Progress

[jpayne]

and captive nuts for the gaiter

and welded in

also closed another hole in the bulkhead as the wiring has to be located as the inlet plenum is in the way and welded the base feet for the front cage legs, added additional stitch welds to the link boxes, and finished welding the seat rails.

JP

[jpayne]

A couple of Gussets made tonight.
Awaiting the big weldathon soon.



and a handbrake.
I will make provision for fitting this but may not install. The car may do other duties later in its life or not but 50 bucks worth a punt

the question now. Push or pull?

JP

[ozstang65]

Having made quite a few hydraulic handbrakes in my time, my first impressions are that the handle is not long enough. Also, that style of master cylinder relies on an internal valve to block off pressure back to the master cylinder. If you land hard on the footbrake then lean on the hydraulic to lock up the rears there is usually enough residual pressure in the rear lines to lock the internal valve on and therefore lock on the rear brakes. This requires a hard quick stab on the footbrake to release the rear brakes.

I made the mistake of this style of cylinder on an X19 that I have and can readily demonstrate it! It can be driven around, but makes you slower.

Next hydraulic handbrake i make will use something like this one: Wilwood MasterCylinder No: 260-12384 5/8

[Matt1975]

That's interesting Ozstang, I have recently installed a hydro handbrake and notice that when the handbrake is on the foot brake is next to useless. It seems that I need to use one or the other but not in tandem.

I want a smaller m/c anyway as the current one (0.7) doesn't quite lock the rears without maximum effort even with a longer handle.

Would a better m/c or some sort of pressure valve alleviate this?

Sorry to hijack JP.

Cheers

Matt

[crusey]

For a circuit racing car a handbrake is rarely required and certainly not cumpolsory. I'd delete it unless your considering drifting it/using it for motorkhana (the turbo will be less than ideal if that's the case).

With a tight LSD or locked diff and 15/16 inch wheels a little bit of steering lock will solve it rolling away on you.

[ozstang65]

I'm still running a Mk2 diff with drums so I have the original handbrake in place and wouldn't want to be without it. Sprints and hillclimbs usually have a lot of 'inching' towards the start line where it comes in very handy. You could work around not having one, but much easier if its there. Also, I'd never use hydraulics for a park brake.

For motorkhanas and rally hairpins you really want to be hard on the footbrake to transfer weight forward, then turn in, clutch and a quick hard jab on the handbrake, just long enough to break the back end free then off the clutch and slide it around on power. Seeing as you're on the footbrake already, the hydraulic handbrake will barely move when you get on it as the lines will already be pressurised. That's where the master cylinders with the internal valve fall down as they won't release the pressure.

The style of m/c I linked to above has a piston with 2 seals on it and an inlet and an outlet port. In normal operation there is nothing inbetween the inlet and the outlet ports so brake fluid can move in either direction easily. As soon as you begin to move the hydraulic handbrake the first seal moves past the inlet port and pressurises the lines downstream of the handbrake only. As soon as you release the handbrake there is once again no restriction to the normal flow of brake fluid so the pressure in the rear lines is released back to the master cylinder.

The type that Justin has, and I have in my X19, has only one seal on the piston and you can see that the outlet to the rear brakes is closest to the piston. The only way that this m/c can pressurise is that there is a spring loaded one-way valve on the inlet line. As soon as you pull on the handbrake fluid will begin to go back towards the inlet line, but the valve rapidly closes and you pressurise the rear lines. This is all well and good if you use the handbrake on its own as you need a lot more m/c travel to get the rears to lock. when you release the handbrake the pressure in the rear lines can lower enough to release the check valve and your brakes will operate normally. If you are driving properly however, you have the rear lines already pressurised when you go for the handbrake. The handbrake piston still moves and shuts off the check valve, the rears will lock, but when you release the handle there is not enough release in pressure to release the internal check valve and the rears will stay pressurised, possibly locked.

Also, regardless of which style of m/c you go with, there must be a positive stop on the handbrake lever as the piston inside the hydraulic handbrake m/c will be seeing pretty much the same force that you are stomping on the footbrake with. The circlip that holds the cylinder inside your hydraulic m/c will not take this force and will quickly fill the inside of your car with brake fluid.

And one final word of warning, I once replaced a worn out hydraulic handbrake m/c which then failed almost immediately. Upon inspection it turned out that the piston inside the new m/c was plastic! Luckily the one which I had replaced had an aluminium piston which was the same size so i swapped it over, then all good.

[jpayne]

Stang,

you make a compelling argument so its into the spare parts bin for this part.
Ill still make provision for one just in case Kanahs et al are on the cards. I know turbos are not as good for this But I have 9 and a bit:1 comp for off boost power.
Car must do multiple duties if its to be warranted.

JP

[jsa]

[jpayne]

[jsa]

That's a fair bit of cam, what revs you taking this turbo beast too ?

[jpayne]

Redline at 9K

JP

[stuart]

On the handbrake subject i am running twin R31 callipers a set dedicated just to the hand brake so that you can have you foot on the brake and if you want more rear brake you can pull on the handbrake. I can get the bracket laser cut for standard escort diff , hilux using twin R31 on the audi 100 disk and also hilux with twin R33/R34 using the r33 disk

[jsa]

9k, big hair dryer then.

[jpayne]

managed to assemble and disassemble the rear suspension without taking a photo
But i did assemble the front suspension so I could weld the Compression strut brackets on




Also filled in a few left over holes seam welded the transmission tunnel and finished off welding the front wing rail on drivers side. Tested the sand blaster on the shell and its going to take a long time to finish so Ill farm this out.
Intercooler, hoses and harness arrived this week too. If only I could order some spare time.

JP

[ozstang65]

It's great to be able to work on a car upside-down isn't it

[jpayne]

sure is.
But I have a bad habit of smashing flouros with it .
Keep leaning them against the shell and spin it then boom! another trip to bunnings. I buy 4 packs at a time. I just cant seem to remember.

JP

[jpayne]

Nothing like a long weekend to get stuff done
Spend a good 4 hours touching up welds and finishing little bits and pieces of grinding etc.
then pulled the new dash out oft he bag and offered it up.
After drilling the required holes and scolloping out the dash opening

Its f.....g crooked!


So finished the other wing rail.

Will be back on the ground on Monday as its off to the sand blasters next week for inside underside engine bay and boot to be stripped.
Maybe more photos then.

JP

[MK1_Oz]

Where was the dashed flocked? Looks good

[jpayne]

dash was flocked in the UK and we bought it back with us. first time its been out of the box since.
Pity its warped

JP

[jpayne]

A bit exciting.

but a bit tight


But also good articulation

One more

Anyone have a measurement to centerline of rear axle from a known part of the car as its all too far back. Might leave it there however and cut the arch and reshape!??!?!

Also got to sit in it and everything is in reach or can be seen past. The A pillar gusset is not visible and the roll bar is as tight against the original windscreen surround as possible so good visibility. Seat is at right height as I can just see the guard humps.


JP