Z4mc track brake pad questions

[schwank]

Hi guys,
I recently did a track event with hawk ht10's front and rear at mid Ohio. I typically run in the intermediate groups solo. I have kw v3 coilovers, and ran r comps this time for the first time.

I've been using ht10's on my last few events (mostly on sticky street tires) and I find that they are generally good for one three day event, MAYBE two 2 day events (that's 12-16 30 minute sessions) and then theyre toast. What is your experience with them? How long do they last for you? Any other suggestions for track pads?

Yes, I do think about my braking style, and if I'm burning them up prematurly!

Has anyone made brake ducts?

Thanks!

[BTM]

Never ran those pads, but contemplating making brake ducts, since mine finally flew off somewhere in Ohio or Indiana recently. Turner sells the high temp flex duct, and there is a thread on E90post which could serve as a starting point

http://www.e90post.com/forums/showth...ht=brake+ducts

Found a Z4M specific post:

http://www.zpost.com/forums/showpost...40&postcount=8

[The HACK]

How long track pads last is partially dependent on the amount of cooling you have available. If you can manage to keep the temperature well below the MOT (maximum operating temperature) and above the minimum, you will see longer pad life regardless of your braking style.

For example, I've done a few events on my MZ4 Coupe on stock rotors and Cobalt XR3s. While there's no tangible data, I switched to RacingBrake front rotors about 1/2 way through the XR3's life. The first half of the XR3s lasted about 4 events for me (that's about 10 25 minute sessions, unfortunately), and then it took me another 2 years to wear down the XR3s to a point where there's only about 25% of pad left. In that 2 years I did about 10 events a year, or equivalent to about 20 days and 40-45 25 minute sessions, plus a couple of private events where we rented a track for the whole day and just had fun and drive whenever we want. In the same span of time I actually went through 2 full sets of rear pads while only using up about 1/3 of the front.

I spoke with my friend Warren at racing brake at length about this, and his theory was that on the stock rotors I was operating near the maximum operating temperature, and the RB rotors dropped the operating temperature significantly and therefore extended the life of the pads. This Thread over at E90Post has some very interesting empirical data when comparing a two piece floating rotor to a one piece design. However, since the BMW Motorsports rotors on the MZ4 Coupe is a true 2 piece floating design too, I don't know how much the RB rotors "cool" compared to factory (since I've long got rid of mine).

[The HACK]

Also, you should be using DTC-60s or better. The HT-10s are at least a full generation older and there's some definite drawbacks compared to DTC line of track pads.

[Shipkiller]

Hack,

Have they figured out a rear pad for the Raceing Brake rear rotor yet?

I remember you mentioning that a 'not official' pad was able to be use but you had to monitor the pad thickness once it got to 1/2 done/worn so the backing plate did not come into contact with the mounting bolts.

[The HACK]

Originally Posted by Shipkiller

Hack,

Have they figured out a rear pad for the Raceing Brake rear rotor yet?

I remember you mentioning that a 'not official' pad was able to be use but you had to monitor the pad thickness once it got to 1/2 done/worn so the backing plate did not come into contact with the mounting bolts.

Warren said that if you use RB ET800 pads then it'll work. He's looked very closely at the mounting hardware and there's no simple solution to it. He said that if you order a set of rears, and order a set of pad from him at the same time he'll machine off the part of the pad that'll come in contact.

You can use ET500 for the street and DTC-60 for track, if you buy the pads from him he'll machine both.

In fact, he asked me if I want to get a group buy of his rotors AND pads together for a significant discount, and if I can get a set of 10 rotors he'll go ahead and make the matching front and rear. If I can get 3 or 4 commitment here from the MZ4 community, I'm confident I'll be able to secure the remainder from the M3 community.

[onelove]

I've been running the DTC 70 for the past 6 months with great resutls, only have 20-25% wear after many weekends (albeit at a shorter circuit with only 1 150+ braking zone), but pedal modulation has been great, very consistent, and absolutely no fade. Albeit I've got a stop tech setup on the car, but I'm sure similar results can be found with stock calipers (although slightly quicker wear from temperature).

[schwank]

is that sets of front and rear rotors? or rear rotors with pads? Im thinking about the fronts at least...

[The HACK]

Originally Posted by schwank

is that sets of front and rear rotors? or rear rotors with pads? Im thinking about the fronts at least...

To clarify...

The front rotors work as direct stock replacement. There's no interference with pads. You can use whatever pad that fits within the BMW caliper.

The rear rotors, due to the 2 piece replaceable hardware, will eventually grind into the fastener (not a good thing) unless you modify the pads. If you buy the rear rotors, he can machine any set of compound he has in stock to accommodate the rear rotor. So if you buy a set of rear rotors from him, and a Hawk DTC-60 or DTC-70 pad for the rear, he'll machine about 2mm of the pad off on the bottom to accommodate the rear rotor design. Or if you buy the rear rotor along with a set of ET500 for the street, he'll do the same for the ET500.

This limits your choices. Obviously if you watch the rotor and pad wear consistently, like after every track weekend, you won't have a problem running whatever hardware. Just be aware that you will need to eventually grind away part of the pad that will be extruding into the fastener. Not an ideal solution, obviously. Or if you want to run the ET300/500 pads for the street, and DTC-60 or DTC-70 pads for the track, you can buy it from RB and then Warren will have the pads machined down just for the rear rotor application.

Also, if we can arrange for 10 sets of front AND rear rotors, I can see about getting some special pricing for the entire group buy. Maybe a free set of pads (about $200 worth), or even a special pricing with the rotors AND pads together. I haven't worked out the details yet but Warren is open to the idea since his BMW business doesn't seem to be taking off like his Mercedes, Porsche, and Z06 rotors.

[tikamak]

Originally Posted by The HACK

However, since the BMW Motorsports rotors on the MZ4 Coupe is a true 2 piece floating design too, I don't know how much the RB rotors "cool" compared to factory (since I've long got rid of mine).

Doesn't all Z4Ms have the 2 piece floating rotor?
http://www.trademotion.com/partlocat...layCatalogid=0

check this link, are these the 2 piece floating rotors?

Before you had changed to the racing brake rotors, you had the OEM 2 piece floating rotors i suppose, correct ? and now the racing brake rotors are better ? (eating away at the XR13 for 2 years time without killing it)

any sign of quicker wear on the racing break rotors? quicker than OEM i mean?

waiting for your reply.

[onelove]

They're a floating rotor, but have a different mounting setup than traditional aftermarket floating rotors. Most aftermarket units allow you to replace the friction surfaces only, making it much easier to say bring a few spare friction rings with you along with your pads to the track. (essentially the center aluminum and lighter portion holds the outer friction ring, allowing weight to be reduced).

[tikamak]

And that is better than OEM floating rotor because? (performance wise)

No pun intended with my reply, just looking for an honest and informed answer.

I deeply believe that the OEM rotors are extremely performant and you will have to spend serious bucks on BBKs to get more performance than an OEM rotor + aftermarket racing pads + brake Lines + fluid. amirite?

[Finnegan]

Originally Posted by tikamak

And that is better than OEM floating rotor because? (performance wise)

No pun intended with my reply, just looking for an honest and informed answer.

I deeply believe that the OEM rotors are extremely performant and you will have to spend serious bucks on BBKs to get more performance than an OEM rotor + aftermarket racing pads + brake Lines + fluid. amirite?

The Performance Friction replacements have a rotor ring that is removable from the hat. Aftermarket and OEM replacement floating rotors are a one-piece replacement. It costs more initially, but if you track or plan to keep the car awhile subsequent replacement costs are lower since you only replace the rotor ring.

As for the cooling capacity, I don't know how/if the Performance are better. They do claim the design is lighter than OEM by 2 lbs. and there are some other marketing claims--including lower wear on pads. (See link above.)

Here is a longer discussion on on this type of hat/rotor. It may answer more of your questions.

[tikamak]

my point is that the replacement rings are about 198$, the OEM rotors are about 208$ from tischer.

That's what's throwing me off.

Are the ones from tischer the OEM 2 piece floating rotors or some fluke replacement?

[onelove]

Originally Posted by tikamak

And that is better than OEM floating rotor because? (performance wise)

No pun intended with my reply, just looking for an honest and informed answer.

I deeply believe that the OEM rotors are extremely performant and you will have to spend serious bucks on BBKs to get more performance than an OEM rotor + aftermarket racing pads + brake Lines + fluid. amirite?

Lighter. (comparing an aluminum lightweight hat to OEM integrated steel.)

You're not replacing the entire rotor, merely the friction surface.

2lbs a corner is 8lbs of rotational mass saved, which is well worth it.

Personally if you don't need your rotors replaced, you don't go to the track, or you rarely drive the car to the point you would need a BBK, then it isn't a huge advantage over a proper OEM setup. At this point you a BBK may be a better option for some, personally I went that route for replaceable friction surfaces, availability of pads (compounds and availability at the track since quite a few of our cars run the same package) and most importantly a top loaded pad which I can change in a quarter of the time the OEM takes.