Another brake pad question...
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Another brake pad question...
Car: 225 TT roadster ie fat but relatively quick.
Current brakes: Stoptech big brakes with R4 Porterfield track pads up front, Porterfield R4-S on the rear
Problem: doggin' the NSX's and Corvettes in the curves (they pull away on the straights to be caught again in the curves) means braking late and hard. Tuesday's track session could have been unpleasant as just on the last laps of the 3rd session the pedal went to the floor; turned out to be boiled fluid and a quick pump got me safely to the pit. I bleed the brakes and went on..
The pads show signs of heat fracture. Rears are fine... suggestions on pads that might help keep the fluid from boiling and they themselves deal better with the heat?
Current brakes: Stoptech big brakes with R4 Porterfield track pads up front, Porterfield R4-S on the rear
Problem: doggin' the NSX's and Corvettes in the curves (they pull away on the straights to be caught again in the curves) means braking late and hard. Tuesday's track session could have been unpleasant as just on the last laps of the 3rd session the pedal went to the floor; turned out to be boiled fluid and a quick pump got me safely to the pit. I bleed the brakes and went on..
The pads show signs of heat fracture. Rears are fine... suggestions on pads that might help keep the fluid from boiling and they themselves deal better with the heat?
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After putting StopTechs on my TT and going to the Track for the first time ever, I really rode the
brakes hard into the corners. After a dozen laps the pedal went soft. No brake smell, just soft pedal. I let cool off with an easy lap and then let sit without touching the brakes.
I suspected fluid boil since there was no pad smell. Also, as I got to be a bit smoother, and faster, there was never another fade problems the rest of the day despite running many more laps at ever increasing lap times.
Prior to that I had run my TT several times through Deals Gap when at TT-East and really drove the car hard and never had fade or pad smell. Although many others with stock pads did.
I will be changing the fluid to Motul 600 very soon. Although I hear it is very hydroscopic which concerns me a bit.
John
I suspected fluid boil since there was no pad smell. Also, as I got to be a bit smoother, and faster, there was never another fade problems the rest of the day despite running many more laps at ever increasing lap times.
Prior to that I had run my TT several times through Deals Gap when at TT-East and really drove the car hard and never had fade or pad smell. Although many others with stock pads did.
I will be changing the fluid to Motul 600 very soon. Although I hear it is very hydroscopic which concerns me a bit.
John
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Castrol SRF ...
.
is what I'm using in my S8. I've melted pads, but have never boiled the brake fluid.
Castrol SRF is expensive stuff, but the high wet boiling point makes it particularly suitable in street/track cars that may not get brake bleeding as frequently as with a dedicated track/race car -- a great brake fluid for our great cars.
Actually, we only use the DOT3 Ford HD brake fluid in our Forumla Continental, a serious race car. The Ford HD has a high 550 oF dry boiling point (if I remember correctly), but a very low wet boiling point. This brake fluid is dirt cheap, and since we bleed brakes every weekend, we don't worry about the low wet boiling point.
<img src="http://pictureposter.audiworld.com/17157/bumpsteer.jpg">
This is our FC, taken at last year's SCCA RunnOffs at Mid-Ohio.<ul><li><a href="http://www.swedishbricks.net/700900FAQ/Brake%20Fluid%20Comparison.htm">Brake Fluid Comparison</a></li></ul>
is what I'm using in my S8. I've melted pads, but have never boiled the brake fluid.
Castrol SRF is expensive stuff, but the high wet boiling point makes it particularly suitable in street/track cars that may not get brake bleeding as frequently as with a dedicated track/race car -- a great brake fluid for our great cars.
Actually, we only use the DOT3 Ford HD brake fluid in our Forumla Continental, a serious race car. The Ford HD has a high 550 oF dry boiling point (if I remember correctly), but a very low wet boiling point. This brake fluid is dirt cheap, and since we bleed brakes every weekend, we don't worry about the low wet boiling point.
<img src="http://pictureposter.audiworld.com/17157/bumpsteer.jpg">
This is our FC, taken at last year's SCCA RunnOffs at Mid-Ohio.<ul><li><a href="http://www.swedishbricks.net/700900FAQ/Brake%20Fluid%20Comparison.htm">Brake Fluid Comparison</a></li></ul>