With the extended weekend, I figured that I would start planning my attack on how to run brake ducting. I bought some 2.5" hose, raised the car up on jack stands and started messing around. From what I find, there really isn't a way to effectively run ducting directly to the center of the rotors. There just doesn't look to be enough room to fix the end of the hose to point directly at the hub. I know D was working on something a while back, but I don't remember hearing about how effective it was.

While I was checking things out, I decided to check the rest of my brake system out. I noticed my StopTech rotors looked a little scored, so I decided to pull them off to see if I could just have them turned, and this is what I found...
NOTE The weekend after the EXPO, I attended an event at Heartland Park in Topeka, Kansas. A couple of days before the event, I put on my brand new set of StopTech rotors, and once I got to the track, I put on a brand new set of Porterfield R4E pads.





You can see all of the cracks in the rotor...

I was out there for 4 - 20 minute sessions, and my rotors look like this, and I went through the set of R4E's - nothing left of them Needless to say that I am not too happy considering the StopTech rotors run ~ $500 a set, and the rotor replacement isn't cheap.

This doesn't make ANY sense to me. For that kind of money, I was expecting them to last for a much longer time. And from the looks of it, it appears that the rotors ran hotter, hence frying the pads.

Anyone have any thoughts on this?



[Modified by White Dragon, 7:24 PM 11/23/2001]

 

looks like you got those rotors smoking hot..............i can see heat/stress crack on them.......damn...........and those were new?

wow.........

 

Let's see... you wore your pads OUT??? Which means you were scoring the rotors with the metal backing plates? (You can see where the rotors are scored.) And that's what got them so hot that they cracked.

Next time replace your brake pads BEFORE they're down to metal. You'll save your rotors that way.

 

Ditto what nsxtcjr said. Maybe it's time for a set of regular Brembo OE replacements.

 

I know what you guys are saying, but I don't understand why I went through a set of pads that quickly. I agree that I should have checked my pads sooner, but I would have never guessed that they would be gone that quick.

So, because I didn't check my pads after each run, I ruinned a set of rotors... Lesson learned, unfortunately, the hard way.

Hey Ken, what pads do you run, and how much track time do you get out of them and your rotors?

Hmm, now I can't decide wether or not to replace the StopTech discs, or just go back to OEM rotors...


[Modified by White Dragon, 8:29 PM 11/23/2001]

 

WD:

unfortunatly, i havn't been to the track since getting my ducting about 90% finished. that whole quitting job, going back to school thing has had a bit of an effect on my 'racing career' what i have done is pretty well documented on our site....

so, are those stoptech lighter than factory components? i'd love to get into another argument about lighter rotors being good for less unsprung weight, but incredibly ineffective at dealing with heat effects of braking... .... i love that argument.

Go with brembo blanks IMO... fug it, 30 or 40 dollars each..... beat the hell out of em at the track and replace them at will.

D


[Modified by D, 12:00 AM 11/24/2001]

 

Wes, it isn't the pads. We have used those Porterfield R4E pads a lot with Stock rotors, Porterfield OEM slotted rotors, & Brembo OEM slotted rotors. They usually last 8 - 12 Track days with my son & me, often driving in back-to-back 30 minute sessions.

We have never used those Stop Tech rotors, but maybe it is retaining the heat more than the OEM ones causing the pads to overheat and wear out quicker. One Track day shouldn't wear out the pads like that much. Something wrong somewhere.

Just stick to the OEM-sized rotors, but get them slotted. The ITR's braking capability is really good to begin with. No need to upgrade it and sacrifice reliability. After all, Galati won the 99 WC with the stock brake setup, ABS and all.

 

OUCH! Sorry to see this happen. I just recently finally put my StopTech rotors on and tested them out at Summit Point for a day. I had some new pads from a local imported parts store (Akibono?). I couldn't get a decent set of pads in my time frame. Well with new ATE Blue and all, I was braking harder and later and didn't experience any problems. It could have been all in my head, but I felt comfortable with the setup. I've been running then since now from Nov. 3rd and am still happy.

Thanks,
Victor Perri II

 

Why not try Endless rotors and pads ?? I have Endless basic (ceramic) rotor and Endless CC-X pads and I never have any over heating problems even I push them so darn HARD..... I run them on the street and track too.

 

D: The StopTech rotors are suppose to be a little bit lighter, but there big selling point was that they were suppose to run 'cooler' with the way the vanes were designed, and with the aluminum hats. I think they were also a couple mm thicker than the stockers.

At $400 dollars a pop, the StopTech replacements are not looking too good. That is pretty weak IMO.

Robbie: Thanks for your input. It sure didn't seem reasonable that I went through a set of pads that quickly, especially since the rotors are suppose to run cooler. The box that the pads came in were labled R4E's, but it might be possible that they sent me the R4S's. What pads do you and your son usually use, and what rotors have you been most happy with?

Also, what do you guys think about removing the dust shields both front and back? Where is a good place to get the Brembo Slotted Rotors? How much do the Porterfield slotted rotors run?

V.P. How many events have you run on the StopTechs?

The only thing that I can think of that happened with the StopTech rotors, is that I either got sent the wrong set of pads, and they just couldn't handle the heat, OR the rotors were each put on the wrong side. If the second one were the case, what would that do since the vanes are directional?

Well, maybe it is just me. maybe I can have one of you more experienced guys ride with me and see if I can change my particular style of braking. The thing is, my style can't be too bad I wouldn't think if I am turning out really good lap-times.

This whole think is really frustrating

 

thats really odd. I would think that you either you installed them on the wrong sides, the pads were the wrong type, or the pads wore down to fast due to your driving type and/or length of using them.
I have the StopTech rotors with R4S pads, ATS blue, and Spoon calipers and I have no signs really of that type of wear. I havn't tracked with them yet, but I have done some serious braking with them to make sure they are working right. I will take some pictures of my rotors right now from the front and back and you can compair the wear marks. However still from looking at your pictures it seems the pads wore down and caused that. As for why they wore down so fast, I have no idea.

 

go with brembo blanks, and get spares.. you can get them 95$ shipped from http://www.collettimotorsports.com Also, Slotted rotors will wear pads quicker.. It looks like its time for you to get some REAL pads.. Try carbotech panther plus or R4.. The carbotechs are comparable to R4 and a lot cheaper.. Both can be driven on the street if need be, but the carbotechs will not chorode you paint..

Lighter rotors = more heat build up = cracking

 

There are actually multiple issues here, and some questions, and such. I think I'll try addressing some of the specific points, and then try to summarize.

I keep meticulous records of my track miles and regular miles. That's the good news. The bad news is, my ITR is pretty new, so I don't have a lot of data points yet, the way I do on my NSX. But here's what I've got.

Started with stock pads and rotors (new car).

After 3,809 total miles including 223 track miles, front pads were shot. (I try to replace them anywhere from 2 to 4 mm thickness of pad material.) I replaced them with Endless CC-X pads.

After another 2,850 total miles including 279 track miles, front pads and front rotors were shot. (Rotors were shot due to unacceptable amounts of shudder, probably caused by "hot spots" on the rotors.) I replaced the pads with RM Racing street/track pads, and the rotors with Stoptech aerorotors.

I only put 25 track miles on the car since then, so I don't yet know how long those rotors or pads will last on the ITR.

On my NSX, I have been using RM Racing street/track pads, and I usually get 250 to 450 track miles on a set of front pads before they need replacement. I get 650 to 800 track miles on a set of rear pads (but they don't make rear pads for the ITR). I have been using PowerSlot rotors on the NSX and they have lasted 750 to 1200 track miles per set, at which time they crack and need replacement for that reason. (See more info below.)

I've recently picked up some Carbotech Panther Plus brake pads, so I'll be trying those out as well. (They will be going onto the NSX as soon as I take it out in the spring, and I'll probably try them on the ITR next time it needs pads.)

I would stick with the Stoptech rotors, and see how long they last while you're monitoring the pads closer (and not wearing them down to the backing plates).

All of these are advantages with the Stoptech rotors. There's another BIG advantage - they use a "floating hat" design. More in a moment.

Most rotors (including the stock rotors, PowerSlot rotors, and Brembo blanks) are a solid disk surface, a flat piece of metal that extends from the hub (fitting over the lug nuts) all the way out to the area where the pads grip the rotor. They may have vents (veins) inside, slots, and/or drill holes, but it's all one piece of metal, from the center to the edges. As rotors get hot (on the track), they expand. However, the "outer ring" wants to expand more than the "inner ring" (around the hub) can, and so cracks form. Actually, the rotor can expand fine when it's HOT; the cracks actually form when the rotor cools down after getting so very hot. Take the car out on the track, and the cracks fill in when the rotor expands from the heat; let it cool down, and the cracks get bigger. You need to keep an eye on the cracks. If they're big enough to feel with the edge of your fingernail, you need to replace the rotors. (If you keep going past that point, they can grow to the point where the entire rotor can crack apart. THIS IS A BAD THING.)

The Stoptech aerorotors, OTOH, use a "floating hat". This means that the surface that the pads grip is a ring. It is connected to the hub (the "hat") using bolts that allow that ring to expand with heat, while allowing them to "float" (change distance from the center as they expand). This way, the outer ring can expand and get larger without cracks being generated as easily, since the metal isn't as stressed as a conventional rotor.

Since I just started using my set of Stoptech rotors on the ITR, I don't yet know how long they will last or how they will compare with conventional rotors. (I have a set for the NSX also, but have not yet mounted them on it.)

It doesn't cost that much. Remember, you don't have to buy the entire assembly, including the hat; you only need to replace the disks themselves and some of the bolts and washers. The disks are $120 each, so even with the hardware, you're looking at maybe $280. BTW, they don't show the hardware on their website, so you may want to order them over the phone rather than order the disks on the web, then find out later that you also need the special hardware that they advise replacing at the same time, and have to have the hardware shipped separately. (Ask me how I know this. )

Granted, $280 is more than some other rotors cost, but if they last a lot longer before cracking or developing hot spots, they may be worth it.

I'm not. Instead, I'm planning to do the same thing with my dust shields on the ITR that I did on the NSX. I had some high-temp brake cooling ducts fabricated. The inlet is in the front air dam. They left each dust shield on the car, and cut a hole in it, to which they welded a flange that they used as a mounting surface for the other end of the air ducts, so they blow the cooling air directly onto the surface of the rotor.

I think you're confusing two different things that happened:

1. You used up your brake pads.

2. Your Stoptech rotors got scored and cracked.

I don't think there's anything wrong with the Stoptech rotors! I think they just got too damn hot because you kept driving when there was no more pad material on your brake pads. Not only were they in contact with your metal backing plates (not as good a friction surface as brake pad material), but they were getting gouged by the fasteners that Porterfield uses to affix the brake pad material to the backing plate, hence that deep groove in the middle of the rotor surface.

Incidentally, in case you want to check whether they were mounted on the proper sides - the pattern of slots in the photos you show above are the same as the OUTSIDE surface of the LEFT rotor.

Now, you've been speculating as to why you used up your brake pads in one track event. I can't answer that... but look at the mileage that I've gotten out of the various brake pads I've used. I've toasted sets of front brake pads in only 200-250 track miles. If that's how many track miles you put on your pads, then that's not really an unusual lifespan for front brake pads. Perhaps you can expect more (from the R4E) or less (if they were actually R4S); the number of miles you get may depend on your driving style and experience as well. That's why you might want to start keeping some detailed records of what you're using and how long things last, just like I do. That way, you'll know how many miles YOU can expect from YOUR pads, rotors, etc.

You mentioned having to check your brake pads after every run session, as though this is too much trouble. In fact, this is a very good idea, and should be second nature. Each time you go out on the track, you should have a pretty good idea of how much pad material you have on your brakes. Get to know the wear pattern. With the ITR's stock wheels, you can look through the spokes of the wheels at the edge of the brake pad and see the thickness of the pad material on the top edge of the outside pad. It won't necessarily be the same uniform thickness on the inside pad or on the bottom edge, but it will give you some idea of how they're wearing. For example, I know that the inside pad might be wearing 1 or 2 mm faster than the outside pad; the fact that I am changing pads with anywhere from 2 to 4 mm visible thickness should prevent me from going down to bare metal on the inside. (I don't want to wear them too close anyway, because the pad material itself acts as an insulator, and the pads will be getting even hotter when the pad material is thin, even before you're down to bare metal.)

So... to summarize, this is my guess at what happened, and my best advice on what to do about it:

What happened? You wore your pads down to bare metal and kept driving on them. The pads gouged a circular notch in the rotors and got them really, really hot, resulting in cracks.

What to do about it? First, I would get replacement disks and hardware from Stoptech, and install them on the hats you have. At that point, you're essentially starting over from scratch. I would flush the brake fluid in the spring at the start of the track season, and maybe consider installing some cooling ducts too. Next time you go to the track, start keeping detailed records of which rotors and pads you're using, and how long they last. Keep a close eye on your pads, to make sure they have enough pad material, and on your rotors, to see if any cracks start developing.

Also, you or whoever works on your car should periodically check the condition of your fluid and of your calipers. If your pedal gets mushy and/or you feel the brakes fade, it may be a sign of boiling fluid, and you may want to flush it after that event. Any time you get the brakes really hot, after the event make sure you check the rubber boots around the pistons in the brake calipers to see if they've melted or gotten "crispy", and if so, you'll want to replace them (you can get individual parts for this, you don't have to replace the whole caliper).

If you want to try some other kinds of pads, and other kinds of rotors, feel free. But keep track of how each one works for you, how long it lasts, etc, so that you can use that information to guide your future purchases.

Finally, don't get too upset about this. Brake rotors are just like brake pads and tires - they're consumables. As you keep going to the track, and as you get faster, you're going to be replacing these parts. There are things you can do so that you don't have to replace them quite as often (cooling ducts, and even big caliper kits that probably need bigger wheels if you want to start spending big bucks)... but you're still going to need to replace them from time to time. The good thing is, this gives you the chance to experiment by trying different brands of replacements, and seeing what kind of results you get each time.

HTH



[Modified by nsxtcjr, 10:04 PM 11/24/2001]

 

God I am glad Ken's back, great info!

 

I've heard that argument over and over. And I've been answering them over and over. It all depends on the material. Some materials are lighter but it doesn't necessarily mean that they have less heat resistence. Some good (but expensive) rotors are lighter but with BETTER heat resistence than oem steel rotors (ie. carbon ceramic, ceramic, etc.) So don't generalize the idea of lighter rotors = more heat build up = cracking, plus the hammer.


[Modified by Wai, 9:01 PM 11/24/2001]

 

nsxtcjr: That is one of the best posts I have read here at H-T. Thanks for the great info...

 

Yes, they are directional...chances are you did install them on the wrong sides, keeping the heat in rather than pushing it out. You'd want the veins pointing backward (from middle-out).

 

**** Porterfields...after I saw what Corey did to his after 1 day, I will never buy a set.

 

[QUOTE V.P. How many events have you run on the StopTechs?[/QUOTE]

I've just installed these the day before the Summit Point NASA event. So only 1 track day and daily driving since. I have plenty of pad left and could just use some bleeding from the calipers some.

Thanks,
Victor Perri II

 

Ever try Hawk Blues? Track only use and they do the job right. As for the rotors, why the slots? I mean, I know why, but do you really need em? Esp at the cost of shorter pad life? Blues and OEM rotors stop me fine w/o issue. I got that info from serious track guys....not ads in magazines....figured it had to be spot on...and it was!

Good luck.

 

yeah, and we all have a set of ceramic rotors laying in the garage.......

D

 

RBoosted: Going from one of the pictures that you posted a while back, mine were installed the same way. I am not sure what to think about the pads, maybe I am just that fast (yeah right!). I know I would not have had this problem on the street or autoXing. I try not to drive quite that aggressive on the streets I agree that the rotors cracking are totally and unarguably my fault.

Corey: $95 for those Brembos seems a bit high. People have been saying that you can pick them up for around $30 a piece. Also, I was under the understanding that I was using some “real” pads. When I ordered them through Porterfield, they told me to go with the R4E’s over the R4’s. Where do you get the Carbotech Panther Plus pads?

Fangtl and Flux: I agree!!!

Wai: Thank you

And finally Ken:
I keep meticulous records of my track miles and regular miles.

Makes perfect sense to me, and I will start doing that from this day forward.

After 3,809 total miles including 223 track miles, front pads were shot.

I had no idea that you could do that many miles on the track with stock pads. I honestly couldn’t fathom the idea of going that long on stock pads at full speed. Were you driving on the aggressive side or the conservative side? Also, when you give you pad wear / track miles, does that typically consist of mostly aggressive driving? This is in regards to the NSX and the Type R.

I replaced the pads with RM Racing street/track pads, and the rotors with Stoptech aerorotors.

Where do you get the RM pads? What do they typically run? Am I safe to assume that you always run the same set of pads till they run out? That is, do you change to a street pad for the everyday driving, and then change to your racing pads when you are at the track? The R4E pads (as well as the Hawk Blues) do not really work that great for daily driving as they don’t work well till they are hot. Do you find this to be the case with the RM pads?

Is there any negatives to going from a street pad to a track pad while using the same rotors? I have heard both ways. Some say to use some emery cloth on the rotors before switching pads. Does this have any merritt?

What about the rears on your ITR – both pads and rotors? Also, I haven’t heard you mention Hawk Blues. Is this for any particular reason?

There's another BIG advantage - they use a "floating hat"…
Thanks for the explanation!!!

Brake Shields/Ducting
I'm not. Instead, I'm planning to do the same thing with my dust shields on the ITR that I did on the NSX. I had some high-temp brake cooling ducts fabricated. The inlet is in the front air dam. They left each dust shield on the car, and cut a hole in it, to which they welded a flange that they used as a mounting surface for the other end of the air ducts, so they blow the cooling air directly onto the surface of the rotor.

That is what I wanted to do with mine, but with the driver side wheel at full left lock, there doesn’t look to be any room for the flange to be welded on the shield. The best place looks to be right where the ABS sensor is (I think that’s what it is), which wouldn't work because it is in the way. If you end up figuring a way to do this, please let me know!


I think you're confusing two different things that happened:
1. You used up your brake pads.
2. Your Stoptech rotors got scored and cracked.
I don't think there's anything wrong with the Stoptech rotors!

I would agree with # 1 and 2. I just am confused why I went through my pads so quickly, and thought that maybe there was a relationship to this and the rotors. Just to make things a bit clearer, I agree that I am totally at fault with the cracking of the rotors. No argument there.

As far as the fluid goes, I always bleed the brakes after each event, and I have always gotten bubbles. This is with Motul 600. But this may also be a cause of everything getting too hot because I don’t change my pads often enough – that is I run them too thin, hence more heat build up.

Any time you get the brakes really hot, after the event make sure you check the rubber boots around the pistons in the brake calipers to see if they've melted or gotten "crispy", and if so, you'll want to replace them (you can get individual parts for this, you don't have to replace the whole caliper).

Can you get the rebuild kits for the calipers at Acura, or you local parts store?

Now on the Spoon calipers, is there anything comparable that one would need to watch for?


Thanks a lot for the time you spent on this post Ken. I know I sure learned a lot! THANKS!



[Modified by White Dragon, 9:30 PM 11/24/2001]

 

Slotted rotors do not shorten pad life. That's a myth.

 

Autozone rotors...=

very cheap too

 

Here. Don't forget to ask for your honda-tech.com discount.

I drive my cars pretty hard on the track. However, I don’t overuse my brakes - IOW, get on them hard, get off them quick.

Here, and they list for $159 for a front set.

I use the same pads, street and track, and do not swap them out specifically for the track. If you are willing to swap them, there may be some pads that are better for the track than these, such as some of the Hawk pads or the Endless MA-11. Typically, track-only pads stand up to heat better, but have downsides (squealing and/or dusting and/or need to warm up) that make them less desirable for the street.

No, the RM pads work fine, even when cold.

I don’t think so. I’ve heard some people swear that you have to turn your rotors before EVERY pad change, but I don’t buy that, either.

The idea there is to remove any deposits that may have formed on the rotors. I don’t bother. Braking hard removes any previous deposits quite well.

I’m sure you’re aware that the fronts do most of the heavy braking on the track, due to weight transfer.

I still have the stock pads on the rear. They have about 6 mm pad material on them. So they have a ways to go.

I’ve never had any rotor problems with the rear in either car. Ever. I’ve never had any brake shudder or rotor cracking, and I’ve never replaced rear rotors because they were too thin. I’ve got maybe 6000 track miles on my current rear rotors on the NSX and they’re just fine.

No particular reason. I’ve usually heard Hawk pads mentioned as a track-only pad, which I’m not interested in. If they have a street-track pad, I’d be willing to try them. But I’ve been very happy with the various other street-track pads I’ve been using - the stock ones, the Endless CC-X, and the RM pads all seem to do quite nicely for me. As I mentioned, the nice thing about pads is, you use them up, so there’s always a chance to try a different brand.

Okay. I haven’t proceeded with this because I’m hoping to do this with the mechanic I use for fabrication-type work, and I’m still waiting for some HID’s to come in for him to install. Once I get them, I’ll have him do what he can with it.

I have absolutely no idea. I know that some pads wear quicker if you don’t have a chance to heat-cycle them before taking them onto the track - but still, that’s the difference between getting say 300 track miles vs 400 track miles on a set. I’ve never heard of getting only 100 track miles on a set of decent (track-worthy) pads.

You can get them at your dealer. That’s where I get mine.

I don’t know. Wai? Anyone else?



[Modified by nsxtcjr, 11:21 AM 11/25/2001]