One other factor I forgot to mention that may have come into play was this is the first event that I had 18" wheels with R compounds on the car. I probably need to modify my breaking as well. I try to brake hard and short but have a habit of over slowing in many corners. Hopefully, that will improve with more seat time.

This thread was very informative for me and I learned much from all of you.

Plans before the next event:
-upgrade brake fluid
-new rotors
-new track pads

If these are still inadequate I will pipe my ducts. Might plan to do this anyway since it probably has no down side. Although, I did read some threads that mentioned cracked/shattered rotors with air ducting that was suspected due to too rapid cooling. Not sure how true that was but probably not a problem in the south

Can someone give me source for duct hose that will work?
Thanks!

 

I used Pagid Oranges and then switched to PFC-97 and have loved them. For the brake duct hoses you can try www.discoveryparts.com or any local plumbing store.

 

If you are over braking, you are probably (definitely?) also braking over too great of a distance. Work on compressing the brake zones so that the heat can dissapate before it soaks into the hubs, bearings, etc....Any discussion over pads or fluids you will get wildy different answers because technique has a lot to do with performance of specific equipment. Of course safety is most important, if the brakes are totally going away then better to solve it with equipment so you don't crash. If the pedal just gets a little spongy and the car still stops well (and you have to bleed the calipers more often) then maybe focus more on developing a technique so this doesn't happen.

The SRF is great, no doubt, but way too pricey. I've had more luck with Motul instead of Super Blue, and its a similar price...

I've also noticed (with how I brake) that pads that have more initial (aka cold) bite, tend to build up more heat in some situations. I have had more issues boiling fluid with Performance Friction 97 Pads, for example, which have excellent initial bite, and almost no issues running Pagid black, which need a little heat to work well. This is true on my 3050 lb 996 AND on my 2400 lb Integra race car.

All brake pads create stopping power in 2 ways -- adherent friction and abrasive friction. Each manufacturer and each model of pads does a different combination of these 2 things. Adherent friction is where the pad material transfers a thin layer of itself to the rotor surface, and continually breaks and reforms bonds with the pads. Abrasive friction is basically breaking down the bonds in the brake pad itself (and on the rotor surface). This is why some pads wear rotors more, and why other pads have great initial bite (and glaze more).

For my braking style, with the high initial bite pads (comparively more adhesive friction) I tend to boil the fluid much earlier. So I'm better off using pads that wear the rotors more. If you are trying to save your rotors AND boil the fluid less, you might be asking for too much.

Anyway, I don't want to get into a huge debate here (a little one is ok . With brake pads and fluid you need to experiment to find something that suits you, or refine your technique so that what you are using works.

As a final comment, I had a race weekend with my Acura this year where I forgot my spare pads and tried to run on HPS -- for some reason I thought I was good enough to make them work. They went away after 2-3 laps and were so bad that I wouldn't have raced on them.

I think the good news here is that your skills have surpassed your current brake pads, i.e. you're going faster!!!

 

Mark,

I'm a big fan of SRF, I have never boiled it (even when I don't bleed). Can't say I'm a fan of Pagid Oranges. I've used and like the Pagid Yellows, Hawk HT-10/14 and DTC70, and now the PF 97's. My next set will probably be the PF 01's.

George

 

There was a great thread a while back showing all of the properties of our favorite brake fluids. It showed that basically if you change infrequently, SRF really is the best. If you change a couple of times a year, then Motul 600 might actually be better. You see SRF is great even when "wet" while Motul (and all others) drop off the more water that finds its way into the system. I always used to change fluid 2-3 times a season with my M3, so that way Motul would be fine. But with the 997S, put in SRF early spring and can rest well knowing I don't have to touch it again until next spring (3 seasons DE here in CT).

As to the pads -- many current threads on these. I don't like the Oranges I have now and will go to PFC 97s as soon as I complete the disintegration process started on the Pagids. I hear good things about the Yellows, but I have a good friend that has used them for 3 years on 996 products (Turbo and then GT3) and he keeps going through rotors 1-2 times a year. Feels to me that as Farnbacher Loles advised me -- go with the 97s as they are the best "new" technology pad for the 997S. I'm sure they make them for your car too...

 

Are we talking about the Hawk HPS or the HP Plus pads. I have the HP Plus and the jury is still out. They are sold as DE / Autocross pads and entry race pads. I am not sure if the HP Plus are good street pads, they are very loud and I don't know how to keep they quiet. I even replaced my rotors since I had a large lip on my old rotors.

 

Another vote for SRF - the only fluid I have used on any race/track car for many years - awesome.

More expensive but no failures or boiling...

Norm

 

I've posted this chart before. Brake fluid specs:

http://members.rennlist.org/911pcars/brakefluid.htm

While other brands offer slightly superior dry boiling specs, SRF still has no competition for wet boiling specs (e.g. fluid that has absorbed/exposed to moisture).

Sherwood

 

Make sure you got better than DOT 4 fluid in the system. Next time, do a "hot" bleed of the system after the first session. This will normally remove the residual air and moisture in the fluid that boils out when you heat 'em up for the first time after a normal brake service.

Sebring is really hard on brakes. You need to be as smooth as possible and use them as little as possible so they can cool some on the straights. Good luck.

 

Thanks for the compliment Darren. Although I would like to believe the faster part I think you are correct on my braking.


I just checked mine and confirm they are Hawk HP+ all around.

That is a great chart!!!

I spoke to a representative at Hawk today and he suggested getting some brake rotor temperature paint before deciding on a track pad. Sounded reasonable. How helpful do you think that will be. Wow, do you need a prescription for that stuff, best I can find is about $65 an ounce!

 

The temp paint is very helpful, as is an IR gun to check your rotor temps as soon as you come in from the circuit. It sounds to me like a combination of better matched equipment to the applicaton and some work on your technique will solve this problem. Remember, Porsches are known a lot more for braking and handling than horsepower.

 

I use temperature strips that I stick on the calipers. They work great. Here is the link: http://www.hrpworld.com/index.cfm?fo...action=product

George

 

I found the HP+ to work OK on the track (my 951 has nearly the same brakes & weight as the 993) but as noted they wore out fast on track. I didn't like them on the street since they squealed like stuck pigs. They also leave dust that'll rust (damaging the wheel finish) if you let it get wet. They are a good starter track pad IMO, and darned cheap if you get them at Vertex.

I never boiled the fluid in my car but a weekend on track would have the HP + crumbling and thin. The PF97s I just tried a few weeks ago in the 993 were rather more robust and also stopped better.

 

Please clarify something for me. Is measuring the caliper temp the same thing as the rotor temp?
My real question is when looking at recommended brake pad temp ranges what are they specifying?

 

It measures the caliper temp which to me is more important than the rotor temp. It tells me when I've overheated the fluid. I have the rotor paint and used it but once you start using the right pads, it's useless.

George