Hydraulic Handbrake questions

[wagonist]

After the motorkhana at Dubbo, I wish to investigate this option more.
Especially after seeing Shane & Phil basically turn on the spot.

The standard Toyota cable & drum handbrake doesn't cut it for this kind of use & I may as well use the new 2 spot calipers & 315mm rotors I've now got on the rear of my car.

I think the biggest catch is that I want it sit under the original centre console when not in use.
ie I'll remove the centre console for when I want the hydraulic version to be in use. (there's a bit of room under it because there's the controller for the airbags plus space for decent sized wires used on an AC outlet on the back of the console.

Does this mean I'm going to have to hide a fluid reservoir under there too?
Obviously, I'm going to have to tap into the rear brake lines and re-route them also.

So how much chance is there of having a way to disconnect the tailshaft when this lever is pulled

[Billzilla]

Does this mean I'm going to have to hide a fluid reservoir under there too?
Obviously, I'm going to have to tap into the rear brake lines and re-route them also.

No, a hydraulic handbrake doesn't have a reservoir it just has another master cylinder sitting in the rear brake line. I don't know what one it is in my rally car but it works really well - I can hit the brakes normally and then add pressure to the rears with the handbrake as well. So with the foot brake the pressure goes straight through the handbrake cylinder.
It's off some English car I believe.

[Rodger]

I had used a Celica clutch master cylinder. Tapped into the rear brake line. Rear brake line feeds into where the reservoir normally goes and the rear line then comes out of the cylinder's port. A bit of lathe work to make adaptors to screw M10 brake fitting into the M16 port (dont re-quote this one but its a big size).
In my old Celica I fabricated a bracket welded to the rear of the handbrake mounting ears to support the MC horizontally and an upright off the handle to connect the pushrod to. It sat up around 250mm from the tailshaft tunnel.

Picture may still be in this link I cannot see them on this PC.

http://www.toymods.org.au/forums/showthread.php?t=3232

Perhaps you can mount the MC vertically to your handbrake and have the pushrod act vertically.

Mount a parallel MC same as your existing clutch one, tapped into the clutch line and it can activate the clutch at the same time as locking your rear wheels.

Regards

Rodger

[lexsmaz]

So how much chance is there of having a way to disconnect the tailshaft when this lever is pulled

Sorry to be so frank, but Its called a clutch pedal ...

[wagonist]

Sorry to be so frank, but Its called a clutch pedal ...

Well Frank, I think you guys missed the point of my last line.
How many drive wheels does a Caldina GTT have?

I think you guys also need to remember that I have 2 rear brake lines, unlike your old live axle equipped cars. And these need to be kept completely separate due to the ABS system.

[thechuckster]

you need to talks to bates & co about how they did the hydro handbrake on the non-WRC-spec GT4s. Subaru & Mitsu have the advantage of a centre diff controllers that can do funky stuff like disconnect the rear from the front when you reef on handbrake (and other much smarter stuff like changing the torque transfer rate based on yaw rate, accel, road speed, etc).

Have you talked to Ben Cullen & co. about how the handbrake works in their Evo?


btw - you can get dual cyl hydraulic handbrake - clicky.

[wagonist]

Cheers, that looks pretty compact. Would be wicked to have a full on vertical lever in there (but would look severely out of place in a wagon)

I had been planning on looking at some of the rally setups, but I also know that they don't have to worry about it being concealed under the console for normal use.

The disconnecting of the rear was only meant as a bit of a gag.
I should try it in the "new" work car.
Auto impreza wagon. They have a spot for fitting a fuse so that the box runs in FWD mode). Hook this upto the handbrake light & all is sweet
Pity about the small clause in the use contract about "non competition" use. That & it's a gutless piece of pus.

[Disturbed1]

onm;ly think i dotn like about hydraulic handbrakes (im sure u coudl set one up better) but if u pull up the hand brake , then press the foot brake - the fluid pressure will want to force the handbrake lever back down (off)

[wagonist]

There's not many situations (in fact I can't think of any) where you'd have the handbrake on for long enough for this to be a problem.

ie a handbrake turn takes much less than 1 second to do & the pulling of the handbrake to initiate it is on for less than this.

[Rodger]

Double up the number of MCs as in that clicky link from the chuckster. Build two side by side, you may not need the balance bar arrangement.

Regards
Rodger

[takai]

Dont bother with the balance bar arrangement, put the entire thing under the center console and then have a removable lever. I.e. just bolt the long lever in place when you need it.

[wagonist]

I was talking to a Subaru workshop today who did this for one of their customers with an 02 STi (ie Brembos all round).

Basically, the system didn't work as the rear discs wouldn't lock up as easily as the drum handbrake.

I know there were a couple of cars at Dubbo, but they were both RWD & one was an auto, so therefore they weren't fighting against the tailshaft for drive.
ie my car will have drive from the front wheels trying to transfer to the rear wheels which would be overcoming the braking force.
Later STi's & the EVOs have electronic centre diffs whereby they can "disengage" the rear drive.

Based on this, I'm just going to continue with my current philosophy of just tightening the buggery out of the cable adjustment before events.

Thanks for the enlightenment, hopefully the info is useful to others.