P71
P71 GRM+ Memberand New Reader
6/5/08 11:34 p.m.

So I'm taking the P71 to an HPDE and I'm upgrading the brakes. (Off topic for a sec, I edited that and Wally's intro into the P71 in the Reader's Rides and it reset the Comment/Rating meters!)

Anyways...

I already bough the rotors (stock size, but cross-drilled/slotted/zinc coated) and some Wilwood 600 DOT 4 Fluid. I did some pad research, and EBC only offers the "base" Green Stuff's, and Hawk only offers the "base" HPS (IIRC). I could find loads of OEM "Severe Duty" pads, but I'm talking 2.5 mile road course here, I want some damn stopping power!

After all of that I picked up a set of Performance Friction pads (Carbon-Metallic) based on some searches on heavy (4,000+ Lbs) car boards. Will I be OK?

Oh and if anybody knows where I can get SS brake lines, that'd be a plus! (It's a 2001)

nickel_dime
nickel_dime HalfDork
6/6/08 6:30 a.m.

With a car like that take extra pads with you - and lots of them!!!!

Carbotech will put their race material on any backing plate and make you a special set. It's not that much more than their off the shelf race pads. That's the only place I found to get race pads for the Toyota 4X4 calipers I put on my Z. I think I'm safe in saying that any pad you buy at the autoparts store won't hold up for the entire weekend.

Things to take to the track (this could be a thread by itself) Extra brake pads (front and back), brake fluid, tools, jack, jack stands, ground cloth, WATER and lots of it,

stumpmj
stumpmj HalfDork
6/6/08 7:45 a.m.

Get rid of those cross drilled rotors before you go. They are only sold as a fashon statement. Real track cars don't use crossdrilled rotors. The stress risers from those holes make the way too susceptible to failure. I don't want to read a thread about the aftermath of a rotor failure at the track. Get quality blanks; no crossdrills, maybe slots (but it needs to be someone that knows to make them properly). The zinc coating won't help you but it won't hurt you either.

+1 on custom pads from Carbotech. Get XP8 compound at a minimum on something that heavy. I like the XP12 compound but it's way to powerful to be able to properly modulate the brakes with street tires.

And one more time, NO CROSSDRILLED ROTORS!!

confuZion3
confuZion3 Reader
6/6/08 7:58 a.m.
stumpmj wrote: Get rid of those cross drilled rotors before you go. They are only sold as a fashon statement. Real track cars don't use crossdrilled rotors. The stress risers from those holes make the way too susceptible to failure. I don't want to read a thread about the aftermath of a rotor failure at the track. Get quality blanks; no crossdrills, maybe slots (but it needs to be someone that knows to make them properly). The zinc coating won't help you but it won't hurt you either. +1 on custom pads from Carbotech. Get XP8 compound at a minimum on something that heavy. I like the XP12 compound but it's way to powerful to be able to properly modulate the brakes with street tires. And one more time, NO CROSSDRILLED ROTORS!!

Porsche uses them on their cars. With that said; Porsche uses different techniquest to make them, right? I remember something about drilling blanks v.s. making the rotors that way from the start. Can anyone shed light on this? I'm sure it was going to be brought up as a counterpoint.

Xceler8x
Xceler8x GRM+ Memberand Reader
6/6/08 8:05 a.m.
confuZion3 wrote: Porsche uses them on their cars. With that said; Porsche uses different techniquest to make them, right? I remember something about drilling blanks v.s. making the rotors that way from the start. Can anyone shed light on this? I'm sure it was going to be brought up as a counterpoint.

Aren't Porsches fashion statements as well?

aussiesmg
aussiesmg HalfDork
6/6/08 8:22 a.m.

Porsche offered carbon fiber rotors as a $10,000 option, I think the brake budget for those cars is a little out of the GRM fold on principle

7pilot
7pilot New Reader
6/6/08 8:30 a.m.

You need RACE pads, maybe more than one set. OR, you shorten your sessions. Go out for 8 minutes, watch for fade. come back in for 5mins or so, then rejoin. If you cannot swing a couple of sets of race pads, you'll need to keep your enthusiasm to 7/10ths to be safe.

I have been using my E36 M3 for HPDE while I rebuild the engine in my E30 M3. The E36 needed race pads, the street autox pads I used on the E30 and the seven faded within 6 laps. I had also switched to stainless lines and ATE brake fluid. It was not enjoyable to nurse the brakes while on track, and it prevents you from learning how to go faster.

m

confuZion3
confuZion3 Reader
6/6/08 8:43 a.m.
Xceler8x wrote:
confuZion3 wrote: Porsche uses them on their cars. With that said; Porsche uses different techniquest to make them, right? I remember something about drilling blanks v.s. making the rotors that way from the start. Can anyone shed light on this? I'm sure it was going to be brought up as a counterpoint.
Aren't Porsches fashion statements as well?

Blasphoemy!

confuZion3
confuZion3 Reader
6/6/08 8:45 a.m.

I think the idea of going to Carbotech and having custom pads made is a great idea! I didn't think manufacturers did that.

P71
P71 GRM+ Memberand New Reader
6/6/08 8:49 a.m.

Thanks for the advice!

I knew about the cross-drilling, but they are from PowerSlot so they should be OK (I haven't heard/read anything bad about them).

The stock pads/rotors stopped it well on the 12 laps I've already done, with a little fade at the end, but it boiled the brake fluid! So I'm guessing heat build-up is my enemy?

The Performance Friction's weren't cheap, and I've heard good things about them from autocrossers and drag racers alike, so I hope they're up to the task. At any rate, they do seem to be the only thing I can get by the 22nd at this point. They do have a 60-day unconditional warranty though

It's my first HPDE, so I'm thinking shorter/lighter sessions anyways so I don't over-do it (it is my DD, I should be using the RX-7).

Keep it coming! I'll give Carbotech a ring.

Wally
Wally GRM+ Memberand SuperDork
6/6/08 9:03 a.m.

Most of the smaller cars there probably have more brake than they need, so use theirs. You have a push bar so scratches shouldn't be an issue. (for you anyway) Besides, eight tires and brakes are better then four.

iceracer
iceracer New Reader
6/6/08 9:24 a.m.

While at the Gand AM race at Lime Rock I took notice of brake discs being used. Almost every car, Porsches included used solid rotors. Some had slight grooving. I saw one RX8 that had a zillion holes drilled. I asked one of the mechanics and he said it was just an experiment and they wouldn't run them in the race. P71, rig up some cooling ducts for the brakes.

P71
P71 GRM+ Memberand New Reader
6/6/08 9:37 a.m.

The push bumpers will work wonders since I'm running with the Porsche Club of America

The rotors were on a serious sale (second hand but NIB) so I kinda had too. If they suck I won't really be out much, as long as they last 1 HPDE!!

I could always throw out an anchor and some mooring lines...

nickel_dime
nickel_dime HalfDork
6/6/08 11:23 a.m.

If you already know you have a fluid boiling problem take lots of it with you. Rig up some ducts or something to get more air in there to cool the brakes. Rims with big open areas help move air around the brakes. Do anything and everything you can think of to get air in and out of the brake area.

Make sure you completely flush the system with new racing fluid and bleed them often at the track. I know people who bleed their brakes after each session.

Also remember that brakes like harder/shorter braking rather than lighter/longer braking. Brakes work by turning motion into heat. It takes the same amount of heat to slow a car down a given amount whether you brake lighter for 500 ft or harder for 300ft BUT the longer your generating heat the longer it has to heat soak the pads, calipers and fluid.

Just my 2 cent, hope it helps. Have fun.

Oh, if you go with the anchor idea use a grappling hook. That way maybe you can hook a Porsche and pull him behind you and push the one in front.

CrackMonkey
CrackMonkey Reader
6/6/08 11:41 a.m.

I used Carbotech Panter+ on my Caprice 9C1. They stayed on year-round - track, towing, street. Worked great. Also used one of their compounds on the drum shoes, but don't recall which one.

The XP8 is a more race-worthy compound, but if you're on street tires, and stay sane, the Panter+ should do fine.

stumpmj
stumpmj HalfDork
6/6/08 12:48 p.m.

Porsche uses solid rotors on their race cars (and the cermanic rotors are solid too). They have since the '80's when pads stopped having problems with out gassing.

I have personnally seen powerslot cross drilled rotors crack. A heavy car with stock brakes and race pads is going to accentuate the problem of stress risers in the rotors. You can try to reduce the stress risers by casting the rotor with the holes in it and chamfering the hell out of the holes but it's still a disaster waiting to happen. Look at World Challenge and Koni Challenge cars (the only two proffesional production based race series). None of those cars has cross drilled rotors. If you go to Stoptech's website and read up on crossdrilled rotors, they go out of their way to tell you that they're for show and not for track use.

Spend the $200 on a new set of quality blanks (I like Centric, the parent company of stoptech, myself) and be safe. I'm not normally a safety nazi but I can't emphasize enough how bad an idea cross drilled brake rotors are. Save the drilled rotors for the street or try and return them or throw them in the trash. They have no business being anywhere near a track.

If you want further explanation, there's a thread from a Nissan Altima forum on drilled rotors that is filled with excellent tech. I have it bookmarked at home. I'll try and dig it up tonight and post a link if I have time.

P71
P71 GRM+ Memberand New Reader
6/6/08 1:08 p.m.

Link please?

fornetti14
fornetti14 GRM+ Memberand None
6/9/08 10:11 p.m.

I use Carbotech's (XP10's) and there's lots of options available for heavier cars. You'll have much more fun with a dedicated brake set.

nickel_dime
nickel_dime HalfDork
6/10/08 9:49 a.m.

Be sure to come back and tell us how you did on your first HPDE.

TOZOVR
TOZOVR New Reader
6/10/08 1:10 p.m.
confuZion3 wrote:
stumpmj wrote: Get rid of those cross drilled rotors before you go. They are only sold as a fashon statement. Real track cars don't use crossdrilled rotors. The stress risers from those holes make the way too susceptible to failure. I don't want to read a thread about the aftermath of a rotor failure at the track. Get quality blanks; no crossdrills, maybe slots (but it needs to be someone that knows to make them properly). The zinc coating won't help you but it won't hurt you either. +1 on custom pads from Carbotech. Get XP8 compound at a minimum on something that heavy. I like the XP12 compound but it's way to powerful to be able to properly modulate the brakes with street tires. And one more time, NO CROSSDRILLED ROTORS!!
Porsche uses them on their cars. With that said; Porsche uses different techniquest to make them, right? I remember something about drilling blanks v.s. making the rotors that way from the start. Can anyone shed light on this? I'm sure it was going to be brought up as a counterpoint.

IIRC, the Porsche cars in the showroom have them...the Factory race cars do not...

fiat22turbo
fiat22turbo GRM+ Memberand Dork
6/10/08 5:43 p.m.

Go read the GRM Brake articles and you'll gain some understanding.

Venting the brakes will make the largest difference. You may find some ready-made adapters on the market, otherwise you'll have to make them using tin cans, aluminum pop rivets, some tin flat stock and of course vent hose.

http://www.afcoracing.com/tech_pages/brake_prob.shtml

http://www.zhome.com/ZCMnL/PICS/BrakeDucts/ducts.html

Good luck, Stefan

ignorant
ignorant SuperDork
6/10/08 6:13 p.m.

carroll smith was against cross drilled rotors..

he used to use an 1/8" ball end mill to put light slots for cleaning in his rotors.. just 2 parallel slots per side. It's in engineer to win.

stumpmj
stumpmj HalfDork
6/11/08 7:06 a.m.
ignorant wrote: carroll smith was against cross drilled rotors.. he used to use an 1/8" ball end mill to put light slots for cleaning in his rotors.. just 2 parallel slots per side. It's in engineer to win.

And tune to win and I think in prepare to win....

confuZion3
confuZion3 Reader
6/11/08 8:32 a.m.
TOZOVR wrote:
confuZion3 wrote:
stumpmj wrote: Get rid of those cross drilled rotors before you go. They are only sold as a fashon statement. Real track cars don't use crossdrilled rotors. The stress risers from those holes make the way too susceptible to failure. I don't want to read a thread about the aftermath of a rotor failure at the track. Get quality blanks; no crossdrills, maybe slots (but it needs to be someone that knows to make them properly). The zinc coating won't help you but it won't hurt you either. +1 on custom pads from Carbotech. Get XP8 compound at a minimum on something that heavy. I like the XP12 compound but it's way to powerful to be able to properly modulate the brakes with street tires. And one more time, NO CROSSDRILLED ROTORS!!
Porsche uses them on their cars. With that said; Porsche uses different techniquest to make them, right? I remember something about drilling blanks v.s. making the rotors that way from the start. Can anyone shed light on this? I'm sure it was going to be brought up as a counterpoint.
IIRC, the Porsche cars in the showroom have them...the Factory race cars do not...

Good point.

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