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Prius E-Brake Upgrade

Discussion in 'Gen 3 Prius Accessories and Modifications' started by priusguy09123, Mar 20, 2020.

  1. priusguy09123

    priusguy09123 New Member

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    Hi all, thanks for your time & Help.I used to have an old subaru wrx and enjoyed it but I got married and my new wife made me trade the subaru in for a 2012 toyota prius. I still wanted to do slides and drifts in it so I thought that the first step towards that would be to upgrade the e-brake/Parking brake. I know that the prius has very small but efficient tires which are very easy to break grip with and should make for some fun sliding around so there was my idea, Please give me some feedback if you can!

    I would install a hydraulic valve(s) to the front brakes controlled by a simple 12v momentary switch so that when the switch is engaged, the valves are closed. Theoretically, when I want to drift I would hold down that switch which would separate the front brakes from the main braking system and then the normal brake pedal would only apply pressure to the rear brakes. This would serve functionally as an ebrake in other cars and means that if someone who doesn't know about the system (Wife even though she rarely drives), the momentary switch would be disengaged and the front brakes would still be in the line. The only alternative I thought of was separating the front/rear brakes and having a hydraulic lever on the rears and the hybrid/main brake system on the fronts. Thoughts? Comments? Suggestions? Please don't discourage the drifting in a prius but if I'm technically or realistically not getting something, definitely let me know, Thanks!
     
    #1 priusguy09123, Mar 20, 2020
  2. SnowMexicanuck

    SnowMexicanuck Member

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    You'd need to disable abs and traction control... Traction control is there to do its normal job, but also there to protect the hybrid system from over reving.

    Driving around in maintenance mode isn't a good idea either.
     
    #2 SnowMexicanuck, Mar 22, 2020
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  3. Grit

    Grit Senior Member

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    Sounds like a Prius wasn’t made for drifting :D
     
    #3 Grit, Mar 22, 2020
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  4. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    FWD cars (like the prius) can't drift. You can still have a little fun sliding, but true real-deal drifting requires torque on the rear wheels.

    The brake actuator in a Prius is substantially different from the master cylinder in any Subaru (or most other cars) for that matter.

    It is already doing some pretty sophisticated wheel-by wheel management for brake force distribution during braking and also for ABS and traction control. Simply blocking flow on a couple of channels would be undefined behavior. It might work, but I think it's fairly likely to freak out several ECUs the first time you shift flow and hit the pedal.

    Just to be clear, I'm a big fan of modding and personalizing cars but I would caution you that this is a tall order. Even without the complexity of the brake system, the physics of FWD mean that you just aren't going to get a very satisfying oversteer out of the skinny pedal no matter what you do.
     
    #4 Leadfoot J. McCoalroller, Mar 22, 2020
    Last edited: Mar 22, 2020
    Ed Beaty and Grit like this.
  5. Ed Beaty

    Ed Beaty Active Member

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    JeanLucFacepalm.jpg
     
    #5 Ed Beaty, Mar 22, 2020
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  6. SnowMexicanuck

    SnowMexicanuck Member

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    FWD isn't really the problem, I usually spend my winters throwing my car around using the hand brake, but that was before I had the Prius. With my former Tercel and multiple gens of Corolla, I was actually having some fun in the snow. I'm planning on getting another winter beater for that reason as I cannot stand not being able to do anything with the Prius without messing with electronics and possibly damaging something.
     
    #6 SnowMexicanuck, Mar 22, 2020
  7. Leadfoot J. McCoalroller

    Leadfoot J. McCoalroller Senior Member

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    Understandable. The torque of the Prius electric drive is capable of dangerous acceleration in low or no traction environments. That is, dangerous to itself. It can rip the drivetrain from zero to beyond redline faster than a human can react unless traction control is available to catch it.

    Our 2007 Accent has been a wonderful winter beater. You can probably find one of the MC models ready to go for under $3k.
     
    #7 Leadfoot J. McCoalroller, Mar 22, 2020
  8. Mendel Leisk

    Mendel Leisk Senior Member

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    Why I always buy new...
     
    #8 Mendel Leisk, Mar 22, 2020
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