Groove
 

Transferred this out of a different thread and put it somewhere more applicable where I also wouldn't be thread jacking:

At my last track day with the XP10s on the front I was getting pretty thick visible deposit buildup on the rotor surface.. After a while I could definitely feel the rough surface of the rotor in the brake pedal in a few brake zones. Didn't warp or significantly crack the rotors though. I did drive around the paddock for a few minutes after the cooldown lap and pushed my car back and forth a bit after I parked it. Thinking of hacksawing a shallow tangential groove (and filing the edges) into the middle of the XP10 pads since they don't have one (even though I do use slotted rotors) and they do have those 2 small holes which are maybe intended to perform the same function?

Which is why I haven't done it and mentioned it here ;). It used to be common practice with some race teams (cutting them), (don't know if its still done, I had assumed all race application pads now had them from the factory) in fact Carrol Smith talks about it in his book Tune to Win. The goal is to give the (new and old) brake dust somewhere to go rather than being pushed back into the rotor material by the rest of the pad. This way more of the pad is seeing a clean/clear surface when it makes contact with the rotor. It also helps somewhat with cooling the pad. It doesn't have anything to do with gassing, which is a thing of the past.

Also I don't believe there is anything special about the material at the front or back edge of the pads to begin with so how would adding another front and rear edge do anything bad?

not sure the point of this thread, but some groove is normal. my G has grooves on its factory brembo rotors that i could feel with my finger tips, braking is still plenty strong.

i see that the original post was edited... but im still :confused:

I think you misunderstood, so I rewrote my post just slightly to make it more clear. In short I am proposing hacksawing a groove into my front XP10 brake pads perpendicular to their long axis (don't know how to express that clearly with smaller words) with the goal of getting a smoother and more consistent transfer layer of pad material on the rotor surface. Curious if anyone has done this modification to pads before and seen any difference. Even the less track oriented pads I use for the street (Endless MX72s) have this groove from the factory.

oh, you mean like this kinda?

http://www.roadrunner.travel/wp/wp-c...Brake-Pads.jpg

Yep, exactly :tup:

:tup: but not sure if okay to alter just any pads like that? :ugh:

Radial is the shortest word I can come up with. YMMV

TFIWYAM!

the f- is with your acronyms mang! :mad:

:rofl2:

Yeah, before I go hacksawing my pads and end up in a wall just wanted to run it by the forum and see if there was any 1st hand experience with this.

Yes I did a quick google of that, still not quite sure how it was applicable but I just went with it and tried not to be offended that he thought a link to the definition of radial was necessary :tup:

yah, im thinking it might disintegrate if the hardness is not right. those pads (as you know) can get EXTREMELY hot. :D

Yes, they certainly do. But there are already 2 edges on them, why would 4 be bad? If you look at factory pads with these cuts it actually looks like they were cut after the fact as well.


Nice rims btw, what are those?

That would be my worry. In theory, it should work (lots of pads have one or more grooves) but the pad may not handle the stress of cutting the groove and/or any extra stress created in use.

Personally, I'd get pads that are designed/manufactured with the groove rather than risk failure from a mod gone wrong. Brakes are pretty high on my No Experimenting List. Better safe than sorry.

Yes, I have considered that and I appreciate the opinion. Just trying to see if anyone has actually done this or not so I can get some info based on experience.

Ie, you may be able to find a better/shorter word.

Link wasn't necessarily for you. If someone needs it, they can click.

BTW, I've been BBSing since the mid-'80s when bits were expensive to transfer and store. Sorry if all the acronyms/abbreviations are confusing. Old habits are hard to break.

"busy googling BBSing"

Edit: ah, I understand now!

I've seen people add additional notches in pads at the track before, though I've never done it personally. Most of the time it's done to assist in gas dispersion as I understand it

Yeah, it used to be done for that reason, back when pad material was bonded together with resin, that resin when heated to high temps basically boiled off and created a gas which would get stuck between the pad and rotor and cause pad "fade". Pads are no longer constructed this way though. If you saw people cutting radial ( ;) ) grooves in their pads it was for the reasons I stated above... or at least that was the only effect it was going to have. Thanks for the input DJTodd

Engineers designed that pad in one piece. Cutting it is not advised. As another said here, having that pad break into chunks at high speed / temps when you need it most is not good. I would buy pads purpose designed with gaps/notches in between the pads.

After doing more research. No offense, but anything to do with modding a piece concerned with saving/losing my life I would do a little more research than asking a bunch of knuckleheads like us for a definitive answer on that. Talk to an expert.

fixed... :mad:



:icon17:

I'd be afraid it would act like a scribe line on glass or tile if you know what I mean. You would want the bottom of the groove to be rounded, not square as it would be from a hacksaw cut. The square 90 degree angles would create stress points that would cause it to crack. I agree with the post above; find some pads designed for racing and pop them in before you go to the track.

Let's call Carbotech and ask

I'll post whatever they say up here so this thread actually ends up with some potentially useful info ;)

I'm just going to have to somehow avoid them just giving me the off the cuff speech of "dont do it [because we are worried you will sue us or something]"

The Bobcat's come with an angled edge on the leading/trailing edge. takjak is right though... Carbotech can tell you if it's safe and if it isn't they might be able to make a set for you that have what you want!

So I just got off the phone with Carbotech. They said there is absolutely no reason not to add a radial groove or two, just don't cut into the backing plate obviously. Also said to not chamfer the edges of the slot in order to minimize the reduction in pad surface area. Make sense to me and is pretty much what I thought they would say if I was able to get an honest answer, which I was. There wasnt any hesitation or asking why i was asking. So that's the official word. Testing shall commence when I next get an opportunity.

if that is to provide higher performance, is there a reason why carbotech doesnt do this from the getgo? :confused:

cost driven? really?

I was also wondering the same thing.

Probably deem it unnecessary. I am not sure, it might not even help.

I think my problem is that I am actually getting the XP10s right up to their max temp range right at the contact surface (1600 F). I dont want to go with a higher bite pad though like the 12s or the 20s, just not enough modulation in it to use with street tires imho. I am afraid it could also increase my chances of confusing the sh*t out of the ABS system and causing the dreaded "Ice Mode" by drastically changing the amount of retardation (:rolleyes:) generated by the pad for a given amount of caliper pressure so far away from what the computer expects when it attempts to modulate the braking force. Even though I very very rarely find myself getting into the ABS. This may or may not be a cause. To the best of my knowledge it is not a learning unit. I don't want to get too far into this and turn this into another Ice Mode thread, we already have [at least] one of those! (As do the Porsche and Lotus forums, with a lot of good info btw)

Think I need to start taking it easy on laps where I run into traffic and only going full out on clean laps. This will also give me some more time to think and really analyze the track surface and my own performance as well. And give my equipment a break. Sounds like a good idea "on paper".

But I think I will try the groove out all the same. Just fyi the small holes in the pad material are where it is riveted to the backing plate (kinda thought they would use a "higher tech" method for this like the "special" method that EBC makes a big deal of, but /shrug.) He said that the XP10s are such a low volume seller that they are hand made. At my next track day I will try cutting a relatively shallow groove to see if it does anything useful. I have no plans to ever completely halve the pad material. If it doesn't help, in a day or two of track use, it wont be there any more anyway.

^ yah, good point on the premature triggering of ABS. that's one thing i dont like about messing with pads with aggressive bite.

might even be better figuring out a way to disable ABS on the track.

Isnt the abs tied in with vvel or something crazy?

car does have yaw correction even if you turn off vdc.

Yeah, I have seen this said before, what does it do to correct yaw? use the brakes or limit power?

Anyway, how in the world did you make that jump from talking about ABS and VVEL to VDC? :rolleyes:

Tse only times I leave VDC on at all on the track is if the conditions have changed drastically - leave it on a lap or two to safely learn the new limits or if its my 1st couple sessions, I'll leave it on for a lap or two while the tires (and myself) warm up.

from my experiment it used brakes to straighten the car when i abruptly throttle lift mid-turn intentionally. so if i want the rear to swing out, i need to apply throttle, or yank the e-brake hard. e-brake uses drums.

basically once you notice you lost control of the car, let off the throttle and brake momentarily. the car will recalculate and get the car back out of a spin, then apply brakes.

most often people over compensate and crash. :D ofcourse thats if youre not going excessively over the car's limit.

Myth, this is not a g35

I can attest that I have used trailing throttle oversteer to help rotate the car on many occasions though (most recently midcorner in T6 at Sonoma).Might not be quite the fastest way through a corner but sometimes its what the situation calls for. I think the system only kicks in if its a really sudden slide. I can also attest to very nearly spinning a few times when for some reason I carried my braking into an off camber corner once or twice (cough, Sonoma T8, VIR T10). I can say I have felt it straighten out the car when, under heavy braking, the chassis is upset by a bump. You feel a bit cheated and relieved at the same time!

:gtfo2: go play with your leaf. :shakes head:













:rofl2:

:rofl2: I'm laughing at the reply.