17 replies to this topic

[SmacT]

G'day,

I am building a LX four door, with a 9-inch diff with commodore disc rear to go in, and a set of Hoppers Stoppers 300mm front brakes already bolted up. The car currently has a standard single diaphram brake booster, with the standard PBR 15/16 master attached. I have a standard (for now) VS SS 304i engine going in and the car is for street use only.

I like the look of the dual diaphram V8 boosters in the engine bay, and wanted to go with that, but also want to get rid of the ugly proportioning/bias valve.

Will the below master (with 1-inch bore) I found on ebay: 1. fit the V8 booster, 2. work with the disc rear (have internal proportioning that is effective) and 3. still give good pedal feel? I will be going to the seller of course, but first want to know if anyone has any experience with this particular type, or has a better alternative. It appears a quick fix, but I'm old enough to know there's no such thing, and am wary of anything on ebay. The brakeline holes appear to be for a LHD car, too?




http://cgi.ebay.com....e=STRK:MEWAX:IT

I have read the commodore brake option tutorial stickied above, but really want the fat booster. Actually stopping is most important though. :-)

[dattoman]

OK... first up

How do you have a 15/16 master on the car now.?
The common mass produced 15/16 is Commodore and therefore has prop valve built in... you say you want to remove your prop
So I'm guessing... that you guessed the factory master is 15/16 and thats incorrect

Factory is 1"

Now... onto the pictured master.... it has no proportioning valve in it... so that doesn't help you delete yours
Ands its 1" just like your original
But it looks pretty

If this is the style of thing your after might I suggest
1. Get a double booster first... there are a couple of types for LX depending on the rod to the pedal
Straight or bent end
Try Hydroboost for this
Early straight rod http://cgi.ebay.com....=item1c19b82bc3
Late bent rod http://cgi.ebay.com....=item1c19b8274a

2. If this is the sort of master your after... get the 1 1/8 version for higher volume displacement to better suit the calipers. You will find that has the outlets on both sides and plugs that blank off the non required holes
I prefer the alloy Corvette masters myself in 1 1/8 but they have wire holding the cap on... not that wanky flat top thing

3. Get the booster front pushrod sorted to suit the master cylinder... this adjustment is important

4. You still need your valve with this master... hide it under a guard


Or alternatively... if you want the Commodore style to remove the valve assy rather than just hide it

1. Buy booster (this one if you have a bent rod to pedal) http://cgi.ebay.com....=item1c19b82b16
2. Buy master (P10050 at any reputable brake shop)
3. Pushrod clearance adjust
4. New pipes
5. Enjoy

[ls2lxhatch]

The Hopper Stoppers kit does not require a 1 1/8 master.

AU calipers 2 x 41 mm pistons. Pair area 264 mm2
Torana PBR Alloy 1 x 63.5 mm piston. Pair area 317 mm2
Torana PBR Cast iron 1 x 54 mm piston. Pair area 229 mm2

The 1 1/8 master will require more pedal effort than the factory 1" master.

[dattoman]

True... but if stepping up to the double booster.... it won't matter

[76lxhatch]

The Hopper Stoppers kit does not require a 1 1/8 master.

Not required but I'd highly recommend it, the larger master gives far superior pedal feel

[ls2lxhatch]

The penalty for reduced pedal movement is reduced brake pressure.

The 1" master will give you around 25% more brake pressure than the 1 1/8" master.

[SmacT]

Great thanks all for your input.

Yes, I had assumed it was 15/16 - thanks for setting me straight. I enjoy your bluntness Dattoman. :-). Ok, I'll go the dual diaphragm booster ( need the bent rod one) but will think about the master. Im fussy on pedal feel so want to get it right.

Also,'anyone know if brake bias valves are illegal? Being able to tune the back end braking would be a nbig advantage in a light-assed Torana, but I think they are a no go in NSW. Must be easy hide though, eh?

[ls2lxhatch]

It is my understanding that adjustable proportioning valves are legal as long as they can not be adjusted whilst driving the car.

[SmacT]

Cool, thanks ls2lxhatch, that actually makes sense, which is surprising for a law. Ok, I will research it a bit more and think about adding that in.

[ls2lxhatch]

To register the Torana in Australia it has to comply with ADR 31. ADR 31 is a brake fail indicator.

This is normally achieved via the factory distribution block/proportioning valve which has a brake fail switch. As far as I am aware none of the aftermarket distribution blocks with proportioning valves have a brake fail switch. I did contact SSBC a couple of years ago to see if they were interested in making a distribution block with integrated proportioning valve and brake fail switch but it has not eventuated.

SSBC do make a master cylinder with an intergrated adjustable proportioning valve however you still have the ADR 31 problem. The wires are for the brake lights.



An alternative method if detecting brake fail is to use fluid level switches in the master cylinder which are available for some of the Wilwood masters.

The simple solution is to retain the factory distribution block/proportioning valve but with the proportioning valve disabled. Then fit the adjustable valve near the drivers side rear suspension trailing arm

I used the distribution block with brake fail switch from the HQ, LC/LJ and drum brake LH/LX with a separate SSBC adjustable proportioning valve mounted near the drivers side rear suspension trailing arm.

The brake lines in these photos are just prototypes. There is a cover that goes over the distribution block and another cover for the proportioning valve.

Edited by ls2lxhatch, 30 March 2011 - 02:57 AM.

[ls2lxhatch]

You can not replace the brake light switch with a brake fail switch in the Wilwood or SSBC units.



The brake fail switches are triggered by a difference in pressure between the front and rear circuits. The brake light switches are triggered by pressure in the front circuit only.

I did not want to use the fluid level monitoring as I was did not want the associated wiring in the engine bay.

Edited by ls2lxhatch, 30 March 2011 - 10:46 AM.

[Struggler]

FWIW I have used a Ford XA/B 1" M/cyl before (3 or 4 times).

Needs the pushrod lengthened a bit and the mounting holes filed out a bit to fit, has an intergrated switch and the lines come out on the inner guard side. Not sure on the balance factor, still locked the fronts before the rears so I just ran with it.

JMHO

[Hybrid]

Or alternatively... if you want the Commodore style to remove the valve assy rather than just hide it

1. Buy booster (this one if you have a bent rod to pedal) http://cgi.ebay.com....=item1c19b82b16
2. Buy master (P10050 at any reputable brake shop)
3. Pushrod clearance adjust
4. New pipes
5. Enjoy

Would this recommendation also apply for an LC Torana? Would the resevoir of the master cylinder end up pointing "down hill" in a LC?

Cheers.
Brett