thisismyusername

I had my brakes go (pedal to the floor) yesterday during an open lapping event. Fortunately, this happened during my cool down laps, so there were no off-road excursions.

So here are the details. It happened all three sessions I ran yesterday, when I started my cool down lap. Sessions were 15-20 minutes on a ~2 mile road course. The brakes came back after cooling down for 30-45 minutes. Yesterday's temperature at the track was in the 90's. For equipment, I have the Z51 rotors, run Hawk HPS pads, and had pretty fresh Motul 600 brake fluid (fluid was only run at one other HPDE event). Stock LS2 with a Callway Honker, only other upgrades are Z51 sway bars and Z06 springs (I have the F55 suspension). Rotors, sways, and springs and pads are all recent modifications.

Thoughts as to what might be going on? I'm not that great with heel-toe and have the Elite Engineering heel-toe gas pedal. I do know that sometimes when I'm heel-toeing, I'm hitting the brake and gas at the same time, which will heat up the brake fluid. I run in Competitive mode and do see the active handling kick in when I 'try' to do heel-toe.

Thanks!

Joe_Planet

you've said it... practice more heel toe, you can do it on the street. you're supposed to hit brake and gas at the same time, just remember to clutch in before you hit the gas
there's a bunch of other stuff to try like titanium backing plates and stainless steel caliper pistons (or whatever they make them out of) but you shouldnt need any of that stuff. just focus on your technique and beeing SMOOTH, the reason why active handling is coming on is because you're not smooth. if you dont give it enough throttle on the heel part and release the clutch the car will jerk because the rpms of the engine arent matched to the trans/wheel speed and ah gives you a kick in the head. practice..

Jason

Better ducts and SS lines. You're losing pedal on the cooldown lap because there's not as much air moving through the wheel-well. FWIW, try to stay off the brakes on your cooldown lap, drive the line smoothly without using the brakes. Check them before pulling into pitlane/paddock though. Gets crowded fast if you can't stop.

thisismyusername

Any recommendations on SS brake lines? I should also add that my C6 is a 2005. I read somewhere that the life of stock rubber lines is about 6 years. Maybe the age is also a factor?

Jason

The rubber lines just get hot and soft and will more easily expand instead of pushing the fluid down to the caliper. I think you can get SS from MidAm or Ecklers, or wherever, don't think 1 is better than another.

thisismyusername

Thanks. Still gotta work on my damn heel-toe...

Jason

Practice every downshift, on the street, in any stick shift car/truck. Suddenly the light will come on.

geerookie

They problem is the pads.
I literally melted a set of HPS pads on a lapping session.
They cannot handle the heat at all. If AH is kicking in it is only making it worse.
Try Cobalt Friction CSR or some of the new CL pads 5+ or 6E compounds.
They will handle the heat much better.
Then practice, practice, practice. If you get heel and toe down on the street (much harder) then you will be an ace at the track.

PeOR

I have the exact same experience. My advises are like some of the suggestions above

- coolong ducts (I got mine from Quantum and am happy with them)
- stay away from Hawk+. Not only did they overheta, they also made some damage to my rotors. I am doing DTC70 / 60 now and have very good performance
- titanium plates (not sure how necessary this is but I did boil my brakes a 2nd time when the pads were almost completely worn out. So I have the titanium plates to reduce heat transfer to the calipers.

PeO.

AU N EGL

HPS are STREET brake pads, not for track use.

and Pretty fresh is NOT changed right before the event.

So next Race brake pads ( Hawk DTC70s and 60s or other race pads) and FRESH changed brake fluid

plus cooling ducts

mikefili

I had similar results with HP Plus, which are the next step up from the HPS, the HPS are only a street pad and not at all suited for the track, total wrong pad for the application.
I then went to Carbotech XP 10 and 8, they work great, It will take you 1/2 a day on the track to burn off all the hawk material off the rotors to get the XP to work, in all fairness I never tried the correct Hawk compounds, went right to the Carbotech.

Adam@Amp'dAutosport.com

XP10 $206 XP8 $161 -7% Discount.

Goodridge ss lines
Corvette - C6 2005-2010 12290 $176.00

Carbotech XP8™ (1108™)
A high torque brake compound with a wide operating temperature range (200°F-1350°F+). Carbotech XP8™ is the first of our racing compounds. Outstanding initial bite at race temperatures, high coefficient of friction, excellent modulation and release characteristics. Extremely high fade resistance, very rotor friendly with 100% non-corrosive dust. Excellent as a front brake pad for lighter ITA, ITB, ITC, SRF, H4, H5, and other cars that weigh less than 2,400lbs. Perfect for novice, intermediate and advanced track day (HPDE) use with any tire, and can still be driven safely to and from the track. There are several vehicles that use XP8™ on the street, autocross, and at track day (HPDE) events. Carbotech does NOT recommended XP8™ as a daily driven street pad due to elevated levels of dust and noise. XP8™ is also a great rear brake pad for almost any race car (Spec Miata-T1/T2/CMC). XP8™ is a great compound on the front & rear of most open wheel and sports racers.

Carbotech™ XP10™ (1110™)
When Carbotech unleashed the XP10™ to the general public, and it was an instant success, gathering multiple regional, divisional, and national championships. The XP10™ is a very high initial bite friction material, with a coefficient of friction and rotor friendliness unmatched in the industry. Fade resistance is in excess of 1650°F. Due to the high level of friction and bite, this material is recommended for cars weighing around 2,000lbs or more, not including formula cars and cars with brake bias bars weighing less than 2,000lbs. This is the preferred compound for the front of Spec Miata racers, SSC,SSB, T3, SRF, ITS, ITE, H1,H2, H3, H4, 944 Cup, ST, GS, Factory Five Cobra’s and many more Grand-Am/ALMS/SCCA/NASA classes. XP10™ is also ideal for advanced/instructor level HPDE drivers. XP10™ still maintains the highly praised release and excellent modulation, rotor friendliness, and 100% non-corrosive dust that have made all Carbotech compounds so successful. XP10™ is not recommended as a daily-driven street pad due to possible elevated levels of dust and noise.

thisismyusername

Thanks for all the replies. Now I don't trailer the Vette and drive it to/from the track. Furthest track is about 2 1/2 hours away, closest is about 45 minutes. Carbotech and Hawk do not recommend using their race pads for street use, but would this driving to/from the track be OK? Should I look at using my Z51 rotors with the race pads and use my non-Z51 rotors which I still have for street use with the other street pads?

gmccreary

I have Goodridge on my C6Z and like them very much.

AU N EGL

For that short distance you will be fine.

Jason

Just be mindful when pulling out of your driveway or up to the first stop sign that they need a little bit of heat in them to work.

Bill Dearborn

Was just wondering about your previous track experience. How many times have you run on a track and how many times have you had instructors ride with you?

HPS pads are definitely street pads but they wouldn't be causing the pedal to go the floor. If they got too hot the pedal wouldn't have gone to the floor but you wouldn't be able to exert enough force to get them to slow the car. If the pads overheat (especially several times) they usually glaze and do not stop the car as well afterward. The fact that your brakes recovered after 40 minutes or so makes me think the pads weren't the problem.

Recent brake fluid is not new enough. It needs to be changed just a few days before the event. If you use Castrol SRF you might get by with recent. From your description it sounds like your fluid boiled. Maybe there was a hard braking point just before you finished your sessions and you didn't drive fast enough after that point to cool the rotors/calipers.

Bill

thisismyusername

I've been running HPDE with NASA for three years now. I don't run every weekend, but if I was to estimate, I do around 12-16 days a season.

So here's the interesting thing... before my current setup, I ran the previous two seasons with OEM non-Z51 rotors, OEM pads and OEM brake fluid, and never had any issues with losing my brakes.

Once again, thanks for all the replies.

PeOR

I would agree on latest post. With standard components, I did not boil my oil. But with Hawk+ it did. Not only did it heat up to the point that the oil boiled, it also made my rotors get grooves.

PeO.

JimbeauZ06

And you're probably driving faster as you gain more experience. So driving faster and leaving the AH on leads to hotter brakes. As already stated bad choice of pads aggravating the situation as well.