Track Guys - What brake fluid are you using?
06-14-2009, 01:29 PM
#47
Rennlist Member
the new Cup and RSR's are using Endless Racing Fluid and I see in another thread that almost all of the more successful endurance teams are running Endless Racing pads as well...looks like Pagid is an also ran lately....
06-14-2009, 01:58 PM
#48
Rennlist Member
My racing budget has been slashed. Everyone know me for my use of used Toyos. Now, im using used rotors and I'm thinking of using Wesson oil for brake fluid. 
06-14-2009, 02:35 PM
#49
Rennlist Member
Let us know how that goes. 
My car with an instructor in it weighs about 3800lbs. I change SRF at the beginning of the season, never bleed the brakes, never have a soft pedal or fade, or any other brake issues.
I was told that it's not a problem to just flush out your system with the SRF when you change from another fluid. No worries about the small amount of residue from the previous fluid.
My car with an instructor in it weighs about 3800lbs. I change SRF at the beginning of the season, never bleed the brakes, never have a soft pedal or fade, or any other brake issues.
I was told that it's not a problem to just flush out your system with the SRF when you change from another fluid. No worries about the small amount of residue from the previous fluid.
06-14-2009, 04:05 PM
#50
Rennlist Member
Spec-wise, I'm not sure what makes the Endless fluid that special.
06-14-2009, 04:31 PM
#51
Rennlist Member
IMHO, all that really matters is the Dry point in a heavily maintained race car, does the Motul 660 go to 660F Dry? Do Cup car owners just ignore the brake systems, maybe changing the fluid once a year or so?
06-15-2009, 02:17 PM
#53
Track Day
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06-15-2009, 02:33 PM
#54
Track Day
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I believe I have an answer for that question. Just got an e-mail back from Endless USA and I've exchanged various e-mails and phone conversations with them since I started this thread.
Originally Posted by Endless USA
I’ve noticed that most tuner guys run Motul RBF600 for whatever reason. Motul’s fine in terms of boiling points but so are AP600 and Castrol SRF.
BUT, what you guys have to pay attention to in addition to boiling points is stuff like boiling point with water content or compressibility. Why? Because racing brake fluids absorb more water than street fluids do.
Here’s a graph of boiling points according to water content. Our RF-650 and the AP600 are very stable, with the RF-650 being a bit better. However, the SRF drops off violently when you get water in it. This means you can keep the RF-650 in there longer without having to do a full flush in fear of having water in the system. Water in the system means it’ll boil giving you a spongy brake pedal.
Now the other issue; compressibility. With our RF-650 brake fluid being standard original equipment on all Porsche GT3 Cup cars (Yes. Standard equipment from Porsche.), a lot of various teams in the US have been in close contact with us regarding it. Most have never heard of it before Porsche started using it as an OE part 2 years ago. Most of them had been using Castrol SRF.
What these GT3 Cup car teams have been telling me is that they’d put the fluid in the system, bleed it, and then go out on track. 5 or 10 minutes into the session the drivers would report the brake pedal feeling soft. So, they’d bring the cars in and check for air only to find none in the system. The actual issue ended up being compressibility. In short, different brake fluids compress more than others which accounted for the drivers reporting a soft pedal.
The teams tried a bunch of different fluids before realizing they should try ours (reason being they had never heard of Endless and they didn’t know where to get it). The teams tried AP, Motul, and others even I had never heard of, all still ending up with the same issue. Finally, when the GT3 Cup cars ran at the Formula 1 Grand Prix in Canada, they talked to the F1 teams. What they found out is that there are only two brake fluids used in Formula 1; one being Endless. Turns out the Brembo fluid and ours are the only ones without severe compressibility issues. And no, you’re GTR isn’t factory equipped with the Brembo fluid.
BUT, what you guys have to pay attention to in addition to boiling points is stuff like boiling point with water content or compressibility. Why? Because racing brake fluids absorb more water than street fluids do.
Here’s a graph of boiling points according to water content. Our RF-650 and the AP600 are very stable, with the RF-650 being a bit better. However, the SRF drops off violently when you get water in it. This means you can keep the RF-650 in there longer without having to do a full flush in fear of having water in the system. Water in the system means it’ll boil giving you a spongy brake pedal.
Now the other issue; compressibility. With our RF-650 brake fluid being standard original equipment on all Porsche GT3 Cup cars (Yes. Standard equipment from Porsche.), a lot of various teams in the US have been in close contact with us regarding it. Most have never heard of it before Porsche started using it as an OE part 2 years ago. Most of them had been using Castrol SRF.
What these GT3 Cup car teams have been telling me is that they’d put the fluid in the system, bleed it, and then go out on track. 5 or 10 minutes into the session the drivers would report the brake pedal feeling soft. So, they’d bring the cars in and check for air only to find none in the system. The actual issue ended up being compressibility. In short, different brake fluids compress more than others which accounted for the drivers reporting a soft pedal.
The teams tried a bunch of different fluids before realizing they should try ours (reason being they had never heard of Endless and they didn’t know where to get it). The teams tried AP, Motul, and others even I had never heard of, all still ending up with the same issue. Finally, when the GT3 Cup cars ran at the Formula 1 Grand Prix in Canada, they talked to the F1 teams. What they found out is that there are only two brake fluids used in Formula 1; one being Endless. Turns out the Brembo fluid and ours are the only ones without severe compressibility issues. And no, you’re GTR isn’t factory equipped with the Brembo fluid.
06-15-2009, 02:39 PM
#55
Three Wheelin'
Brian,
That could be on the later cars. I was going by what was spec'd on my '97 993 & '00 996 Cups. I think my 993 had a tag specifying SRF but I'm old & it's been awhile
That could be on the later cars. I was going by what was spec'd on my '97 993 & '00 996 Cups. I think my 993 had a tag specifying SRF but I'm old & it's been awhile
06-15-2009, 02:53 PM
#56
Track Day
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I think the underlying statement that Endless was trying to communicate to me, was that what used to be the standard on OE Cup cars, has no changed. I'm just eager to share what I learned.
No harm, no foul. Just trying to spread some knowledge while making a few new friends along the way. 
06-15-2009, 02:54 PM
#57
Burning Brakes
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Totally disagree. The wet boiling point is what matters. No matter how hard you try there is always some amount of moisture that will get in. The wet point is where these fluids all differ.
06-15-2009, 03:20 PM
#58
Rennlist Member
My understanding is that SRF is actually made from a different product than others and that is part of why it is so expensive and so good. It was all I used for years until switching to GS 610 a couple years ago which I have found to be as good with temps and better with pedal feel. There is an explaination for why this is but it's too much for me to explain here.
I know that you know better than that, All DoT 3, 4, 5.1 brke fluids are hygroscopic, SRF is just at the good end of the curve in this regard.
SRF is great stuff but it's not necessary to pay the SRF price to get SRF performance. You can do 2 Motul 600 fluid changes for the cost of 1 SRF change and w/ biannual changes(which won't be needed for many users) the wet performance difference approaches zero
CASTROL SRF 590°F 518°F $69.99/33.8oz.
MOTUL RACING 600 593°F 420°F $15.00/16.9oz.
each car setup stresses the brakes to a different extent, for some the high end stuff is absolutely neccessary, for others an annual flush w/ AT200(blue or yellow) is fine, each owner needs to evaluate their own needs. Certainly at the very least an anual flush is necessary but in stressed systems much more frequent changes are needed.
Besides cost the other issue w/ SRF is that though it can be mixed w/ other DoT 3 & 4 types, it looses much of it's ability to deal w/ moisture. SRF needs to be kept separate from others to attain peak performnace
SRF is great stuff but it's not necessary to pay the SRF price to get SRF performance. You can do 2 Motul 600 fluid changes for the cost of 1 SRF change and w/ biannual changes(which won't be needed for many users) the wet performance difference approaches zero
CASTROL SRF 590°F 518°F $69.99/33.8oz.
MOTUL RACING 600 593°F 420°F $15.00/16.9oz.
each car setup stresses the brakes to a different extent, for some the high end stuff is absolutely neccessary, for others an annual flush w/ AT200(blue or yellow) is fine, each owner needs to evaluate their own needs. Certainly at the very least an anual flush is necessary but in stressed systems much more frequent changes are needed.
Besides cost the other issue w/ SRF is that though it can be mixed w/ other DoT 3 & 4 types, it looses much of it's ability to deal w/ moisture. SRF needs to be kept separate from others to attain peak performnace
06-15-2009, 03:29 PM
#59
Rennlist Member
How much moisture gets into a race car brake system that bleeds out a pint+ of fluid every 2 months and fully flushes at least once per year? That was my point, but if you have data that contradicts what common sense tells me, I would certainly look at it and give it more thought..
06-15-2009, 03:41 PM
#60
Track Day
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SRF is great stuff but it's not necessary to pay the SRF price to get SRF performance. You can do 2 Motul 600 fluid changes for the cost of 1 SRF change and w/ biannual changes(which won't be needed for many users) the wet performance difference approaches zero
CASTROL SRF 590°F 518°F $69.99/33.8oz.
MOTUL RACING 600 593°F 420°F $15.00/16.9oz.
each car setup stresses the brakes to a different extent, for some the high end stuff is absolutely neccessary, for others an annual flush w/ AT200(blue or yellow) is fine, each owner needs to evaluate their own needs. Certainly at the very least an anual flush is necessary but in stressed systems much more frequent changes are needed.
Besides cost the other issue w/ SRF is that though it can be mixed w/ other DoT 3 & 4 types, it looses much of it's ability to deal w/ moisture. SRF needs to be kept separate from others to attain peak performnace
CASTROL SRF 590°F 518°F $69.99/33.8oz.
MOTUL RACING 600 593°F 420°F $15.00/16.9oz.
each car setup stresses the brakes to a different extent, for some the high end stuff is absolutely neccessary, for others an annual flush w/ AT200(blue or yellow) is fine, each owner needs to evaluate their own needs. Certainly at the very least an anual flush is necessary but in stressed systems much more frequent changes are needed.
Besides cost the other issue w/ SRF is that though it can be mixed w/ other DoT 3 & 4 types, it looses much of it's ability to deal w/ moisture. SRF needs to be kept separate from others to attain peak performnace
ENDLESS 424°F 622°F $33/16.75oz.
DOT5.1 approved fluid, and thus compatible with all DOT3 and DOT4 brake systems.