TECH: excellent brake article (attn: SteveR) - The Unofficial BMW M5 Messageboard (m5board.com)

greg · 23rd April 2002, 10:10

Having just gotten back from Tracquest at Laguna Seca, the timing of "discovering" this article (The Myth of the Warped Brake Rotor on the Stoptech site) could not have been better. The article describes what happens at the rotor/pad interface, why and how to bed pads, how and why to break in rotors, etc. Oh, and by the way - rotors do NOT warp!

I ran Pagid Orange pads on my Porsche at the track - they were stupendous, although I experienced some vibrations under braking. Steve Runyan ran his sweet M5 (with stoptech brakes, bigger wheels and tires front and rear, and a host of other goodies) - and had his share of problems as well. And although there were lots of "experts" there, there were almost as many inconsistent answers. And I learned stuff in this article that absolutely positively explains and clarifies info that Steve and I were unable to confidently extract from much larger amounts of info we've both heard one place or another.

Ordinarily I wouldn't trust an article on a vendors' site - but this one is written by my personal automotive GOD, Carroll Smith. I trust this guy's opinion more than anyone else when it comes to automotive knowledge. (He is the author of the "Prepare to Win", "Tune to Win", etc. book series, and has over 3 decades of experience in racing, and he is very smart. He DOES know his stuff - just read one of his books and you will believe.)

FYI - please leave this thread about brakes - I know some of you want to know about Laguna Seca, and I promise to tell you - have some videos to process and some other stuff to do first - might take me a day or two - but I WILL tell you. Suffice it to say, I whupped some serious ***.

Adam · 23rd April 2002, 12:57

Any pics of your tt at the track?

thank you for the article..very informative

all the best
Adam

MarkM5Lauderdale · 23rd April 2002, 16:32

Great article!

louv · 23rd April 2002, 21:17

Really good article...

...but now I feel the need to go scrub my rotors with garnet paper.

...and upgrade my brakes.

stever · 23rd April 2002, 22:13

thanks Greg, i certainly missed this -- will clean out my box and send you a message

Johnny D · 23rd April 2002, 22:47

Great article!
I learned a great deal from reading it, THANKS!

Terra Byun · 23rd April 2002, 23:38

Quote:

From the article
Typically, a series of ten increasingly hard stops from 60mph to 5 mph with normal acceleration in between should get the job done for a high performance street pad. During pad or disc break-in, do not come to a complete stop, so plan where and when you do this procedure with care and concern for yourself and the safety of others. If you come to a complete stop before the break-in process is completed there is the chance for the non-uniform pad material transfer to take place and the results will be what the whole process is trying to avoid. Game over.

Sometimes I feel "proper" thing is impossible. 10 stops from 60 to 5 without complete stops... where can you make it unless it is 3am in the morning on highway? And what should you do you have to drive like 20 minutes to get to the right place to do 60-5 runs? By then brake would be warm and you probably made 10 stops already...

(Ahh... is there hope?)
It is a great article and I am not against the author, but it is a bit unrealistic to, at least, me.

steve adams · 24th April 2002, 16:59

Greg,

Thanks so much for posting this vaulable info. I've had problems with my brakes from the start. The dealer has replaced the pads and rotors twice in only 7K mi.... this seems very weird ... I have not tracked the car , but I do not baby it either (it's a sports car for pete's sake!) ...

the second set of brakes are now pulsating and vibrating under heavy braking (very nerve-wracking) ... I plan to bring it up with the dealer on my next scheduled maint visit , and perhaps use the whitepaper from StopTech as a discussion point about how best to approach this issue... seems ridiculous to have to keep replacing the brakes ...

will also consult some of the local tuners in this area (Korman , BimmerWorld, Motorsports Connections) ... I am hesitant to replace the stock brakes with StopTech or Brembo until I am confident that it will address the issue ....

I wonder if asking BMW to buy the car back and start over would be the best way to approach ? But whats to say the newer car would not have the same issue? It would be cheaper to put Stoptechs on the car rather than take the loss on a buyback from the dealer, I suppose.

Love the car ... hate the brakes..

Steve
'02 Titanium/Silverstone (stock)

Jim H · 24th April 2002, 21:01

That was an interesting article all right. Is he saying that there is no such thing as warped rotors and that ALL brake system shuddering is due to 'cementite' build up on the rotors?

He sure knows more about race car engineering then I do, but I'm skeptical that nobody has ever warped a rotor due to too much heat and/or improper cooling. My wife's Subaru 'warps' rotors after several thousand miles. Is that caused by uneven pad material build up on the rotors? Hmmm...

If anyone wants to continue this thread, or if you want to send me an email, I'd be happy to discuss the practical (I.E non engineering) experiences I've had running track days in various cars using stock brakes, Stoptech upgrades, Baer Alcon upgrades, AP six pistion upgrades, and several different pad compounds on single piece and two piece slotted and plain rotors.

Jim

steve adams · 24th April 2002, 21:44

Jim H ..

thanks for your post ... I'd like to find out more about your track experiences with different brakes ... my email address is sadms6@aol.com ...

steve

stever · 25th April 2002, 04:31

Jim H -- brakes are an issue with a number of us and i think it would be great if you'd post some of your experience -- having made the brake decision, i'm particularly interested in figuring out what kind of pads to use