High performance brake issues...

[Quick_lude]

Here's my scenario and also a few of my friends. As some of you know I have a 2000 Prelude. Me and a few other club members attend lapping and auto-x days. I have Brembo "blank" rotors and AEM aftermarket pads which are a little more agressive than stock but not a true harsh track pad. In the past two years I've never had brake problems while lapping BUT most of those dates were on short, twisty tracks without many highspeed scrubbing straights.

Well 7 weeks ago we attended an event at the Shannonville raceway, full track. I hit about 190km/hr on the back straight with a stop to 100km/hr.. As the day progressed the pedal got softer and softer.. The car still stopped, pedal was firm but the travel got longer to the point where I could not heel and toe properly and lost my confidence in the brakes. Ever since I haven't regained the pedal travel firmness. I took out the pads, they were glazed and I sanded them down. Flushed the fluid. Took apart the caliper, cleaned and greased the sliding pins. Refilled the fluid. Pedal travel/firmness improved but not to the original point.

Last week went lapping again. Smaller track, never above 140km/hr. Again the brakes got progressively worse and I was done on the third session. Again, the feel/travel improved the next day but not back to where it should be.

So what are my options? Personally I don't think it's the fluid, otherwise the brakes would be bad always and not get better the next day. So I'm leaning towards the pads and maybe even the rotors. Someone theorized that the rotor itself should be perhaps sanded down lightly with an orbital sander and 200 grit paper to get rid of the grooves that might be producing "pad float" And of course sand down the pads again. Some people suggested problems with the master brake cylinder. I'm using Ford Dot3 550F high temp fluid.

Oh, and I'm not the only one experiencing those symptoms.. a few other fellow Luders have the same issues. They were also NOT using race pads so this is why I think the issue lies ie rotors/pads.

Any input/insight will be greatly appreciated.

[ July 17, 2003, 06:34 PM: Message edited by: Quick_lude ]

 

[RussellA]

quote:

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I don't think it's the fluid, otherwise the brakes would be bad always and not get better the next day

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Well unless there is moisture/water in the fluid that is turning to steam when very hot.

Had a friend that raced bikes. They alway uses steel braided brake lines to the calipers. The idea is they don't "balloon" under pressure thus making the brakes firmer.

Your glazing does sound like pads though. Had this problem driving my 240Sx very hard in the hills of southern California in the very early 90's. Some specialty shop sold me some sort of German aftermarket pads that did not glaze. They really did the trick. But in about 20K miles my stock rotors were shot, pads were still fine. I guess they were some sort of near full race compound.

 

[digitaldrifter91]

i dont like glaze on pads. makes driving irritable. since ur sanding down the pads, u might as well sand down the rotor.

i was going to suggust ur master cylinder, i had a problem with it before, but really that means it would go to the floor but it is something to concider.

im surprised u dont just go with a big brake upgrade. bringing a car down from 140 to 100 is very hard on the brakes and really heats them up.

isnt EBC brakes operating at a higher temp than AEM brakes? ceramic pads are really pads that can withstan heat and brake continuously i think up past 600 degrees, but a little hard on standard rotors. probably u didnt have a problem cause as u said before, the other tracks were short. time to upgrade pads. i cant find the temps that AEM runs at. and i believe they are kevlar composite material.
ebc
http://ebcbrakes.com/?src=overture
aem
http://www.aempower.com/product_pad.asp


heat and the gas (air) between the pads and the rotor is where it becomes unstable, or hard to deal with. most auto cross or people who are hard on brakes run cross drilled, or slotted rotors to reduce that air between the pads, reduce glaze and improve performance a little. in the future after i run through these rotors of mine, i am upgrading to slotted rotors.

i would at least be running some slotted rotors and quite possibly get as much cooling to that rotor as possible.

i have had my share of brake problems. iono if i helped or not, just sharing my experiance and opinions.

 

[ALS]

You could go to a semi metalic pad. You have to remember most brake pads that are available are designed as a happy medium. Low noise, long life, and decient hot stopping. BUT they were never intended for severe track duty. Check out Jegs or Summit Racing they should have what you need and could possibly solve your problem over the phone. Both have pretty good prices.

 

[sbc350gearhead]

I use cross-drilled and slotted rotors with titanium ti pads on my truck and camaro and they work very well. I have virtually no brake fade. I would have to say that the truck is harder on the brakes than the camaro, due to the 4200 LB curb weight.

 

[VaderSS]

I'd stay away from cross drilled rotors on a hard driven street car. They reduce mass, do not add enough cooling to compensate, and put a bunch of stress risers for cracks to start from. The original reason for the holes was to relieve "outgassing" of the pad. Outgassing is no longer an issue with todays compounds.

It really sounds like you are regularly braking harder than your current system is designed for. You probably need to put a new, non-directional finish on your rotors. At the least, I would go to a true track pad, at least for those events where you are having issues, and run some ram air ducting to the brakes. If that doesn't do it I'd go up a size on the rotors. Keep in mind, the more the pad wears, the quicker it will fade and boil the fluid.

 

[JohnBrowning]

First things first get rid of of slideing style calipers!!!! You need to get some non-slideing calipers with at least two pistons per side. If you can not afford brembo's see if you can not find some Honda made calipers from another model or a Toyota. I am sure someone has a retrofitt kit. You should also consider bigger rotor for the front! You can also duct cold air to your rotors. Worst case you can use water spray to cool them down. Try to use engine brakeing as much as you can. Have you check the master cylinder? How about Vacum leak or two little vaccum?

 

[digitaldrifter91]

yea drilled rotors suck really in my opinion. i heard too many cases where they crack, thats why i want to go with slotted. porshe has a great system in which a duct goes to the rotor to cool it down.

but as john said as well, caliper upgrade is needed. honda brakes arent really for racing. 4 piston calipers make my mouth water..i think porshes new one has a 8 piston caliper OMG.

bigger rotor, bigger caliper, better braking.

steel brake lines i like as well.

now that u mention it i still have OEM stock rotors on my 86 300zx. i want to upgrade those.

 

[outrun]

Following the string:

My .02$ worth

A)Sounds like what you are feeling is textbook brake fade?

B)Ceramics are excellent all purpose compounds in general.

C) In your case I would look into running Hawk HP+ street/race pads on track day. There ferro carbon pads are of the same type used on Boeing Aircraft by the way. The only other pads of the caliber would be EBC Red, and Metal Masters.

I have no experiance with the Titanium Ti pads mentioned above...although they sound really neat.

D) Yes, drilling can induce cracking. However if you are quite serious in this oval track racing. Look into stopyoucold . com .

This company offers cryogenic metal treatment....cryo treated anything offers incredible results. Chiefly, dimensional stablity and much much longer life. 300% longer living Rotors is not unheard of.

even your calipers, pistons, engine block, differential gears can be cryo dipped as well...sorry off topic but a good future topic all by itself

 

[Quick_lude]

Thanks guys. Yeah I know about the caliper upgrades and the cryogenic process but since I'm getting rid of the car next spring, those are not in the plans. Like some of you said I think the problem is with the pads and maybe some grooves in the rotor. Time for an upgrade and a little sanding down. Another luder was using Hawks HP+ and had no issues at all.. and his car is turbocharged with almost 300 WHp!

 

[vvk]

Most likely the pads. Once you overheat them, they never recoved. Material gets overbaked and that's that. Get some race pads and install them before a race weekend.

 

[widman]

You said you didn't get back the pedal feel. that can often mean brake lines. They get soft. I had big problems with my Grand Cherokee and replaced everything that moved. Finally checked the lines and the insides were soft (outside looked fine) new hoses fixed it all.

 

[rimmer1]

I've got the same AEM ceramic pads on my Prelude and they're great for the street but would never take them up the level you're using them at. I suspect its the temperature the pads have reached on the track that renders them useless.

Cross-drilled and slotted rotors are just $$ in the pocket of vendors. Air ducts have merit.

Take a look at the technical stuff at Stoptech. I especially like the article written by racing guru Carroll Smith.

http://www.stoptech.com/whitepapers/brake_systems_and_upgrade_selections_122701.htm
http://www.stoptech.com/whitepapers/warped_rotors_myth.htm

Good luck and try to stay off the walls,
Rimmer

 

[shortyb]

One other item, besides what has been mentioned. Alot of Japanese imports, Honda in particular, seem to have master cylinder seals and "pusher cups" that can deform slightly under high heat conditions. Boiled fluid is the biggest cause for this. Several racing suppliers can offer these pieces in materials that stand up to the heat a bit better than OEM.

i'm gonna second the pad/SS lines swap. fresh fluid and you should be good to go. Or stop, such is the case.

While you're reading the StopTech White Papers, pay attention to what to use when "sanding" the rotors. They don't like the use of regular sandpaper, rather you use emory cloth.

 

[Neonmike22]

I'm also going to vote for HP+ for your next event.

A friend of mine has a 2000 prelude, and he built some brake ducts out of dryer hose which greatly helped his car with brake fade.

 

[sbc350gearhead]

Baer Brakes are virtually without peer in the world of high performance braking systems, and almost all of their systems use crossdrilled and slotted rotors. I too have heard of the cracking issue, I have just never witnessed it. A friend of mine races autocross and such in his camaro and his Baer rotors have 30000 HARD miles on them, and no cracking. Perhaps the cracking issue is more prevalent with the cheaper rotors out there.

 

[rimmer1]

Actually Carroll Smith says to use garnet paper (a very smooth, non-metal imbedded sandpaper) not emery cloth to clean the rotors in the Stoptech article.

Rimmer