Brake issue
08-20-2011, 08:40 AM
#1
Drifting
Thread Starter
Brake issue
In early at the office today and finally have a chance to put this question out there.
I've had this issue for awhile now and honestly don't quite now what it is.....
When I'm at the track and braking agressively, I find that after a few laps my pedal gets long (not really really long but more than on the street)...however it's not just that there's a couple of peripheral things to consider.
A) when the pedal starts doing this, the car still brakes really well
B) (This is the wierdest part to me)When I first apply the breaks, it feels like I'm pushing through something, then the pedal travels down a bit and that's where I find my firm pedal (almost like there was a small thread tied to the pedal, and I have to break it during each application, I know this sounds weird but I don't know how else to explain it. I've checked and there's nothing in the cabin that the pedal is catching on.
I first noticed this at my first track day, a couple of years ago and have done a ton of upgrades to the brakes since then but this still seems to be present. I'm running in intermediate groups when I go to the track, but this problem is always haunting me and has me braking early and is really holding me back.
My current setup consists of:
- Wilwood 14 rotors front and rear
- Wilwood 6 piston calipers up front and 4 piston in the rear
- Wilwood stainless lines
- Pads are still the ones that came with the kit (I'm going to try the carbotech ones after these are toast)
- DRM and Quantum brake ducts
- Factory master and slave.
- Wilwood 600 fluid
I bleed my brakes after each track day, and I'm sure there's no air in the system but at a loss for what could be causing this.....thoughts??
I've had this issue for awhile now and honestly don't quite now what it is.....
When I'm at the track and braking agressively, I find that after a few laps my pedal gets long (not really really long but more than on the street)...however it's not just that there's a couple of peripheral things to consider.
A) when the pedal starts doing this, the car still brakes really well
B) (This is the wierdest part to me)When I first apply the breaks, it feels like I'm pushing through something, then the pedal travels down a bit and that's where I find my firm pedal (almost like there was a small thread tied to the pedal, and I have to break it during each application, I know this sounds weird but I don't know how else to explain it. I've checked and there's nothing in the cabin that the pedal is catching on.
I first noticed this at my first track day, a couple of years ago and have done a ton of upgrades to the brakes since then but this still seems to be present. I'm running in intermediate groups when I go to the track, but this problem is always haunting me and has me braking early and is really holding me back.
My current setup consists of:
- Wilwood 14 rotors front and rear
- Wilwood 6 piston calipers up front and 4 piston in the rear
- Wilwood stainless lines
- Pads are still the ones that came with the kit (I'm going to try the carbotech ones after these are toast)
- DRM and Quantum brake ducts
- Factory master and slave.
- Wilwood 600 fluid
I bleed my brakes after each track day, and I'm sure there's no air in the system but at a loss for what could be causing this.....thoughts??
Last edited by GOTHAM VETTE; 08-20-2011 at 12:00 PM.
08-20-2011, 11:43 AM
#3
Drifting
Thread Starter
It was there even with the factory brakes!
I just thought of another way to describe it......
The pedal actually feels (for just a second) the exact same way it does when the ABS engages, and then it goes down a bit and then feels like a normal pedal again.
I just thought of another way to describe it......
The pedal actually feels (for just a second) the exact same way it does when the ABS engages, and then it goes down a bit and then feels like a normal pedal again.
Last edited by GOTHAM VETTE; 08-20-2011 at 12:07 PM.
08-20-2011, 12:18 PM
#4
Le Mans Master
Disclaimer: I am NOT a brake expert, so these are only my opinions or comments.
You don't state your pad type. It may be that your pads are operating outside of their optimum temperature range.
I have ridden with instructors at the Laguna Seca race school in street Porsche 911s. With stock (street) pads, fluid and tire pressure, we ran MANY laps at race speeds and (after the first few laps) the brakes got softer and longer, while the instructor had to pump up the brakes more times prior to each corner.
In my opinion, the initial softness was due to fluid boil and the attendent gas in the brake fluid which had to be compressed in order for the brakes to function. HOWEVER, the street pads were also operating outside of their optimum temperature range, and eventually, they would have failed (separated, melted or disintegrated) putting us off. I assume the instructor knew where the line was, cause I didn't.
(Sidebar story: Car and Driver had the stock (street) pads melt and disintegrate on a track driven G37S, leading to totaling the car....even tho this car had the optional Big Brake calipers and discs)
I use only Castrol SRF on Track, altho I use Motul 600 in my street car. If you use track (RACE) pads and SRF on track with properly bled and cooled brakes, the Willwood BBK package that you currently use should be functional for the track usage that you have described. Please post your feedback here when you have resolved your problems.
You don't state your pad type. It may be that your pads are operating outside of their optimum temperature range.
I have ridden with instructors at the Laguna Seca race school in street Porsche 911s. With stock (street) pads, fluid and tire pressure, we ran MANY laps at race speeds and (after the first few laps) the brakes got softer and longer, while the instructor had to pump up the brakes more times prior to each corner.
In my opinion, the initial softness was due to fluid boil and the attendent gas in the brake fluid which had to be compressed in order for the brakes to function. HOWEVER, the street pads were also operating outside of their optimum temperature range, and eventually, they would have failed (separated, melted or disintegrated) putting us off. I assume the instructor knew where the line was, cause I didn't.
(Sidebar story: Car and Driver had the stock (street) pads melt and disintegrate on a track driven G37S, leading to totaling the car....even tho this car had the optional Big Brake calipers and discs)
I use only Castrol SRF on Track, altho I use Motul 600 in my street car. If you use track (RACE) pads and SRF on track with properly bled and cooled brakes, the Willwood BBK package that you currently use should be functional for the track usage that you have described. Please post your feedback here when you have resolved your problems.
08-21-2011, 10:12 AM
#5
Safety Car
Try SRF brake fluid and Titanium shields on the pads + SS pistons in the calipers. This cocktail fixed my pedal with the stock calipers even at the track I go to w/the most agressive braking zones which causes the most brake & tire wear.
08-21-2011, 03:32 PM
#6
I'm with 63Corvette on this one.
It sounds like it's the pads.
Had the same thing happen to me, once I changed over to a set of Carbotech's problem went away
If your breaking is aggressive you're probably putting the pads out of operating temp fairly quickly. I know in most cases the BBK's come with "street friendly" pads that may not hold up to extended track use.
It sounds like it's the pads.
Had the same thing happen to me, once I changed over to a set of Carbotech's problem went away
If your breaking is aggressive you're probably putting the pads out of operating temp fairly quickly. I know in most cases the BBK's come with "street friendly" pads that may not hold up to extended track use.
08-23-2011, 10:42 AM
#8
I have no issues with the Wilwood 600 fluid in my Racing. I run the Wilwood WS6 package with the thermolock pistons. Upgrade the calipers to the Thermolocks and you'll reduce caliper temps by up to 300 degrees. Maximize air to brakes front and rear.
You may also be experiencing some pad knockback. Install the wilwood 2 lb residual valves at all 4 corners where the brake hard line meets the SSline. This cured my issues with a low pedal and I have had no problems since. BTW, I use Wilwood H cmpd front and A cmpd rear.
Jerry Onks
2010, 2011 SE div STO Nat champion
2010, 2011 SCCA national STO points Champion
You may also be experiencing some pad knockback. Install the wilwood 2 lb residual valves at all 4 corners where the brake hard line meets the SSline. This cured my issues with a low pedal and I have had no problems since. BTW, I use Wilwood H cmpd front and A cmpd rear.
Jerry Onks
2010, 2011 SE div STO Nat champion
2010, 2011 SCCA national STO points Champion
Last edited by svcjmo; 08-23-2011 at 10:44 AM. Reason: More info
08-23-2011, 01:52 PM
#9
Former Vendor
I suspect that it's pad related also.
The fact that you went to great length to list the specifics of the brakes in use and neglected to quote the pad compound would lead me to believe you are not familiar with the requirement to change to dedicated pads for the track. *Stated "came with the kit; would to me suggest BP10 street pads
There are no dual purpose pads. Only compromised ones when trying to keep street pads under you at the track or vise-versa. Track days are clearly a need for both proper pads and fluid.
I also would look to the pad knock back issue mentioned above as hub flex can lead to a longer pedal also as Jerry mentioned.
The fact that you went to great length to list the specifics of the brakes in use and neglected to quote the pad compound would lead me to believe you are not familiar with the requirement to change to dedicated pads for the track. *Stated "came with the kit; would to me suggest BP10 street pads
There are no dual purpose pads. Only compromised ones when trying to keep street pads under you at the track or vise-versa. Track days are clearly a need for both proper pads and fluid.
I also would look to the pad knock back issue mentioned above as hub flex can lead to a longer pedal also as Jerry mentioned.
08-23-2011, 02:49 PM
#11
Drifting
Thread Starter
Going to pick up a set of Carbotech pads for my next track event, I knew that I'd need dedicated track pads as my experience progressed, I just didn't think it would happen so quickly.
If this doesn't completely cure the problem, I'll move forward with looking into the knock back issue.
Thanks for all the posts everyone
If this doesn't completely cure the problem, I'll move forward with looking into the knock back issue.
Thanks for all the posts everyone
08-23-2011, 03:06 PM
#12
Supporting Vendor
Member Since: Oct 2002
Location: Cleveland OH
Posts: 50,209
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St. Jude Donor '11,'13
Going to pick up a set of Carbotech pads for my next track event, I knew that I'd need dedicated track pads as my experience progressed, I just didn't think it would happen so quickly.
If this doesn't completely cure the problem, I'll move forward with looking into the knock back issue.
Thanks for all the posts everyone
If this doesn't completely cure the problem, I'll move forward with looking into the knock back issue.
Thanks for all the posts everyone
__________________
Adam Adelstein
Amp’D Autosport.com
Internet's largest retailer of Carbotech Performance Brake Pads.
PH:216-780-8825.
Email: sales@ampdautosport.com
Web Site & Direct ordering http://ampdautosport.com/
All major CC and Pay Pal accepted.
Check out Promo code:z28
Adam Adelstein
Amp’D Autosport.com
Internet's largest retailer of Carbotech Performance Brake Pads.
PH:216-780-8825.
Email: sales@ampdautosport.com
Web Site & Direct ordering http://ampdautosport.com/
All major CC and Pay Pal accepted.
Check out Promo code:z28
08-23-2011, 03:25 PM
#13
Le Mans Master
Disclaimer: I am NOT a brake expert, so these are only my opinions or comments.
You don't state your pad type. It may be that your pads are operating outside of their optimum temperature range.
I have ridden with instructors at the Laguna Seca race school in street Porsche 911s. With stock (street) pads, fluid and tire pressure, we ran MANY laps at race speeds and (after the first few laps) the brakes got softer and longer, while the instructor had to pump up the brakes more times prior to each corner.
In my opinion, the initial softness was due to fluid boil and the attendent gas in the brake fluid which had to be compressed in order for the brakes to function. HOWEVER, the street pads were also operating outside of their optimum temperature range, and eventually, they would have failed (separated, melted or disintegrated) putting us off. I assume the instructor knew where the line was, cause I didn't.
(Sidebar story: Car and Driver had the stock (street) pads melt and disintegrate on a track driven G37S, leading to totaling the car....even tho this car had the optional Big Brake calipers and discs)
I use only Castrol SRF on Track, altho I use Motul 600 in my street car. If you use track (RACE) pads and SRF on track with properly bled and cooled brakes, the Willwood BBK package that you currently use should be functional for the track usage that you have described. Please post your feedback here when you have resolved your problems.
You don't state your pad type. It may be that your pads are operating outside of their optimum temperature range.
I have ridden with instructors at the Laguna Seca race school in street Porsche 911s. With stock (street) pads, fluid and tire pressure, we ran MANY laps at race speeds and (after the first few laps) the brakes got softer and longer, while the instructor had to pump up the brakes more times prior to each corner.
In my opinion, the initial softness was due to fluid boil and the attendent gas in the brake fluid which had to be compressed in order for the brakes to function. HOWEVER, the street pads were also operating outside of their optimum temperature range, and eventually, they would have failed (separated, melted or disintegrated) putting us off. I assume the instructor knew where the line was, cause I didn't.
(Sidebar story: Car and Driver had the stock (street) pads melt and disintegrate on a track driven G37S, leading to totaling the car....even tho this car had the optional Big Brake calipers and discs)
I use only Castrol SRF on Track, altho I use Motul 600 in my street car. If you use track (RACE) pads and SRF on track with properly bled and cooled brakes, the Willwood BBK package that you currently use should be functional for the track usage that you have described. Please post your feedback here when you have resolved your problems.
The DOCTOR is in!
Jim
08-23-2011, 03:34 PM
#14
Drifting
You may also want to try a TECH II brake flush just in case you have an air bubble in the ABS portion of the braking system. I paid about $90 and provided 4 qts of my own fluid.
Good luck,
Jim
Good luck,
Jim
08-25-2011, 11:55 AM
#15
Drifting
Thread Starter
I've ordered some Carbotech's as a starting point, I'll let you know if those do the trick.
Now all I need to do is figure out how to get this stupid hurricane to blow back out into open water!!!!
Now all I need to do is figure out how to get this stupid hurricane to blow back out into open water!!!!