[TheRealJA105]

Originally Posted by TrackClub

Well, technically only an SS *needs* them. Clearly there is something very different going on with brakes and cooling for this specific model vs SS 1le, zl1 and zl1 1le for GM to insist a 12 step process be followed and then reversed (for street). I havent had a chance to compare SS with SS 1le brakes side by side, but o obviously they differ. Even the splash guard is different and oriented differently. There are proly other significant differences too.

So exactly what are we taking about here regarding SS 1le specifically? Doing all 12 steps per GM for the SS? Or just adding a lower control arm larger deflector (which hangs way too low for street use to my liking). Lastly, whatever it is, how cooler do calipers run? Any measurement available regarding cooling gains?

Technically you are correct, only the 4 piston SS brakes need them for tracking. However, I have the 6 pistons and run them full time with the track splash shield also.
The 12 step process you are referring to is really only difficult if you are removing the calipers and rotors to change the splash shield. The deflectors only have 3 bolts that can be easily changed out with only removing the wheels making it a very simple process. My point is why not run them for as cheap as they are?

[Homeless Junkie]

Originally Posted by TrackClub

What PTM mode are you running?

I'm still running with all the nannies on. I'm not touching the PTM mode button. I planned to on the second session but one, my tires are close to chording and two, I could feel myself getting faster than the last day out. I know that sounds crazy without a lap timer but I really could tell.

My next event I'll have Apexi wheels(unless they change delivery date for the 100th time) with brand new SC 3Rs and a track alignment. I plan to run the PTM in sport mode. Any advice?

[TrackClub]

Originally Posted by TheRealJA105

Technically you are correct, only the 4 piston SS brakes need them for tracking. However, I have the 6 pistons and run them full time with the track splash shield also.
The 12 step process you are referring to is really only difficult if you are removing the calipers and rotors to change the splash shield. The deflectors only have 3 bolts that can be easily changed out with only removing the wheels making it a very simple process. My point is why not run them for as cheap as they are?

It is a valid point. And one i would likely pursue if heat was an issue for me. Personally, i also have a mile long gravel road to content with and ever lasting summer road construction in our Province So dont want anything to stick below what things are at already, as i catch tons of crap as it is.

[TrackClub]

Originally Posted by Homeless Junkie

I'm still running with all the nannies on. I'm not touching the PTM mode button. I planned to on the second session but one, my tires are close to chording and two, I could feel myself getting faster than the last day out. I know that sounds crazy without a lap timer but I really could tell.

My next event I'll have Apexi wheels(unless they change delivery date for the 100th time) with brand new SC 3Rs and a track alignment. I plan to run the PTM in sport mode. Any advice?

A quick, "dog leg" like progression in laptimes is normally what happens at a novice level, as early laps are quite slow, hence fairly big gains are rather easy with just a bit of more familiarity with a car, venue, basic instruction, etc.

The real effort (and serious fun) begins when one soon reaches a plateau, thinking they are going as far as they can possibly go, yet a more experienced driver in the same car - is x seconds faster! That's when real learning starts to reach another level. And then it continues, hopefully for as long as the "career" does.

To get the most out of the car, one has to feel the car's limits. Lest it is a guessing game at best and wrecking at worst (even with nannies on). There are other skills one has to develop with proper vision being the prime one imo. Without proper vision it is almost impossible to drive at a true limit.

I can share some thoughts with you (if you like), but best to take it off line, as this thread is about a different subject altogether. Feel free to PM if interested. NB I am not a pro, but i have been at it for a while and have benefited and continue to benefit from ongoing learning from pro sources. All i can tell ya without a shadow of a doubt, that the greatest improvement in pace always comes from a driver skill vs any other aspect - bar none.

This may sound somewhat melodramatic, but all it takes is to see a pro, drive circles around other drivers in much more capable cars. However, the same principle applies to us amateurs as well! And frankly, that's why i am completely content driving my car bone stock. But that's just me

Cheers!

[Norm Peterson]

Originally Posted by TrackClub

As far as calipers...stockers are just fine as long as you dont go crazy with high torque pads. I can tell ya from first hand experience, that running even top shelf race spec brakes with high torque pads WILL require rebuilds (and per several posts by DTC70 users).

I've been meaning to revisit this particular aspect. My question is, is it the high-mu property in and of itself that generates more frequent caliper rebuilds, or is it more because the formulations generally used to create high-mu also conduct heat from the friction surfaces back through the pads and backing plates to the calipers? I'm thinking that an approach to pad design that put more metal content in the friction material would make the pad material less effective as an insulator, while the total amount of heat generated during any given stop would remain unchanged. I would be assuming comparable decelerations, just with different amounts of pedal force.


Norm

[TrackClub]

Originally Posted by Norm Peterson

I've been meaning to revisit this particular aspect. My question is, is it the high-mu property in and of itself that generates more frequent caliper rebuilds, or is it more because the formulations generally used to create high-mu also conduct heat from the friction surfaces back through the pads and backing plates to the calipers? I'm thinking that an approach to pad design that put more metal content in the friction material would make the pad material less effective as an insulator, while the total amount of heat generated during any given stop would remain unchanged. I would be assuming comparable decelerations, just with different amounts of pedal force.


Norm

Hi Norm, this may indeed have something to do with it, perhaps as a contributing factor? Dont know much about thermal physics here to offer an opinion...
One thing which is seems rather certain, is that the mass (car) gets decellarated in a shorter distance, hence my layman logic would suggest: same mass + shorter distance (because of higher mu) = more heat.

Now maybe a pro would be able to somehow equalize it with superior braking technique, but given that many top pro teams dont seem to use high mu pads and given that for race teams and pro brake suppliers heat management is a top priority...i find it interesting that some amateurs reach for the top mu, while pros dont.
I suspect retail marketing has a lot to do with it - perhaps by "experts" who havent spent a single day on a race track? Who knows.

All i know is what pads boiled my fluid and lit my brakes on fire (a slight exaggeration here!) and which didnt.
And what pads facilitated my PBs vs not. But obviously we all differ as drivers, use our cars differently and as such i respect others choices. Cheers!

[Norm Peterson]

Originally Posted by TrackClub

Hi Norm, this may indeed have something to do with it, perhaps as a contributing factor? Dont know much about thermal physics here to offer an opinion...
One thing which is seems rather certain, is that the mass (car) gets decellarated in a shorter distance, hence my layman logic would suggest: same mass + shorter distance (because of higher mu) = more heat.

Heat input is basically mass times the change in velocity, so that would remain the same regardless of mu. If we assume that a driver using the lower-mu pads increases pedal pressure to maintain the same rates of deceleration, then both distance and heating time would be essentially the same. If the decel rates aren't the same, you get the same total heat input but have a slightly longer period of time during that braking to reject some of it (the 'where' and' how much' here gets really messy and involves knowing which heat flow paths are the ones of less thermal resistance).

High-mu pads may ramp up their initial bite a little quicker because it takes a finite amount of time to build force at the pedal, so the high-mu pad friction surface skin-effect temperature might well be a bit higher all else held constant. But linear temperature distribution through the pad thickness and bulk temperature of the friction material (both being slower to respond) won't change as much, and pad surface temperature at the backing plate interface slowest of all. I don't remember if I kept any of my notes on this stuff, which included the documentation for a computer program written to do all the actual math involved.

That's why I'm suspecting thermal conductivity rather than mu while understanding that it may not be possible to separate the two effects due to the specific materials necessary.

Now maybe a pro would be able to somehow equalize it with superior braking technique, but given that many top pro teams dont seem to use high mu pads and given that for race teams and pro brake suppliers heat management is a top priority...

I can think of a few possible reasons other than heat conductance, though I'm sure that plays a part.

i find it interesting that some amateurs reach for the top mu, while pros dont.

My guess here is that amateurs tend to bring too much of their street driving baggage with them when they go to the track - it's what they've been practicing for perhaps 99% or more of the driving they've ever done.

A medium-high-mu pad (I'm going to say low 0.6's tops) actually feels pretty good on the street if you're up to the task of modulating them; lots of braking happening right away from less force at the pedal, and of course in any sane street driving you're not inputting anywhere near enough heat often enough to risk boiling even OE brake fluid regardless of the actual effect that makes it happen.

All i know is what pads boiled my fluid and lit my brakes on fire (a slight exaggeration here!) and which didnt.
And what pads facilitated my PBs vs not.

No argument with that. You found out what worked well and what flat-out wasn't going to, and in the end the detail reason doesn't have to matter unless you're inclined to get curious about exactly why the differences were what they were.


Norm

[TrackClub]

Originally Posted by Norm Peterson

Heat input is basically mass times the change in velocity, so that would remain the same regardless of mu. If we assume that a driver using the lower-mu pads increases pedal pressure to maintain the same rates of deceleration, then both distance and heating time would be essentially the same. If the decel rates aren't the same, you get the same total heat input but have a slightly longer period of time during that braking to reject some of it (the 'where' and' how much' here gets really messy and involves knowing which heat flow paths are the ones of less thermal resistance).

High-mu pads may ramp up their initial bite a little quicker because it takes a finite amount of time to build force at the pedal, so the high-mu pad friction surface skin-effect temperature might well be a bit higher all else held constant. But linear temperature distribution through the pad thickness and bulk temperature of the friction material (both being slower to respond) won't change as much, and pad surface temperature at the backing plate interface slowest of all. I don't remember if I kept any of my notes on this stuff, which included the documentation for a computer program written to do all the actual math involved.

That's why I'm suspecting thermal conductivity rather than mu while understanding that it may not be possible to separate the two effects due to the specific materials necessary.


I can think of a few possible reasons other than heat conductance, though I'm sure that plays a part.


My guess here is that amateurs tend to bring too much of their street driving baggage with them when they go to the track - it's what they've been practicing for perhaps 99% or more of the driving they've ever done.

A medium-high-mu pad (I'm going to say low 0.6's tops) actually feels pretty good on the street if you're up to the task of modulating them; lots of braking happening right away from less force at the pedal, and of course in any sane street driving you're not inputting anywhere near enough heat often enough to risk boiling even OE brake fluid regardless of the actual effect that makes it happen.


No argument with that. You found out what worked well and what flat-out wasn't going to, and in the end the detail reason doesn't have to matter unless you're inclined to get curious about exactly why the differences were what they were.


Norm

Well, as usual a well thought out response Norm
I can't profess to understand it nearly well enough to offer any further data, other than higher mu pads seem to heat up things in a hurry. Whether it is due to shorter stopping distances involved, or pad composition to achieve the mu - or a combo of both - no idea.

Ive read a few papers from racing pad manufacturers and indeed heat management seems always a top of mind concern. Together with longevity, but those two go together - zero doubt - especially in enduro racing.

Now amateur track events are sort of like an enduro imo.
Albeit they may only last 30mins at a time, folks sure expect braking systems to last a while: several days for pads, about a season for rotors and a few years for calipers. Yet race teams chuck all of them after a single race...Heck, they chuck them all after each event, be it practice, qualy, etc. And for those that go with "full race" pads that's where a major disconnect happens as far as expectactions re longevity et al. IMO.

[Norm Peterson]

Originally Posted by TrackClub

Well, as usual a well thought out response Norm
I can't profess to understand it nearly well enough to offer any further data, other than higher mu pads seem to heat up things in a hurry. Whether it is due to shorter stopping distances involved, or pad composition to achieve the mu - or a combo of both - no idea.

Ultimately to the individual as a driver, it's probably moot.

Ive read a few papers from racing pad manufacturers and indeed heat management seems always a top of mind concern. Together with longevity, but those two go together - zero doubt - especially in enduro racing.

Now amateur track events are sort of like an enduro imo.

This ↑↑↑

Especially at the HPDE level.

Albeit they may only last 30mins at a time, folks sure expect braking systems to last a while: several days for pads, about a season for rotors and a few years for calipers. Yet race teams chuck all of them after a single race...Heck, they chuck them all after each event, be it practice, qualy, etc. And for those that go with "full race" pads that's where a major disconnect happens as far as expectactions re longevity et al. IMO.

It's bad enough when after only 3 or 4 track days your front pads are right on the edge of not passing event tech. I can't imagine having to toss pads after every single event, never mind calipers or even rotors. As self-funded individuals driving up toward real-racing pace, most of us probably do seek some sort of balance between the cost of consumables and the desire for ultimate potential performance. At some point, anyway.


I did find that the XP12's didn't last as long as the 10's, no more than 2/3 as long even though mu was less than 10% higher. But at least the 12's weren't harsh as far as rotor wear or caliper issues were concerned, so I only got 'burned' on the pads themselves. I may take another look at the calipers that were running the 12's, since I stumbled across them a couple days ago.


Norm

[TrackClub]

Ya, balancing pace vs cost can be an interesting game indeed! And empty one's wallet in a hurry
At this stage i am mainly about maximizing funometer.
And this means seat time to me by and large.
I still continue to make progress with my car bone stock, which clearly means it is not the car that's holding me back. Cheers!

[Ckeels724]

Originally Posted by Jimbeau11

I've been driving my Hawk DTC-70s and DTC-60s on both track and street. Zero noise, but a lot of dust (I don't really care, just FYI as it bothers some people).

I commute 106 interstate miles per day, with frequent (high-speed) stop and go. I actually prefer having the racing pads for DD and to me there isn't enough "wear and tear" to make it worth swapping back and forth.



The DTC-60s are a nice "next step" pad for the track and work very well on the street, if you don't mind the dust.

Im thinking about running dtc60s next season, the hardest track i go to on brakes is watkins glen, besides there i spend alot of time at njmp lightning and limerock which arent hard on brakes, so my question is do you guys recommend running ti shims with the dtc60?

[Mountain]

I haven't seen this chart before and thought it useful to post up on, mainly becuse there seems to be a question on what the temperature vs. mu curve looks like on the Rabestos pads.

I found this searching about the web and wasn't sure if it was legitimate since the ST43 compound doesn't seem to follow the notion it is a low mu pad, averaging around .38 across it's operating range. However, I found a broken link for this chart leading to the Raybestos Facebook page. Beyond that, the chart does show up in Raybestos YouTube videos:
https://www.brakepartsinc.com/raybes...formation.html

I think the 0.38 number that gets thrown around comes from this chart, below. The "HOT 1200 F/Ave. Friction Mu" statement is confusing and doesn't seem to correlate to this more recent compound chart.

[TrackClub]

Originally Posted by Mountain

I haven't seen this chart before and thought it useful to post up on, mainly becuse there seems to be a question on what the temperature vs. mu curve looks like on the Rabestos pads.

I found this searching about the web and wasn't sure if it was legitimate since the ST43 compound doesn't seem to follow the notion it is a low mu pad, averaging around .38 across it's operating range. However, I found a broken link for this chart leading to the Raybestos Facebook page. Beyond that, the chart does show up in Raybestos YouTube videos:
https://www.brakepartsinc.com/raybes...formation.html

I think the 0.38 number that gets thrown around comes from this chart, below. The "HOT 1200 F/Ave. Friction Mu" statement is confusing and doesn't seem to correlate to this more recent compound chart.

Good find. The MU at 1200F is not that other manufactures seem to calculate by. All i know when i ran ST43s (several times, including once by mistake - dont ask...) my pedal would go to the floor after 2 fast laps or so and the front wheels were ready to go on fire Glad some folks like em, but they are not for me, that's for damn sure. Btw never managed to improve my laptimes with them even tho they stop the car fast, they lack release modulation for effective trailbraking. Imo of course.

[thescreensavers]

Originally Posted by TrackClub

Good find. The MU at 1200F is not that other manufactures seem to calculate by. All i know when i ran ST43s (several times, including once by mistake - dont ask...) my pedal would go to the floor after 2 fast laps or so and the front wheels were ready to go on fire Glad some folks like em, but they are not for me, that's for damn sure. Btw never managed to improve my laptimes with them even tho they stop the car fast, they lack release modulation for effective trailbraking. Imo of course.

How did they compare to OEM pads? I'm wondering if you somehow didn't get ST43s by accident.



Compared to stock pads in my experience the ST43s allow for up to ~.25 G increase of decel and had zero fade issues at Sebring with them. I was able to turn lap after lap with the ST43s where stock was on the floor after one lap(maxed the brake bar on the PDR too )



Ofcourse driving style/preferences will be different person to person but just curious.