Twin emergency brake handles

[justyfied]

Planning on putting a stripped out Justy back together for Street driving with the occasional Winter Autocross race. This is the kind of racing on a large gravel parking lot in winter using traffic cones to mark out a course. Which means that the first few runs around the course one has to deal with packed snow drifts that are 100 to 200mm deep over patch's of ice on the gravel. Once the cars have gone a couple of rounds with everybody racing, the course is more established with the snow slung aside revealing the gravel underneath.
This kind of racing really favours a LITE four wheel drive car with a low center of gravity and a short wheel base. A reasonable amount of horse power really helps too when it comes time to muscle thru those snow drifts.
The fastest cars are generally Subaru Impressa STI cars with a warmed over engine and carefully selected WINTER tires.
However there is a couple of epiphany's. A Dodge Neon that has a very high horse power turbo engine and a rally prepped(full cage and non open front diff) Volkswagen Jetta. These last 2 are front wheel drive and are as fast or rarely faster than the STI's.

When I race a stone stock Justy it comes in, in the middle of the field. About the same time as a stock N.A. Impressa or older stock turbo Subaru XT. It could really use some extra power to help in the snow drifts, but later in the day Iam not that far behind the leader's when the course gets established. That is the Justies lite weight helping out.
The Justy is only available with an open differential in the front and the rear drive axle's. There is no differential from front to back, when engaged the rear drive is locked.
This means that when one front tire is on ice and spinning the opposite diagonal rear tire is the only one that will spin. This gives the Justy great traction for a car with open diff's.
My fantasy which I believe is realistic is to modify my car with a turbo and some suspension mods to win this race.
This thread is about my Idea to add a second Emergency brake handle. Which would be staggered more towards the rear, so that without looking the driver can pull a brake for either just the left or right rear wheel only.
Often the course has some very sharp corners which are best negotiated by spinning, over steering or drifting. whichever term you are used to.
My idea would make the back act as a skid steer vehicle with the ability to lock up and drag the inside tire and all of the power would be directed to spinning the outside tire. Should make for a rapid change of direction on the ice
This is a picture of my stock Justy at the Apex of a corner, marked by the cone. Iam going about 70 KPH (42 MPH). ;D

[cpc]

That sounds like a fun project. Could you modify the tunnel and have the levers side by side? It might make it easier to control in the heat of the moment. Will you use a cable of hydraulic system? I have a mate that builds 4X4's for competition with these sorts of mods. Here's a pic of his old competition vehicle. He uses hydraulic systems obviously:



He has customers on your side of the pond and does anything, from the smallest job to complete 6 figure builds. Here's his website:

www.yuri4x4.com/index.php

Do you have any more pics? Are you going to start looking for more power?

Chris.

[ultra_porcupine]

what if you garbed a gm abs with tacton control hard wire with no abs controler so when you hit a button on the steering wheel it locks either left or right rear wheel or both for some kick ass j turns

[cpc]

That's an idea. Maybe you could adapt the electric brakes from a trailer and have them work at full on or off. Use 2 switches like u_p suggested.

Chris.

[justyfied]

Jul 13, 2011 19:43:32 GMT -4 cpc said:

That sounds like a fun project. Could you modify the tunnel and have the levers side by side? It might make it easier to control in the heat of the moment.

Yes, this is what I had in mind, 2 levers. Mounted side by side with the right side one a little bit further back. That way I imagine you could use your thumb to feel if there was a handle to the left of the one you were using. I would eliminate the locking button from the end so that they would snap back and unlock as soon as it is released. Also it might still be possible to grab both at once and operate them together if there is no lock button.
Do you have any more pics? Are you going to start looking for more power?Yes and yes, subjects for more threads I think!
Chris.

Jul 13, 2011 21:24:33 GMT -4 ultra_porcupine said:

what if you grabbed a gm abs with traction control. Hard wire it with no abs controller so when you hit a button on the steering wheel it locks either left or right rear wheel or both for some kick ass j turns

I didn't really want to get into TOO much about the pros and cons of ABS here but,
Any experience I have with ABS in the winter on ice has not been pleasant. Suffice to say that I feel that ABS is best for general public who is most likely to freeze at the controls in a panic stop with the brake pedal firmly planted against the floor. They would be sliding into the back of a stopped car or into an intersection. Without any steering control due to there inability to think under pressure and give the car the steering or braking input needed!
ABS was first used in Formula 1 and is now banned as it would give cars too much complexity. Sure Power brakes and ABS give the ability for higher brake pressures, but that is only good on high traction dry pavement. You do not need higher pressures in the brake lines when the wheels are already locked up sliding on ice. I still feel that a decent driver can stop on a frozen lake faster with out ABS than with it. However they would most likely be spinning and out of steering control----Which is why modern cars have ABS. To enable the general public a chance to steer while braking.
So when I see a mass of extra brake lines and a great big steel box that makes up an ABS system, I see a chance to remove a useless system and reduce the weight of the car. Plus then I could eliminate the powersteering pump which is required to give extra power for the ABS, thus saving some horsepower.
Anyway,end of ABS rant! So any way, I will take this use of an ABS controller only Idea and see.......

[justyfied]

So after having some time to reflect from my ANTI ABS rant.
I realized that I do not need to retro fit an entire ABS system with sensors and a supplemental power steering pump. If I want an electrically controlled, separate rear brake system I could use part of what I already have at home sitting in the shed! It is the ABS from:



Which uses this electrically boosted ABS unit:



Would require adapting a second set of Hydraulic slave cylinders to the bottom of the rear brake backing plates, at the bottom where the anchor is. Would require some careful whittling with an angle grinder to change the brake shoes to fit the cylinders at the bottom. It might even be possible to still retain the Emergency/park brake cable actuated brakes. This would give 3, count em, 3 ways to apply the rear brakes! ;D
Then I could mount a 3 way switch to the shift knob, It would be spring loaded momentary to the left or right from normally open center.

[tomi14robie]

Here in the UK cars used for off roading sometimes have 2 handbrakes(or parking brakes)in order to give some aid as to which wheel gets the traction,they are usually referred to as "fiddle" brakes.
tom