News

308 aftermarket parking brake available?

Discussion in '308/328' started by greg328, Oct 15, 2005.

  1. greg328

    greg328 F1 Rookie

    Nov 17, 2003
    4,134
    Austin, TX USA
    Full Name:
    Greg
    Did the search, found no definitive answers....

    I'm about to upgrade to larger rotors and 4-piston Wilwoods, and I'm going to lose my park brake. Does anybody know of a currently-available system for the 308 (mine's a 1977 GTB) that would bolt on?

    I read about the possibility of using a second MC and rear calipers as a park brake, but obviously this wouldn't function as an emergency brake, in the event of loss of hydraulics. Might there be a cable-operated method, if not acting upon the main caliper, a second, smaller caliper, located by a custom bracket? Any of you engineer types up to it....??!!

    I dread the loss of my park brake, and probably will have a hard time passing inspection, if the place I go to is picky......

    Any ideas?


    Greg
    1977 308 GTB USA
     
  2. To remove this ad click here.

  3. Doug

    Doug Formula 3

    Nov 13, 2003
    1,467
    Louisville KY
    Full Name:
    Doug
    When I had a Pantera with upgraded brakes, it had a line lock on it that worked well.
     
  4. greg328

    greg328 F1 Rookie

    Nov 17, 2003
    4,134
    Austin, TX USA
    Full Name:
    Greg
    Doug,
    Tell me more about the line lock. I've never heard of that...

    Greg
     
  5. Doug

    Doug Formula 3

    Nov 13, 2003
    1,467
    Louisville KY
    Full Name:
    Doug
    It actually locked the hydraulics. You press the brakes and flip a small lever that was installed where the brake lever originally was. Did a google search and today they all seem to be electrically controlled. Mine was not.
    http://robrobinette.com/brake_valve.htm
     
  6. jvecchi

    jvecchi Formula Junior

    May 5, 2005
    331
    Sarver, PA
    Full Name:
    John M. Vecchi
  7. To remove this ad click here.

  8. greg328

    greg328 F1 Rookie

    Nov 17, 2003
    4,134
    Austin, TX USA
    Full Name:
    Greg
    Have any of you ever installed one of these line locks on your 308?
    Is it practically the same as the OEM park brake? Meaning, will it provide the same functionality?


    Greg
     
  9. ferrarifixer

    ferrarifixer F1 Veteran
    BANNED

    Jul 22, 2003
    8,520
    Melbourne
    Full Name:
    Phil Hughes
    All authorities I'm aware of require a mechanically operated independant system for roadworthy emergency brakes.

    A line lock will work perfectly, but most likely not satisfy regulations.

    The idea is that in the event of loss of hydraulics, you have a back up.

    We all know that a 308 handbrake is really only a parking aid, and could never stop the car from cruising speeds, but that is not the point!
     
  10. greg328

    greg328 F1 Rookie

    Nov 17, 2003
    4,134
    Austin, TX USA
    Full Name:
    Greg
    If not a line lock system, what are my other options? Possibly a second rear cable-operated caliper? That would involve some serious machining/bracket geometry to provide a solid mounting point....

    Has it been done? Can it be done?

    Greg
     
  11. Jdubbya

    Jdubbya Two Time F1 World Champ
    Silver Subscribed

    Dec 28, 2003
    24,713
    PNW
    Full Name:
    John
    The only rear brake upgrade I've seen for a 308 uses the stock calipers for exactly this reason. As I'm sure you know the park brake is integrated into the rear caliper.
     
  12. To remove this ad click here.

  13. ferrarifixer

    ferrarifixer F1 Veteran
    BANNED

    Jul 22, 2003
    8,520
    Melbourne
    Full Name:
    Phil Hughes
    To be honest Greg, unless you're racing your car, there is very little, if any, need to change the rear brakes. Small mods to the discs (slots) and racy pads will suffice... and even installing a brake pressure bias adjustment if you really want. But to change the whole rear brakes is massive over kill and really creating all sorts of unnecessary costs and time delays.

    I advise against changing them if it's a road car. The gain isn't worth the pain.
     
  14. greg328

    greg328 F1 Rookie

    Nov 17, 2003
    4,134
    Austin, TX USA
    Full Name:
    Greg
    Phil,
    Well, I guess I could install only the front set (rotors/calipers), and the bias knob. Experimentation with the bias may provide all I need. Maybe ********'s lighter rear discs may help. Also the Durable1 brake proportioning valve....
    I still would prefer to install the larger rear rotors and Wilwood 4-piston rear calipers, and somehow find a method to retain a cable-actuated park brake. Didn't I read hear about a guy in Australia who custom-fabbed a rear caliper that had a park brake?

    Greg
     
  15. atlantaman

    atlantaman Formula 3

    Mar 31, 2002
    1,726
    Roswell, Georgia
    Full Name:
    Charles
    Greg--im working on a new set of calipers with integral parking brake----other that that you are pretty much SOL for mechanical brake--unless you can obtain a set off of at crashed 360
     
  16. greg328

    greg328 F1 Rookie

    Nov 17, 2003
    4,134
    Austin, TX USA
    Full Name:
    Greg
    Charles,
    I sent you a P.M....

    360 rear calipers will fit a 308? Do they require a special mounting bracket?
    Or, they bolt right up?

    I would imagine the rotor size would have to be exactly the same as the 360 the calipers came off of.....

    Greg
     
  17. greg328

    greg328 F1 Rookie

    Nov 17, 2003
    4,134
    Austin, TX USA
    Full Name:
    Greg
  18. chrismorse

    chrismorse Formula 3

    Feb 16, 2004
    2,149
    way north california
    Full Name:
    chris morse
    check this out:
    http://www.precisionbrakescompany.com/
    This is just the first one i have seen. it looks like the direction of "Pull" is wrong. Keep looking, i will too.

    I am working on a 355 to 308 brake upgrade, utilizing 40-36 brembo fronts and stock brembo rear calipers. Just downloaded some stuff from Philip Airey re the mounting brackets & discs.

    keep working on it.
    chris
     
  19. mk e

    mk e F1 World Champ

    Oct 31, 2003
    11,954
    The twilight zone
    Full Name:
    The Butcher
    Wilwood makes a small mechanical caliper for $56

    http://www.4wheelonline.com/Products.aspx?CategoryId=1551&ProductId=5348

    I'm pretty sure that the lever can be mounted to pull in either direction, and I'd guess so can the one on the percision unit.

    You can get a hydraulic brake lock for $22.00. I had one on a car a few years back. I don't thing they are stickly legal, but mine when through incpection at a few different shops without a problem.

    http://www.mooreparts.com/Merchant2/graphics/00000001/JAMPK1.jpg

    A few years back I saw a mastercylinder/hand lever kit, but I can't find it now, but it is pretty easy to make. Basical it is a mastercylinder designed for a remote reservoir conected to the hand lever. You just splice it in to the rear brake line and the hand lever will operate the rear brakes. Pretty slick....still not strickly legal, but I have never seen anyone look past pulling on handle and about 1/2 the time checking if the brakes actually hold. I'm leaning this way when I do my brakes. It makes a neat, clean install.
     
  20. Mike C

    Mike C F1 Veteran
    Lifetime Rossa Owner

    Aug 3, 2002
    6,075
    Southeast USA
    Full Name:
    Mike Charness
    I don't see that listed on their site. Their brake valve I use is their vacuum valve for the power brake booster.

    As you may remember, I adjusted the bias in my setup (Brembo GT fronts, ******** rotor upgrade rear) via pad choice, which worked quite well for both aggressive street and occasional track.

    www.ferrarichat.com/forum/showthread.php?t=39712

    Mike
     
  21. greg328

    greg328 F1 Rookie

    Nov 17, 2003
    4,134
    Austin, TX USA
    Full Name:
    Greg
    Mike,
    That's what I meant, sorry...!

    Thanks to all you who posted possible solutions to my 308 park brake dilemna.
    Wonder how difficult it would be to mount these on a 308....
    Also, it would be preferable to use the stock park brake handle (on the interior console) and stock cable.

    I was resolved to only install my new fronts, and leave the rears stock, but now that I see these possible park brake solutions, I'm pumped!! Has anybody done this mod to their 308/328?

    Greg
     
  22. greg328

    greg328 F1 Rookie

    Nov 17, 2003
    4,134
    Austin, TX USA
    Full Name:
    Greg
    Mike,
    Why was this thread moved? Isn't it "technical" in nature?

    Greg
     
  23. BigTex

    BigTex Seven Time F1 World Champ
    Rossa Subscribed Owner

    Dec 6, 2002
    74,228
    Houston, Texas
    Full Name:
    Bubba
    Talk to velocityengineer at ********....

    You are covering old ground, as this is the main stumbling point on the 308 upgrade..

    That's why all these people, ferrarifixer and other highly experienced folks are steering you towards the solution of leaving the original rear parking brake in place......

    Did you go track at TWS, last weekend?

    Play with pad compounds as Mike has recommended......I'd just go with OEM sized slotted discs and some nice pads......you still have 14" rims???

    That would be the limiting factor, IMO.....

    Valeria's brothers are all drag racers, they'd know about that 'burn out' stuff.....can you say "snapped halfshaft??? I knew you could." ;)
     
  24. BigTex

    BigTex Seven Time F1 World Champ
    Rossa Subscribed Owner

    Dec 6, 2002
    74,228
    Houston, Texas
    Full Name:
    Bubba
    Most likely cuz it's a 308 specific situation,..........I dunno.
     
  25. velocityengineer

    velocityengineer Formula Junior

    Nov 8, 2003
    488
    Globally
    Full Name:
    Eric Dahl
    Hi Greg,
    I have been over this issue with a fine tooth comb.
    It is possible. It will be time consuming and difficult at best.
    The reality is that there is NO bolt on, no worries, comes in a box setup.
    You are basically going to have to re-engineer the whole rear corner assemblies from the upright out. If you are ready for the challenge, then its mission impossible time.

    Here are some of the main considerations:

    1. Parking brake caliper. Which one? Make shure it can work with the rotor diameter and thickness you choose. This is critical. There are just not many of these on the market, and you will need to find the critical mounting dimensions before you buy. You may find that it wont work with the rotor size and offset you have chosen. If not start at number one again.
    2. The upright has identical mount bosses on the front and rear sides. Only the rear bosses are face machined to mount the OE caliper. You will need to find a competent machinist to face mill and drill the face is critical in placing the parking caliper axially, so make sure you know the dimension. your design needs to take radial and axial dimensions into consideration.
    3. Placement of parking caliper. Do you place it in the front, 3 o clock, or rear, 9 o clock position? Is the parking caliper you choose a pull type lateraly or longitudinally? Consider how you will get a cable to it. And if you move the main caliper position, consider that you will eed to engineer a new rear hydraulic brake line.
    4. Mount bracket, you will not find a parking caliper with dimensions that will allow you to bolt it in place. Some type of bracket will be required between the upright bosses and the caliper mount flange. Better hope there is enough radius in the rotor you choose to allow space for a bracket, or start with step one again.
    5. If you can use the OE cable assembly or not. A new cable will require brackets and proper length adjustment capability. The OE will likely be too short or long, so check for modifying that as well. know the ratio of pull at the lever vs pull at the caliper. The new e brake caliper may require more or less pull than OE.
    6. If you use a one-piece rotor, this will dictate the axial placement or offset. Hope it doesnt screw up the plans for the bracket and cable run, as well as whatever the main caliper bracket mount dimensions are.
    A two piece rotor can be tailored to suit, but they are not on the shelf anywhere as you need. So this is another custom part.

    I have been through this routine. I have done several designs for this type of system for the 308. In the end, the total cost of the machine work plus parts is completely over the top for the benefit. This is why we settled on a rear two piece rotor with great pads for the ******** kit.

    There is an outline of the mission should you choose to accept it.
    It can be done. It will not be easy. It will cost more than it should. It will take many hours from your life. etc...

    But anything of value always does.

    -Eric
     
  26. BigTex

    BigTex Seven Time F1 World Champ
    Rossa Subscribed Owner

    Dec 6, 2002
    74,228
    Houston, Texas
    Full Name:
    Bubba
    Thanks so much...he needed to hear that from YOU!!!! LOL!

    He doesn't believe ME, when I say "Leave it alone and go drive somewhere......."

    What would be your recommendation for someone like me still running OEM wheels on two cars, or more specifically, 16" rims most of the time but putting OEM sets on for show.....so 14" limitation.

    Just need sexy rotors, and some street level pads......I like the idea of the two piece rotors....
     
  27. enjoythemusic

    enjoythemusic F1 World Champ

    Apr 20, 2002
    10,675
    Worldwide
    Full Name:
    Steven
    As always, Eric provides sane, honest advice. i debated various setups and in the end felt i was not going to have a 'pure' race car setup so use the larger front brakes and ******** slotted/floating rears with DS3000 rear pads. With the Mich PS2 tires i am pulling well over a full G in braking and could do more if i used R-compound race slicks. Agree with Eric that at SOME point you hit the wall of HIGHLY DIMINISHING returns.

    Am willing to go the Law of Diminishing returns.. to a point. So guess what i am saying is YES you could have a better brake package with an emergency brake... but at what costs?

    But hey, i say go for it, work it all out, then mass produce it for guys like me to buy at less expensive than a one-off price :)
     
  28. greg328

    greg328 F1 Rookie

    Nov 17, 2003
    4,134
    Austin, TX USA
    Full Name:
    Greg
    Gee guys, you're raining on my parade!!

    I know it will be difficult, but I guess I didn't realize it would be THAT difficult..

    Decisions......

    Greg
     

Share This Page