elle88

i want to make brake's cooling ducts.
please look at pics.
i have that square hole left open from removing those arms that supports the front bumper.

i would connect there the cooling duct but then? what about wheel's clearance at full turn?where the other end of the duct goes and how to hang it?
pics are welcome

Jason Staley

Here's how I ran mine. Since mine is mostly a street car that see occasional track duty, I went with 2" ducts to keep them tucked up under the car nicely. There not as good as 3" ducts, but they have kept me from warping the front rotors (which I did once without the ducts in place).

I placed the ducts behind the grill and the flexible tubing is clamped onto a piece of exhaust pipe I welded on the back of the factory dust shield. Just have to trim some sheet metal away and the air is ducted nicely into the center of the rotor.

elle88

thanks for the input.
btw on my car I'll remove the dust shields...and possibly go for 3" ducts with a different arrangement (air directed toward the front-to caliper, instead than routing the duct toward the rear)

gkull

It was a two day event at the local track with new rotors and hats "H" pads. Checking them after the first day the 1100 degree paint was burned away and metal turn brown. The second day the slots were gone.

elle88

Gkull, scary!
thanks for pics.

been at a racetrack on monday and i'm still astonished by the brake's matter.

two c6 z06 owned by friends. the only one that could stand safe track operation was the one with usd 12000 brakes by Brembo (the owner sayed the are the same of the Ferrari GT Challenge). the other Z06 had good aftermarket brakes : they faded...
another guy (on a wheelchair!!!) was crazy fast with a Lamborghini. out soon because he broke a brake's caliper. he says that his disks and pads last just 2 trackdays.
that's a crazy world this...

OregonVette80

true... I did a TC Drivers Intro to road racing course a few years ago. I thought since each session would only be 10 minutes, it was mid 40's to low 50's and wet, I would just leave the brakes as is.

nope. After the first 10 minute session, I had massive OEM fade

by my 3rd session the pedal went straight to the floor on the back straight at PIR with speeds around 60-70. This doesn't sound all that fast in bench racing forum board fodder but, in reallife, when you lose brakes at that speed it's "OH S**T!" time. I down shifted to third, second then 1st using the trans to slow me down to safely negotiate turn 10, 11, 12. Made it into the paddock safely.

So, even just a training day in the cool wet weather I wasn't even pushing it like a track day or a HPDE day. So, anytime it's on a track, it's DOT 4 in the metal can (the blue stuff from germany) & decent Hawk HP+ pads or nothing. That was too scary for me.

gkull

To combat heat they came up with several things. Two piece. The rotor and aluminum hat. Less heat to the grease and wheel bearings. Also improved air flow.

Iron calipers retain heat. But the biggest improvement was using titanium or the Wilwood Thermloc pistons that transfer very little heat from the pad to the fluid.

Your real racing brakes are also recirculating. So the heated fluid is returned after the pressure goes away.


I have faith in my Wilwoods. I used to think that the stock caliper with hawk pads were the cats meow. Until I had complete loss of brakes and could have taken out other cars on the track or really had a major wreck. That is reason I changed is when I had total brake failure out lapping into a 90 degree turn at over 90 mph with my stock calipers, 600 degree fluid and Hawk pads.

I get to drive a variety of fast cars at the tracks and I am saying from experience that Z-06 brakes or C-5 brakes under the same conditions would have boiled the fluid within a few laps and you would be pulling into the pits before the session was done.

These Wilwood never failed. No matter how hard on them I was. It ground the metal away with terrific heat and kept asking for more. I have since changed to the BP-20 wilwood pads and now the rotors last longer with only a small loss of braking TQ. They don't lock up my fronts as easy!

gkull

We have some car owners that in the past years did the Ferrari challenge Series of races. All the Ferrari 430's have these monster 15 inch or so $ 15,000 carbon fiber rotors and caliper setups as the optional brake package from the factory.


Like I said I was very dissapointed that a stock C-6 couldn't even do a few laps at a track.

AutoX-Z06

What is the set-up you are running gkull?

gkull

Wilwood's 13.06 inch two piece and the biggest 4 piston Super Lite calipers with the Thermloc piston option. They actually have more piston area than the 6 piston. Which might be more desirable if you are only using sticky sub 275 width 17 or 18 inch front tires. The good thing about them is that it doesn't require any additional F/R biasing hardware

Talk to Keith at http://www.store.corvettengineering....od&productId=8


http://www.wilwood.com/Rotors/RotorList1.aspx

GT 48 Curved Vane Rotor 13.06 X 1.25


GT-48 curved vane rotors are built for the extreme conditions of professional motorsports. The superior heat absorption and dissipation characteristics of these heavy wall directional vane rotors are the keys to preventing heat fade and realizing long service life from the rotors and pads. All rotors are cast from premium grade, long grain carbon iron for long wear, thermal stability, and resistance to distortion. Every GT rotor is fully detail machined to eliminate stress points and unnecessary weight away from the pad sweep face. The faces and O.D. are precision turned to less than .001" for flatness, parallelism, and run-out. An asymmetrical face slot pattern provides smoother engagement through reduced harmonics and improved thermal balance between the I.D. and O.D. of the rotor. Every rotor is then individually dynamic balanced to provide vibration free performance at any speed. These rotors provide the highest cooling capacity and longest service life for extreme braking short tracks and road course competition.

Solid LT1

Gkull is probably the expert here, I'll put in my small amount and dated knowledge here (I last worked on real Vette race cars in the late 70's early 80's.) I would make sure and plumb the vent hose to the center of the rotor to try to build-up high pressure air at the center of the rotor and force the heat out towards the wheel. In the old days I observed Vettes with ducting encapsulating the outer part of the rotor trying to force air inward, you want centrifugal forces working for you so, put the air into the center of the brake rotor for best results.

You can use the sheet metal dust shields and cut away the outer shielding, while using the center as a base to weld your ducting pipes to them, this works pretty well. You can also use more than 1 hose to feed the cooling system, this is done quite often in NASCAR racing, sometimes you will see 3-4 hoses going to the brake ducting, some of these parts are on Ebay for really cheap prices, (they are usually carbon fiber in construction.)

Biggest fight you have is the weight of your Vette, the lighter you can make it, the easier it is to stop it

Brake fade can be either pads or fluid, like George says, you can lose a pedal in the middle of a track session, this is usually the fluid boiling in the system, going to better pistons/insulators helps quite a lot, plumbing a re-circulating system can be a real challenge.

gkull

Solid LT1 these heavy wall directional vane rotors are the keys to preventing heat fade These actually work like a fan drawing air from the center. So they are sold as right and left rotors.

My brake boil failure went like this. I was a couple of laps into a road course practice session. Coming into a turn my brake petal felt mushy and went father down instead of becoming solid so I did a quick couple of pumps and the brakes were solid. So I wrongly thought from where I was on the track that by not using the brakes for a short period of time they would cool. That was a wrong assumption Mushy meant small air bubbles in the line because of heat and pumping them to get hard just really added more fuel to the fire and really boiled them over. So stupid me comes fly hard into a turn and the brakes went to the floor. I yank the wheel hard to cause my vette to do 360's to scrub off speed before flying off in to the gravel traps. Some cars roll when you do that. I was lucky and just came to a stop with a chipped up paint job.

On real race cars we actually bleed all the brakes after every session. 580 -600 degree brake fluid is only $15 - $20 bucks a pint. So it is a very cheap worthwhile investment to be changing the fluid all the time.

TheSkunkWorks

Some good info posted there, gkull.

Are you guys using Motul RBF, or what?

turtlevette

Those did that because they were not properly bedded in.

gkull

At the shop we used to have Motul and now we have cases of BP I'm not sure why the change. I've looked them up on the charts of wet and dry boiling point and I don't think that wet comes into the picture when You pump half of it through all the time in a dry climate.

pauldana

WOW George... you are bad a$$!!!:coo l:

gkull

No, we always do the bedding like the pad instructions say. The wilwood "h" pads were way beyond normal use. Look them up on the Wilwood site. I have them in a box on the shelf. I use the bp-20 now and don't really race my vette any more.

I've been converting my vette more back into streetable. It lost the joy. Purpose made real race cars are so much better. You really can't call an old street car a racer no matter how much you put into it compared to open wheel F2 and formula atlantic cars that can do near 3 "G" turns and braking.

Years ago I went to a track day and tried to spend every minute I could on the track on every session. Then it became a couple of laps for practise and pull in to the pits because you want to save your Hoosier R1's for the race. Then you go out and put in one hot lap during qualifying to get a good grid position for the race. Then you go out for the gusto and try to stay with or around some other cars and screw off. Only trying when you had to and flat tracking for fun when you didn't. So what if you were flat spoting your tires or burning up the brakes. You don't win a dime anyway. At the end of year they hand you a $100 dollar trophy for first place overall because you racked up enough points during the series. It only cost you $15,000 to get it.

Then the next level. My boss drives a million dollar car and it costs him $250,000 to race it for a year when he only races it on a few times a year and he has a collection of medals and trophys. Oh and you are in the record book!

If I want to drive a car and drive it well I can. I've been bless with enough money and a job around real race cars

here is a question for you? Do you think that my crank shaft in my first 427 small block broke because I was being nice and wanted it to last a life time? Why should I care about $400 dollar rotors lasting about two hours of track time when the tires cost $1200 and they were gone and the entry fee was $425 for two days?

elle88

Gkull
you can't imagine how much i agree with you!
last monday has been my first day at a racetrack and i was so disappointed by the big $$$ involved and how so much better (and unbeatable) are the true race cars. I can't afford it! I'm planning to go to the racetrack sometimes ( and that's why i want to fix the brakes without spending a bunch) but i'll go easy on everything (motor, suspensions, brakes ) to avoid sure failures and accidents. the racetrack would be the chance to do more safely what i can't do on public roads.

gkull

Get some good brakes and go do it. I know people that their life goal is to hit as many tracks as they can. You have lot's to choose from in Italy.

Autodromo del Levante, Binetto
Autodromo del Sele, Battipaglia
Autodromo dell'Umbria, Magione
Autodromo di Anagni, Anagni
Autodromo di Franciacorta, Castrezzato
Autodromo di Mores, Mores (SS)
Autodromo di Pergusa, Enna
Autodromo di Siracusa Siracusa
Autodromo Enzo e Dino Ferrari, Imola
Autodromo Nazionale Monza, Monza
Autodromo Piero Taruffi (ACI Vallelunga Circuit), Campagnano di Roma
Autodromo Riccardo Paletti, Varano
Circuito di Adria, Adria
Circuito di Cellole, Cellole
Circuito di Collemaggio, L'Aquila
Circuito di Lombardore, Lombardore
Circuito di Torretta, Torretta
Misano World Circuit, Misano, Emilia-Romagna
Mugello Circuit, Tuscany

elle88

yes Gkull,

but the most cool miss on that list .

look at this

the 400kmh ring:
http://www.ctbkgroup.com/pagine/circuiti/NARD%C3%B2.HTM

and inside the ring , the 4 miles handling circuit:

http://www.corrieredellosport.it/ima...magine_det.jpg

this place is 50 miles from me. even if placed very south in Italy, check the map, all european car companies come here to test their supercars.
the ring is so huge that you can see it from the space:

http://upload.wikimedia.org/wikipedi...C3%B2_ring.jpg

planning to go there...