Brake Cooling - Advice?

[jrtoffroad]

Hey Guys,

Took my ZR-1 to my first DE event this weekend at Tallagega Grand Prix (miniTalladega). Had an absolute BLAST! The car did amazing with the exception of one thing...the brakes.

The stopping power was fine, but after ~6 hot laps the pedal would start to get very soft. I was obviously boiling the fluid. Admittedly, this is a tough course on brakes (with very little time for cooling), but I don't like having to take a few cool down laps and let the porsche's I just passed back by me

I'm running GS calipers up front with powerslot rotors and unknown pads (whatever the car came with) all around. Prior to the event I changed the the brake fluid out to some new valvoline syn. (~480 dry & 313 wet boiling points I believe).

The solution I'm planning is to step up to some better brake fluid and add cooling to the front brakes.

-For fluid I'm looking at the Wilwood 600 http://www.summitracing.com/parts/WIL-290-6209/ having a 626 dry & 417 wet boiling points. I'd love to run Castrol SRF with its 518 deg wet boiling point, but it's just too expensive for me.... With the wilwood fluid I can afford to regularly bleed it.
-For cooling I'm thinking about combining the midamerica spoiler: http://www.mamotorworks.com/corvette...-371-3979.html with the quantum motorsports brake cooling duct plates: http://store.quantummotorsports.com/...products_id=69

Finally, I'm thinking about stepping up to some Carbotech brake pads while I'm at it. (XP10 pads up front and XP8 pads in the rear)

Thoughts? Any one had similiar issues and solved it without stepping up to some ubber expensive rotors and calipers?

Thanks!
Jordan

[mike100]

Somebody tracked my car before and the passenger side caliper boots were melted from pad sparks catching them on fire.

I found it cheaper to buy C5 replacement parts rather than the J55 stuff (previous owner had collected a bunch of the needed parts to convert it) so I went that route. Don't know if it would hold up under track use, but the pad, caliper and rotor thickness/thermal mass is much greater than stock.

[DaveK]

The quality on that spoiler isn't great - I have one but haven't put it on yet. The spoiler itself is a bit cheap and the mounting for the tube isn't what I would call professional - just zip ties. Also I suspect the quality of the duct tube too - it looks very cheap.

Combined with the Quantum parts it would probably work okay - just not on it's own. I was thinking of getting a standard air-dam and cutting the holes in myself using the quantum ducts -

http://store.quantummotorsports.com/...products_id=67

[lbszr]

Originally Posted by jrtoffroad

Hey Guys,

Took my ZR-1 to my first DE event this weekend at Tallagega Grand Prix (miniTalladega). Had an absolute BLAST! The car did amazing with the exception of one thing...the brakes.

The stopping power was fine, but after ~6 hot laps the pedal would start to get very soft. I was obviously boiling the fluid. Admittedly, this is a tough course on brakes (with very little time for cooling), but I don't like having to take a few cool down laps and let the porsche's I just passed back by me

I'm running GS calipers up front with powerslot rotors and unknown pads (whatever the car came with) all around. Prior to the event I changed the the brake fluid out to some new valvoline syn. (~480 dry & 313 wet boiling points I believe).

The solution I'm planning is to step up to some better brake fluid and add cooling to the front brakes.

-For fluid I'm looking at the Wilwood 600 http://www.summitracing.com/parts/WIL-290-6209/ having a 626 dry & 417 wet boiling points. I'd love to run Castrol SRF with its 518 deg wet boiling point, but it's just too expensive for me.... With the wilwood fluid I can afford to regularly bleed it.
-For cooling I'm thinking about combining the midamerica spoiler: http://www.mamotorworks.com/corvette...-371-3979.html with the quantum motorsports brake cooling duct plates: http://store.quantummotorsports.com/...products_id=69

Finally, I'm thinking about stepping up to some Carbotech brake pads while I'm at it. (XP10 pads up front and XP8 pads in the rear)

Thoughts? Any one had similiar issues and solved it without stepping up to some ubber expensive rotors and calipers?

Thanks!
Jordan

Your having too much fun, have to catch up with you at a track, would be good to have more than one ZR out there!! Hopefully after June 20th I'll be able to get back to the track.

Did the brakes have good braking powing on the first lap? If they did, they probably weren't track pads. I used Hawk hp plus when I started, they could hold the temps pretty well but faded when braking hard from 130mph, if I braked too late, but they were back by the next turn, didn't have to slow down. They transfer too much material to the rotors when overheated though and cause vibration and melt the caliper boots. Some leave the boots off. When they overheat, they wear really quickly too, I was going through a set in one track day.

I went to Hawk HT-10 (would not recommend for the street though) and cured all those problems and the rotors life is a lot longer. Haven't tried Carbotechs, there probably better, cost more too. At the same time I did the mid america spoiler and made brake ducts that fit the back of the roter to push the air out of the rotor vents. I still contribute the good brakes mostly to the Ht10's. The 7$ bias spring from DRM helps quite a bit going into turns when your using trailbraking. DRM also recommneded to use the same brake compound on front and back, even though a lot mix them up.

The mid spoiler is 2.5 inch duct, I didn't look, but the quant bracket might be 3 inch. They do sell the plastic duct to rivet to your own spoiler if you want 3 inch. The 3 would be hard to route around the suspension. But that seems to be the standard.

I use ATE super blue or amber, flushed it before and after every track event. Wilwood is good too. Some run the SRF all season, but I feel better flushing it. I've never boiled the brakes. As a passenger, a c4 boiled his brakes and they went straight to the floor, pumping didn't help. It even came out of the resovoir cap and went everywhere.

Here's a pic of a good place to check for cracks before your events also. I learned the hard way, but at least the wheel stayed on.

[gbrtng]

lbszr: Is that an AC Delco wheel bearing or some aftermarket bearing. That looks pretty close to fatal to me.

And I agree on the ATE brake fluid - I've used it for years.

[lbszr]

Originally Posted by gbrtng

lbszr: Is that an AC Delco wheel bearing or some aftermarket bearing. That looks pretty close to fatal to me.

And I agree on the ATE brake fluid - I've used it for years.

The bell shaped center section kept the flange from departing and the brake caliper bracket helped, which was damaged and needed replaced. It snapped in the middle of a turn, it really didn't loose traction at all when it happened, just a bang sound, but I slowed to about 40 and cam in.

It's National Federal Mogul, but depending who sells them, they are not all the same. It lasted longer than most I've had, over 10 events and the bearing was still tight when it snapped. I've heard of c5s doing the same thing.

The National on the other side is still going strong and is tight, but feels like it's out of grease. Autozone Timken, and Pepboys SKF was 1 day and the bearing was sloppy, and mid america no brand bearing after one day had enough play to grind the antiskid sensor down to a nub. The newer style SKF, from a post I've seen, with the sensor attached seem durable, but haven't tried those yet.

The National was replaced with AC Delco and after about 4 events, it's still tight. (newer style with the sensor)

[jrtoffroad]

Originally Posted by DaveK

The quality on that spoiler isn't great - I have one but haven't put it on yet. The spoiler itself is a bit cheap and the mounting for the tube isn't what I would call professional - just zip ties. Also I suspect the quality of the duct tube too - it looks very cheap.

Combined with the Quantum parts it would probably work okay - just not on it's own. I was thinking of getting a standard air-dam and cutting the holes in myself using the quantum ducts -

http://store.quantummotorsports.com/...products_id=67

hmm, those seem a little pricey, but I could always just pick up some NACA ducts and run 3" hose...

I have heard the tubing that is included in the MAM kit is not the best.

[jrtoffroad]

lbszr,

Thanks for your input as always. If you ever head south for an event let me know and maybe I can drive up and meet you.

Yes, the brakes felt good on the 1st lap. I'm sure they're just some over the counter pads from the local parts store.

That's good to hear about the hawk pads, I'll have to check those out before ordering the carbotechs. Does the dust from those come off okay, or is it corrosive?

When I purchased my car I was told the DRM spring had already been installed, so should be good there.

BTW, what rotors are you running? I noticed mine have developed some grooves. Not sure if I can get away with having them turned, or if I'll need a new set. It'd be cool to get some fancy rotors with aluminum hats, but I don't want a drilled rotor for fear of cracking, and don't want to pay the price . Wondering if my best bet would just be a new set of Napa premiums.

Cooling ducts look good. That's scary about the hubs, had no idea they only lasted a few events, I'll start checking mine! Are you running r-comps or street tires?

-Jordan

[lbszr]

Originally Posted by jrtoffroad

lbszr,

Thanks for your input as always. If you ever head south for an event let me know and maybe I can drive up and meet you.

Yes, the brakes felt good on the 1st lap. I'm sure they're just some over the counter pads from the local parts store.

That's good to hear about the hawk pads, I'll have to check those out before ordering the carbotechs. Does the dust from those come off okay, or is it corrosive?

When I purchased my car I was told the DRM spring had already been installed, so should be good there.

BTW, what rotors are you running? I noticed mine have developed some grooves. Not sure if I can get away with having them turned, or if I'll need a new set. It'd be cool to get some fancy rotors with aluminum hats, but I don't want a drilled rotor for fear of cracking, and don't want to pay the price . Wondering if my best bet would just be a new set of Napa premiums.

Cooling ducts look good. That's scary about the hubs, had no idea they only lasted a few events, I'll start checking mine! Are you running r-comps or street tires?

-Jordan

Carbotechs are the only pads I've seen that say they are non-corrosive. I asked a Hawk rep at the track if theirs were, and he didn't seem to really know, or didn't want to say. The hp pluses dusted really bad, black streaks down the side of the car, not to mention the wheels turned black. I've never seen any evidence of corrision and I was looking close. I always washed it off soon with no trouble.

The HT-10 pad doesn't really dust at all. I use stock style rotors with no holes. Napa rotors were recommended to me from a local shop that sets cars up for this. As you mentioned, they crack from the holes. The hp plus pad were killing the rotors, not from grooves though, vibration. They never lasted long enough to crack. With the ht 10 it looks like they are going to last long enough to crack, starting to show heat stress cracks now. I put street pads and discs back on when the events are over. The ht-10 don't brake good until they're up to temp, so they are not street friendly.

I can't really say on turning the rotors, could make a good track set, or backup set. I turned one set and they lasted one day before vibrating, but that was on the hp plus pads, so it wasn't a very good test.

R-comps nt-01

If you want to fabricate ducting, here's another place.
http://porterfield-brakes.com/manufa...aca+Ducts.html

[jrtoffroad]

Quick update:

I went ahead and swapped over to some willwood 600 brake fluid, carbotech 10's front & 8's rear, and a new set of blank centric rotors.

I ran this way for a couple months and a few autocross events. The carbotech pads offer AMAZING braking, BUT require a great deal of heat and produce a large amount of dust. Getting a little sick of cleaning my wheels every couple days and not getting the full benefit of them in my autoX events, I have now swapped to Hawk HPS pads (and shelved the carbotechs for my next real track day).

I find the HPS pads still like a little heat for max baking. They do NOT stop as well as the carbotechs, but are a much better compromise, and do better at lower temps.

Still looking to build/buy some ducts eventually.