Engineering tomorrow

[Outwest34au]

Well done, all minor things to rectify.
Got plates picked out yet? :-)

[Merv and Sharon]

Good news Greg. Loved the abilities of the "14-year-old boy"!

RE: Adjust brake bias as front locks up before back (Warwick's given me the fix for this)

Let me know what this advice is please as this is a common issue with all the Harrisons, even the more recent model numbers. Some us have managed reasonable solutions to this through pad changes, but interested in what Warwick suggests in your case.

RE: Fit an extension to the front internal bumper. Apparently something an inspector at Zirlmere has been picking on. Not sure what you mean here but I was asked if I had a 'grille'. I claimed that I did - see the pics of the car (it is only an bar that extends from the front chassis frame inside the nose.

[byroncobra]

Merv
On the brake issue. Mine has an XF master cylinder, Warwicks' fix is to remove the piston and take off what he called a frilly cup/o ring thingy on the end. This apportions the right f/r bias apparently, so be removing this i should end up with equal pressure.
There was another story from Ray via Warwick that i may need to swap the m/cyl for a stationwagon spec as the bias is different from sedan. We'll see.

Re the bumper, the later cars i think have a horizontal member that extends from below the radiator support and bends up behind the headlights. It's hardly a bumper, mounted as it is well behind the fibreglass, but apparently it passes the test. My car #38 doesn't have this bar, so I think i can pick up the overrider mount points and weld or sleeve a couple of 30x30 pieces of square tube there to extend into the unprotected area.
I may still need the bar that you have, if nothing else to mount the number plate on.

[Merv and Sharon]

Will be interested to see how the brake bias is with the MC piston 'modified'! Also Ray's comment is interesting about the station wagon MC.

I have fitted softer competition pads on the rear (as done by several others - see Racer Industries). That has made a vast difference and I only now get a slight 'chirp' out of the front left on a full 'panic' stop. Seemingly no lock up is able to be induced. However, I suspect that under repeated braking I could get fade that upsets the balance. Another option is to use the GRT callipers on the front as well, with an adapter.

Anyway interested in your removal of the "frilly cup/o ring thingy"!

Cheers,

[byroncobra]

So do the softer rear pads make them lock up faster, thus earlier than fronts?

My car has Hopper Stoppers 'Big Brake' upgrade on the front, so the callipers are upspeced.

[Merv and Sharon]

I am certainly no expert on brakes but I understand that increasing the braking at the front (via better calipers, softer/higher friction pads, and/or larger rotors) would increase the front/rear bias problem that you and most of us with Harrison's face. The fitting of higher friction pads at the rear helped a lot in my case for little cost (I got mine from Pedders), as they did for some others.

The key issue is the 'crack point", where the fronts are supposed to lock (on non-ABS systems) before the rears - just. You don't want the rear end coming around to meet you. For QT inspection they will (separately) test the rear braking on their roller. You need to have enough there to pass their test but not so much that they lock first.

See: http://autospeed.co.nz/cms/title_Bra...1/article.html

I believe that this is similar to the PBR MC that you will have:

[Pecal]

The bias problem can be fixed by fitting the station wagon/Panel van master cylinder. You can tell the difference by the colour of the reservoir - the station wagon is orange and the sedan is yellow.
This detail is an ommission from the Harrison build manual.

Peter

[Merv and Sharon]

Thanks for that. Cob07 will b interested too

[Outwest34au]

If the wagon master cylinder is the same in bore size it might be easier to just swap out the main spring in the proportioning valve. Even if you score a totally stuffed master cylinder the spring would be unlikely to be damaged.
You could shim or shave springs but even I wouldn't stuff around with that, the time and testing wouldn't be worth it.
The local wrecker (emerald) was doing a car collect and crush before xmas but the weather got him, if he has xf wagons with masters in the pile I will grab them for whoever needs them. I'm hoping he will be back out here this weekend coming if the weather holds.

[Merv and Sharon]

If he has some XF wagon ones we would certainly be interested!

[Krait]

Greg,

All in all a fairly short list to deal with, good work.

Look forward to seeing you the road soon.

Cheers

[byroncobra]

Thanks Geoff

Good info on the brake issue thanks fellas, I've spokento local brake guy, he suggests trying pads first, so Merv can you tell me what you used on your Nissan rears please?

I'm not sure what's on there now so I'll whip em off and see if i can work out what they are.

[Merv and Sharon]

OK - on the Racer Industries site there is a connection to a Project "mu" (the Greek symbol I don't have on this keyboard!) and they have some competition/soft pads there that a few guys have used). However, I called the local Pedder's crowd and found a similar one called (Bendix) Ultimate for the Nissan rear. There are different pad shapes for the R32 and R33 rear end, so make sure you have the right one. I got a set of 4 rear pads from them for about $180. The ones I took off were hard and glazed!

Fitted in 15 mins as you can leave the calipers on.

[byroncobra]

Thanks Merv

[sambo]

Has anyone looked at EBC Green/Red/Yellow-Stuff pads?

"The latest version of Greenstuff is a deliberately softer compound to improve pedal feel on lighter cars at lower speeds. This resulted in a medium dust material with good lifetime and minimal rotor wear."

More details here.

[Zedn]

Guys,

Wouldnt it be better to fit a brake bias valve to the car so it doesnt matter what pads are in it?

Seems to be a potential issue that someone will buy a car second hand and put different pads in. This could lead to a serious accident if it has that much effect on bias.

[byroncobra]

Zedn, I spoke to the engineer about an adjustable valve, apparently the authorities take a dim view of them.
Sambo, already ordered the Bendix Ultimates.....as Mervs' had success with them. Interesting the EBC Green ones though.

[boxhead]

I would have just ordered a Goon master cylinder, that seems to be the factory recomended fix for it?
Not too sure about removing parts from the master cylinder, after all I am sure Ford and PBR spent a fair bit of coin in testing to get these right, if an off the shelf unit is correct, get it.

[Merv and Sharon]

My fall back after more 'testing' will be the station wagon MC.

[Zedn]

Originally Posted by byroncobra

Zedn, I spoke to the engineer about an adjustable valve, apparently the authorities take a dim view of them.
Sambo, already ordered the Bendix Ultimates.....as Mervs' had success with them. Interesting the EBC Green ones though.

Thats interesting, my engineer recommended i install one. I think its just the cabin adjustable ones of real concern.