By making your initial braking input the heaviest, you're traveling at a higher speed when you generate the most heat. This allows airflow to work to your advantage. You get more cooling from your higher speed at the same time that you're delivering the maximum heat to the rotor.

2) You've settled the car before turn in so it responds more predictably.

3) You're slow in and fast out of the corner giving you greater straightaway speeds.

To brake like this you need a pad with a high initial bite. I've found DTC 70s deliver that, whereas IMO PFC01s do not. There are a number of members that love PFC01s, but their braking style may be more conducive to that pad.

Here's a vid from Spring Mountain with a coach in the right seat that gives you a flavor of their braking philosophy. They are running C7 Corvettes which are heavy high horsepower track cars like ours.

https://www.youtube.com/watch?v=nAhM6r6Fbsg
 
Bob said:
Gary, what's he mean when he's saying "lighter"? Are you on the brakes or throttle at these times?

b
He's saying lighter on the brakes. You start with a high initial braking input, then gradually "bleed" pressure off the brake pedal. It's an interesting philosophy because when I went through Spring Mountain's Level 1 class about 5 or 6 years ago they were teaching more trail braking technique. However, last year when Rick, John and I were at Chuckwalla, Mickey was teaching a "lighter longer" technique somewhat similar to what Spring Mountain is now. Mickey said get on the brakes sooner but let your speed carry you to the corner rather than "late braking". The idea is to not kill the brakes especially during longer sessions or an actual race. Unfortunately I find a way to kill the brakes, tires and just about every other part of the car anyway :p
 

dmichaels

Papa Smurf
547
30
CT
Little update - I seem to have an issue with one of the speed bleeder valves I have installed... the pedal kept going soft but then maintaining the same level of "softness" recently. I found that about an inch of air was coming out of one bleeder valve - but no air from any other valve. So it seems one speed bleeder is not working right... replacing it with a basic bleeder and will see if that completely fixes the problem (I suspect that it will).
 

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