Drilled and grooved discs? your 2 pence!

[tysonzane]

Drilled and slotted are without a doubt a waste of time. Good quality blanks are the only way to go.

 

[Ash-EK9]

Ordered the carbone Lorraine RC6 pads on the Wednesday got them on the following Monday!

After Reading through this thread it seams to be each to there own but now owning the CL pads I think blanks are the better option as the pads are very abrasive so the discs won't last long and the blanks are so dert cheap!

 

[tama666]

Drilled and slotted are without a doubt a waste of time. Good quality blanks are the only way to go.

This is total BS.

 

[tysonzane]

Please do explain because I've run various setups in endurance rallying and on the circuit. I found no increase in braking performance and using temperature paint found they weren't running any cooler. When the pressure really got up the drilled and slotted rotors which were heat stress releaved cracked alot earlier then oem and high quality blanks. I've cracked many sets of rotors.

I take it you already understand that rotors don't physically warp but that it's pad material on the rotor which makes them feel warped?

 

[tama666]

Disks warp/ fact/

 

[tysonzane]

Disks warp/ fact/

Come on man lets have a logical conversation about this. There is no point getting bitter and thinking what you know is 100% fact.

"The term "warped brake disc" has been in common use in motor racing for decades. When a driver reports a vibration under hard braking, inexperienced crews, after checking for (and not finding) cracks often attribute the vibration to "warped discs". They then measure the disc thickness in various places, find significant variation and the diagnosis is cast in stone.

When disc brakes for high performance cars arrived on the scene we began to hear of "warped brake discs" on road going cars, with the same analyses and diagnoses. Typically, the discs are resurfaced to cure the problem and, equally typically, after a relatively short time the roughness or vibration comes back. Brake roughness has caused a significant number of cars to be bought back by their manufacturers under the "lemon laws". This has been going on for decades now - and, like most things that we have cast in stone, the diagnoses are wrong.

With one qualifier, presuming that the hub and wheel flange are flat and in good condition and that the wheel bolts or hat mounting hardware is in good condition, installed correctly and tightened uniformly and in the correct order to the recommended torque specification, in more than 40 years of professional racing, including the Shelby/Ford GT 40s – one of the most intense brake development program in history - I have never seen a warped brake disc. I have seen lots of cracked discs, (FIGURE 1) discs that had turned into shallow cones at operating temperature because they were mounted rigidly to their attachment bells or top hats, (FIGURE 2) a few where the friction surface had collapsed in the area between straight radial interior vanes, (FIGURE 3) and an untold number of discs with pad material unevenly deposited on the friction surfaces - sometimes visible and more often not. (FIGURE 4)

In fact every case of "warped brake disc" that I have investigated, whether on a racing car or a street car, has turned out to be friction pad material transferred unevenly to the surface of the disc. This uneven deposition results in thickness variation (TV) or run-out due to hot spotting that occurred at elevated temperatures.

In order to understand what is happening here, we will briefly investigate the nature of the stopping power of the disc brake system."

StopTech : Balanced Brake Upgrades

So where were we?

 

[tama666]

Please do explain because I've run various setups in endurance rallying and on the circuit. I found no increase in braking performance and using temperature paint found they weren't running any cooler. When the pressure really got up the drilled and slotted rotors which were heat stress releaved cracked alot earlier then oem and high quality blanks. I've cracked many sets of rotors.

I take it you already understand that rotors don't physically warp but that it's pad material on the rotor which makes them feel warped?

Well, my disks were warped, I can have them resurfaced but elected to just replace with new, replaced with a set of brembo's cross drilled and slotted ... I have yet to crack a set, but have warped others on this car.

First oem set warped. Replaced with another oem set, they too warped...replaced again with brembo cross drilled and slotted and never had an issue--50K miles. Had to upgrade and put on another set of oem blanks which warped after only a few months from new. I will see if these warp or crack, doubt they will tho...as brembo's rock from my previous experience.

Its hard to find ITR oem pads these days! omfg!

 

[tysonzane]

Just remember you're not actually 'warping' them as such.

Different discs are made of different materials so i encourage you to put on some Brembo oem style blanks and i gaurantee you'll experience a similar result to your current Brembo rotors. Comparing the Brembo blanks to the drilled and slotted Brembo's the blanks are going to do better up in the extreme temperatures. The advantage of using a good quality drilled rotor over a cheap one is that your Brembos will be cast with the holes and not drilled so will be alot less likely to crack there.

 

[stevenEK9]

Worth noting that it can feel as if your discs are warped if you do not torque your wheels accurately and correctly with a torque wrench

A mate of mine ran his on track with the wheels unevenly torqued and was getting WILD vibrations through the wheel, came into the pits and once the wheels cooled, loosened all the nuts and retorqued correctly, took the car out, roasted the brakes and was fine after

You would have to be doing something serious to warp brakes, I use full on cintered race pads with what can be considered as "cheap" discs and have never had any issues, HAVE had bad vibrations through the wheel but that was due to pad deposits, took the car out and ROASTED the brakes, soon burnt it off and brakes were better than ever after

 

[tama666]

Worth noting that it can feel as if your discs are warped if you do not torque your wheels accurately and correctly with a torque wrench

A mate of mine ran his on track with the wheels unevenly torqued and was getting WILD vibrations through the wheel, came into the pits and once the wheels cooled, loosened all the nuts and retorqued correctly, took the car out, roasted the brakes and was fine after

You would have to be doing something serious to warp brakes, I use full on cintered race pads with what can be considered as "cheap" discs and have never had any issues, HAVE had bad vibrations through the wheel but that was due to pad deposits, took the car out and ROASTED the brakes, soon burnt it off and brakes were better than ever after

I swap my wheels out often, race set, street set, done and done. There is no issue with my torque wrench or me using it. Been swapping out wheels 4-5 times a month for racing for years.

I did try roasting the pads like you write about above, I thought this was the issue at first, nope.

Im telling you folks, the dam disks are bent, warped, defective. Done and done. **** happens folks, nothing is guaranteed when it comes to metal and cars, especially if your always taking things to the limit like I assume I have been, but I don't think I have been hard on these disks compared to what I have done in the past.