dgreenb1

Just back from weekend of instructing and driving at Sebring for PBOC. First time with a '99 Boxster. My mechanic installed the new Pagid orange pads that I gave him but did not have time to flush the stock fluid and replace with ATE Blue. After seven or eight laps flogging the 986 like my Spec Miata, my brakes went away completely. Had a thorough pressure bleeding done to no avail. Couldn't get my hands on enough ATE Blue to do a full flush. Spoke with several people at the track and got two classes of opinion:

1 Full flush with ATE Blue would cure the problem.
2 Need to fabricate air ducts or buy them and remove the backing plates in addition to the ATE Blue in order to to cool the brakes.

Can I get some suggestions? If I need ducting, does anyone make a kit and what should it cost? If not what would be involved in fabricating ducts and what should that cost? Before losing the pedal, the car's braking capabilities were adequate for the speeds I was driving.

TIA
David Greenberg
Fort Myers, Florida

Glen

Buy the Cup brake ducts. They will snap right onto Your control arm. Also use Pagid Blacks, not Orangewill help also.

JW in Texas

David,
If you enjoy bleeding, ATE is fine. Just bleed the night before every event. I had the same issue as you on my 964 DE car 5 years ago. Had the pedal go to the floor! I have run Castrol SRF since then & wouldn't ever go back to ATE. Porsche specs SRF in our cup cars. You should be able to do a flush/bleed once a year with it. Also, get the ducts Glen mentioned. They are a cheap, easy fix to getting air to your brakes. Do those two things & I bet you won't have any further issues. Good Luck!

38D

Agree on the SRF recommendation. I would have to bleed my turbo brakes at the end of each day with SuperBlue. Since I have switched to SRF, I haven't had to bleed yet (9 track days).

bobt993

Unfortunately, I was down that road in 2000, with yes, a 99 Boxster. My prior ride was a 944 Turbo. Yes, blue, yes better pads, yes to cooling, but the real bummer is the 99 Boxster does not have enough brakes for heavy track use. I warped rotors, cooked pads, fluid etc and then moved to a Boxster S with the better brakes and all around better car. (This was a transitional car so my wife could do DE events.) My 993 stock brakes combined with hawk pads and S cooling ducts while not as big as the Boxster S brakes, exihibit no fade and good stopping power. If you really are going to stay with the car for the track, either lighten it, or look at a brake upgrade $$$$. PS, if you are running R tires, you most definitely need to make some changes.

ceboyd

interesting observations on the super blue... I must not be as hard on my brakes as I thought because I've never boiled my ATE super blue on my 993 and I only bleed or flush every 3 or 4 track days (not after every one).. and have never seen it black while bleeding...

karlooz

i had the same experience with ATE blue, foot to the floor and me yelling oh ****.

SRF is supposed to be the best. if you have the bucks then go for it. i live in a dry area so the wet boiling point isn't so much of a concern. i have been using motul RBF600 with great success. it has the same dry boiling point as castrol SRF. i have just flushed with prospeed GS610 which supposedly has the highest dry boiling point, 610 degrees . got it from CDOC. we'll see how they fare at the next track day.

one thing about the cup brake ducts. when installed with oem 996 rotors, the ducts actually funnel the air below the rotors not on it. the oem rotors are smaller in diameter than gt3/cup rotors hence the mismatch. i'm not saying they won't work but they are just not optimal for a standard boxster with an even smaller rotor diamer than a 996.

good idea to remove the dust shields.

any good race shop/retailer (eg.smartracingproducts.com) should have the materials/ducting for you to fabricate your own ducting.

i use pagid yellows-ft and black-rear for better rear brake bias and upon recommendation from gt3 forum owners. since you have a boxster YMMV.

if you are going to use the boxster for heavy track use then upgrade to boxster S/stoptech/brembo gt/etc... i.e., bigger brakes.

Chaos

I would suggest hawk blues and Motul 600 brake fluid ,not as good as castrol but much cheaper. ATE will not hold up !

Rob in VA

The stock 986S brakes are fine. I'm running pagid orange pads with NO issues what-so-ever.

kurt M

The least expensive and best overall long return on investment is added cooling. True added cooling, not just some hose and clamps stuffed under the front bumper but much more air flow over the heated parts of the brake system. Install and test to see that what you have added actually works. I have seen some home made and pro sold after market kits that don't work worth a darn. Methods to increase the heat resistive capacity are not bad in their own right but will only mask the reason for the problem and push the problems elswhere. Going to a higher temp fluid might/would help there but the rotors, pads and piston seals will still be subjected to higher temps and fail sooner than if run at lower temps. It is OK to dump in the heat, you just have to be sure the system can dump it back out ASAP. Personally I would both add cooling and increase the system max operating temp.

From what I have seen with some boil point testing, one flush to a better fluid is not enough. You need to flush, drive the car and flush again to dilute/mix and remove as much of the older fluid as you can. Each flush removes a large percentage but not 100% of the older fluid. Going from ATE to SRF is an example. Two or three flushes to have the system fully benefit from the higher dry boil point.

TD in DC

I largely agree. I use SRF in my 996 and swear by it.

I also have the GT3 RS brake ducts but had to modify them due to the rotor issue.

Removing dust shields is also a good idea since they tend to warp and squeel anyway.

I use PF97s, which I think are very good for modulation.

Make sure your rotors and pads are not too thin, which can make the overheating worse.

You should be able to pick up a stock Boxster S brake system very cheaply. Hell, now that I think about it, entire Boxster Ss have depreciated so much it might be bettter in the long run just to get an entire Boxster S (only partially kidding).

dgreenb1

Thank you all for responding. It's great to have access to this kind of knowledge and input. I would love to buy a Boxster S which sounds like it would solve all problems. Since I get most of my track Jollies racing Spec Miata and will only track the Boxster 3 or 4 times a year and since I have two college students costing $60K next year after each has been awarded $10K scholarships, I think I have to start with more modest solutions. So I will go with the SRF and remove the backing plates and possibly add some ducting and see how that does. Can anyone tell me if S brakes would be a direct bolt on or would serious modification be necessary?
Thanks again.
DG

karlooz

i think you will have to use boxster S wheel carriers along with boxsterS/996 calipers and rotors. it may turn out to be pretty pricey.

Ed Newman

Three things...

1. SRF
2. Cup brake ducts (better if you can modify them a bit to get more air to the disc
3. Upgrade to 986S/996 brakes. I am not sure if this requires new uprights. I have a full take off set of discs, clipers and front uprights from my 996 I would give you a blowout deal on. I upgraded to full Cup car brakes. PM me