308 Brake Master Cylinder Upgrades....? | Page 2 | FerrariChat

308 Brake Master Cylinder Upgrades....?

Discussion in 'Technical Q&A' started by greg328, Oct 26, 2005.

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  1. Dave

    Dave F1 Rookie

    Apr 15, 2001
    2,722
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    David Jones
    The other option, as pointed out earlier, would be to use a caliper that has the parking brake mechanism built in.
     
  2. don_xvi

    don_xvi F1 Rookie

    Nov 1, 2003
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    Don the 16th
    I'd assume info is available from the manufacturers on how much pull is needed on these calipers. Also, I don't think the Wilwood is made to be stretched over some super thick vented rotors in the rear. It looks like it might be able to be stretched, but you may well not get much park brake effectiveness once you do that. For that matter, Brembo also makes a park brake caliper, a search of some posts from atlantaman (?) will reveal some info on it and his reasons for not using one.
     
  3. chrismorse

    chrismorse Formula 3

    Feb 16, 2004
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    #28 chrismorse, Oct 31, 2005
    Last edited by a moderator: Sep 7, 2017
    Greg,

    You and i have the same Tilton proportioning valve. Philip Airey, (my donor), had it mounted by the drivers seat for ease of adjustability.

    Two thoughts:
    I don't know how this unit could be mounted so that it couldn't get accidentally readjusted, with perhaps tragic results.
    Two, for ease of instalation and safety, it might be good to try wedging in up front by the master cylinder, (not forgetting of course to locate and remove the stock proportioning valve). The attached photo shows a knob type installed on a mazda?

    Does anyone know the actuation pressure of the stock 308 valve? It would be good to have a starting point for adjustment, (which assumes that we have the set points for the Tilton unit) ;-)

    chris
    Image Unavailable, Please Login
     
  4. pma1010

    pma1010 F1 Rookie

    Jul 21, 2002
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    Philip
    Chris:
    Stock proportioning valve is 0.7.
    You have to calc the internal pressures from the OEM MC size(s) - its a tandem - and F, R piston sizes to figure the impact. Or you can just put the unit on and experiment. Remember, Carroll Smith doesn't like the prop valves for track use (hysteresis and speed).
    Philip
     
  5. greg328

    greg328 F1 Rookie

    Nov 17, 2003
    4,178
    Austin, TX USA
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    Greg
    Chris (and others),
    Thanks for the park brake and Tilton proportioning valve info.

    I guess I now have 3 issues to tackle:

    1A) rear main caliper solution--looks like it could be done by mounting my new Wilwood Superlite on the leading edge of the rotor. This would require machining of the front boss. I would need to locate a VERY reliable machine shop who could machine/tap/thread the mount hole in the EXACT right location. Pretty scary.

    1B) rear park brake- the ones Chris posted pull fore/aft, not laterally like the OEM cable mechanism. Can anybody post a pic of the Brembo park brake? Maybe it's actuated laterally. Does anybody know of any other park brake caliper options?
    Mounting this small caliper in the stock location would require a custom bracket to compensate for the larger rotor. Again, a reliable machine shop would be needed.

    2) Master cylinder size. Now that I've installed my front system--Wilwood Superlite 4-piston calipers and 12 5/8" rotors, my brake pedal is a bit longer. Livable, but not preferred. When I install the rear system, I most definitely will need a larger master cylinder.

    My questions are (and have been posted before) are:

    A) Are there ANY known interchangeable MCs out there? Gerrit mentioned a Dodge minivan MC fitted his 308 GT4... Maybe a slightly larger Dodge unit with the same mount points would be the answer. Can anybody else out there confirm the Dodge connection?
    B) Can the stock MC be bored out to a larger bore? That is the issue, right? Internal bore size, to enable more pumped fluid per stroke?
    C) How about a 328 master cylinder? Are they larger, with the same mount points?
    D) Any other European manufacturer interchangeablility? Porsche/Alfa/Maserati.....?
    E) What about a dual MC setup? Sounds like a larger headache--I'd prefer to keep it simple and single, if possible.


    3) Tilton brake bias valve install....

    This is the last thing I'll deal with, don't HAVE to have it right away, unless installing it at the MC/booster is easier during MC replacement. The stock proprtioning valve should keep things properly balanced.... I'd prefer a safe interior location.


    #s 1 and 2, I'd love to resolve soon. I'm eager to install these larger rear Wilwoods and rotors (rears will be 12")

    Any ideas welcome,
    Greg
     
  6. pad

    pad Formula 3

    Sep 30, 2004
    1,418
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    Paul Delatush
    Wil,

    I have the Series IV 4 piston Coleman calipers and rotors front and rear with Tilton dual master cylinders with the cable operated bias adjuster. In addition, in the cockpit are dual liquid-damped brake pressure gauges to monitor for consistent adjustment. Coupled with the Coleman racing brake pads, the car stops on a dime, and has never given me pause for concern on the track. If you like, I'll post some pictures later this week, or since you are only about a hour away, you are certainly welcome to come up and check out the installaiton in detail.

    And no, I do not have an emergency brake nor do I miss it.

    -Paul
     
  7. wildegroot

    wildegroot Formula 3
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    Nov 19, 2003
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    Wil de Groot
    Paul,

    Yes, thanks. I would love to see pictures and thanks for the invitation. I would like to come up and take a peek at your rig.

    I believe I remember you telling me before that yours is a track car. I'm not hyper about the possible lack of parking brakes but it could come in handy on a mostly street driven car.

    Wil
     
  8. wildegroot

    wildegroot Formula 3
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    Nov 19, 2003
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    Wil de Groot
     
  9. wildegroot

    wildegroot Formula 3
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    Nov 19, 2003
    1,513
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    Full Name:
    Wil de Groot
     
  10. greg328

    greg328 F1 Rookie

    Nov 17, 2003
    4,178
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    Wil,
    Thanks, I know, I want the rears to be contributing maximally.
    Right now they're stock, but when I install the rears I'll have much more rear braking torque.

    I can't go any further until I figure out the park brake and MC issues though.

    Thanks for the Testarossa MC/booster idea. Can anybody confirm/reject a 308/TR master cylinder-booster interchangeability? How much larger is a TR booster? Only so much space under the small 308 bonnet!

    Anybody that can give me a detailed response to post #30 in this thread gets a Christmas card this year!!!


    Greg
     
  11. wildegroot

    wildegroot Formula 3
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    Greg,

    As far as I remember the two boosters are virtually the same in design and size. The MC is slightly larger on the TR if I remember right. I just never measured any differences in MC bore diameters or mounting hole spacing. It didn't matter at the time.

    I really regret that I got rid of an old MC/booster from a TR last winter. You can't sit on old junk forever but you'll always see that as soon as you chuck something out, you find you need it, not much later.

    Wil
     
  12. greg328

    greg328 F1 Rookie

    Nov 17, 2003
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    Thanks Wil. Maybe somebody else on here can confirm that TR/308 master cylinders interchange. Further, maybe somebody here has a used one to sell!!

    Of course, this is of no use unless the TR MC is a larger bore.

    PM me if you do....in the event of a fit.

    Greg
     
  13. don_xvi

    don_xvi F1 Rookie

    Nov 1, 2003
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    Do like Aston Martin does: run the cable through a bent tube to change the direction of the cable pull.
     
  14. greg328

    greg328 F1 Rookie

    Nov 17, 2003
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    Don,
    Interesting. Seems like that method would present mounting problems, and friction issues, though.

    How exactly does Aston Martin do that? They must have a way to keep that cable lubed..

    Greg
     
  15. chrismorse

    chrismorse Formula 3

    Feb 16, 2004
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    chris morse
    If the new e brake caliper has the same length lever arm and the screw mechanism has the same pitch as the stock 308 set up, (same pull requirement), then a tube or sleeve support or a supported pulley will suffice to change the application of force 90 degrees.

    I am leaning toward a bearing suported piece of steel that has a series of holes drilled in a disc at 90 degrees to attach the cable and the actuating arm, so that a suitable, (ergonomic and stronger than stock) clamping force may be applied. This would be adjuastable, where a cable routed through a 90 degree turn would not.

    Sorry, a couple of beers has robbed me of my eloqutition :)

    chris
     
  16. greg328

    greg328 F1 Rookie

    Nov 17, 2003
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    Greg
    Chris,
    Wow.....!


    Greg
     
  17. greg328

    greg328 F1 Rookie

    Nov 17, 2003
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    Greg
    OK, I'm dredging up my old thread again...

    Anybody care to add any new info? Still looking for a larger MC, and a park brake solution, including cable pull issues.....


    Thanks,
    Greg

    77 308
     
  18. wildegroot

    wildegroot Formula 3
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    Nov 19, 2003
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    Greg,

    Did you ever try a TR brake master cylinder?

    If you can wait, I'm working on having available an aluminum, direct replacement parking brake caliper for the 308/328 early next year. No fitting or cable issues, install and play.

    Wil
     
  19. BigTex

    BigTex Seven Time F1 World Champ
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    Dec 6, 2002
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    He's gonna HAVE to wait, 'cause no one else in the whole wide world is re-engineering 1977 cars but HIM...;)


    Greg328, come by the Art Car Ball on Thursday! The Meridian, right down the street from work.....I'll loan you my Parking Rock....LOL!
     
  20. BigTex

    BigTex Seven Time F1 World Champ
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    Wil, your 308 job is awesome...it appears very similar to what Chris Parr did with his F40 system...nice work!
     
  21. greg328

    greg328 F1 Rookie

    Nov 17, 2003
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    Will,
    Sounds great--I'd love to hear more... Finally, somebody took the bull by the horns!

    Are you going to mount it via the stock upright position (rear of rotor using existing holes)?

    Nevet tried a TR master cylinder--don't have access to one. Kinda risky to buy one on a gamble! Anybody care to loan me one for a test fit?

    BT,
    What time does the ball @ the Meridian start? My gig starts @ 6pm @ Vic and Anthony's downtown..... I'd like to check it out!
    Don't need to borrow your parking rock just yet, still haven't swapped out my rear calipers yet. My car's back from the body shop. looks great. Still waiting on a rear shock rebuild return, though. She's up on jack stands right now. :(
    Wonder why the 308 owners around the world aren't more interested in upgrading all 4 brakes? The brakes are the only part of the car I feel make it sub-standard. I have no problem w/ the power output and handling, just the darn brakes seem so wimpy to me. Of course, my daily driver is an M3, and brakes on that car are simply incredible. Guess I expect too much from old machinery! :)

    Will, I'd love to hear more about your park brake design...

    Greg
     
  22. wildegroot

    wildegroot Formula 3
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    Big Tex,

    Thanks for the compliment. Where can I see Chris Parr's F40 work?

    Wil
     
  23. wildegroot

    wildegroot Formula 3
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    Nov 19, 2003
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    Greg,

    Yes, my intention is to mount a light-weight aluminum parking brake caliper exactly where the stock rear caliper mounts and on the stock mounting ears with the stock brake cable. I'm way too busy on all kinds of projects that are keeping me from getting my 308 on the road right now so the last thing I need at this moment is one more distraction but I definitely plan to start on the project this winter. I'd rather not say anymore than that if you don't mind.

    I got rid of a TR brake master cylinder not long before you asked about an alternatine to the 308 unit a while ago, haven't removed one since then and don't have aTR in the shop right now. If I run into one I'll let you know. But like I told you before, the design is very similar to the 308 unit. It's worth it to chase after one to take some measurements.

    Maybe you can talk a TR owner into at least measuring the mounting stud spacing for you but an adaptor block can always be made.

    Come to think of it, I would start measuring old master cylinders from mercrdes and BMW cars. Years ago we perked up the brakes on a couple of Maserati Ghiblis with Mercedes master cylinders that fit perfectly. The Bonaldi units on the Ghiblis have square section O-ring type piston seals that always leave a squishy feeling pedal. The Mercedes units use superior cup type piston seals that give a rock hard pedal. It may just take some begging and rumaging to find something usefull for your 308.

    Wil
     
  24. greg328

    greg328 F1 Rookie

    Nov 17, 2003
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    Thanks Will,
    Good info. I'll try to hunt down a TR MC. Any certain year I should pursue?

    They made the TR in different iterations from 1985 to 1994, right?

    I look forward to hearing more about your park brake concept and execution, (and marketing plan/pricing!) as the time nears.

    Thanks for all the good info/tips!

    Greg
     
  25. wildegroot

    wildegroot Formula 3
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    Greg,

    I'm pretty sure all the original TRs made in the eighties used the same MC but a parts guy can tell you better than I can. I would seriously look into the alteratives I mentioned though. The reason I looked at what Mercedes had available was that they make fairly heavy cars and they use standardized European parts. An MC from a little econo-box would be too small and many Mercedes use a four hole square mounting flange and a similar plastic reservoir.

    BTW: Before you start asking other info about Mercedes cars I should tell you that I know very little about them. I just know this MC info from looking for alternatives for the Ghibli.

    Wil
     

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