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Thread: Porsche Cayman S ABS failure or something else?

  1. #11
    FYI most vacuum boosted braking systems in street cars and pressure reserve ABS systems will allow the pedal to go soft once the car is shut off after a few pedal pumps. You have enough vacuum in the reservoir to provide a few vacuum assisted stops should the engine die when the car is moving, but after that it's only mechanical advantage, which in a street car is pretty huuuuge compared to a 'real' racing car (read: LIGHT) without boosted brakes, where the driver doesn't mind 150-200 lbf pedal force.

    At least all street cars I have ever done this with. Every one of my cars does this with the engine off. Firm for one or two pumps, then goes squishy. Start car, shut off, same story.

    A brake pedal that starts firm and then goes squishy is (nearly) always going to be a fluid boiling issue.



    I will now do my favorite thing in the world, and refer you to an excellent book by my favorite, Carroll Smith, Engineer to Win, pages 189-192. Page 192 in particular will interest you because he specifically tells his drivers to do a cool-down lap after their runs to help keep the braking system from heat-soaking and boiling the fluid in the calipers (which is bad for the fluid) and to allow everything else to cool down a little.



    What you need to do if the pedal is going squishy once everything is all hot and bothered from the fluid in the calipers boiling is to FIRST:

    DETERMINE THE TEMPERATURE THE CALIPERS ARE ACTUALLY REACING WHEN THE PEDAL STARTS GOING SOFT, so go out and drive it hard, bring it into the pits, and let everything heat soak and you think the pedal is going squishy, and buy or borrow an infra-red temp gun (or get those trick adhesive color chart temp indicators that AP Racing makes - you are talking about spending $10k on a racing ABS system [which is not your culprit in this case] so I can assume you can afford a nice temp gun for $150) and see what the temp is actually coming to.


    THEN!:

    1) Go to fresh new brake fluid with a higher boiling point.

    If none is available, then:

    2) Improve cooling to your brake CALIPERS, which can be better ducts in the car side, a water spray duct-air-cooling system or possibly even different wheels with more air-space or pumping action....

    3) Insulate the calipers from the hot bits in the system better - Page 190 in Smith's book shows a nice little diagram of how to make ceramic / carbon / Bakelite piston insulators that isolate the pad from the caliper pistons.



    When you put new fluid in, make sure to get all the old fluid out, and all the new in. Bleeding the system with one of the colored fluids (like the blue colored ATE 'Super Blue') before putting in Wilwood 570 or the other 600* fluids makes it really easy to see when you've got all the old fluid out. Only use fresh fluid from a new sealed bottle, if you don't use the whole bottle, DON'T USE IT NEXT TIME for the brakes - it's ok to save for use in the clutch, but toss it if you are in danger of using it for the brakes. Once it's been opened, it'll start absorbing water vapor from the air and it's boiling point goes down down down.



    ALSO as was mentioned above, this is a forum of student designers, not nearly all of whom are weekend racers, you will get lots of oppinions by posting here, so of your original options:


    <STRIKE>1. Change to expensive Bosch ABS Racing System.
    2. To find some other less expensive Racing aftermarket ABS System.
    3. Find the way to cool down the fluid before it gets to the original ABS</STRIKE>

    ABS is NOT YOUR PROBLEM!!! It's boiling the brake fluid in the calipers. BUT you won't know that for sure until you get some temperature measurements.



    Lastly, that's all just my oppinion, since I'm a college student with aging Saab 900 Turbos, who has never owned a Cayman to use for track days.

    Just because your car says Porsche on it doesn't mean you're getting Porsch LMP prototype racer technology, especially since it doesn't say GT3 or GT2 on the side - it says Cayman, a very tidy, very attractive sports coupe meant for the street. You will invariable find limits in the stock hardware if you are doing extensive track driving in hot weather on very high speed endurance road courses.

    I can't think of a single factory stock braking system that would be up to the task of extended periods of driving at Watkin's Glen. That's why there's a racing aftermarket supply industry to sell you that $10k racing ABS pump and controller in the first place.



    Best,
    Drew
    _______________________________________

    Northwestern Formula Racing Alum
    Head Engineer, Frame/Suspension 2006-2009

    My '73 Saab 99 Road Race Build

  2. #12
    Are you using full ABS in all braking zones?This is the only way I can see this being an ABS related issue and like the others it sounds as though this is related to the base brakes. With that said no expense ABS unit is going to do anything different if you're not in ABS. If you're in full ABS in every braking zone, you shouldn't. Threshold brake jsut below the ABS activation threshold. The system is generally very stout, but if you're stomping into ABS everywhere you'll probably work the system very hard and get it very hot, but with no fault being set you're still not failing the system. Learn to brake better and less and be easy on the car and the issue will should go away.

    Most likely, you're running with PSM on, which uses the brakes. You're probably overheating the brakes.
    University of Cincinnati
    Alum -> 2003-2008

  3. #13
    <BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Drew Price:
    I can't think of a single factory stock braking system that would be up to the task of extended periods of driving at Watkin's Glen. That's why there's a racing aftermarket supply industry to sell you that $10k racing ABS pump and controller in the first place.
    </div></BLOCKQUOTE>

    I can and know of systems that do it readily. The Porsche is one of them. Again, PSM is most likely the culprit. Realize that the Bosch race ABS comes from a company that supplies ABS and ESP as to OEMs. Its not very likely that the race ABS unit is a one off and not based off the OEM supplied pieces.
    University of Cincinnati
    Alum -> 2003-2008

  4. #14
    <BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by dende890:
    I don’t have time to list what I have done in my life; you will be listening with open mouth for days and days. </div></BLOCKQUOTE>


    Huh, from the amount you just wrote trying to justify yourself to a college student, I'd disagree with that statement.


    I don't know where the fuck you come off of, but coming onto some new exchange of information, requesting help, then insulting anyone who happens to have a different point of view DOES happen to be something that I associate with the old Soviet ways, my happening to grow up across from a 7-11 has nothing to do with the issue.

    That is not an OK way to behave, or so I was taught.

    Regardless of how you found this site, you're still responsible for how you act, and you just lost most of any amount of credibility you had trying to brag about all the babushka babes you had back home, none of us could care less.

    If you're going to ask for help, you have to do what we all learned a long time ago, to take everything with a grain of salt, think the proposed solutions over, then decide how to proceed -


    ......at least that's how engineers think about problems.



    Why don't you start here, with the StopTech technical papers, they're excellent, and might help you make a more informed decision,

    StopTech White Papers

    ....since you have 15 mins to sit and type out all the reasons that a young professional who has engineering experience working with the OEM who built your car about why he should respect you more because you can recognize a shitty situation (your being a threat to the Soviet government, and being in danger of going to prison for your capitalist ideals) and getting out of it.



    Best,
    Drew
    _______________________________________

    Northwestern Formula Racing Alum
    Head Engineer, Frame/Suspension 2006-2009

    My '73 Saab 99 Road Race Build

  5. #15
    <BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by dende890:
    Hello,

    I have Cayman S 2007. Just bought it in mid Feb. with 11,000 miles.
    I modified the suspension, brakes, etc…, but it is not important.
    I mostly use it for tracks from VIR to W.Glen. It happened at the Watkins Glen when I pit after a session and the car cooled off slightly. I seat in the car with ignition off and pressed the brake pedal. To my surprise the pedal easily traveled to the floor. I started pumping the pedal and it became firm again. It happened that Spencer Cox from Farmbacher Loles was at the track with a client and he as a generous man bled the whole systems, inner and outer. He also made a suggestion that it is an ABS failure and I have to change it to the Racing Unit which is very costly. Now I know that the unit cost $10,675 without installation. Back to the Glen.
    The pedal was firm again as it suppose to be. I went to another session and everything was okay during the run. But after pit in I turned the ignition off, wait a few minutes, pressed the brake pedal and to my surprise it surrenders again. After pumping it became firm again. I decided not to do anything this time and went to the track for the next session in an hour. I drive hard as usual but with alert senses towards the brakes. Everything was working perfect, however after 10-12 minutes I stated feeling that after the long straight where I reached 130+ mph the brake pedal started feeling like going some more distance then usual. After some less speed on shorter straights but still hard braking I felt the same and quit driving. With Spencer we went to the Porsche dealership which was with their team of GTs on the track at the time, they immediately connected the computer, checked the system but there was no any troubles found. By the way, ABS or PSM lights were never on. I drove with PSM “on” since I never driven Porsches yet and as I said it was my 3rd day with this car on track.
    After that Spencer bled whole system again and I just drove 100 yards, stopped the car switched the ignition off and the pedal traveled to the floor again.
    It was possible to pump the pedal to the firm point again.
    There was another man on the track who made the suggestion that it is the main, master, cylinder problem.
    I had nothing to do but abort the track sessions and go 270 miles back to New York, where I lived. There was no problem with braking on the high way; I even tried some on speed of 90 mph.
    The main or master cylinder was changed in a couple of days.
    I went to 2 days even at Shenandoah. Everything was perfect. I get use to the car more and more and switched the PSM off.
    I drive in advanced groups at all the tracks and drive hard on the car.
    I’m not really very clean with the turn in points and usually start turning earlier and thus increase the throttle application earlier in the turn to keep the speed and “fight with the car” often overseeing and braking hard, and short, and some mechanics thought that because of that the overheating happened. I personally wasn’t agreeing with them feeling that there is some other issue.
    After the Shenandoah I immediately drove to Thunderbolt and next morning was able to drive 2 sessions without problems with PSM on. There were only 2 run groups, so 30 min on track, 30 min off. Quite a stress to the machine. After the third session I was sitting in the cooling off car and pressed the brake pedal and it was traveling to the floor again. After pumping became hard and then surrendered to the floor under the foot pressure.
    I started the 4th session caution and turn off the PSM, but quit very soon feeling that the braking pedal is started surrendering slightly again after hard braking.

    Next the Titanium Shims were added to my calipers to deal with excessive heat, the brake lines were bled thoroughly again with Motul RBF 600.

    I went to the Glen, last year I had 39 track days, and on the third sessions everything was back again.
    I quit and went home angry to the Porsche f… engineers.

    I spent couple of days reading diff. articles about such problems with Caymans and now I’m looking for people who already dealt with it and want to know the result.

    There are a few suggestions I picked up from what I read.

    1. Change to expensive Bosch ABS Racing System.
    2. To find some other less expensive Racing aftermarket ABS System.
    3. Find the way to cool down the fluid before it gets to the original ABS.
    4. To trade the car in for BMW M3 2006 which I had before and loved it.

    So anybody, who already went through such problem and solve it successfully in any of the first 3 solutions, please share the experience. Help me and others who is already desperate and those who are going to get in to the troubles sooner or later in the future.

    Or is it something different and not ABS at all?

    Thank you,
    Lev. </div></BLOCKQUOTE>

    Hi Lev,

    I also have a Cayman S 2007 and had the exact same issues last year while racing. I changed to the expensive Bosch ABS Racing System and it solved the problem happily and easily. It is costly but it made the problem solving part very easy.

    Best,
    Horace
    Horace Lai

  6. #16
    I would recommend the first option. If that doesn't work at least you'll be faster from the lighter wallet with all the money you'll waste.

    Or you could heed the good advice already posted and save a bajillion dollars.

  7. #17
    <BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Drew Price:
    <BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by dende890:
    I don’t have time to list what I have done in my life; you will be listening with open mouth for days and days. </div></BLOCKQUOTE>


    Huh, from the amount you just wrote trying to justify yourself to a college student, I'd disagree with that statement.


    I don't know where the fuck you come off of, but coming onto some new exchange of information, requesting help, then insulting anyone who happens to have a different point of view DOES happen to be something that I associate with the old Soviet ways, my happening to grow up across from a 7-11 has nothing to do with the issue.

    That is not an OK way to behave, or so I was taught.

    Regardless of how you found this site, you're still responsible for how you act, and you just lost most of any amount of credibility you had trying to brag about all the babushka babes you had back home, none of us could care less.

    If you're going to ask for help, you have to do what we all learned a long time ago, to take everything with a grain of salt, think the proposed solutions over, then decide how to proceed -


    ......at least that's how engineers think about problems.



    Why don't you start here, with the StopTech technical papers, they're excellent, and might help you make a more informed decision,

    StopTech White Papers

    ....since you have 15 mins to sit and type out all the reasons that a young professional who has engineering experience working with the OEM who built your car about why he should respect you more because you can recognize a shitty situation (your being a threat to the Soviet government, and being in danger of going to prison for your capitalist ideals) and getting out of it.



    Best,
    Drew </div></BLOCKQUOTE>

    There was no different point of views, the student called me a PUSSY, just because I was looking for the help in the wrong place.

    I didn't deserve to be called the pussy by somebody who don't know me and for something that really shouldn't be even reproach.
    For a GOOD engineer anything that relates to his profession is interesting at any time in any place.
    I just simply gave him some minuscule info about me from which I think no reason to call me P....

    And you are trying without probably reading all the replies to me to judge my behavior and insult too saying something like babuska babes.

    What is it with you young men? Little amount of sex or no sex at all, so you resided to have it in emails, or just typical hate for immigrants ?
    But all came to US, at some point everybody was an immigrant, insulting me on this ground is insulting all your ancestors.
    Leave me alone, I'm old enough to be yours grandfather and how ever I behave myself I still deserve some respect, you will understand it by age.

  8. #18
    <BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by Horace:
    <BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by dende890:
    Hello,

    I have Cayman S 2007. Just bought it in mid Feb. with 11,000 miles.
    I modified the suspension, brakes, etc…, but it is not important.
    I mostly use it for tracks from VIR to W.Glen. It happened at the Watkins Glen when I pit after a session and the car cooled off slightly. I seat in the car with ignition off and pressed the brake pedal. To my surprise the pedal easily traveled to the floor. I started pumping the pedal and it became firm again. It happened that Spencer Cox from Farmbacher Loles was at the track with a client and he as a generous man bled the whole systems, inner and outer. He also made a suggestion that it is an ABS failure and I have to change it to the Racing Unit which is very costly. Now I know that the unit cost $10,675 without installation. Back to the Glen.
    The pedal was firm again as it suppose to be. I went to another session and everything was okay during the run. But after pit in I turned the ignition off, wait a few minutes, pressed the brake pedal and to my surprise it surrenders again. After pumping it became firm again. I decided not to do anything this time and went to the track for the next session in an hour. I drive hard as usual but with alert senses towards the brakes. Everything was working perfect, however after 10-12 minutes I stated feeling that after the long straight where I reached 130+ mph the brake pedal started feeling like going some more distance then usual. After some less speed on shorter straights but still hard braking I felt the same and quit driving. With Spencer we went to the Porsche dealership which was with their team of GTs on the track at the time, they immediately connected the computer, checked the system but there was no any troubles found. By the way, ABS or PSM lights were never on. I drove with PSM “on” since I never driven Porsches yet and as I said it was my 3rd day with this car on track.
    After that Spencer bled whole system again and I just drove 100 yards, stopped the car switched the ignition off and the pedal traveled to the floor again.
    It was possible to pump the pedal to the firm point again.
    There was another man on the track who made the suggestion that it is the main, master, cylinder problem.
    I had nothing to do but abort the track sessions and go 270 miles back to New York, where I lived. There was no problem with braking on the high way; I even tried some on speed of 90 mph.
    The main or master cylinder was changed in a couple of days.
    I went to 2 days even at Shenandoah. Everything was perfect. I get use to the car more and more and switched the PSM off.
    I drive in advanced groups at all the tracks and drive hard on the car.
    I’m not really very clean with the turn in points and usually start turning earlier and thus increase the throttle application earlier in the turn to keep the speed and “fight with the car” often overseeing and braking hard, and short, and some mechanics thought that because of that the overheating happened. I personally wasn’t agreeing with them feeling that there is some other issue.
    After the Shenandoah I immediately drove to Thunderbolt and next morning was able to drive 2 sessions without problems with PSM on. There were only 2 run groups, so 30 min on track, 30 min off. Quite a stress to the machine. After the third session I was sitting in the cooling off car and pressed the brake pedal and it was traveling to the floor again. After pumping became hard and then surrendered to the floor under the foot pressure.
    I started the 4th session caution and turn off the PSM, but quit very soon feeling that the braking pedal is started surrendering slightly again after hard braking.

    Next the Titanium Shims were added to my calipers to deal with excessive heat, the brake lines were bled thoroughly again with Motul RBF 600.

    I went to the Glen, last year I had 39 track days, and on the third sessions everything was back again.
    I quit and went home angry to the Porsche f… engineers.

    I spent couple of days reading diff. articles about such problems with Caymans and now I’m looking for people who already dealt with it and want to know the result.

    There are a few suggestions I picked up from what I read.

    1. Change to expensive Bosch ABS Racing System.
    2. To find some other less expensive Racing aftermarket ABS System.
    3. Find the way to cool down the fluid before it gets to the original ABS.
    4. To trade the car in for BMW M3 2006 which I had before and loved it.

    So anybody, who already went through such problem and solve it successfully in any of the first 3 solutions, please share the experience. Help me and others who is already desperate and those who are going to get in to the troubles sooner or later in the future.

    Or is it something different and not ABS at all?

    Thank you,
    Lev. </div></BLOCKQUOTE>

    Hi Lev,

    I also have a Cayman S 2007 and had the exact same issues last year while racing. I changed to the expensive Bosch ABS Racing System and it solved the problem happily and easily. It is costly but it made the problem solving part very easy.

    Best,
    Horace </div></BLOCKQUOTE>

    Thank you.

    If I go for the racing Bosch ABS I'll have no money for HPDE events.
    I'll try do drive without PSM on tracks. I never use Stability Control during my 39 track days last year on the BMW M3.
    But Cayman is a very new car for me yet.

  9. #19
    <BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by 2BWise:
    Are you using full ABS in all braking zones?This is the only way I can see this being an ABS related issue and like the others it sounds as though this is related to the base brakes. With that said no expense ABS unit is going to do anything different if you're not in ABS. If you're in full ABS in every braking zone, you shouldn't. Threshold brake jsut below the ABS activation threshold. The system is generally very stout, but if you're stomping into ABS everywhere you'll probably work the system very hard and get it very hot, but with no fault being set you're still not failing the system. Learn to brake better and less and be easy on the car and the issue will should go away.

    Most likely, you're running with PSM on, which uses the brakes. You're probably overheating the brakes. </div></BLOCKQUOTE>
    During braking the ABS quite rare kicks in, however the PSM, you right, working sometimes and that might be the problem.
    I'l try to drive without PSM.

    Thank you,
    Lev.

  10. #20
    Does anyone else think it's hilarious that the first person this goober ripped on for being a snot-nosed American is actually from Germany?

    Also, if 10 grand is too much to drop on an abs system, why not try some of the low cost tips people have posted here first instead of getting your former soviet issue panties in a bunch? It's not like cheap temperature guns, fresh brake fluid, and taking a cool down lap are outlandish ideas or huge capital investments.

    Of course, if you just want to throw money at the problem, if you give Drew and I the comparatively low sum of $5000 we will be glad to take care of all your brake pedal issues.

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