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View Full Version : Brembo tech session feedback...


The HACK
08-29-2002, 11:03 AM
It was a lot of good technical knowledge...However we were surrounded by shop people, not club people.

It was funny, the guy running the presentation was my high school classmate. It's been over 10 years since I've last seen him and it was the strangest thing...He remembered me but I can barely recognize him...I haven't really changed all that much (except for the 40 lbs I put on) but he's really changed a lot. I wasn't really aware that he was into the racing scene in high school, but I guess that's how he got hooked up with Brembo...But I digress.

Tidbit #1: Brembo rotors are DRILLED, not cast. Only Porsche cast drill their rotors. What Dave (my high school classmate) was telling me that they've found that cast drilling isn't really improving the tendency to crack that much.

Tidbit #2: Brembo GT brake kits will NOT fit under any of the OEM wheels without spacers. Also, they highly recommend running slotted rotors but selling drilled rotors, because drilled rotors are easier to sell. One of the biggest selling point of the drilled rotors is that they look better vs. the slotted.

Tidbit #3: Drilled rotors cool down the brakes significantly faster than slotted rotors, hence it's not good for racing applications where the pads need to stay HOT for maximum braking. What they've found on racing appliations, is that the drilled rotors will cool the rotors and pads past the threshold on long straighaways while slotted rotors will hold the heat better yet cool enough so it won't warp prematurely or fade.

Tidbit #4: Some very interesting floating rotor discussion. Appearantly floating rotors are named not because they're two piece, but literally the two pieces of rotors are bolted together loosely while a spring clip holds them against each other, so it will actually rattle and move around under brake pressure...Pretty interesting.

Tidbit #5: Brembo is coming out with a new cooling vane design, very innovative. The vanes are no longer these long, divided slats but a cool matrix that allow hot air to escape via all kinds of route AND it does not diminish structural rigidity of the rotor.

The 4 pot caliper was a sight to see...

scottn2retro
08-29-2002, 11:31 AM
does the cool matrix invlove using ceramics (a la space shuttle tiles)?

The HACK
08-29-2002, 11:33 AM
Originally posted by scottn2retro
does the cool matrix invlove using ceramics (a la space shuttle tiles)?

No...You know the fan like vanes inside the rotors for cooling (the "vented" part of our rotor)? They're no longer these long vanes but a maze of small aerodynamic stubs.

They did mention carbon ceramic brakes but they're still way too expensive for road use.

WAM
08-29-2002, 12:02 PM
I haven't checked what different Brembo brakes are available, but are regular vented disks, without slots and holes available?

For street use, they would be fine.

scottn2retro
08-29-2002, 12:52 PM
Originally posted by The HACK

. . . Also, they highly recommend running slotted rotors but selling drilled rotors, because drilled rotors are easier to sell. One of the biggest selling point of the drilled rotors is that they look better vs. the slotted.


The lowered Civic with 4" exhaust tip market strikes again :lmao:

I think I remember hearing that slotted will help keep the pad surface 'fresher' (scrape dust and debris off better) for better braking, but I guess you pad usage would increase. :dunno:

The HACK
08-29-2002, 12:58 PM
Originally posted by WAM
I haven't checked what different Brembo brakes are available, but are regular vented disks, without slots and holes available?

For street use, they would be fine.

Yeah...You can get them really cheap too.

Check with Gino Yan @ Eliteauto.ca. Ask for none drilled, none slatted rotors.

Mr Paddle.Shift
08-29-2002, 01:13 PM
Thanks for the feedback!:thumbup:

CD-55
08-29-2002, 01:14 PM
cross drilled rotors also decrease your unsprung weight.

scottn2retro
08-29-2002, 01:21 PM
At the club session I was at, the slotted rotors were also drilled (best of both worlds) :dunno:

I had also heard (perhaps falsely) that the holes helped gasses of highly heated brakes 'trapped' between the pad and rotor escape :dunno:

Ben Chou
08-29-2002, 01:32 PM
Originally posted by scottn2retro
At the club session I was at, the slotted rotors were also drilled (best of both worlds) :dunno:

I had also heard (perhaps falsely) that the holes helped gasses of highly heated brakes 'trapped' between the pad and rotor escape :dunno:

The Slots would have the same effect, No? I was under the impression that that was what most fade is from, the fact that gases are building between the pad and rotor causing the pad to "float" of "skate" on the rotor rather than biting directly onto it.

The HACK
08-29-2002, 01:41 PM
Originally posted by Ben Chou


The Slots would have the same effect, No? I was under the impression that that was what most fade is from, the fact that gases are building between the pad and rotor causing the pad to "float" of "skate" on the rotor rather than biting directly onto it.

Yes, the slotted rotors would have the same effect...In fact, the slotted rotors are more effective than the drilled rotors, the drill rotors tend to expand and contract quickly as it cools down much faster and cause cracks where the holes are drilled. Take a look at World Challenge and other event's brake specs...I'll bet a good majority of teams run with slotted rather than drilled rotors.

One other interesting tidbit: Bedding in brake pads. My classmate (Okay, Dave Salsburry) mentioned that proper pad bedding is essential to maximizing your brake effectiveness. Basically, you need to rub off a microscopic amount of pad to be adhered to on the rotors...The first brake session should be a sucession of gradually harder and harder braking so pad material can fill in the porus part of the rotor (any rotor), thus when you brake, it's actually brake pad material rubbing pad material that creates the maximum amount of brake effort. From then on, it's basically scrubbing off a microscopic layer of the rotor and pad every time you brake, but more pad material should get deposited into the minute, microscopic crevices of the rotor so in essence, if you properly bed in the pads, you will always get effective braking because pad on pad friction provides the maximum friction.

Kinda interesting...I didn't properly bed in my pads. :(

Ben Chou
08-29-2002, 02:03 PM
Originally posted by The HACK


Yes, the slotted rotors would have the same effect...In fact, the slotted rotors are more effective than the drilled rotors, the drill rotors tend to expand and contract quickly as it cools down much faster and cause cracks where the holes are drilled. Take a look at World Challenge and other event's brake specs...I'll bet a good majority of teams run with slotted rather than drilled rotors.
:(

When applying my brakes from high speeds 80+ hard, I get a feeling of what I guess is brake fade, but if I let off the brakes and quickly reapply I get more bite back. I wonder what is causing this sensation. Could it be that I am just getting that gas buildup between pad and rotor and the quick let up release some of that gas?

Also when driving in the rain, my brakes for some reason have a slight delay before biting. I guess that is the tradeoff for big rotors is you have to clear the water before they stop.

The HACK
08-29-2002, 02:06 PM
Originally posted by Ben Chou


When applying my brakes from high speeds 80+ hard, I get a feeling of what I guess is brake fade, but if I let off the brakes and quickly reapply I get more bite back. I wonder what is causing this sensation. Could it be that I am just getting that gas buildup between pad and rotor and the quick let up release some of that gas?

Also when driving in the rain, my brakes for some reason have a slight delay before biting. I guess that is the tradeoff for big rotors is you have to clear the water before they stop.

I'll trade you my brakes. They don't have that annoying delay in the rain. ;)

Seriously, normal driving conditions you will NEVER see brake fade. What you describe sounds more like air in the brake lines...Have you had your brake system flushed? You would have to be like braking hard every few seconds from 80-35 mph over and over again to exhibit brake fade on a 330i brake.

Nick325xiT 5spd
08-29-2002, 02:07 PM
Originally posted by Ben Chou


When applying my brakes from high speeds 80+ hard, I get a feeling of what I guess is brake fade, but if I let off the brakes and quickly reapply I get more bite back. I wonder what is causing this sensation. Could it be that I am just getting that gas buildup between pad and rotor and the quick let up release some of that gas?

Also when driving in the rain, my brakes for some reason have a slight delay before biting. I guess that is the tradeoff for big rotors is you have to clear the water before they stop.

You should have read about that on the Audi forum... 1 to 2 seconds delay before the brakes cit in the rain...

Ben Chou
08-29-2002, 02:09 PM
Originally posted by The HACK


I'll trade you my brakes. They don't have that annoying delay in the rain. ;)

Seriously, normal driving conditions you will NEVER see brake fade. What you describe sounds more like air in the brake lines...Have you had your brake system flushed? You would have to be like braking hard every few seconds from 80-35 mph over and over again to exhibit brake fade on a 330i brake.

I had a 99 323i before this and I never had any delay on the car.

I have not had it flushed. I really would like to get that feeling out of brakes. The car has about 17K on it since I got it last May. Would they do this under warranty?

You got it on the brake trade. I just wish I lived out on the West coast so you could perform a HACK job on my car. :thumbup:

chukiechz
08-29-2002, 02:10 PM
Originally posted by WAM
I haven't checked what different Brembo brakes are available, but are regular vented disks, without slots and holes available?


I bought replacement M3 rotors from bimmerparts.com that were made by brembo. 40 bucks each or something. Pretty cheap.

eugeneDC/TX
08-29-2002, 04:36 PM
Originally posted by Ben Chou


I had a 99 323i before this and I never had any delay on the car.

I have not had it flushed. I really would like to get that feeling out of brakes. The car has about 17K on it since I got it last May. Would they do this under warranty?

You got it on the brake trade. I just wish I lived out on the West coast so you could perform a HACK job on my car. :thumbup:

i just recently replaced my OEM brake fluid with superblue at about 25-26k. lemme just tell you how much air was in my lines. omg. scary. if ayn is around he can tell you too. we used a pressure bleeder to put in the superblue and the piss yellow was FULL of bubbles. now my pedal feels firm. although i think there is still a tiny bit of air left. :dunno:

i'd highly recommend changing your brake fluid. it's super easy

AG
08-29-2002, 05:48 PM
Originally posted by Ben Chou


When applying my brakes from high speeds 80+ hard, I get a feeling of what I guess is brake fade, but if I let off the brakes and quickly reapply I get more bite back. I wonder what is causing this sensation. Could it be that I am just getting that gas buildup between pad and rotor and the quick let up release some of that gas?

Also when driving in the rain, my brakes for some reason have a slight delay before biting. I guess that is the tradeoff for big rotors is you have to clear the water before they stop.

I've got the exact same problem. The problem is worse in winter when I have my Moda's on than when I have my M68's on.

Stuka
08-29-2002, 09:16 PM
Originally posted by The HACK
Seriously, normal driving conditions you will NEVER see brake fade. What you describe sounds more like air in the brake lines...Have you had your brake system flushed? You would have to be like braking hard every few seconds from 80-35 mph over and over again to exhibit brake fade on a 330i brake.

I'll show you faded brakes on normal highway driving.:p

Andy
02 M3 CB/Cloth SMG

Nick325xiT 5spd
08-29-2002, 09:18 PM
Originally posted by Stuka


I'll show you faded brakes on normal highway driving.:p

Andy
02 M3 CB/Cloth SMG

We all knwo M3s have totally inadequate brakes. :p

Raffi
08-29-2002, 10:14 PM
Originally posted by Nick325xiT 5spd


We all knwo M3s have totally inadequate brakes. :p

Especially when Stuka the mad man drives one... :tsk: :yikes: :tsk: :yikes: :rolleyes:

Plaz
08-29-2002, 10:36 PM
Originally posted by Stuka


I'll show you faded brakes on normal highway driving.:p


Normal? :lmao: :lmao: :lmao:

(granted, I've only heard the stories)

Raffi
08-29-2002, 11:26 PM
Originally posted by Plaz


Normal? :lmao: :lmao: :lmao:

(granted, I've only heard the stories)

It all depends on your definition of "normal"... :tsk: :yikes: :rolleyes:

Jspeed
08-30-2002, 12:54 PM
The HACK:
Thanks for sharing w/ us the great info! We should save this for future reference. Enough people frequently ask about plain vs. drilled vs. slotted rotors.