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 :p

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-c4-spoiler+1984+1996-front-with-brake-cooling-ducts-1-371-3979.html with the quantum motorsports brake cooling duct plates: http://store.quantummotorsports.com/index.php?main_page=product_info&cPath=12_26_28_37&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/index.php?main_page=product_info&cPath=12_26_28_36&products_id=67

[lbszr]

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 :p

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-c4-spoiler+1984+1996-front-with-brake-cooling-ducts-1-371-3979.html with the quantum motorsports brake cooling duct plates: http://store.quantummotorsports.com/index.php?main_page=product_info&cPath=12_26_28_37&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.

http://i188.photobucket.com/albums/z41/myphotos123456/PIC_0008.jpg
http://i188.photobucket.com/albums/z41/myphotos123456/PIC_0014_1.jpg
http://i188.photobucket.com/albums/z41/myphotos123456/PIC_0013_1.jpg

[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]

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]

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/index.php?main_page=product_info&cPath=12_26_28_36&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]

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/manufacturers/shop/Brake+Naca+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.

[lbszr]

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.

I have never tried the Carbo's, I don't know where from, but I always thought they were suppose to be low dust, oh well.

I have to change a previous post from me, the Hawk HT-10 are dusters too. I bedded in a set the other week with about 10 hard brakes and probably 15 miles, the wheels are pretty black.

[Daniel_Mc]

FWIW with the J55?s I ran Performance Friction SA01?s with great results (not a pad for the street). The pads respond well when heated and you still have very good petal control. I ran the VB&P rotors with DRM bias spring and the only issue I had to fight was the heat in the caliper. I had changed to the DRM SS pistons and it helped along with ZR1 MK?s duct plates and the Wilwood fluid. I still had issues boiling the fluid and was considering this coating from Swain http://www.swaintech.com/store.asp?pid=10968 Finally I got tired of screwing with it and just bit the bullet and did the Wilwood GN III?s and haven?t had to deal with the issue since. I use the ducting from HRP World, 2 for each side. http://www.hrpworld.com/index.cfm?tpc=Brake-System-Temperature-Control&form_cat_id=167&action=category
One duct for the caliper itself and the other for the rotor. You can get what you need here and do the ducting yourself the Mid America kit is garbage.

Hope this helps,

Daniel

[jcruz]

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/index.php?main_page=product_info&cPath=12_26_28_36&products_id=67

I can confirm the above -- I recently took that Mid-America spoiler and zip tied tubes off my Z. It was quite cheesie.

[lbszr]

FWIW with the J55?s I ran Performance Friction SA01?s with great results (not a pad for the street). The pads respond well when heated and you still have very good petal control. I ran the VB&P rotors with DRM bias spring and the only issue I had to fight was the heat in the caliper. I had changed to the DRM SS pistons and it helped along with ZR1 MK?s duct plates and the Wilwood fluid. I still had issues boiling the fluid and was considering this coating from Swain http://www.swaintech.com/store.asp?pid=10968 Finally I got tired of screwing with it and just bit the bullet and did the Wilwood GN III?s and haven?t had to deal with the issue since. I use the ducting from HRP World, 2 for each side. http://www.hrpworld.com/index.cfm?tpc=Brake-System-Temperature-Control&form_cat_id=167&action=category
One duct for the caliper itself and the other for the rotor. You can get what you need here and do the ducting yourself the Mid America kit is garbage.

Hope this helps,

Daniel

Would you be willing to sell the DRM stainless pistons if you still have them? They don't make them anymore.

Did you ever try the stainless shims between the pistons and pad? Just curious if it would be worth it.

If you haven't seen it, I thought this clip from DRM was interesting. http://www.youtube.com/watch?v=3vetZamStsE

You must race? I have only run HPDE and back off with hard braking if I'm not running in a group, which is probably why I haven't boiled yet, and braking from 130ish is the fastest tracks I've been on. I've used temperature labels and the front calipers have been over 220, but not 320 yet(although the 320 label has been on there a while with the elements, might not be working anymore), I guess the pistons next to the fluid could actually be hotter though.

[Daniel_Mc]

Lbszr,
I gave the calipers away to a fellow GSR member for his car. I wasn?t aware that they were no longer available; who did you check with at DRM? I had heard about the shims but never have done that I do want to have some made for the wilwoods so as the pads wear I can press the pistons back into the boar.
I run HPDE?s hard I have not been W2W yet but several friends and I are building a lemons racer for this fall so it should be a blast. Texas World Speedway and Road Atlanta were the the hardest on the J55?s. At TWS the car was coming down hard from 150 plus for turn one running CCW (not really sure how fast I was going but was clocked at 141 in turn one running CCW). I have a buddy that runs with me and we use his temp gun and I have never see super high temps on the brakes. I will flush the fluid after each track day before the next days runs. Have you changed the bias spring? This will help some and also I wouldn?t try to compromise on the pads have you a street (no dust) pad and a track pad.

Look at the way this Z is set up it is extreamly well thought out and done properly:
http://www.cardomain.com/ride/418999/1990-chevrolet-corvette/page-3
Also see his notes starting on page 8.

Daniel

[ZZZZZR1]

They do sell the upgraded DRM pistons for the C5 / C6 brakes....

That is a VERY cheap and big improvement over J55's.

Many track guys have upgraded. I know of a friend that did the upgrade about 7 months ago, and nothing but permagrins!

Figure the brake upgrade would cost (including the best pads and powdercaoting the calipers about $800 MAX).

:cheers:

David

[lbszr]

Lbszr,
I gave the calipers away to a fellow GSR member for his car. I wasn?t aware that they were no longer available; who did you check with at DRM? I had heard about the shims but never have done that I do want to have some made for the wilwoods so as the pads wear I can press the pistons back into the boar.
I run HPDE?s hard I have not been W2W yet but several friends and I are building a lemons racer for this fall so it should be a blast. Texas World Speedway and Road Atlanta were the the hardest on the J55?s. At TWS the car was coming down hard from 150 plus for turn one running CCW (not really sure how fast I was going but was clocked at 141 in turn one running CCW). I have a buddy that runs with me and we use his temp gun and I have never see super high temps on the brakes. I will flush the fluid after each track day before the next days runs. Have you changed the bias spring? This will help some and also I wouldn?t try to compromise on the pads have you a street (no dust) pad and a track pad.

Look at the way this Z is set up it is extreamly well thought out and done properly:
http://www.cardomain.com/ride/418999/1990-chevrolet-corvette/page-3
Also see his notes starting on page 8.

Daniel

It was Randy from DRM, but I think he posted it on the forum when somebody asked about the c4, maybe he has some laying around if I called.

The lemons racing would be a lot of fun, I was checking out the websites for it not long ago.

I probably would have heat issues on tracks like that. I might be able to make Mid Ohio in august, could be a problem there. The fluid gets flushed after each event, so if it's a two day event, I've gone two days. I've changed the bias spring also, it seemed to help a lot going into the turns with trailbraking to get the car settled sooner. I use probably, origianal rotors and pads (pba) on the street and another set of OEM rotors with Hawk Ht-10 on the track, and trailer it to the track.

Do you know if the 17 inch stock 5 spokes fit the Wilwoods, 6 piston, or is there another caliper? And did you upgrade rear brakes also? Or not, with no handling issues? Just one more question, does the stock master cylinder still work with Wilwood?

I have slobbered over zrMK cardomain for days. There's a lot of good info in his notes. I need to configure my cooling system like his, so no more short shifting would be required.

[mbabbitt]

It was Randy from DRM, but I think he posted it on the forum when somebody asked about the c4, maybe he has some laying around if I called.

The lemons racing would be a lot of fun, I was checking out the websites for it not long ago.

I probably would have heat issues on tracks like that. I might be able to make Mid Ohio in august, could be a problem there. The fluid gets flushed after each event, so if it's a two day event, I've gone two days. I've changed the bias spring also, it seemed to help a lot going into the turns with trailbraking to get the car settled sooner. I use probably, origianal rotors and pads (pba) on the street and another set of OEM rotors with Hawk Ht-10 on the track, and trailer it to the track.

Do you know if the 17 inch stock 5 spokes fit the Wilwoods, 6 piston, or is there another caliper? And did you upgrade rear brakes also? Or not, with no handling issues? Just one more question, does the stock master cylinder still work with Wilwood?

I have slobbered over zrMK cardomain for days. There's a lot of good info in his notes. I need to configure my cooling system like his, so no more short shifting would be required.

Hi lbszr,

I have a set of those spindle ducts that I'll sell you. I tracked my ZR-1 for 6 years with over 20K+ track miles.

I installed the Willwood GNIII calipers at the 5 year point. That was the BEST thing I could have ever done tracking my car. I should have done it the first year. I went through CarboTech pads like butter. They stop you well but have NO longevity. PFC01's are what I used and they lasted a LOT longer that CarboTech's. I also used Castrol SRF fluid. Get the best.

I also installed a Dodge 3/4 ton master cylinder with at 1 1/8" bore that made a world of difference in braking. I NEVER had ANY braking problems with that setup.

PM me for any questions. I'll give you a good deal on the spindle ducts.

Mark

[lbszr]

Hi lbszr,

I have a set of those spindle ducts that I'll sell you. I tracked my ZR-1 for 6 years with over 20K+ track miles.

I installed the Willwood GNIII calipers at the 5 year point. That was the BEST thing I could have ever done tracking my car. I should have done it the first year. I went through CarboTech pads like butter. They stop you well but have NO longevity. PFC01's are what I used and they lasted a LOT longer that CarboTech's. I also used Castrol SRF fluid. Get the best.

I also installed a Dodge 3/4 ton master cylinder with at 1 1/8" bore that made a world of difference in braking. I NEVER had ANY braking problems with that setup.

PM me for any questions. I'll give you a good deal on the spindle ducts.

Mark

PM sent

[Daniel_Mc]

Lbszr,
Call Randy he may be out but if he finds anything he will call you. The stock A-Mold wheels will clear the Wilwoods but not the others. Neither will Gen I Dymags, Fikse wheels will clear however. I am running just the fronts (per Randy and Doug?s advice) They have told me that it was not that much difference since I was not running W2W with the car. I have a camaro MC but I have not installed it yet. It should give me a much better petal but as of now I have no issues and the car handles just fine. let me know if I can help you in any way with this.


Daniel

[lbszr]

Lbszr,
Call Randy he may be out but if he finds anything he will call you. The stock A-Mold wheels will clear the Wilwoods but not the others. Neither will Gen I Dymags, Fikse wheels will clear however. I am running just the fronts (per Randy and Doug?s advice) They have told me that it was not that much difference since I was not running W2W with the car. I have a camaro MC but I have not installed it yet. It should give me a much better petal but as of now I have no issues and the car handles just fine. let me know if I can help you in any way with this.


Daniel

Thanks for the info, that makes it a lot more affordable to just upgrade the front.